Friday, 28 December 2007

Compliments of the Season

Well I hope every one is enjoying the holiday season. For once our summer is actually being summer and it was nice to have a lot of sun on the solstice (our wedding anniversary - 3 years), of course it helps to be in the southern hemisphere. Though I must admit the December is usually out wettest month and there is now some concern for lack of water for the rest of the summer and into early autumn (ie March) which is our period of usually good weather.
Two thoughts I wanted to leave you with prompted mainly by the season:
  1. Why oh why would shepherds be out in the fields tending their flocks in the middle of winter?
  2. Do nun's habits remind anyone else of a Burkha?

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Wednesday, 28 November 2007

Giving Thanks

In the spirit of the US holiday of thanksgiving that occurred so recently (Ok it was a week ago now almost), and that I got a chance to participate in due to a friend of ours from the states hosting a thanksgiving dinner, I would like to post some thoughts I had about the general tradition of giving thanks before meals (rather than the tradition specific to this holiday).

Yes I have some thoughts about saying grace before meal.

It is supposed to be sauying thanks for the food that we are about to receive but how inconsiderate is it to not give thanks to the people who actually provided the food the farmers who grew it, those invovled in the processing of it (ie bakers butchers etc) and possibly most importantly in our consumer age the person who earned the money to buy it. (ok I could really get pedantic and talk about the ancients who domesticated the crops and cattle - by genetic modification through cross breading and artificial selecttion but then that really should be a subject for its own whole history of science post).

How arogant is it to ignore all the effort that goes into the food we eat and give thanks only to god.

If you take the farmer or the baker out of the equation it pretty much falls over for most people in this day and age so it is to them that the bulk of thanks should go.

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Monday, 5 November 2007

How to...prevent the prevention of cancer

Well you may have heard the word about the 'tubes' several months ago about a vaccine for Human papillomavirus (HPV) and how this will lead to a reduction in cases of cervical cancer.

Well it has been recently announced here that the government intends to fund it for preteens (I remember hearing 12 year olds mentioned on the radio this morning- have not been able to find much recent information on the web to follow up this). Religious groups (mostly with "family" in the name) are up in arms about this since HPV is a sexually transmitted infection and so promotion of this vaccine, is seen (by them) as a free pass for young girls to have sex.

Mostly this ranting by religious groups is done in relation with the promotion of abstinence only sex education which has been shown in studies to not work. So unsuccessful is the idea of abstinence only sex education, that some regions have experience higher STI rates, higher teen pregnancy rates (and abortions), and most importantly lower ages of first sexual experience.

Even if the abstinence only education programs worked, that would still not be a reason for the fallacious argument being made here. Unfortunately whatever you do teens will have sex mostly when they want to rather than when you want them to, largely because they are trying to be adult and have some control over their own lives. A lot of young teens will regret experiences that that try, such as having sex, but for them to have to deal with cancer as a possible repercussion of that, when they can be protected against it, is cruel and unusual.

Now I am in agreement that young teens are not ready to have sex (in fact some older teens aren't either) it is a complex mental and emotional development issue which tends to run contrary to the physical development and urges of puberty. But what is the best way to get some one to do something - forbid them to do it, and then provide no further information.

If you are going to teach adolescents responsibility you have to give them all the information about it and let them be responsible. Teach them about safe sex practices, and tell them about the consequences and counsel them so that they know when they are ready.

So whatever high horse the religious groups are on they should get off it before they fall. Of course this would not have been a problem in the days when girls where married off at 13 (or younger), no need to worry about premarital sex then.

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My favourite holiday

Well this one I did mean to have up last week but well things happen. So I wanted to just pass on a happy Halloween to all out there.

It is my favourite holiday, mainly because it is one that the christians can actually claim most of the credit for unlike christmas and easter where they just stuck there own ideas over pre-existing events (winter solstice and spring equinox - to give them the northern hemisphere names) and yes I know Halloween is near the autumnal equinox, but what I am trying to get at is that despite many christian churches trying to dismiss the ghosts and ghouls these are the christian creations (actually to be fair to christmas so is santa).

Halloween is the night before All Saints day and the day after that is All Souls day, so it was customary to think that the spirits of the dead in particular the saints (those who are hallowed) to be active. So don't any christian tell you anything about Halloween and worship satan or witches, this one is all theirs.

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Recent Comments

Ok well I have had a bunch of spam comments appearing on some of the old posts, mostly this one, and so I have turned on the comment moderation just because I don't really want people advertising things here.

Any comments that are real feel free to leave them even if you want to honestly plug for something I will have a look at it but please out of dencency for me do to be sensible. If this standard is kept to then I will unmoderate them.

I really want people to leave comments here, both to add to what I have written and to prove that my site meter is not just making things up, I will endeavour to moderate the comments as fast as possible.

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Friday, 5 October 2007

My son has a doppelganger




Either that or they got him to act in it with out my premission. Must ask his grandfather if he taught him to drive his Hyundai?


And yes I should have put this text in to explain why I posted the video somepoint closer to the time when I originally posted it.

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Friday, 28 September 2007

Skeptic's Circle

Well, it has been a while since I really had a chance to get on and blog about stuff but I do have several ideas/posts in the works but for now you will have to be content with the latest, and very funny, edition of the Skeptic's circle, oh and it looks like there are some good submissions too.

On a similar subject other carnivals that I should pay attention exist as well and I do hope to be getting involved with when I get back on my horse again as far as keeping this thing running but for now enjoy the latest tangled bank as well for the bio-y side of science.

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Monday, 10 September 2007

Contradiction in Terms

Low Calorie Energy Drinks. Such as Tab.

C'mon.... Seriously.... Are you kidding me?

How can an energy drink be low calorie?

OK we ALL know that they are stimulant drinks. Maybe something should be done about the false advertising.

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Wednesday, 29 August 2007

Bad Medicine and Microwaves

I have just finished reading Christopher Wanjek's Bad Medicine, a book that in my opinion everyone on the planet should read. It is thoroughly well written and well set out with easy to understand debunking of most health fallacies.

However a review of the book is not my main reason for this post. One of the topics covered was radiation and the worry people have of microwaves. Chris covers the topic well but I realised something rather ironic when I read this section and that is: Infra-red (IR) radiation has a higher frequency than microwaves so standing in front of the stove while cooking is more likely to cause cancer than the the microwave.

For the physics of it all, electromagnetic radiation (light, UV, IR, microwaves, gamma rays, x rays and radio waves) interacts with matter as a photon. The energy of a photon is determined by the frequency of the radiation.

There is a cutoff in energy level for a photon to remove an electron from an atom (called the photoelectric effect), and this is required for their to be any harm (esp. to DNA) other wise the only effect is heating (which is short term and goes away as soon as you remove the source of radiation i.e. cell phone).

Now the cutoff frequencies for this is in the spectrum of visible light, so anything with a lower frequency (IR, microwaves, radio waves)than this is not going to do any lasting damage (like cause cancer).

So to reiterate, although neither is going to cause cancer, IR radiation from your stove top is more dangerous than your microwave.

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Thursday, 16 August 2007

Well Since My Baby Left Me

I found a new place to dwell
Down at the end of lonely st
Heartbreak Hotel.

The King IS Dead. Long Live the King

Thank you, Thank you very much, You're beautiful.

PS Today is the anniversary of the passing of Elvis Presley.

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Sunday, 22 July 2007

It's another Boy

Well my family seems to be expanding at a rapid rate with nieces and nephews coming from all over. But this time it was our turn.

Yep that is right our second child was born at 8.20 pm yesterday (Saturday) and no he will not in any way be named for the Harry Potter book that came out the same day.

I had better get back to hospital and spend some time with Mother and baby but you never know I might even get some photos up in the next few days.

(Update 16/08: For those of you interested in names we went with Quinn - it means the wise in Celtic - and no we did not take this long to decide just to post the update)

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The Skeptics' Circle

Well the latest edition of the Skeptics' Circle is up at NeuroLogica Blog. It is the 65th edition and is an exciting trip to the Museum of Skepticism where you can see exhibits on cranks and crackpots of all shapes, sizes and colours and of course how to see the reality of it all. Well worth the trip, especially since admission is free.

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Monday, 16 July 2007

If I were American

I saw this on The Greenbelt and decided that it would be fun just to see roughly whose policies are in line with my own. Now since I am not a US citizen this is rather pointless, and of course I have never heard of about half of them (and some of the rest by name only) but I am not too surprised at some of the names at the top and the bottom of the list.

