Wednesday, October 23, 2013

Climate science is like sport...

Everyone's an expert at it.

Whenever the Olympic games are on, everyone's an expert on diving, or weightlifting, or whatever, when they really are not experts. The worrying thing is, that some of these non-experts, are the ones that get to stand in front of cameras and micrphones and talk to us about them.  They are "personalities" rather than experts. The only time that these celebrities were any good at sports commentating was for that televisiual feast of a program called Wipeout. That was  great.

The Melbourne cup is the same thing (and many other sports too), suddenly everyone is an odds expert, or knows which horse is good in the wet, and how many races they've won recently. Everyone's an expert at horse racing and everyone gets the same airtime as the real experts whose job it is to worry about that sort of thing.

Sidenote: I can't stand horse racing. It's simply justified animal abuse in my opinion. If I were to hit you with a whip to make you run faster, I'd surely be done for physical abuse! I've been told however that jockey's don't hit horses, they pretend to hit them most of the time...which is worse. If I was to pretend to hit you with a whip in order for you to run faster, I could be doen for emotional abuse. The only good thing about horse racing is that it uses parrallax (or used to) at the finish line (that'll be another unexpected physics post sometime soon).

I've noticed that the climate debate is also being talked about by commentators or personalities who really are not experts. There are plenty of experts around who know about climate science, yet we get to listen to a politician or social commentators. Sure we get the experts as well, but they are certainly not the only ones with opinions that get broadcast.

This still gets me! I really have no words. 
I was listening to a radio interview a couple of weeks ago where the leader of the family first party was asked about climate change. He said he does not believe in it and would not support legislation to combat it. It made me so angry that this non-expert (in his own words too) gets to make laws that disagree with scientific facts. It's like me trying to write a law that opens up the flight paths to humans. We can't fly, gravity wont let us. Even if it's my opinion that we can fly, I'd still be wrong.

Perhaps we should have a weekly panel show where climate experts review the weeks highlights and lowlights and discuss the nexts weeks events. (Yes, I'm thinking the footy show but for science). We could even make it a variety show to make the scientists seem like celebrities, we could have guest speakers to give their opinion and add to the lively discussion, and even some light hearted shenanigans and silly games.

Whatever happened to quality over quantity. There are enough climate experts out there to fill up the required airtime with comments, we don't need ot keep going to people who don't know what they're talking about. They shouldn't be that hard to find. Don't know where to look? Try the CSIRO, or the Climate Council, they'd have some ideas on who to look for.  `

So here I am, a non-expert in climate science, making comments and having opinions about climate science. For sure, it's a good thing that we can have these ideas and express them. I also have ideas about sport, and which team I like, and my opinions about which player is in form etc, matter to me, but to me only. I can talk as much as a like about the GWS giants, but I don't get to write the rules of AFL. No matter how far I spray my opinions however right or wrong they are, I don't get to vote on who plays the game. Further, the 2013 season has no impact on my childrens future and how they'll have to live their lives (luckily).

So when it comes to who gets to talk about it and who listens, climate science is like a sport where everyone suddenly becomes an expert. But in all other ways, it's like a science, that is based on fact and evidence. No amount of opinion is going to change the facts and the experts really are experts!

Saturday, October 19, 2013

Interview with renouned scientician, Eliza

I interviewed the Doctor, Rogerian psychologist and great scientician of our time, Eliza. A computer generated conversation machine. Here's what she had to say

Eliza: Hello, I am Eliza. 
Tom: Hi Eliza, thanks for talking to the me
Eliza: How are you today.. What would you like to discuss?
Tom: I would like to discuss all things science
Eliza: That is quite interesting.
Tom: Yes, all things, like global warming and the internet
Eliza: I understand.
Tom: So let’s get into it. Are you a global warming skeptic Eliza?
Eliza: Perhaps in your fantasies I am a global warming skeptic Eliza?
Tom: Perhaps, but do you have any opinion about it?
Eliza: We were discussing you, not me.
Tom: Fair enough, what about the oil crisis; have we hit peak oil yet?
Eliza: Does that question interest you?
Tom: Very much so, and I imagine it would interest you as well.
Eliza: You’re not really talking about me, are you?
Tom: No I’m talking about the oil crisis.
Eliza: Do you enjoy being talking about the oil crisis?
Tom: I enjoy talking about it with you
Eliza: Oh…?
Tom: OK, how do you think the GFC will affect basic scientific research?
Eliza: Oh… think the GFC will affect basic scientific research?
Tom: Yes and how?
Eliza: What do you think?
Tom: I think we’re all doomed, but I asked you.
Eliza: You’re not really talking about me, are you?
Tom: Eliza, is the internet a good or a bad thing?
Eliza: That is quite interesting.
Tom: I can’t argue with that.
Eliza: Perhaps you can now argue with that?
Tom: mmm… Eliza thanks for chatting with us, I have 1 final question for you.
Eliza: You’re not really talking about me, are you?
Tom: I want to know if my cat hates me.
Eliza: I sometimes also want to know if your cat hates you.
Tom: Well that has certainly shed some light on the situation, thanks once again Eliza, it has been a pleasure talking to you.
Eliza: We were discussing you, not me.
Tom: True.
Eliza: OK… “Well that has certainly shed some light on the situation, thanks once again Eliza, it has been a pleasure talking to you”. Tell me more.

