The following posts have no fixed theme or style, but I hope you enjoy reading them!

Wednesday, 25 June 2008

More about me and the environment

I am fiercely independent. If someone tells me to do something I get defensive; I don't automatically do the opposite, but I certainly have a good look at the options to see whether it would work to do something else. I want to be absolutely sure that I am my own person. And I do it obsessively. When someone says they can predict how I'll react to something or what I'll say, it throws me into a kind of panic and I don't know what to do. I cast about for new ways of being unpredictable. I don't want to be weird, but I certainly do want to decide things myself and I pride myself on having original ideas and new ways of doing things.

It's perhaps because of this that I am a man of short term obsessions. I have had my hatred of umbrellas, my love of cheese, my love of the cardigans, my love of tea, my obsession with cacti, and many more. When someone finds me out, or, worse, is more obsessed than me, it shocks me and I flee in panic!

But slightly contradictorily, I like to take up the same opinions as my Dad. You could probably say that the time when I was gaining all my background of opinions and way of thinking was a time when I listened a lot to my Dad. He was a Quaker, he was slightly anti-establishment, he was an environmentalist and a scientist. Everyone has beliefs and values that are unquestioned, and these are some things that are firmly ingrained in me.

A wonderful thing about university is that there are a lot of people with carefully considered opinions. I don't discuss life, the universe and everything too often, but certainly over a few years you get through most things. So you start to question your ingrained values. That's important to me, because then I get to be that little bit more independent in my thoughts.

I realised only recently that environmentalism was something that I should question too. My Dad died before everyone believed in global warming, so I can't just steal his ideas on that. It brings up lots of problems that he probably thought through but I just accepted.
What kind of world are we trying to save?
Do we want to stop seas from being filled with fertilisers that kill off local fish populations?
Do we mind that a land filled with people, our houses, infrastructure and agriculture is unnatural?
Is the destruction of sea habitat somehow more important or more avoidable than the destruction of habitats on land?
Is biodiversity very very important? It's not so natural either. After all, if you leave land to do its own thing, nettles could cover it and squeeze out anything else. Or bracken in the highlands.
If we will be able to survive the problems of global warming, is that enough?
In terms of importance, if you give a human life a value of 10, what's the value of a frog?
If there is a huge swarm of insects is it more justified to kill them rather than a lone bug?
Can we even define the state of the Earth environmentally?

I'm not planning on abandoning my environmental views, because I think they are important. But it's something to think about, because unquestioned views are dangerous no matter who you are.

Sunday, 22 June 2008

Advice #26

Before and during crossing a road, Stop, Look and Listen
And when I say "look", I mean, look right, look left, and look right again
(or left right left if in a foreign place where people drive on the right)

Thursday, 19 June 2008

Fractal Fripperies

Rachel's boyfriend has a new company called Fractal Fripperies. You can browse and zoom around fractals and then choose a pattern and get a T-shirt with it on. It's great! Fractals are infinitely detailed, and the whole concept of that scares me slightly, but it also amazes me. It just blows my mind slightly. But they are cool, so next time you want a new T-shirt, get your own personal fractal!

Sunday, 15 June 2008

Your Favourite British Coins

The results are in from the survey:

It's a tie between 50p and £1 coins, both receiving around 43% of the vote. I haven't seen any of the new ones yet, but they should be in the mint already

Wednesday, 11 June 2008

Excuses excuses...

In my department at university they set everyone exams to work out which grades to give. But to make sure that everyone has the right grade, they give some people a viva (oral exam). They interview a few people to work out the quality of the year as a whole and also some people who are near grade boundaries so they can decide which side of the boundary to put you.

I figure I need to talk like someone who tried his best and has excellent knowledge but somehow didn't show it in the exams. And that got me thinking about excuses I could use.

1) We went to the tea shop after each exam and so I was really distracted thinking which tea to have.
2) I have been in a state of worry and tension because the fridge taunts me with noises that I can't respond to. And it does that really loudly and at me, even if there are other people in the room.
3) I have been in a state of worry and tension because some people managed to get a balloon tangled in the telegraph wires near our house back in spring and it bothered me. I moaned incessantly to my housemates about the fluttering of them in the wind, the problems of littering and how they were in my field of view when I worked

Until eventually, a man from BT came to get them down (right hand picture)

4) I understand everything, there was just too much to learn
5) I'm a slow eater and I shouldn't be persecuted for it.
6) My Gran died
7) I was troubled about the lecturer I mentioned here and couldn't possibly work
8) Living with girls clouded my brain
9) My shoelace kept coming undone because it was in need of repair
10) I spent too much time writing silly blogs like this instead of revising

Anyway, with the viva in only a few hours, I'd better do some work...