Thank you for visiting this Selector.
For more information on this selector and your results, go to 2008 President Selector

Rankings:
  1. Theoretical Ideal Candidate (100 %)
  2. Dennis Kucinich (85 %)
  3. Barack Obama (81 %)
  4. Alan Augustson (campaign suspended) (75 %)
  5. Joseph Biden (75 %)
  6. Christopher Dodd (74 %)
  7. Hillary Clinton (74 %)
  8. Al Gore (not announced) (71 %)
  9. Wesley Clark (not announced) (70 %)
  10. Michael Bloomberg (not announced) (69 %)
  11. John Edwards (67 %)
  12. Mike Gravel (not announced) (65 %)
  13. Bill Richardson (62 %)
  14. Kent McManigal (campaign suspended) (55 %)
  15. Ron Paul (53 %)
  16. Elaine Brown (38 %)
  17. Rudolph Giuliani (28 %)
  18. John McCain (25 %)
  19. Mitt Romney (24 %)
  20. Mike Huckabee (23 %)
  21. Chuck Hagel (not announced) (19 %)
  22. Tommy Thompson (17 %)
  23. Newt Gingrich (not announced) (15 %)
  24. Fred Thompson (not announced) (14 %)
  25. Tom Tancredo (14 %)
  26. Jim Gilmore (withdrawn) (11 %)
  27. Sam Brownback (10 %)
  28. Duncan Hunter (3 %)

And all that with no real science questions asked, despite the fact that that would be one of my big priorities.

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Friday, 6 July 2007

Where do Stem Cells come from

A lot of the debate about the use of Embryonic Stem cells (ESC) in research comes from objections that are based about the murder of all those babies to get the ESC. You know the sort of thing where on The Simpsons, Mrs Lovejoy comes along and cries out "oh won't somebody please think of the children".

However this is a very unrealistic point. As anyone who has ever been a parent will know, how and when you find out you are going to be a parent is quite variable. Normally the first signs are morning sickness, or extreme tiredness, but neither of these are themselves a reliable test that you are pregnant. So how do we confirm pregnancy? Usually it involves a take-home pregnancy kit, some urine and human chorionic gonadotropin (hCG).

Well now that we know that what does it actually mean. hCG is produced during pregnancy to fulfill some role (that is unimportant to this discusion but can be found at the link above), and so once you are pregnant this hormone starts to be produced (by the embryo/placenta), and it takes some time for the levels to build up such that it is excreted from the mother's body.

For the test to be accurate you want it to cut down on the false readings. The way this is dealt with is by having a threshold concentration for the hCG, this at least cuts down on the false positives (where the test reads positive when you are not pregnant). However because it takes time for that concentration to build up it is possible to get false negatives (where the test reads negative when you are pregnant).

An example of this was with our first child, my wife got pregnant just before I left for Europe for a conference. Now she had her best friend's hens night several days after I left she was worried that she might be pregnant and didn't want to drink if she was. So she took the test and it came back negative. A week or so later the tiredness really kicked in and she went to the doctor and took another test there, it came back negative. Only another week of so later when the morning sickness was started up did a test finally come back positive (note that the timing of the morning sickness and the positive test are incidental).

So in this case my wife was pregnant for three weeks before actually knowing for sure that she was pregnant.

This delay is long enough such that the harvesting of ESC from a mother is not really an option.

So if this is not an option what is? Well as I see it there are two options either we specifically create embryos to take the stem cells from or we make use of the vast numbers of spare embryos that as we speak are sitting in freezers in IVF clinics all around the world. Spares that will most certainly never be anything more than they are now.

In fact since storage capabilities of any organistion are finite then eventually many of these will be destroyed. They clearly are surpluss to the parents IVF requirements and are unlikely to all be adopted. Since they can't be kept forever they will end up being destroyed, but why then can't they be put to a good cause, that of research in to finding cures to many debilitating diseases and conditions.

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Monday, 2 July 2007

8 Random Facts

Well this meme about 8 random facts has been doing the rounds and suprisingly enough I have been tagged (thanks to Ken at Open Parachute).

All right, here are the rules.

  1. We have to post these rules before we give you the facts.
  2. Players start with eight random facts/habits about themselves.
  3. People who are tagged need to write their own blog about their eight things and post these rules.
  4. At the end of your blog, you need to choose eight people to get tagged and list their names. Don’t forget to leave them a comment telling them they’re tagged, and to read your blog.
Ok so those are the rules to live by and here are the facts.

  1. I have lived in Dunedin all my life. But have been fortunate enough to travel to many other places.
  2. I like to write, although this is the most of my public output thus far.
  3. I am keen on photography and have won an online photo competition. (one day I may even upload the photo).
  4. I am married with a two year old boy and another on the way (due end of this month)
  5. Both my wife's family and my own consist mainly of boys (I have one brother and she 4 - neither of us have any sisters).
  6. The next generation has 4 boys and 2 girls (with one boy due this month and an as yet unknown for December).
  7. I had 13 years of Catholic education and logically I became an atheist.
  8. I have been working on my PhD for 5 years now and I just want it to be finished.
Alright and now for people to tag hmmmm, actually I am goona cheat (but only cause the pooflinger cheated first) and I am going to tag anyone who reads this blog that has not done it yet and you have to leave a comment here saying that you did it.

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Friday, 29 June 2007

BZP and party pills

In an article in the local paper (the Otago Daily Times - note that link is probably only good for a day or so) raises some interesting oppostion to legislation that proposes to ban party pills that contain BZP.

THE party-pill ingredient BZP will be forced underground following the Government’s decision to make it illegal, a Dunedin party-pill seller says.

Associate Health Minister Jim Anderton announced yesterday BZP would be reclassified as a Class C1 drug, making its sale and manufacture illegal. He hoped the legislation could be passed by the end of the year.
Surprisingly enough the move was condemned by the industry which makes and sells them and welcomed by critics (and one must assume Emergency department staff).

But maybe that Dunedin retailer (John Cockburn, owner of South Dunedin BZP retail outlet Herbal Heaven) might also have an ulterior motive

A ban would put him out of business, because he only sold BZP related products,he said.
Hmmmm, maybe he should be selling something other this, which is as herbal as drain cleaner, to kids who want a high.

His decision to recommend a ban to Cabinet was based on research, analysis of submissions and advice from experts and Government agencies. There would be a six-month amnesty for possession of less than 5g of the drug for personal use after the ban came into effect.
That sounds like a reasonable and well thought out action on the part of the minister.

However the comments of the reaction from some of the other points of view quite interesting.
First we have one of the more extremist parties in Parliament:
Green Party drug law reform spokeswoman Metiria Turei said the party was disappointed by the move, but pleased the Government had chosen to make the changes using the full legislative process, rather than by resolution, so the decision was open to full public and parliamentary scrutiny and debate.
Well at least they are all for the process. This guy sounds like he is from an industry lobby group:
Social Tonics Association of New Zealand (Stanz) chairman Matt Bowden said prohibition was not the right way to minimise BZP harm.

‘‘P is prohibited and look at the problems there,’’ Mr Bowden said.

The right answer was regulation, a power Mr Anderton had under the Misuse of Drugs Act, he said.
The main opposition in Parliament clearly have their head screwed on as to this issue but still manage to get a jibe at the government
National Party Otago MP Jacqui Dean said the process had taken too long, but she welcomed the move.

And more importantly from the people who have been studying the issue:
Meanwhile, a doctor who led a major study of party pill use said yesterday’s decision was ‘‘a tough call’’ but on balance was probably the right one.

Dr Chris Wilkins, from Massey’s Centre for Social and Health Outcomes, said there had been no research on the longterm effects of BZP or the role it might play in psychological illness.

‘‘Consequently, there was a strong case for stricter regulation of the use and sale of party pills and on balance a ban appears to be the low-risk decision,’’ he said.
Surely there have to be more fun things for today's youth to do than this. Although just thinking that last statement made me feel very much older than 27.

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Wednesday, 27 June 2007

Lightning and Hurricanes

I found this recent paper by a couple of Israelis that I have had the pleasure of meeting, and that our group has had some ties with. They have come up with an interesting correlation between lightning activity in the East African sector and Atlantic Basin hurricanes. Hopefully the abstract at least should be viewable to the general public at the link. But the crux of the idea is that:

In this paper we provide evidence showing the connection between lightning activity over eastern Africa, and the AEWs that leave the west coast of Africa, some of which develop into hurricanes. We have analyzed the 2005 and 2006 hurricane seasons, one a very active hurricane year (2005), and the other a very quiet year (2006). More than 90% of the tropical storms and hurricanes during these 2 years were preceded by periods of above average thunderstorm activity in eastern Africa.

Before we go to much further we need to define a few things. AEWs are African Easterly Waves, disturbances in the African Easterly Jet a (high altitude?) wind that forms a the region of strongest gradient of the temperature gradient between the relatively cool equatorial Africa (due to the Guinean coast) and the hot hot air above the Sahara - this is the reverse of the usual gradient where it is warmer at the equator than either side.

