Quote from: gospacex on 08/04/2008 09:42 amQuote from: khallow on 08/03/2008 04:58 amany sufficiently dense object (possibly a neutron star just a bit shy of unrestrained collapse) can have a photon sphere. That is, the object through it's deep gravity well can actually trap photons in orbit around the object. Anything moving slower than that will be trapped in higher orbits. One can then attempt to scatter observable stuff off of what is in the photon sphere.I don't think so. Photon sphere is not a stable orbit, you can't "accumulate" orbiting photons there. IIRC lowest stable orbit around non-rotating black hole has a radius of 3*Rs.I'm not sure I understand what you're saying. This would be an orbit, then you effectively have that photon trapped in this zone. It can still escape either by hitting other things or due to the quantum nature of the photon, tunneling either into the massive object or out of the system.
Quote from: khallow on 08/03/2008 04:58 amany sufficiently dense object (possibly a neutron star just a bit shy of unrestrained collapse) can have a photon sphere. That is, the object through it's deep gravity well can actually trap photons in orbit around the object. Anything moving slower than that will be trapped in higher orbits. One can then attempt to scatter observable stuff off of what is in the photon sphere.I don't think so. Photon sphere is not a stable orbit, you can't "accumulate" orbiting photons there. IIRC lowest stable orbit around non-rotating black hole has a radius of 3*Rs.
any sufficiently dense object (possibly a neutron star just a bit shy of unrestrained collapse) can have a photon sphere. That is, the object through it's deep gravity well can actually trap photons in orbit around the object. Anything moving slower than that will be trapped in higher orbits. One can then attempt to scatter observable stuff off of what is in the photon sphere.
Why don't we prove the characteristics of anti-matter first? It takes very little thought, and not that much more typing to come up with usefull applications for anti-gravity.
Assumption 1===========I am assuming that anti-matter wil be affected by gravity in the reverse to normal matter.Assumption 2===========Therefore if we can create an anti matter object we should be able to accelerate it up to FTL. This in itself should allow FTL communications.Assumption 3===========We can currently contain anti-matter by magnetic means, so we should be able to contain normal matter by a similar means inside our anti-matter spacecraft.I expect the new CERN accelrator will be able to answer my probably incorrect assumptions.
Quote from: colbourne on 06/23/2008 06:03 amAssumption 1===========I am assuming that anti-matter wil be affected by gravity in the reverse to normal matter.Assumption 2===========Therefore if we can create an anti matter object we should be able to accelerate it up to FTL. This in itself should allow FTL communications.Assumption 3===========We can currently contain anti-matter by magnetic means, so we should be able to contain normal matter by a similar means inside our anti-matter spacecraft.I expect the new CERN accelrator will be able to answer my probably incorrect assumptions.Nope, basic knowledge will do.First two are wrong.Third is irrelevant.
How did you know that the first two were wrong ?
Quote from: colbourne on 12/04/2011 08:29 pmHow did you know that the first two were wrong ?Observed since the moment we discovered anti-particles.An example:An electron and a positron are antiparticles of each other.They exhibit perfectly predictable behavior.Can I ask:How big is your understanding of physics, it is good to know before continouing this discussion?
I think you better let CERN and other research establishments know, as they are spending a fortune to confirm the properties of anti-matter. As far as I know the exact properties have not been confirmed yet.I only have a BSc in Physics
Even this business major knows that gravity is considered to be a function of mass, not of charge.
Quote from: Cherokee43v6 on 12/05/2011 08:37 pmEven this business major knows that gravity is considered to be a function of mass, not of charge.That is hardly relevant. Antiparticles are not just charge reversed. They are apparently everything-but-mass reversed. Some people speculate that they may be mass reversed as well. You are right there is probably no anti-mass. It is very unlikely, but the premise of this thread is "what if".
I think you better let CERN and other research establishments know, as they are spending a fortune to confirm the properties of anti-matter. As far as I know the exact properties have not been confirmed yet.