## 14 November 2016

### How the universe works

Ever wondered what makes everything the way it is? As far as I can make out there's just one fundamental law that governs everything, it's called the Second Law of Thermodynamics. This states simply that the entropy of any system always increases.

So there you have it. That's all you really need to know to understand how the universe works.

I could stop writing now but I won't. It may be that one or two of you would like an illustration of what the Second Law means.

OK, here goes. If you put a drop of ink in a pool of water, the ink will spread out until the pool is a very light shade of blue. That's the Second Law in action. It may seem innocuous and a bit obvious but it really does have huge significance. Let's take another example. Drop a sugar cube into a cup of hot coffee. The sugar cube disappears because the sugar dissolves. No big deal, you might say. But, consider this. NO MATTER HOW LONG YOU WAIT THE SUGAR CUBE ISN'T COMING BACK.

The diffusion and the dissolving are not reversible. That's entropy for you.

Another word for entropy is chaos. The world we live in moves inevitably from order into chaos. There's nothing we can do about it. The Law is the Law.

It may be that we experience time the way we do because of entropy. Without entropy, time could go either way. It wouldn't matter if it went backwards or forwards. The drop of ink coalescing in the midst of clean water would be just as likely a state as any other. But it's not. The way I see it, the Second Law ensures that time only moves forwards for us, never back. Which is a pity because I've just sent my two main characters in the SF novel I'm writing back to 1977. I'm struggling to come up with an alternative theory that circumvents the Second Law. Any help would be appreciated.

So, if the universe is a cup of coffee and we are grains of sugar, we know what's going to happen to all of us at some time. We'll dissolve away, lose our individuality and become part of the coffee.

The least we can do is to make the universe a tiny bit sweeter.

photo credit: only alice descent via photopin (license)