It appears that ~60 of these AEWs can form in a year mainly in the months of April - November, and they travel west across Africa (in a matter of a few days to a week) and then move out into the Atlantic ocean where they may or may not form Tropical Depressions, Storms or Hurricanes. There appears to be no correlation between number of AEWs and the number of Hurricanes although some 60% of minor Hurricanes and Tropical Storms and 85% of major Hurricanes can be traced back to AEWs.

Now the central African region is the global hot spot for lightning with a rate of over 50 flashes per square km per year. The lightning flash rate here is higher than any where else on the planet, though lightning is a very seasonal and time of day dependant. Lightning seems to prefer the late afternoon-early evening sector so at varying times of the day it will peak in different longitude sectors. Surprisingly enough lighting is more common in summer than winter. Which naturally fits with our increased AEW occurrence in this time period.
The AEWs are associated with deep convection and intense thunderstorms over tropical Africa... One of the key questions relating to these tropical waves is whether the waves trigger the convection, or whether the convection triggers the waves... We investigate whether the intensity of the convection, measured by lightning activity, is related to the AEW intensification.


So we have pressure instabilities that are related to strong lightning activity that originate in East Africa (in the paper they specifically look at 10–20 N and 30–40 E, in the region of the Ethiopian Highlands), and propagate across the continent and out into the atlantic where these drops in pressure can sometimes become hurricanes.

Now to get the local lightning rates for this region you can either stand there and count or you can make use of a network set up to detect lightning. That is all well and good if you are in a developed country which has one of these. Most lightning detection networks are extremely localised and need many stations to cover any decent sized area - mainly because of the frequency range that they use to detect the lightning (MF - 300kHz to 3MHz). Now if you use a much lower frequency range (VLF 3 - 30 kHz) it turns out that the absorption of the wave is less and hence you can see the waves at a much greater distance.

So using this long distance propagation and a few other nifty tricks, a former Professor here at Otago Prof Richard Dowden set up a company (LF*EM Research Ltd) and a World Wide Lightning Location Network (or WWLLN - pronounced "woolen" as wool from a sheep). Because the VLF part of the signal from the lightning travels much further then you need a much lesser density of stations. In fact there in the WWLLN there are currently about 30 stations, (we host one here in Dunedin) and this covers the whole globe since we are able to see the signals of lightning strikes happening many thousands of kilometers away.

This network is far from perfect, it requires at least four stations to register the signal from a lightning strike and then the timing of the reception must be with certain limits (other wise you cannot be sure that the stations are all looking at the same flash) or the network will not register the lightning. So this means you have a trade off between number of "legitimate" detections and the accuracy of these detections but then I imagine that is true of any similar system. So this tends to mean that the detection efficiency (number of "legitimate" detections versus total lightning) is lower than one would like, however those detections are favoured to more intense lightning strikes - since these are the ones more likely to be detected at more stations, as they radiate more power and the signals are likely to be observed further away.

So this is the technique that the authors used to look for lightning (they host a station in Tel Aviv and as such have acces to the full data set rather than just the summary on the web). But I think that the interesting issue here is the one that they clearly are not getting all the lightning happening in the region buit we are reasonably confident that they are getting the locations of all the storms and most of the stronger lightning. The authors certainly see a link between the strong lightning, and the AEWs and hurricanes, but I don't think that this could ever be a forecasting tool for hurricanes.

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Religious Freedoms

Two items from Bob Park's What's New newsletter both of which deal with religion or at least the religious imposing their ideas on every one else.


STEM CELLS: BUSH DECLARES "ALL HUMAN LIFE IS SACRED."
Peace activists say the same thing. The President said this while issuing his second-annual summer-solstice-veto of legislation to lift his ban on embryonic stem cell research. He said that the United States is "founded on the principle that all human life is sacred" – unless you’re in Iraq, where 80 American lives have been sacrificed so far this month. I couldn’t find such a principle in the Constitution; instead I found the First Amendment. By imposing his bizarre religious belief that embryonic stem cells are people on the rest of us, the President has violated the constitutional rights of every living, breathing American.

POPULATION: HOUSE REVERSES BAN ON CONTRACEPTION AID.
Before you applaud, it faces a veto, and there are not enough votes for an override. The ban is a key element of Bush foreign policy, though why the U.S. opposes birth control in other countries is beyond comprehension. Uncontrolled population growth will, in time, overtake every advance in human condition.

But of course you might say that these are Bush's policies and he has every right to act on them. However even the religious among us can see that these policies are grounded in his religion.

And hopefully everyone should understand that having someones will imposed upon then especially when it comes to religion is outlawed by among other things the first amendment to the constitution of the USA and Article 18 of the Universal declaration of Human Rights.

I am not claiming that Bush is not allowed to have his beliefs but what he is not allowed to do is to force others to have those beliefs too.

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Tuesday, 26 June 2007

More terror

Which religion promotes terrorism again?

The Ridger over at the Green Belt points out that a group in Milwaukee are holding up terrorists as heros.

Read the post and the links that she provides, and then hope maybe that this one makes the list for Bush's "War on Terror".

What is the USA coming too. Some one please tell me that this is not what Christianity in America is all about. And once you have done that go and tell these guys that too.


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Thursday, 21 June 2007

Positive News

Just wanted to say that we had good news yesterday. It would seem that my father-in-law's cancer has gone into remission, the doc couldn't be completely sure from the scan (there is some scar tissue that they are not 100% about) but so far so good, he will have another scan in 6 months and regular blood tests between now and then, so heres hoping that it all comes out clear.

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Skeptic's Circle the Solstice Edition

Welcome to the 63rd edition of the Skeptics' Circle, celebrating today's Solstice (June 21 2007 18:06 GMT).

Now if you are in the Northern hemisphere this will be the longest edition of the skeptics' circle and conversely if you are in the Southern hemisphere it will be the shortest.

And now you may want to know how I am going to do this... well the answer is I'm not after all today is still 24 hours long regardless of where you are on the planet and so this edition of the skeptics' circle will be the same length for all.

That and the fact that my lack of ability to come up with anything better leads us straight to the meat of this last fortnight's skeptical round up in no particular order with the exception of the first.

Infophile has a good post, explaining part of what it means to be a skeptic, that really should be a must read for everyone (not just us skeptics).

The Discovery Institutes latest and greatest Dr Egnor continues to offer his ignorance on plate for the rest of us and his recent ideas about dualism (mind/brain) have provided much fodder. PZ of Pharyngula, Blake Stacey of Sunclipse and Orac of Respectful Insolence all take him to task for this.

The Hoofnagle brothers at Denialism has a good couple of posts, on the dangers of unrestricted advertising and how to be a crank

And now for a nice relaxing break a look at some good old fashioned (or not so old fashioned as the case may be) quackery, thanks to Tara of Aetiology, Andrea's Buzzing About, and Orac of Respectful Insolence.

Away from the Bench has a brief look at what went on at DC's Improbable science and DC himself tells how the saga has been some what resolved.

We will follow this up with Aurora Walking Vacation's little illustration of eggs and bad science, Infophile showing the absence of evidence can be evidence of absense and Prof. Bleen tells of the Peer review process at the IJCR

The old adage is that you are what you eat, however Junkfood science explains just what food processing is before illustrating that the point that if you are going to study what is in the food and what it does to the body it might pay to put it in the body (or at least a part of it). On a similar topic the Holford watch shares us the tale of quack being put to the sword on live tv, heck you can even watch the video.

And to finish up where would us loyal skeptics be with such classic targets as UFOs, Creationism and the autism mercury link for us to rant against.

I want to thank everyone who submitted posts for this, I just couldn't include everyone but they were all great posts.

And for all of you who stopped by please do follow all the links, they are great examples of what we want to see more of in this world.

Well that is all from me for this round of the skeptics' circle...
but never fear for it won't be long 'til we next appear...

In fact I hope to see you all at The Skeptical Alchemist in two weeks time for the 64rd Skeptics' Circle on July 5.

Any and all feedback is welcome so that I at least know that you are reading this. You never know, if you don't tell me how bad this is I might have to host it again.

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Friday, 15 June 2007

More bad news for Pluto

The Bad Astronomer has a post up about new measurements on the size of Eris. Remember Eris it is the one that started out as Xena and caused the demotion of Pluto. Any way it turns out that Eris is a bit bigger than Pluto so there is no way we can ever have 9 planets again.

Call it a planet if you want. It doesn’t matter that much to me — and less to Pluto itself — but you’ll be doing the object, and yourself, a disservice. And Eris is bigger anyway. Nyah nyah.