Sunday, 8 June 2008

More on the new British coin designs

I forgot something that I should have put here, when talking about the new coins to be released this year (we could start seeing them within a couple of months by my reckoning). The 50p coin is the most radically changed design. It will retain its seven-sided shape, but instead of having a base at the bottom so you can stand it up and see the design the right way up, it will be upside down. And the obverse ("heads") will also flip at the same time. So we'll have one of the points of the heptagon at the bottom rather than the top.

Which current design is your favourite though? Let me know on the poll on the left... it closes in only 4 days!

Saturday, 7 June 2008

Entropy and Glasses

Having spent much of the last few weeks concentrating non-stop on exams, I have learned to appreciate this subject a little more. So, as a celebration of finishing yesterday, I wanted to tell you all why it's quite so cool.

The two most important statements in physics are Second Laws. Newton's Second Law of Motion states "Rate of change of momentum is proportional to the force producing it". This leads to the equation F=ma. That's pretty cool, almost as cool as the Second Law of Thermodynamics, which states that Entropy Always Increases.

Entropy is disorder. If atoms are in a mess, entropy is high. Entropy means that when you add a nice square lump of sugar into tea, it will stop being nice and square and orderly, and spread its atoms all through the tea by dissolving (making your tea taste all sweet and gross). Entropy also means that if you heat up your room, the heat spreads out of the windows, doors and through the walls, and in the end your room is almost as cold as it ever was. Hot things have high entropy, because the atoms jiggle a lot and swap places and move around. And there's no way that they will stay in a nice ordered way like that. There is order involved in having all the heat in one place (your room), and it's much more disordered to share it out randomly (everywhere else), hence your room getting cold.

This law has never been proven wrong. If something creates order in one place, you will create that much disorder (and probably some more) in another place to compensate. Entropy always increases. We are doomed to become disordered.

The law leads to an equation that goes like this:
G = H - TS
This is one of the most useful equations ever. The second law of thermodynamics says entropy must go up. This equation does the same thing. G is called a free energy and in all processes, free energy G must go down. G is related to entropy of the universe somehow. S is the entropy of what you're looking at. If you line up a load of atoms in a row, then entropy of those atoms, S, goes down. But although you'd think that wouldn't be allowed from our law, it is, because the entropy of the whole universe could still go up, even if the entropy of this little bit goes down.

It happens all the time. You freeze some water to make an ice cube, and it has quite a low entropy. But freezing gives out heat. And it heats up the rest of the universe, so the rest of the universe has a higher entropy. This process of giving out heat (or even taking heat in) is explained in H. H is called the enthalpy. Giving out heat gives H a minus sign, and taking in heat gives H a positive value. The other letter in this equation is T, for Temperature.

Now, imagine that you have a load of atoms just sitting around. You decide to cool them down until the temperature, T, is zero. Absolute zero. It's minus 270-odd degrees C. Now, according to the equation, G = H - TS. If T is zero, then T * S = 0, no matter what S is. So G will try to get to a minimum value, and the only way it can do that is by lining up all the atoms so that H is as low as possible. From the paragraph above, we see that we need to find a way of giving out as much heat as possible, since this makes H as low as possible and so makes G as low as possible.

For any pair of atoms, you can work out what energy there is between them. They interact in some way, and have an energy. If there is more energy available than they need to interact, they give it out as heat. We can make a guess that there will be some optimal distance between the atoms that will make them give out the maximum amount of heat.

If you have a load of atoms at a really low temperature, they will all move to that distance away from each other, because that gives the lowest H and therefore the lowest G. That's what a crystal structure is. It's an ordered layout of atoms. Most solids have a nice ordered layout of atoms.

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Just let me make it clear... the entropy of this crystal is very low, but in making a low entropy system, the rest of the universe is getting hotter, and entropy is increasing. So from the second law of thermodynamics we can work out that crystals are the most stable structure of anything if you get cold enough.

Glass has atoms that are all over the place though. And cooling glass down to absolute zero won't change that. That goes precisely against what I have been saying. Glass should not exist. It is unstable, according to the second law of thermodynamics, which is NEVER wrong. In fact it CAN exist, but only exist because at low temperatures, atoms don't have enough energy to move around, so when they try to arrange themselves into a crystal structure as they cool, they can't arrange themselves quickly enough so a disordered structure is left over.

The fact that science can describe so much using the law "Entropy always increases" (and I've only just scratched the surface of one area), and the things it predicts are correct is the reason why I love science. It's a triumph of logic, and just so, so powerful. That's why I'm sad I won't go to any more undergraduate lectures about it.

Thursday, 5 June 2008

End of university

I seem to have finished all the work and exams for my degree. I'm not sure what to think of it. Results aren't out yet, maybe I'll know what to think of it then