# Gravitational force between matter and antimatter

• B
Homework Helper
Gold Member
What is the current scientific consensus on the gravitational force between matter and antimatter. Is it repulsive, attractive or zero?

## Answers and Replies

Gold Member
Antiparticle of photon is itself and photons attract.

Delta2
Staff Emeritus
It is a prediction of GR than it is attractive. If it were not (and indeed, not the same as for matter) it violates conservation of energy.

Delta2 and vanhees71
Mentor
Yes, it is clearly predicted to be attractive, but this has not been experimentally tested yet.

vanhees71 and Delta2
Gold Member
Yes, it is clearly predicted to be attractive, but this has not been experimentally tested yet.
But, we've made antimatter... didn't anybody notice if the stuff tended to fall down, or up ?

vanhees71
Mentor
But, we've made antimatter... didn't anybody notice if the stuff tended to fall down, or up ?
No. The antimatter that we have made is charged and it is hard to get a region where the EM field is so small that you can see which way it falls under just gravity.

Homework Helper
No. The antimatter that we have made is charged and it is hard to get a region where the EM field is so small that you can see which way it falls under just gravity.
Actually, we have made neutral antimatter, but I think that their gravitational properties haven't been studied yet.

vanhees71, Dale and Delta2