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Wednesday, 13 June 2007

The Circle is Coming to Town

Step right up folks and share the wonders of the skeptical world.

That's right next week I will be hosting the fortnightly blog carnival Skeptic's Circle (I am of the belief that this will be the 63rd edition).

So if you have something that you would like to be considered for this carnival email me before next Wednesday.

  • rmcsquared at gmail dot com
Since I am on the other side of the planet than most of the bloggers (I am in New Zealand!!) who will be submitting here I really actually mean before next Wednesday (which will be my Thursday). My aim is to have the circle up early afternoon my time (which will be early morning on Thursday GMT - late evening Wednesday for those in the States)

I look forward to what everyone has to offer.

Robert

PS My apologies for not having this info up earlier.

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Wednesday, 30 May 2007

Charity for the religious

New Zealand Association of Rationalists and Humanists put out a press release in the last week (Thanks to Des of the New Zealand Brights Local Constituency for alerting me to it) disucssing the recent budget's removal of the tax rebate cap for charitable donations.

The issue is not one of charitable donations are bad as of course they are not but rather that the standards for what makes a charity are somewhat interesting. Here is what Elizabeth McKenzie, President of the New Zealand Association of Rationalists and Humanists had to say:

[W]e support any measure that sees more money being passed into the hands of genuine charitable organisations that provide a tangible benefit for society. However we are concerned that an archaic definition in New Zealand’s charity legislation means that the promotion of religion alone is regarded as a charitable activity.
So the issue is what makes something charitable. It turns out that in New Zealand being a church is enough. All you need to do is ave the intent of spreading your religion.

However there is an ugly side to that in that Des reports that an attempt to create a Humanist trust, he was not allowed to have part of the trusts mission being to promote humanism.

Hmmm that smacks of a double standard, but I will be looking further into this as I find the time.

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Thursday, 24 May 2007

A household of three

I heard on the an ad for the current affairs program Close Up last night, that they were interviewing the "Lion Man" who has been charged with assaulting his partner (and yes she is a woman) who he found in a ménage et trois [sic]. Now if you have any knowledge of french you will know that the phrase is ménage à trois, but the presenter clearly pronounced it with a short "e" sound rather than the short "a" sound that it is supposed to be. (OK here feel free to have a go at me for not using the correct phonetic letters to describe the sounds - but that is just not my thing, at least I have better things to do today than teach my self them.)

This of course like most good mispronunciations, totally changes the meaning of the phrase. So instead of the intended "household of three" (literally) it became "household and three" which a child can see is quite meaningless.

How can someone who is supposed to be one of the countries best TV presenters be so clueless or careless about pronunciation. Especially since this sets an example to people for how they are supposed to talk, or at least say words and phrases that are not natural to them

So what should be done about this? Maybe we should institute lessons in elocution and the "Queen's English" for all TV and radio presenters. Though I doubt that will really prevent the slide into laziness that the English language is currently taking.

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Friday, 18 May 2007

Friday's Physical Law - Mexican Wave

Last time we mentioned that one simple harmonic oscillator (SHO) couple to another SHO can have interesting effects. In fact when you have one SHO coupled to another SHO coupled to another SHO... you get a oscillation that varies not only in time but also in space and what we have is a wave.

Yes you can think of it just like the Mexican wave at you favourite sporting event (ok now that is an interesting thought - can anyone tell me where that name comes from?) first one person stands up and then the next and so on. The main difference between coupled SHO and drunk sports fans is that with sports fans you get a single pulse travelling around the ground (or very occasionally two pulses), but with the coupled SHOs each one continues to oscillate so you get a series of pulses following (often quite rapidly) one after the other.

So what exactly is meant when I say the oscillations varies in time and space. We know from last time how the SHOs vary with time, and that is carried through to the behavior of waves. We see each individual point oscillating with the same equations for position and velocity and acceleration. The variation in space can be described in a very similar way, as a cos or sin function varying with respect to position rather than time. Obviously the angular frequency term of the time variation is also replaced by a term that is related to how the wave repeats in distance, this is sometimes know as the wave vector (k). Remember:

  • ω = 2π/T
well similarly

  • k = 2π/λ
where λ is the wavelength of the wave and is the distance over which the oscillation repeats, much like T is time in which the oscillation repeats.

But what exactly are the oscillators that we are talking about, well these can be almost anything, ok not anything but waves happen in lots of different materials. The obvious examples of waves is those on water, but almost all musical instruments make sounds with waves and then there are earthquakes and electromagnetic radiation and ...

Stay tuned for more exciting developments next time

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Monday, 7 May 2007

The Phoenix rises

I think we have a winner for the most appropriate (and quite cool) name for a professional sports franchise.

And no it isn't the Dallas Mavericks rotflmao.

The new New Zealand side in the Australian soccer competition, which will be the third attempt at having a team in the competition.

Of course being such a small country the resources, particularly for what is a minor sport here, are scarce and so this effort at entering a team very nearly didn't get airborne either.

But the Wellington Phoenix rises.

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Friday, 4 May 2007

Domestication

Wow you know what this has taken me so long to get around to finish off but finally I have it here for your viewing pleasure.

The three main early breakthroughs in the history of mankind have to be the domestication of crops, of cattle, and of fire. All of these can be thought of as major scientific sdvances (and in some cases we are still trying to work out how to improve on what we did at this stage of history) even if the scientific method was not really used.

There is evidence that Homo erectus was controlling fire up to a million years ago. Fire is important as it will have helped with lessening cases of food poisoning and improved the taste particularly of meat, both achieved by cooking the food. It also provided a means for defense, enabling the users to see in the dark and also as a scare for predators (most animals are afraid of fire). Later on as agriculture developed fire was an important tool in clearing land for growing crops.

Early man was a hunter-gatherer, this meant that he had to spend much of his time chasing animals and/or looking for edible plants/leaves/berries. Gradually the hunt became easier to follow the herds of prey animals and from there it was a simple step to instead of trying to follow, to lead the animals (at this point it is probable that man also began the domestication of the dog to help in this herding – although this may have been already started as part of the hunting – certainly this was something that dogs would have been selected for cf modern huntaways and such). And once you have control over the herd, it follows that you will ensure that the feeding and breeding of the herd is to your satisfaction. Selective breeding begins to create differences between the wild herds and the controlled herds. which we can see and indeed continue today with our domestic cattle.

So with the herding of “cattle” we loose the hunt part of hunter-gatherer but still we must maintain a nomadic lifestyle since we still need the gathering and now also we must find grasses for the cattle. This leads to the idea of growing your own. But the largest problem to that is that the feed for the cattle is different to the feed for humans, and indeed most often are found to be in different locations in nature.

The start of agriculture is a big step as it requires not only the finding/cross-breeding of the right types of plants to provide sustenance but also the growing of these said plants in a location where you can also get easy access to stock feed. So we have the domestication of crops leads to permanent settlements forming where access to the new crops and the stock feed is available.

And the permanent settlements leads to the domestication of humans.

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America's deadliest terrorists strike again

A doctor's clinic in Texas where abortions where performed has had a close shave when police found a bomb in a duffel bag outside.

This is an all to common situation at abortion clinics in the US where christian fundamentalists are conducting a reign of terror.

Yet does this even raise the eyebrows of homeland security? I think not... after all good christian Americans are not the problem are they?

The Bush administration's War on Liberty continues unabated as does terrorism!

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Friday's Physical Law - Simple Harmonic Motion

Like we saw last week simple harmonic motion (SHM) is a periodic (repetitive) motion that is descried by sine/cosine functions. There is one other requisite in the definition of SHM and that is a restoring force. What do I mean by a restoring force, well it is mostly what is sounds like, it is a force which acts to restores the system to its original or equilibrium position.

So a restoring force is at its simplest a force that acts counter to the position of the object within the system. Think of a mass on a spring - when the spring is extended it pulls the mass back, conversely if you compress the spring it pushes the mass out. So this force can be described by:

  • F = -kx
where x is the displacement and k is the spring constant, and the negative sign shows that the force counteracts the displacement.

Another example of this is a pendulum where gravity provides the force and is always trying to force the bob (the mass at the end of the pendulum) to its lowest point.

But wait if there is a force that is always pushing it back to equilibrium then how does it keep repeating its motion. Well to explain this lets look at the case of the mass on a spring (the pendulum is the same but its motion tends to be 2d and so slightly harder to explain).

