Posted: Jun 22, 2010 3:32 pm
A very useful fluid analogy
To really "get it" in a visceral way, I urge you to try out Falaco solitons. These offer a fluid analogy that demonstrates a vorticial pair production, attraction, repulsion, and annihilation. For some reason people have difficulty accepting this until they've had some form of demonstration. The fluid analogy is by no means perfect, but I really do recommend it. You dip a plate into a pool, then stroke it gently forward while lifting it clear. You make a U-tube double whirlpool which moves gently forward through the water:
That's something like pair production. Now create another Falaco soliton aimed towards the first, and repeat with various aims. Watch carefully. When the left-hand-side of one double whirlpool is near the left-hand-side of the other, the two similar whirlpools steer clear of one another. When the left-hand-side of one double whirlpool is near the right-hand-side of the other, the two opposite whirlpools move together. That's essentially attraction and repulsion. If you aim two double whirlpools straight at one another, face on, they meet and merge and disappear. This is best in a shallow pond with muddy bottom, when you see a surprisingly energetic kick-up. That's essentially annihilation. There's even something that looks as if it might be akin to low-temperature superconduction. Make two Falaco solitons in quick succession, and watch how the second one daisy-chains through the first, moving forward more rapidly than when it's on its own. It's all just a fluid analogy and it's by no means perfect, but it gets it across very well. Something else it gets across is that there's this round thing there in the water that's made out of movement. it isn't some point-particle, it isn't some billiard-ball, but nevertheless it's there. This is how you should think about a particle like an electron. It isn't some point-particle, and it isn't some billiard ball, it's just spinning stress-energy. Take away that spin, and the electron isn't there any more.
But note that neither a Falaco soliton nor an electron is a whirlpool. There's rotation, but there's nothing flowing inwards towards the centre. And for the electron, there's nothing rotating once you move away from the centre. The electron works more like an office floor polisher on a rubber sheet. Only there is no floor polisher, just the rotation, like a ripple in the rubber sheet going round and round. The rotation twists the rubber sheet round. If you're riding one of these kiddies and I'm riding another, then if the rotations are both clockwise or anticlockwise, we move together. If they're opposite, we move apart. Hence attraction and repulsion. And as you can imagine, if we were scooting around, there's going to be a bit of pirouetting going on.
To really "get it" in a visceral way, I urge you to try out Falaco solitons. These offer a fluid analogy that demonstrates a vorticial pair production, attraction, repulsion, and annihilation. For some reason people have difficulty accepting this until they've had some form of demonstration. The fluid analogy is by no means perfect, but I really do recommend it. You dip a plate into a pool, then stroke it gently forward while lifting it clear. You make a U-tube double whirlpool which moves gently forward through the water:
That's something like pair production. Now create another Falaco soliton aimed towards the first, and repeat with various aims. Watch carefully. When the left-hand-side of one double whirlpool is near the left-hand-side of the other, the two similar whirlpools steer clear of one another. When the left-hand-side of one double whirlpool is near the right-hand-side of the other, the two opposite whirlpools move together. That's essentially attraction and repulsion. If you aim two double whirlpools straight at one another, face on, they meet and merge and disappear. This is best in a shallow pond with muddy bottom, when you see a surprisingly energetic kick-up. That's essentially annihilation. There's even something that looks as if it might be akin to low-temperature superconduction. Make two Falaco solitons in quick succession, and watch how the second one daisy-chains through the first, moving forward more rapidly than when it's on its own. It's all just a fluid analogy and it's by no means perfect, but it gets it across very well. Something else it gets across is that there's this round thing there in the water that's made out of movement. it isn't some point-particle, it isn't some billiard-ball, but nevertheless it's there. This is how you should think about a particle like an electron. It isn't some point-particle, and it isn't some billiard ball, it's just spinning stress-energy. Take away that spin, and the electron isn't there any more.
But note that neither a Falaco soliton nor an electron is a whirlpool. There's rotation, but there's nothing flowing inwards towards the centre. And for the electron, there's nothing rotating once you move away from the centre. The electron works more like an office floor polisher on a rubber sheet. Only there is no floor polisher, just the rotation, like a ripple in the rubber sheet going round and round. The rotation twists the rubber sheet round. If you're riding one of these kiddies and I'm riding another, then if the rotations are both clockwise or anticlockwise, we move together. If they're opposite, we move apart. Hence attraction and repulsion. And as you can imagine, if we were scooting around, there's going to be a bit of pirouetting going on.