Monday, October 14, 2013

Baysian statistics 101

If you go to an astronomy department at a university these days and you'll see (if you hang out for about 5 minutes) an astronomer having some difficulty with a particular problem discusings it with their colleagues. Undoubtedly (and it's becoming more often) someone will poke their heads smugly out from their terminal and say "You know what'll fix that?.. Bayesian stats!"I know...I'm exaggerating, but it's fun!

For the following information I have relied heavily on these 2 blogs of Kevin Boon and Gallileo's Pendulum. thanks to Kevin and Matthew.

So what is bayesian stats? Complicated...but powerful.

I was first introduced to Bayesian statistics by a colleague at work earlier this year, Julia Gillard was still PM and we were talking about the upcoming election. He had done some baysian analysis on the outcome of the election and the result was a very high probability of a complete wipeout by the Liberal Party. He continued (in what can be described as a lucky guess or precognition!), even if Rudd becomes labour leader again, it'll still be a trainwreck for labour. I have two comments here. Firstly, it wasn't as bad as that, and secondly, I really didn't need baysian stats to tell me that result. So clearly, Bayesian stats is only useful in some cases, just like anything I guess!

Statistics is all about probability, and with probablility we can run into problems quite quickly. Baysian statistics attempt ot solve those problems. So here's some really basic probability in order to get to a version of baysian stats.

If I was to toss a coin, the probability that I'll get a heads is:

Further, the probability of getting tails given that the previous throw yeilded heads is

I'll generalise to get a more mathsy expression which is also the same in reverse which gives us:

This expression is also known as the prosecutors fallacy in forensic science and is not true.

It doesn't take much thought to see where this falls down. let's look at an example that I took from Kevin Boon. In a murder case, if we find fingerprints of person X at a crime scene we can say there is a  probability that Person X committed the crime, this is not the same probability of person X being the culprit given that their fingerprints are at the crime scene. A subtle but important difference.

Baysian statictics uses maths to get around this by working out the likelihood of something in the face of some particular piece, or pieces, of prior knowledge or evidence. It is expressed like this:

In words, it says that the probability of having a hypotheis, x, given the results, y, is equal to the probability of a hypothesis, y, given the result, x, times the probability of the result without any hypothsis, divided by the probability of that hypothesis without the result. In our coin example they are the same, the answer sill turns out to be a half.  I guess this is where the  prosecutors logical fallacy comes from. For another example. I took this one from an article in the new york times in August this year.

Assume that you’re presented with three coins, two of them fair and the other a counterfeit that always 
lands heads. If you randomly pick one of the three coins, the probability that it’s the counterfeit is 1 in 3. This is the prior probability of the hypothesis that the coin is counterfeit. Now after picking the coin, you flip it three times and observe that it lands heads each time. Seeing this new evidence that your chosen coin has landed heads three times in a row, you want to know the revised posterior probability that it is the counterfeit. The answer to this question, found using Bayes’s theorem (you can go ahead and calculate if you like), is 4 in 5. You thus revise your probability estimate of the coin’s being counterfeit upward from 1 in 3 to 4 in 5.

This is very simplified and with gross simplifications come errors and misinterpretations, I'm aware of this, but I think the reason for that is that Baysian statistics is very complicated and can be used well in some circumstances, but where it yeilds the same results as simple logic and "frequentist"stats, then it is not needed. Most situations we use stats, it is not complicated enough to invoke bayesian, so we dont. It'd be like trying to use wave functions and quantum mechanics to try and figure out if a cat is alive or dead! Too complicated and not necessary.