If you have a mass attached to a spring and it is sitting at equilibrium and you pull it down a certain distance, then when you release it the spring pulls the mass back towards the equilibrium point, accelerating it as it goes, now as the mass gets closer to the equilibrium the force and acceleration get smaller, but the velocity gets bigger (since it is being accelerated). So when it gets back to the equilibrium x=0, so F = 0 and a = 0, however v ≠ 0 so the motion continues past the equilibrium where the acceleration now acts to slow the mass down, until it stops at the opposite point the where it started, and then accelerate it back again.

So as long as friction is small (or as well like to think for our examples non existent) then this motion will go on and on and on. This gives us our simple harmonic motion:

  • x = Acos(ωt)
  • v = sin(ωt)
  • a = -2cos(ωt)
Now so you don't look at me and ask where there heck did they come from, the first one is found in last time's discussion about circles is just the position of the mass relative toe the equilibrium, and the second two come from the definitions of velocity and acceleration, so are the change of position and velocity with respect to time. Strictly speaking these last two are the derivatives of position and velocity with respect to time which relies on calculus and gives us the instantaneous values for velocity and acceleration.

Now we saw last time that ω is related to the period of motion T. And so combining the restoring force equation and Newton's second law and the above expressions for x and a we can get:
  • F = -kx = ma
  • ω = √(k/m)
  • T = 2π √(m/k)
Now since we talk about how long it takes for things to happen with T, one other factor that is related to this is how often things happen, the frequency, f.
  • f = 1/T = ω/
The frequency of an event is the amount of occurrences in 1 second (usually measure in Hertz, Hz), it is inversely related to the period, of is something takes o.1 second to occur then it has a frequency of 10 Hz etc. OK this is only true for repetitive (oscillatory) motion other wise the frequency does not make sense.

So we can see that a mass that oscillates back and forth about an equilibrium is SHM, however circular motion does not really fit the bill since it does not have that restoring force.

Of course like the name suggests SHM is simple, but harmonic motion in general can be a lot more complicated, such things as friction can damp the motion, or something can drive the motion. Even the presence of other oscillators coupled to the first causes interesting phenomena but that is for next week.

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Friday, 20 April 2007

Friday's Physical Law - Round and Round

We saw a while ago that circular motion requires a centripetal force, but there is also another interesting feature that comes out from all that going round, and that is that you can do it all again (and again and again ... ad nauseum).

So what we have is a type of motion we refer to as periodic motion. That is motion that repeats itself after a period of time, and most commonly this period of time is constant (ie uniform circular motion, such as an orbit). So you start off at a certain point and then you move before coming back to where you started.

This is sort of obvious when you think about travelling in a circle. And as you can see this is a very simple sort of periodic motion.

Now since going around in a circle involves going through 360° we often describe the motion in terms of the rate at which the angle changes - the angular velocity (ω) if you will. The simplest way to think of this is, like I said, a velocity so we will consider the angle changed divided by the time taken (much like velocity is distance moved divided by time taken) and so we get

  • ω = 2π/T
But wait a minute I hear you say what does 2π have to do with angles. Well if instead of the more common degrees as a measure of angle we use radians, which are a slightly more natural way of describing angles (it all comes from the ratio of arc length to radius), then this is a measure of the angle. In fact you probably use radians with out even knowing it, when ever you say the circumference of a circle is 2πr then you have just used radians. So just to clarify:
  • 2π rad = 360°
So in other words our angular velocity is the total angle in a circle divided by the time taken to go round the circle. As we saw in the gravity post:
  • v = 2πr/T
so we can combine this with above and we see that
  • v = ωr
and we also get similar expressions for arc length (s, distance around the circumference of the circle) and acceleration (a)
  • s = θr
  • a = αr
where θ is the angle and α is the angular acceleration.

Now why is all of this remotely important, any one familiar with geometry will note that the position relative to the centre of the circle in xy-coordinates can be described in terms of the angle or indeed ω and t.
  • x = r cos(θ) = r cos(ωt)
  • y = r sin(θ) = r sin(ωt)
So in addition to being a simple periodic motion, circular motion is also a simple harmonic motion, harmonic meaning that it varies sinusoidally (like a sine or cosine wave). Now this term has a very specific meaning in physics and we will see next week just what it entails, and whether or not this is an accurate description.

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Thursday, 19 April 2007

Ooops more trouble on the blogging front

Well at least this is the end of it I hope, I was flat out with work and shifting up until Easter and then after the break I come back to find that my work PC has died (actually very similarly to my laptop - I am of course considering if there is a correlation).

And so the last week has been mad trying to sort out alternate computer resources, get the problem fixed, and of course catch up on all the work i let fall by the way side before Easter.

But never fear as I am back and I will be restarting my weekly series (hmmm what is the plural of series????? I must look into that), I have some long awaited posts on the history of science in the not too distant future and a couple of new features that I will be trial, so hopefully posting will be on the increase.

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Friday, 30 March 2007

Another Temporary Blogging Hiatus

This time because we have had to move flats and it has been a somewhat stressful experience, and most of next week will be taken up with cleaning up the old place but I will be trying to get some more stuff up by Easter.

If not enjoy your chocolate eggs (the darker the chocolate the better)!

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Thursday, 22 March 2007

Now I Really Feel apart of the Wider Community

What you may ask makes me feel this way, well it is the fact that I have my first ever paper to peer review for a journal.

Now you may say that this is terrible and reviewing papers takes up so much time, that you could be using to publish your own work, and I can see that, but as a young researcher I feel it is the biggest responsibility that can be laid upon me. (Well that and having younger students in the lab to mentor).

Of course I have already had a few papers published (ok only one as first author) so I have already made contributions in that regards, but this feels bigger to me. It is peer review so that officially makes me a peer.

Ok well I had better get back to it, deadlines and all.

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Wednesday, 21 March 2007

I wanted numbered lists... and now I do

Well you may have or may not have noticed that all my lists were coming up bulleted, this was not meant to be the case an I have finally got around to digging through my template and learning how to mess with the right parts.

As you can probably see a few other things like the colours got changed too, in fact if you visited the site this afternoon you may have seen changes like crazy as I tried to work out what did what (I apologise if this caused any upset) and if not relax and enjoy my now correctly enumerated lists

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Tuesday, 20 March 2007

Friday's Physicsal Law - Gravity

Ok well yet again this is a catchup post of this series, it was due on Feb 30 March 2.

We all have a good daily experience with gravity, we can feel it pulling us down whatever we do. And our everyday experience on how it effects us is usually limited to the acceleration that we undergo or our weight

  • F = mg
where g is the acceleration due to gravity and is approximately 9.8m s-1. Now this is all well and good for describing the effects of gravity here at the surface of the Earth. But what it does not do is tell us anything about what gravity is or how we work out 'g' for other locations (ie surface of the Moon or Mars).

For our everyday experience, that is so well described by the above equation, we can derive myriad equations to describe the parabolic motion of projectiles, to determine time of flight, maximum height, distance traveled and velocity along the path but these equations are simply those that can be used for any acceleration (interestingly enough this equivalence between acceleration and gravity plays a role in the development of General Relativity too):

  • d = vit + ½at2
  • vf2 = vi2 + 2ad
etc.

However to get the true experience of gravity we must leave this time and place and travel back to the time when Tycho Brahe was observing the motion of the planets. And since we are travelling back in time we might as well get our selves situated nicely above the plane of the solar system so we can see everything.

Johannes Kepler using Brahe's observations deduces three laws that govern the astronomical.
  1. The orbit of every planet is an ellipse with the sun at one of the foci
  2. A line joining a planet and the sun sweeps out equal areas during equal intervals of time
  3. The squares of the orbital periods of planets are directly proportional to the cubes of the semi-major axis of the orbits
And it was upon these, in particular the Kepler's third law that Newton formulated his Law of Universal Gravity, basically by combining Kepler's law with his Laws of Motion.

Now to do this without resorting to inventing (or just using) calculus you and I will make a handwavey assumption (and one that isn't all that bad). The ellipse detailed in Kepler's first law are rather circular so to make the maths easier we will just use circles (note that a circle is a special case of an ellipse where the two foci are in the same place).

Now remember from last time that circular motion requires:
  • a = v2/r
since the velocity around a circle depends on the circumference (2πr) and the period (T) (which probably should have been mentioned in the other post):
  • v = 2πr/T
which gives us
  • a ∝ r/T2
and combining this with Kepler's third law, which for a circle can be written:
  • T2 ∝ r3
then we get
  • a ∝ 1/r2
So the acceleration and hence the force are inversely proportional to the square of the radius of the orbit (as the radius increases the force decreases). So this tells us how our weight (remember this is given by mg) varies as we change our position relative to the Earth, but what about on other planets?

Well if we were to go to the moon and weigh ourselves we would discover the scales read about 16% of what they did before we left Earth, since the Moon is smaller than the Earth then if nothing else was involved in gravity then our weight would go up, so something else must be involved and this turns out to be the mass of the object we are on (be it a planet or moon or whatever).

