An Idiot’s Guide to Time - by Warren Ellis
OK, so this one’s going to be a bit odd, but something came up in physics news this week that amuses the hell out of me, so you’re just going to have to put up with this.
Time’s arrow. A perfectly horizontal line moving from past through present to future. This is how we understand time to work.
If you smash some particles together in an accelerator, they turn into a spray of other particles. If you were to run the movie of that collision backwards—one that showed those other particles forming the original particles—that would, in fact, appear just as valid. This is called time reversal symmetry. Time is basically symmetrical at the quantum level. It’s all just particles and energy moving around. And this quantum bullshit dimension contains all the tiny machinery that decides how everything works.
But these people here discovered a subatomic process that doesn’t behave in that way. Working in antimatter physics, deep down in the hadronic depths with mesons (tiny things, found on a scale several powers tinier than the fields that nanomachines operate in), they found something that wasn’t supposed to happen. Down in the murk, these weird flavors of meson turn into different kinds of stuff all the time. In a world with symmetrical time, the conditions down there say that Thing A will become Thing B more easily than Thing B will turn into Thing A. It’s how the reversed movie makes sense.
But it turns out that Thing B turns into Thing A six times more often. This is a bit like reversing a video of a glass of water being dropped, winding it back to the start—and finding it simply won’t go back to the point before the glass tipped over. Time has a preferred direction. Time is asymmetrical.
In fact, you could possibly conceive of time as being a downward slope. Our slide into the future is inexorable. Everything is slipping down time’s mountainside.
Makes you wonder what’s at the bottom, doesn’t it?