Tuesday, 27 March 2012

The most dangerous idea of all

That we should think for ourselves. That’s it. That’s all. No instruction manuals, no guidebooks, no higher powers, no subservience. Big men do not control society. Society controls society. That we could all live our lives based on what we thought was right, and what we thought was wrong.

This is a terrible and challenging idea - one that has created fear and hatred of it. People can’t be trusted; people might do anything. With no mechanism in place to control them, guide them, shepherd them and decide for them, moral corruption, decadence, and the ultimately the collapse of society would ensue.

Sunday, 4 March 2012

God: On trial.

This is just to prove that the inside of my skull really is the bizarre place you all thought it was.


Thomas: Jesus Christ!

Jesus Christ: Yes, indeed.

Tom: You're back.

JC: Just as I said I would be.

Tom: But wait! How do I know you're really the son of God?

JC: I'll show you.

[A few hours later]

Tom: Wow, just wow. As a physicist, and a skeptical individual, I know that that defies any other explanation. You are, indeed, the Son of God. Would you be willing to repeat that in front of others, so they know I'm not mad?

JC: Of course.

Sunday, 6 November 2011

Neutrinos

A few weeks ago, the blogosphere erupted with reports of faster-that-light neutrinos being measured at a detector in Italy called the OPERA detector. This paper may be old news by now, to many, but today marks a new point in the timeline, one which is perhaps even more significant.

Ever since the paper has been published, those at OPERA have been collecting new data, that will give our first 'confirm or deny' evidence on whether or not this initial, and extremely exciting, result has any merit. By changing the experiment around somewhat, they will now be able to get an exact speed measurement, without resorting to statistics. Enough build-up - what did they find?

Drum roll...

...

Wednesday, 5 October 2011

Gravitational lensing

A while ago now, I finished a four-week placement kindly arranged for me at the Institute of Astronomy, Cambridge, doing some work into, as the title says, gravitational lensing. I had a great time there, and I thought it would be interesting to give a general overview of the topic.

Saturday, 23 July 2011

A ship, an alien, and a puzzle.

Picture the scene - you are the captain of interstellar spacecraft, having left your family and friends (who, due to some of the more unfortunate effects of time dilation at high speeds, you will almost certainly never see again) to seek out new life and new civilisations with your intrepid crew. While inside one interesting-looking solar system, you notice what appears to be a spaceship in the distance. Deciding to investigate further, you see that the spaceship has been heavily damaged, perhaps by a collision with another object. Once you reach the ship, you discover an argon - oxygen atmosphere inside, maintained at 1.3 atm pressure, temperature 290 K (~20°C). Inside, there is a single life form, in obvious distress. It appears to be searching the ship for something.

Saturday, 14 May 2011

Bananas

Plese note: this post is not really about decimals, or fractions, or bananas. It is really about wave-particle duality, the quantum phenomenon in which things such as photons and electrons behave both as waves (like you see on the beach) and particles (by particles we mean things which are a bit like billiard balls). We can write full mathematical discriptions of these things, but we stuggle to understand what this maths means.
Decimals, as we all know, are a logical extension of our base-10 number system the other side of the decimal point. Fractions are a simple way of simplifing and shortening the division operation, the inverse of multiplication, itself the aggregate of many additions. Those are the mathematical explanations - but what is the physical meaning of these?

Thursday, 31 March 2011

Incompleteness

It's often tempting to think, in both science and mathematics, that everything can be proved, everything is consistent, and, having just assumed a few very obvious things (things on the level of 1 + 1 = 2, generally), everything else follows from there. If a particular set of assumptions doesn't allow us to prove something, it's because we've assumed the wrong things, not because of anything to do with the logic. Sadly, even slightly depressingly, this is wrong. In 1931, a very clever chap called Kurt Gödel proved this to be the case, with his two "incompleteness theorems". In a nutshell, the first one states that as long as any logical system is consistent  with itself (read: not wrong), then it cannot prove everything which is true (inconsistent logical systems can usually prove everything that's true, and most things that aren't - see principle of explosion). The second one states that if you have a logical system (by which I mean a set of assumptions, usually followed by some reasoning), you cannot use the logic of that system to prove that that system is consistent. In fact, Gödel proved that if you did that, you have just proved that the system is inconsistent.

Saturday, 26 March 2011

What's the point of physics?

Why do we do physics? As a subject, it seems to fit in something of a gap. On one side you have chemistry and biology, each fundemental to human health, longevity and happiness. On the other you have maths, without which we wouldn't have quantitative science, computers, statistics or (good) engineering.

Saturday, 19 March 2011

Democracy and Libya

First, a disclamer. The situation in Libya is changing so quickly it is difficult to say anything with certainty at this point. That means, by the time I finish writing this, the post may already be invalid.
Well. The West, in fact most of the world, seems to have a brand new war on its hands. Is what we are doing right? Are we setting a dangerous precendent? Now we are in, can we get out?

Saturday, 12 February 2011

Free Will

Do we have free will? In other words, do we, as consious, self-aware individuals, have the ability in some cases to chose for ourselves, independent of outside events, between two or more different options? If you think about it, even if we do have free will, we don't execute it very often. After all, it's quite easy to predict most of what someone will do in a given day - and if we can say that someone will almost certainly get up and go to work on a given day, that person is hardly exercising free will in that case. Most of the things we do are either decided for us (too a greater or lesser extent), or our descision to do them comes through (predictable) logic and reason.