So this gives us Newton's Law of Universal Gravitation:
  • F = G Mm/r2
where G is the gravitational constant and has a value of about 6.67×10-11 N m² kg-2 and M and m are the masses of the two objects (sometimes written m1 and m2).

Now many find it counter-intuitive that because of the M and m in the equation the force of gravity on me due to the Earth is the same as the force of gravity on the Earth due to me. Since clearly the Earth moves me and not the other way around. Of course we must remember that force is not the whole story, it is the acceleration that causes the motion and since the Earth ways more than me the movement of me is much more than that of the Earth.

This can be seen better in the case of binary stars, or Pluto and Charon, or any other objects that are orbiting a spot in between them. This consequence is really just an illustration of Newton's third law, equal and opposite action and reaction.

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Monday, 19 March 2007

Friday's Physical Law - Going round in circles

Again in my vain attempt to catch up on my weekly posting due to the myriad issues some of which I mentioned in an earlier post, this post is late, it was due on February 23.

In an earlier post in this series we touched on the concept of circular motion.

And if this force is always at right angles to the motion then the object will continue at a constant speed the changes in direction will cause it to move in a circle. In this case we call the force a centripetal force, meaning center-seeking, but more about that another time.

And now then is that other time. For the motion to be circular the velocity must also follow the circle, so at each point there must be a change in velocity at right angles to the motion, this change in velocity is the acceleration that points into the centre of the circle (at right angles to the motion) and is caused by the centripetal force acting on the object.

So, to have circular motion you can see we need two things, an object travelling at velocity v and a centripetal acceleration a (and hence force F).

To get the motion to be a nice circle you need to have the correct relationship between these two. Obviously (at least I hope so) the size of the circle (to be specific its radius, r) is also going to play a role, in fact the relationship comes out as (after a bit of complicated maths - some of which can be seen here):
  • a = v2/r
which with Newton's second law gives us the nett force or the centripetal force:
  • F = mv2/r
Now I used the term nett force above, what I mean by that is the force that is the result of adding all the forces on the object together, for example when we are standing still the nett force on our bodies is zero, but we are experiencing at least two forces, that of gravity pulling down on us and the ground pushing back up (Note: these are not an action/reaction pair). In general when we talk about forces especially in relation to acceleration we are really talking about the nett force.

In this case the centripetal force must be the nett force, otherwise the motion would not be circular.

There are many different ways to provide the centripetal force, obvious ones include
  1. Gravity (for orbits and sloped paths like on a velodrome)
  2. tension in a piece of string
  3. Friction (between tyres and the ground)
Now since the centripetal force is required to keep an object moving in a circle, what happens when we remove that force. Like I said above the centripetal force is the nett force, so if it is removed then there is no force acting on the object and hence no acceleration. So an object released from circular motion will travel in a straight line in the direction of its velocity when released, this can be seen when you think about how one uses a sling to propel projectiles.

There is one further issue that people have trouble with when dealing with circular motion and that is the difference between centripetal and centrifugal but that is the subject for another post.

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Friday, 2 March 2007

The Skeptics are at it again

EoR at Second Sight has the latest and greatest of the last fortnight's skeptical blogging all in one place with the 55th Skeptics circle, head on over and enjoy, it is a real special number.

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Thursday, 1 March 2007

How to ... disobey the second law of thermodynamics

OK well this post is very late, it was due up a week or so ago, but things have been hectic and since my laptop died working from home has become impossible, but I am endeavouring to catch my self up with these posts

Well the second law of thermodynamics (SLoT) gets quite a bum rap from all sides of the anti-science. For starters there is perpetual motion, infinite amounts of free energy, but the is also a horrible use of the SLoT as an argument about evolution.

One reason I suspect as to why SLoT is so mis-understood is that while it conveys a fairly simple physical law, when it is applied to different situations it tends to need to be stated in very different ways. To quote P.W. Bridgman

There are almost as many formulations of the second law as there have been discussions of it.
For example:

The entropy of an isolated system not in equilibrium will tend to increase over time, approaching a maximum value at equilibrium.

Heat cannot of itself pass from a colder to a hotter body.

A transformation whose only final result is to convert heat, extracted from a source at constant temperature, into work, is impossible.

The first two statements are from Rudolf Clausius, and the last one from Lord Kelvin. And they are all equivalent, but generally phrased to high-light what the law means with reference to a particular situation. For example Lord Kelvin's statement above is a very mechanical one, essential stating that while we can use heat to do work we can never covert all the heat to work, so there is always some energy lost as heat.

The other difficulty with SLoT is that it is a statistical law, it is based on probability. Essential every system is in a certain state (macro-state) that is comprised of all the states of the atoms (micro-states) that make up the system. The more atom states that correspond to a particular system state then the more likely that system state is to exist. Naturally there are many more disordered (macro-) states than ordered (macro-) states, so systems will tend to wards disorder (an increase in entropy).

The big caveat to this statement is that all this applies only if you do not start adding energy to the system. In other words the law only applies to isolated systems.

So the Earth is not an isolated system, it receives a lot of energy from the sun. So the Earth and everything on it does not obey the SLoT, however if we take the Universe to be our system then this is clear isolated (it is all there is by definition) then the SLoT is obeyed.

And our magnetically levitated spinning top in the foyer of the lecture theatre next to the Physics department here will only spin perpetually if the power is plugged in other wise the interaction of the magnetic fields (and some air resistance) will cause to stop spinning and fall.

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Friday, 16 February 2007

Friday's Physical Law - Work Work Work

As we have previously seen force impacts a lot on motion. Today I want to look at how we apply forces, or rather what allows us to apply forces, and as you may have guess by the title this involves the concept of work.

When we exert a force on an object what we are doing is work on that object. And by work we don't mean what one does 9 to 5 but rather transferring energy. To be precise work W is done on an object when ever and object is moved a distance d parallel to a force F acting on the object

  • W = F d cosθ
when F and d are parallel θ = 0 and then cosθ = 1 and the work is maximum when the angle (θ) between F and d is 90° then they are perpendicular and cosθ and hence W = 0.

Well that can all be a little complicated and daunting, but essentially you can think of it in terms of a box, if I push the box across the floor I give it motion and hence energy (by doing work: force across direction across), however if I hold it while walking across the room the box itself is only in motion because I am and as such is not getting any energy from me (so no work done: force up direction across).Of course while I was lifting the box (before I carried it across the room) then I was doing work on it.

So as you an see (hopefully) work is done and energy transferred when giving an object motion or changing its position with respect to gravity. We refer to these forms of energy as kinetic energy and gravitational potential energy, respectively.

So we will now look at these a bit closer. Firstly, kinetic energy occurs when anything has velocity (is moving), and is dependant only on the mass of the object and the velocity it has:

  • E = ½mv2
And gravitational potential energy, is a form of potential (or stored) energy which depends on position with a gravitational field, and it depends on height (above ground), the mass of the object, and gravity (on Earth the acceleration due to gravity, g, is about 9.8 at the surface of the Earth, but this will vary for other planets and heights, at this stage I plan to deal with this next week):

  • E = mgh
There are many other types of energy that we will get to in the fullness of time, such as the potential energy of a spring, thermal energy (heat), electrical energy, nuclear energy etc, but the important thing to note is that energy can never be created or destroyed only converted (transferred) from one form to another (this incidentally is the first law of thermodynamics).

And when it comes to motion this idea of conservation of energy can simply be put as:

  • ½mv2f + mghf = ½mv2i + mghi + W
where the f indicates the object in a final state and thei indicates the object in an initial state. And we can see that friction is a case of work acting against the motion of an object, reducing its kinetic energy and creating heat (thermal energy).

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Hot off the presses

The 54th edition of the Skeptics circle is up over at Action Skeptics, and Akusai has upped the standard, focusing on "The Stuff That Woos are Made Of"

My cat Loki and I moved in, I arranged the furniture to minimize qi flow, and I called the painter. He made me some very pretty words on the front door: "Jack Bixby, Skeptical Investigator."
With some of the highlights being:

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Thursday, 15 February 2007

How to ... "Design" a Car

OK so yes you may have noticed a certain anti-ID theme appearing in this series of posts, well science education is something that I take seriously, and one of the anti-science themes that is prevalent in my readings at present (such as Robyn Williams' Unintelligent Design) and hence giving me my ideas for this is ID so that is where I am going but I promise I will diversify (at some point).

I digress, this is somewhat of a response to the "Watchmaker" argument that has been put forward at various times. Essentially it states that something that complex cannot have occurred naturally and hence has to have been designed as a whole. In particular this is a response to the idea of "Irreducible Complexity" (IC) that underpins the the ID arguments.

