Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: jeffreyH on 08/03/2018 17:31:36

Title: How do neutral particles interact with gravity?
Post by: jeffreyH on 08/03/2018 17:31:36
Charged particles will interact in a way that can hide gravitational effects. Are there any benefits to studying the way neutral particles interact in a gravitational field? If not then why not?
Title: Re: How do neutral particles interact with gravity?
Post by: Bored chemist on 08/03/2018 19:35:51
This is why Cavendish used neutral objects in his experiments on gravity.
Hardly a novel approach.
Title: Re: How do neutral particles interact with gravity?
Post by: Kryptid on 08/03/2018 20:52:05
Are there any benefits to studying the way neutral particles interact in a gravitational field?

Yes: https://physicsworld.com/a/neutrons-reveal-quantum-effects-of-gravity/ (https://physicsworld.com/a/neutrons-reveal-quantum-effects-of-gravity/)
Title: Re: How do neutral particles interact with gravity?
Post by: jeffreyH on 10/03/2018 15:03:42
Some of the other uses of the techniques are discussed in this interview.
https://www.labnews.co.uk/interviews/big-ask/dr-valery-nesvizhevsky-on-his-serendipitous-discovery-12-05-2014/
Title: Re: How do neutral particles interact with gravity?
Post by: evan_au on 11/03/2018 02:48:46
Quote from: jeffreyH on 08/03/2018 17:31:36
Quote
Are there any benefits to studying the way neutral particles interact in a gravitational field?

Yes: https://physicsworld.com/a/neutrons-reveal-quantum-effects-of-gravity/

I got the impression that this paper was talking about diffraction of neutrons from a periodic surface.
- It was not measuring the quantisation of space or quantisation of gravity.

There is an experiment underway at CERN trying to measure the gravitational attraction of antimatter.
Electric fields are much stronger than the gravitational field, so the only practical way to measure gravitational attraction is to use neutral particles, like anti-Hydrogen.

See: https://en.wikipedia.org/wiki/Gravitational_interaction_of_antimatter
Title: Re: How do neutral particles interact with gravity?
Post by: evan_au on 11/03/2018 19:05:07
Quote from: JeffreyH
Are there any benefits to studying the way neutral particles interact in a gravitational field?
On a more macroscopic scale, larger neutral particles are used to do experiments on microgravity. The drop tower at ZARM can simulate microgravity (10-5 to 10-6g) for around 5 seconds by dropping an experimental module, or almost twice that by throwing it upwards, an waiting for it to come down again...
- They use it to study Bose-Einstein condensates
- Plus chemistry, physics, solar sails, etc
See: http://omegataupodcast.net/279-microgravity-research-at-zarm-drop-tower/

The Pound-Rebka experiment showed the reality of gravitational red shift (or equivalently, gravitational time dilation).
https://en.wikipedia.org/wiki/Pound%E2%80%93Rebka_experiment

In an older era, it was used to produce shotgun pellets.
See: https://en.wikipedia.org/wiki/Shot_tower