Sunday, October 22, 2006

Warning: Nerd post

What’s the matter?
A few years ago there was much excitement regarding the possible discovery of pentaquarks. In 2002/2003 there were six papers published with data suggesting that the pentaquark existed. Some of the papers calculated a 95% confidence limit.

Just in case you’ve forgotten, atoms are made of protons and neutrons which are in turn made of quarks. Previous to these experiments, we had only ever seen particles containing 2 or 3 quarks. For example, protons and neutrons are made of 3 quarks. The discovery of a particle that contained 5 quarks (a pentaquark) would open a door to new physics.

I remember much excitement in my research group about these discoveries, especially from one academic. He concluded that the evidence was fairly conclusive. Being the doubting Thomas that I am, I decided to read one of the papers. After reading this paper, I came to the conclusion that they just did not have the data to justify their claim. In particle physics, I have seen claims made by researchers based on a very low number of data points. I was always questioning how they could possibly justify their claim and whether a same number of randomly generated points could show the same thing. That is, the data could just be a statistical fluctuation.

Anyway, I was due to give a talk to the Physics community and I decide to be mischievous. It was presented as a talk about how physicists use detectors to discover new particles. But the subtext was the use and misuse of statistics, focusing on the paper I had read.

I came to the point in my presentation where I talked about the confidence levels of an experiment. A 95% confidence level can be described as such:
If you think you have a set of data that is evidence, for example, of a new particle, generate 99 graphs using random data points. Mix in the graph of the real data and show the 100 graphs to your friend. Tell them to pick 5 graphs that show evidence of a new particle and if the real data is in that 5, then you have a 95% confidence level that the data does in fact show the existence of a new particle.

This is what I did in my talk with the data from the paper, except that I told the audience that that data was of a fictitious particle. They didn’t know it had come from that paper. Anyway, no one was able pick the graph which had the real data in it. The randomly generated graphs also showed signs of a “new particle”. I then showed them the graph from the paper (they still didn’t know that the data was from a research paper). I asked them if they would conclude that the graph showed evidence for a new particle. Nearly all the audience said no. That’s when I confessed about the origin of the data and the claims made in that paper. After my talk, I remember having a few conversations with those that still thought that the data was conclusive, taking into account the other published papers. I was of the opinion that more data needs to be gathered before making such a claim.

Three years later and after more data gathering it seems as if the pentaquark has bitten the dust. Sure, they may be still a slim chance that it exists, but it seems that the earlier experiments were in fact statistical glitches. And here is the great thing about science, even the original author of the paper now concedes this point. However he still thinks that later experiments may show a pentaquark.

Here’s one for the kitchen
In a two layered steamer, does the food cook faster in the bottom layer or the top layer?
This question was put to me and I gave them my reasoned answer. I then had an interesting discussion with someone who argued the opposite. What do you think and why? (In this discussion, I finally said let’s do the experiment to see who is right. It was interesting to hear them give excuses as to why they wouldn’t do the experiment then and there. Isn’t experiment the way to find out who is right?)

High Voltage Rock and Roll
There was a hard rubbish collection in my folk’s area a couple of weeks ago and I scavenged the electronics from a few old computer screens and video recorders. From the bits and pieces I made a Jacobs Ladder. This is the contraption seen in the labs of mad scientists in old sci-fi films that has two long metal wires sticking up with an electric arc that travels up between them.

Here are photos of it. Excuse the quality. The pictures were taken by a phone.

Jacobs Ladder Electronics

Spark travelling up wires

Exposure time is too long to see one spark

Sunday, October 01, 2006

An idea should be able to be subjected to criticism

I have been a long time listener of 3RRR and was thinking back to the halcyon days in the 80’s and early 90’s and the programs I used to listen to. I would wake up on a Saturday and Sunday and listen to shows like ‘Punter to Punter’, ‘Danger Low Brow’, ‘The Coodabeen Champions’, and ‘The Liar’s Club’.

The ‘Liar’s Club’ was a show that looked sceptically at all sorts of pseudoscientific claims, including crystals, tarot cards, psychic readings and so forth. Sadly this show was pulled off the air because, the presenters claim, of a complaint by the Church of Scientology. It claimed that the show vilified their religion. Go here to read about this case. This was the first time that the Australian Broadcasting Authority upheld a breach of the code of conduct relating to religious vilification.

I've searched throught the Australian Broadcasting Authority annual reports to see how many cases related to religious vilification and how many breaches were found since 1993.

Compliants: 21 Breaches found: 6

Here is a list of the breaches:
3RRR Melbourne Program: The Liars Club
5EBI Adelaide Greek language program demeaning a group on the basis of religion.
TCN9 'Today program' The complainant alleged that a segment on witchcraft misrepresented Zoroastrians by branding followers of the religion in the same category as witches. Found guilty.
2NVR Nambucca Valley 'Program: As I See It' The ABA received a complaint alleging that the program ‘As I See It’, broadcast anti-Jewish material that stereotyped, incited, vilified and perpetuated hatred against Zionists, Israel and Jews. Guilty.
ABC TV 'Backberner' Segment that purported to mock Cat Stevens vilified on the basis of religion. Guilty of dengrating Muslims and reinforced stereotypes of Muslims.
Channel 31 Sydney 'Focus Talkshow' Practitioners of Falun Gong alleged that the program were unfairly presented, instigated hatred towards the spiritual group, and vilified on grounds of religion. They were found guilty of unfair representation.

This is less than one breach every 2 years.

I agree that you should be held to account if you make vicious and defamatory statements and you have no evidence to back up your statements. However, vilification should not be used if you are critical of an idea. Religious beliefs are, in a sense, ideas and an idea should be subjected to critical investigation. Critical examination forces the claimant to produce rational evidence to back up the claim. Just because it falls under the umbrella of a religion should not give it immunity from critical examination.

How is religion defined in Australia? The High Court ruled the following in a 1983 case involving the Church of Scientology.
"We therefore hold that, for the purposes of the law, the criteria for religion are twofold: first, belief in a supernatural Being, Thing or Principle; and second, the acceptance of canons of conduct in order to give effect to that belief, though canons of conduct which offend against the ordinary laws are outside the area of any immunity, privilege or right conferred on the grounds of religion."

However "The law's protection in this context is not directed to safe-guarding the tenets of each religion - it is accorded to preserve the dignity and freedom of persons to adhere to the religion of their choice."

So you should be able to comment on the tenets and question the basis of their beliefs without fear of prosecution.

Another thought, since religious institutions are exempt from certain laws, taxation for example, you should create some dodgy belief in a supernatural principle, write a book of laws, and set it up so you don't have to pay tax. Not that I think religions should be exempt from these laws.