Essentially if a car was IC then if you removed a bit of it, then it would no longer work. And this is approximately the case (well at least if you consider a very basic car model) especially if you fail to account for other uses of the components - in other words if you take away everything but a wheel you no longer have a car or anything that works as a car does but you still have a wheel which is useful in its own right - which seems to be something that has happened from the IC proponents.

So how have we designed (or perhaps evolved would be closer to the truth) a car:

  • we started with the development of using trees as rollers to aid transporting heavy objects (such as one often sees in depictions of the building of the pyramids in Egypt).
  • later these we modified to a pair of wheels linked by an axle and a bed on which to put things to be transported, so now the wheels stayed with the load instead of being rolled over and then moved.
  • Of course something needs to move this simple cart, and we have had plenty of option in terms of man power (or slave labour) or beasts of burden (horses, oxen etc).
  • Wheels are simplified so that instead of being solid wood they now consist of a rim and spokes radiating out of the centre to that rim, this reduces weight of the wheel and allows for greater speed (for example chariots).
  • A two wheeled cart is not a stable platform, if left to its own devices it will tip forwards or back wards so we will add another set of wheels and now we have a stable platform that does not need to be constantly hitched to something.
  • Brakes can help in the situations where you need to stop.
  • In addition to being pulled wheels can also be ridden on lo and behold we have a bicycle (or at least the fore runner to a bicycle)
  • Pedals and maybe some gearing might help with the riding of the bicycle as it comes towards its modern form.
  • An ability to steer (normally the front wheels but rear wheel steering works too) helps you get more accurately to where you are going.
  • Of course for those of you tied of pedal power or with a lame horse why not power it with a steam engine (trains and tractors are good examples of how this was done).
  • If steam is not your thing then why not try the new fangled internal combustion engine.
  • Multiple gearing that is easily switched between will of course help speed up travel.
  • Oh and don't forget the Pneumatic tires.
And of course now you have a car - although you might want to think about adding a stereo so you can listen to your tunes, maybe 4WD for going off road, GPS for when you get lost etc etc etc.

As you can plainly see that a car did not come fully assembled in one foul swoop, but gradually evolved over thousands of years.

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Friday, 9 February 2007

Friday's Physical Law - Conservation of Momentum

Well all have experience Newton's Third Law of Motion in action, every time we push on something like a door we can feel it pushing back on us.

What we have here is action and reaction, and as it is normally put Newton's third law reads every action has an equal and opposite reaction. So if I push the door with a force of 5 N the door pushes back with the same force.

Of course the main thing to note about these forces is that they operate on different objects. Many people seem to get this confused by thinking that the forces cancel out, which can only happen when forces are acting on the same object, which is not the case here. To use my previous example: I push on the wall and the wall pushes back on me.

Of course the action and reaction occur at the same time, they start at the same time and they finish at the same time. So this gives us another measure of the motion that results from these forces. Remember that as we saw a couple of weeks ago

  • F = ma,

and since we know the force applied in the action and reaction and the mass of each object and now the time over which the force acts we can work out the change in velocity (remember that a = v/t). So this gives us what we refer to as impulse:

  • F t = mΔv = Δp
What we have here is another measure of motion, momentum (p) which is equal to an objects mass times its velocity. And from Newton's third law we see that when ever we have to objects interacting (action and reaction) then their is a change in momentum is equal (and opposite). That is the total (nett) momentum of two interacting objects is conserved (the same before and after the interaction).

As we progress through this series we will see many more examples of the idea of conservation of quantities. But in this case we have a very good means to analyse the interaction of objects (the idea of two objects interacting can be extended to multiple objects where momentum will still be conserved) such as in collisions.

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Wednesday, 7 February 2007

How to ... sweep almost all science under the rug

In the "culture wars" with ID (intelligent design) I have always found it amusing at the big tent attempts of the IDists to encompass such a wide range of creationists into their folds.

We know that all creationists try to sweep good science under the rug by ignoring, denying or misrepresenting it, mostly in biology and related fields such as anthropology and palaeontology. But some take their anti-science to greater and greater heights, particularly YEC (young Earth creationists) who manage to be not just anti-evolution but anti-every-thing-else-in-science as well.

The YEC seems to be the most vocal proponents of ID, but why then are other groups such as OEC (old Earth creationists) backing the completely anti-science stance of YEC when they are more intellectually consistent with the rest of us?

This is something that I cannot answer, maybe some one else can for me, but what I want to look at here is just what science exactly does the YEC position deny? (WARNING: this could be a very long list) In brackets I have listed some examples of our understanding of which exactly is undermined by YEC. The ones with * are also in common with all IDists.

  1. Microbiology* (antibiotic resistance)
  2. Botany* (breeding plants)
  3. Zoology* (breeding animals)
  4. Ecology* (co-evolution of plants and animals)
  5. Biochemistry* (protein synthesis)
  6. Medicine* (Germ theory of Disease)
  7. Anthropology* (Descent of Man)
  8. Palaeontology* (fossil records) - Note that YEC also has issues with the dates of fossils
  9. Chemistry/Atomic Physics* (cause of mutations in DNA and hence their effect)
  10. Nuclear Physics (radiometric dating)
  11. Cosmology (age of the universe)
  12. Particle physics (since it goes hand in hand with cosmology)
  13. Geology (formation of rocks and fossils)
  14. Tectonics (the movement of tectonic plates)
  15. Physical Geography (the shape of the land)

Hmmmm well I think my list is not as long as I thought it was going to be, but then again I think that I have pretty much covered the whole spectrum. And if I have forgotten anyone's speciality please tell me. I also realise that I could have made this list longer by including more specialities that I have lumped into generalities (eg medicine). And while the list is longer in the section that is ID general rather than YEC specific those YEC specific areas are rather broad.

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Monday, 5 February 2007

Psychics are bad for you

For all those who are fans of psychics maybe you have found the wrong blog to be reading.

The Amazing Randi has updated the terms of his paranormal challenge, in which if you can prove you have paranormal powers in a mutually acceptable test then you walk home with $1,000,000. Now instead of merely waiting for applicants they will go out and target high profile paranormalists, taking the challenge to them.

Several notable psychics have said they will take the challenge only to back down, one major example of this Sylvia Browne, and there is now an online petition that you can sign to urge her to step to the plate

You can read more about all this here where Skeptico gives us a good run down.

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Saturday, 3 February 2007

OV-102, may she rest in peace

And from the I can't believe I nearly forgot to post about it files comes some thing that is very dear to me.

February 1 2003 (Thursday was the 4th aniversary) the space shuttle Columbia broke up on re-entry killing all seven astronauts aboard.

I have always felt a special bond with the space race and Columbia in particular since my birthday falls on Cosmonaut's Day (April 12), which is the anniversary of the first manned space mission Vostok 1 (1961) in which Yuri Gagarin became the first man in space. And what does that have to do with Columbia, on the 2oth aniversary of Vostok 1, STS-1 the first orbital test flight of the space shuttle was launched. So Columbia (OV-102) with two people on board was launched on my first birthday (1981). Of course I was only one and didn't really register such things, but looking back on it well I thought it was cool and special (ok I really am a nerd aren't I - but is that really such a bad thing) and that Columbia was my shuttle.

Also the STS107 mission was a science mission and one of the experiments was using the Isreali Dust storms Experiment camera to try to take picture of Red Sprites (to put it simply a form of upwards lightning) and to help orient themselves on the storms the made use of the World Wide Lightning Location Network (WWLLN - pronounced "woollen" as in made of wool) which was started by a now retired member of my research group and is a project that we are still much involved in. So I hade multiple connections to this tragedy

So like I mentioned February 1 she broke up on re-entry, killing all seven of the crew, so if we could take a moment to remember Brown, Husband, Clark, Chawla, Anderson, McCool, Ramon. And please give me a moment to mourn my shuttle.

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Friday, 2 February 2007

Friday's Physical Law - Reflections

In the first two weeks of this series I started out with simple motion as my fundamentals and then built from there, and I do intend to continue in that vein but every now and then I am going to feel like something different and this week is one of those times.

Today I am going to discussing some thing that is part of my PhD research and is also something that merits a comment when talking about Climate change. That is reflection.

To begin with we must have a wave travelling along that interacts with an object (or the boundary between two media - ie water and air). Now when this wave (and for the most part I will be dealing with electromagnetic (EM) waves such as light, radio waves etc., although this applies to all types of waves) interacts with an object any of three things can happen:

  1. Reflection
  2. Transmission
  3. Absorption.

Which of these occurs depends on the properties of the object and the wave. And in most cases two or even three of these things happen together.