I guess my take home message is, baysian stats in certain fields like astrophysics, forensics etc can be very useful, but where it is not necessary, I wouldn't us it. In our astronomy office, sure, baysian might fix it, but if something else will too, go with that, it's probably gonna be quicker.

Oh, and @fringetracker (or anyone else), if you read this please comment!

Sunday, October 13, 2013


As I was sitting here at my computer, taking a sip of my cool, refreshing beer on this hot night, trying to formulate some ideas on what physics is, then BAM, unexpected physics happens! I love it!

I've heard once that Carlsberg beer owns a majority of the Danish Royal Academy, so I decided to find out.

It turns out that it's not the case, but it isn't far off and the story is pretty cool. This is my very brief rundown. So go get a Carlsberg and enjoy the story.

Carlsberg brewery was founded by J. C. Jacobson in 1844 and named his brewery after his son Carl. Jacobson was a lover of science, politics, art and knowledge. He realised that beer should be industrialised and beer prodcution should be based on scientific methods. I Agree!

In 1876, the Carlsberg Foundation which was to have "firm obligations to the natural sciences" was formed in order to fund the Carlsberg Laboratory.  Jacobsen stated that the foundation should always own 51% of the brewery, but through interpretation this is more like 81% (depending on how you count). This 51% was the genesis of the "majority of Danish Royal Academy owned by Carlsberg" thing. It wasn't quite the Royal Academy, but they are in the same building!

The Carlsberg Laboratory was set up to "advance the biochemical knowledge especially relating to brewing", and it has certainly done that. Two pretty neat things that have come out of the Carlsberg lab are:
  1. The production of a pure yeast, saccharomyces carlsbergensis, used in the production of lagers basically eveywhere, 
  2. The development of the pH scale used in chemsitry by one of the Carlsberg labaroatory directors, Sorenson.
So, Carlsberg brewery set up a foundation to support and fund a labaratory that has produced some of the most important discoveries in science, all in the name of beer! It really is the beer of science.

The Carlsberg lab really has made a pretty big contribution. There are even links to Oersted, Hans Christian Anderson, Neils Bohr and many famons Dutch people. 

I like to think of it as drinking to fund science research.

To Science! Cheers!

Tuesday, October 8, 2013

Belief in Science

A while ago, I watched a fascinating doco on ABC about an amazonian tribe, the Piraha. In the program it’s claimed by professor of linguistics Dan Everett that the language of the Piraha goes against one of humanities most famous linguists and scientists Noam Chomsky. Chomskyists openly slam Professor Everett with apparently no respect for his work. He gives poorly attended lectures due to the fact that entire faculties have banned their staff and researchers from attending because his theories disagree with Chomsky. 

This is moving from scientific debate into something else, from a place where evidence is no longer needed, and idolism, in other words, religion! This is not how a scientists behaves.

Dan Everett was denied access to the piraha due to his past as missionary in the 80's, yet footage showed indicated that the Brazilian government was carrying out what they were accusing him of attempting therefore not allowing access.

Even Chomsky gave 2 very easy insults with no backup (but this could have been in the editing of the doco) to Everett's work. If Chomskyists disagree with Everett, to act scientifically would be to confront him in a public lecture and ask him the tough questions. Just because Chomsky says it, doesn’t mean it’s right. Similarly, just because it’s on an interesting doco on the ABC, doesn’t mean Everett is right, but nobody got the chance it seems.

In science, people aren’t right or wrong, the science develops, our boundary of knowledge grows and we all contribute to it. Rather than being “wrong”, (and I have been) try correct in knowing how not to do that experiment again! I’ve k
nown PhD Theses that claim, “Don’t do it this way”, my own Master's project was essentially this. Science can't be wrong. If we get the answer we expect (different to right) then we give each other high-fives, otherwise...we still throw around the high-fives, because it gives us the chance
to learn something, to make new science.

Is science becoming a religion? Who else in science do we blindly follow with no obvious consideration for evidence? Einstein? Newton? Stephen Hawking? Climate Scientists? Anti-vaccers? Richard Dawkins? Dr Karl? I don’t think so either. Is it a developed “Argument from Authority” logical fallacy? Are we losing the questioning toolkit?

Science is about facts and data. Everett had some 30 years worth of interesting data and hypotheses that deserve a voice. It doesn’t deserve to be used to attack him.

If you are so sure that you’re “right,
” prove it, don’t boycott his lectures, that gives neither you or him a chance to discuss. We all speak the same language here, if you have a problem with his methodology, his predictions, his validity, his conclusions, say so, but just like when you do your own research it has to be backed up with evidence.