[phkahler]

>> They measured that they needed a magnetic field bias applied to the anti-hydrogen equivalent to "pushing them up" with 0.75g (+/- 0.25g or so), so anti-matter is attractive. No new physics.

Antimatter is attracted to matter. Isn't it still an open question if matter is attracted to antimatter, and if antimatter is attracted to antimatter? What if antimatter is gravitationally repulsive? This experiment wouldn't show that.

Not that I think it's likely, but it hasn't been ruled out by this experiment has it?

[wyager]

> Isn't it still an open question if matter is attracted to antimatter

Conservation of momentum (force*time) means they both experience the same force. The attraction is symmetric

[ben_w]

A mass with negative effect on local curvature, would I think still follow the same geodesics (i.e. fall down).

Same in Newton, though there it would be GMm/r^2 = F = ma but both m have the same sign so acceleration is the same regardless of value (including -ve), though if M was negative then both +ve and -ve valued m would accelerate away rather than towards.

Conservation of momentum and energy is conserved because they're mv and 1/2mv^2, so an isolated equal and opposite +- pair co-accelerating has a total of zero of both all times.

[phkahler]

>> Conservation of momentum (force*time) means they both experience the same force.

That's right. I'm just saying it hasn't been confirmed. Wouldn't that be some exciting new physics though? It could explain why there isn't any around, why galaxies apparently aren't made of it, and why there is annihilation radiation sourced from the edge of galaxies. ;-)

[Georgelemental]

Violating conservation of momentum like that would allow generating arbitrarily large amounts of energy for free.

[phkahler]

Yes it would. Maybe that's what's accelerating the expansion of the universe ;-)

[gmadsen]

wouldn't energy conservation require matter to experience the same force to anti-matter?