Reflection is where the light strikes the object and bounces off. Transmission is where the light passes through the object. Absorption is where the light is ... well ... absorbed.

If we start of with a wave intensity of 1 then:

  • R + T + A = 1

where R, T, and A are the amounts of the wave reflected, transmitted and absorbed respectively.

The obvious examples are a mirror for reflection, a window for transmission, and a black object for absorption.

And you will notice that I mentioned a colour specifically for the absorption, in fact it is due to reflection and absorption that we see colour. Light shines on an object and if red light is reflected and the green and blue light absorbed then we see the object as being red.

Now what does all this have to do with my research, well, I study the electrical interactions of the upper atmosphere (more about this another time) and the main tool we use is by using the ionosphere and ground as a mirror (albeit and imperfect ones) and sending radio waves long distances between these two "surfaces" and so the reflective properties of particularly the ionosphere are very important. And by looking at the changes in the signals we receive we can determine the changes in the reflections along the way and hence the local (or global) changes that has caused them.

And of course I also mentioned that reflections can affect climate change, if you have snow, ice or tundra then the sunlight reflects of this quite well, as any one who has gone skiing can attest to. But as these melt less of the sunlight is reflected and hence more is absorbed (since the Earth is not very transparent). This leads to more heat being trapped in the Earth-atmosphere system leading to more warming (even if only locally) which will lead to more melting which will lead to more absorption and so on. In other words it is a positive feedback loop for the warming which is not a good thing, especially since we can quite easily measure the amount of ground covered by snow, ice and tundra and it is decreasing.

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Tuesday, 30 January 2007

How to... yo yo diet

If you are at all conscious about your body, and lets face it most of us are (not as much with the guys but still), then at one point or another we have been at least tempted to try some sort of fad diet.

The idea behind most of these (apart from making lots of money for their creators) is that be eating only certain things (ie no carbs, or no fats) or eating in certain ways (only raw food) or by substituting "supplement shakes" for meals one can lose weight.

Of course there is one other method by which people often try to lose weight and that is simply by starving themselves. And it is this rather than the others that I want to focus on today.

Our bodies are wonderful mechanism - in times of plenty we store the food for times where food is rather scarce, however one other thing is that in times of scarcity our bodies will also slowdown so that the stores we have can be made to last as long as possible, this is especially useful if you do not know when more food will be available again.

So what happens when you try to lose weight by cutting calories alone:

  1. Your body thinks (rightly) that it is a time of scarcity of food
  2. So your metabolism slows down to conserve your food stores -fats, glycogen (stored carbs) and protein
  3. Since you are still not taking in enough food to subsist, even with the reduced metabolism you body starts to burn its stores.
  4. Your body is used to operating mainly of carbohydrates since these are the easiest to use so you store of these, glycogen, is used first.
  5. This leads to a quick loss of a couple of kilos since the break down of glycogen releases a lot of water.
  6. Once the glycogen is used up the weight loss slows, and the body now must turn to an alternate fuel.
  7. The blood-brain barrier is impermeable to fats, so either that stored fats have to be broken down (a difficult task) or instead protein can be used (what actually tends to happen)
  8. The primary weight loss now is muscle wastage as the proteins from the muscles are used in respiration (which is the process of releasing stored energy not the process of breathing in and out, which is a small part of the former).
  9. If this continues for some time important muscles such as the heart can begin to degrade, which as you can imagine causes no end of life threatening problems.
  10. If at some point you do stop fasting, you body suddenly goes into "time of plenty" mode (which it is at least relative to the fasting) in which the main aim is to restore the used body stores of energy (and of which fat is the most efficient).

Now some people go through this process and are quite pleased with their weight loss, which is why the get to step 10, unfortunately this leads them to put on weight and quite often this is more than they lost so they start again. So it becomes a bit of "Lather, Rinse, Repeat"and of course this can go on and on and on ... Hence the "yo-yo diet" moniker.

Of course the observant of you will have noted that no where did I mention using the stored fats, this is where exercise comes in to the equation, you can only burn fat through prolonged aerobic exercise - ie long and relatively slow (and steady) exercise such as jogging, swimming, and walking that sort of thing

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Friday, 26 January 2007

Fridays Physical Law - Force and Accelleration

As we saw last week a change in motion of an object requires a force to act on the object. Of course with change in motion we mean that an object can speed up or slow down or simply change the direction of motion - all of these acts are covered by the term acceleration.

Technically acceleration is the rate at which the motion changes, or the change in motion divided by the time it takes for the change. So like velocity is how fast you are moving (changing position) acceleration is how fast you are changing your motion (velocity).

So when ever we have a force acting on an object we get an acceleration. Of course multiple forces causing multiple accelerations could also be acting to reinforce or cancel out each other. Two people pushing a car (from the same end) make it twice as easy to get going, whereas if one was pushing forwards and the other pushing equally backwards then these would cancel out.

If we increase the force then we increase the acceleration, but what else effects this relationship? The answer to that is mass, the heavier an object the more force is required to get the same acceleration as a lighter object. This is described in Newton's Second Law F = ma.

A force in the direction of motion increases the speed, and a force counter to the direction of motion will decrease the speed. A force at an angle to the motion will cause a change in direction of motion as well as an increase/decrease in speed.

We also have the interesting case of a force at right angles to the motion, this will not cause any change in speed only in direction. And if this force is always at right angles to the motion then the object will continue at a constant speed the changes in direction will cause it to move in a circle. In this case we call the force a centripetal force, meaning center-seeking, but more about that another time.

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Wednesday, 24 January 2007

How to ... Get cancer from a Cellphone

The energy in individual RF (radio frequency) photons (individual photons interact with individual electrons in atoms) is far to little to cause ionisation (when the electron is completely removed from the atom) or any other known mechanism for causing cancer. So if you want to get cancer from your mobile phone or your wifi network or your microwave (outside of 24/7 use) I will outline a method as follows

  1. Take your favourite RF device
  2. Open up the device and remove the circuitry
  3. Depending on the method of oscillation, you will need to alter the capacitance/inductance or the resistance of the oscillator circuit, or by reprogramming the chip.
  4. The frequency of oscillation was probably in the range of 10 - 1000 MHz (million of cycles per seconds) this will need to be increased to 100-1000 THz (million million cycles per second) ie from radio/microwaves to visible light.
  5. This causes an increase of photon energy by a factor of 10 million or so, enough to now ionise some matter and hence be a possible cause for cancer.
  6. Put device back together and turn on.
OK so a lot of people have concerns about RF radiation, for the most part these fears are unfounded in science, however this does not affect those that are worried. Of course this is not mean that a mechanism may be found in which this frequencies could have a detrimental effect outside of heating.

On the note of heating, as long as the RF radiation is not continuous (ie you have breaks from having you cell phone next to you ear) then the heat rapidly dissipates and is not an issue.

If anyone wants more information about recommended limits that were discussed at the last International Union of Radio Science (URSI) General Assembly, I can provide links to abstracts etc. It was actually a very food and informative session.

Also I would like to thank Jennifer Oullette of Cocktail Party Physics for the inspiration

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Please, Your Tshirt is a Security Threat

A passenger has been barred from an International flight from Melbourne to London for wearing a tshirt which calls Bush "The worlds #1 Terrorist" on the basis that the T-shirt could have upset other passengers.

And to make matters worse:

Qantas issued a statement saying comments made verbally or on a T-shirt which had the potential to offend other travelers or threaten the security of aircraft "will not be tolerated."
Now how on Earth does this threaten the security of the aircraft? Is the Tshirt going to spontaneously combust in mid-air?

Still it is good to know that America's allies are standing proudly along side the USA as they fight the "War on Liberty" all over the globe.

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Schrodinger's Cat

Ok the other day I was standing in the kitchen cooking dinner for the family and looking out the window I could see our cat lying on the concrete by the washing line, and then looking again i could see another very similar cat lying on top of the compost bin. Looking closely I could not make out any differences between them, nor on either cat could I see our cats bright yellow refelective collar (which proves very usefull on an all black cat at night).

To this day I have never seen another lithe black cat in the neighbourhood, and our cat has never been what you would call friendly to other cats (many late night fights are started below our bedroom window).

My wife went down to see the cats and by the time she had gone down the stairs to the yard the cat by the washing line had disappeared and our cat was lying relaxed on the compost bin.

Maybe what I was seeing was the famous Schrodinger's cat, well not exactly (since that had to do with whether the cat in the box was alive or not) but certainly the parallels to quantum mechanics are abound.

Obviously the "catfunction" was a superposition of two states and when my wife went out to make an "observation" the catfunction collapsed to the compost bin state.

Maybe? Or could it be something else?

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