Why is it easy to break an egg, but impossible to un-break it? More generally, why is the past so different from the future? We can’t travel into the past, but we’re inexorably carried into the future. We can remember the past, but we can’t reliably predict the future. But strangely, the fundamental laws of physics work just as well backwards as forwards – so why do we perceive an arrow of time? That’s the subject of my new feature article for BBC Earth….Read more "Back to the Future"
You may have seen some news reports over the last week or two saying that scientists had made a substance with the hottest temperature ever recorded — but that temperature was somehow below absolute zero, a negative temperature on the Kelvin scale. Weirdly enough, this is absolutely true….Read more "What’s Cooler Than Being Cool?"
The Second Law of Thermodynamics — entropy never decreases in a closed system — is among the more famous laws of physics. If you’re reading this blog, I’d be surprised if you’ve never heard of entropy before. You’ve probably also heard that entropy has something to do with disorder, and that the Second Law basically says that the universe tends toward disorder, but that’s not quite what the second law says — entropy isn’t really the same thing as disorder, though they’re related.
So what’s entropy? To answer that, I’ll steal a little bit from Kurt Vonnegut…Read more "Entropy and Billy Pilgrim"