I seem to remember reading at university that light was affected by gravity and was proven by an experiment where the sun would "bend" light allowing stars that should be obscured by the sun to be seen. I have read that photons are massless, so, is it the EM radiation that is affected by gravity and if so surely that would prove that light had mass.

As I know there is no environment things like (sphere) in space, so how do we catch astronauts talking from earth to moon and in future mars to earth ? how signal travels in space? like sound waves!

Over the billions of years that the Earth has been orbitted by the Moon, its rotation has slowed by the slight resistance to the tide as it travels round the planet (relative to the Earth of course, it would appear static relative to the Moon).  The tide is of course caused by the gravitational pull of the moon and the equal and opposite gravitational forces of the Earth and the Moon keep the Moon nicely in orbit around the Earth.

As the force causing the braking effect of the tide is exerted by the Moon's gravity, there should be an equal and opposite force to the braking that is being exerted on the Moon.  As the tide is working as a brake on the rotation of the Earth, it would be expected that the bulge of tidal water is slightly ahead of the Moon with the Moon's gravity pulling it back.  I suspect that this bulge slightly offsetting the Earth's centre of gravity out of line with the Moon's centre of gravity and the Moon's centre of rotation might have some such effect.

Admittedly the effect would be rather small, but over the periods of time such as the time it has taken for the Earth's rotation to change from 6 hours per day to 24 hours per day surely there has been some effect.  If so, am I right in thinking that the Moon's orbit has quickened over time?  If so, I hope the Moon has stayed in equillibrium by adjusting its altitude (is that the right word?) and isn't thinking of leaving us to it once it has built up an escape velocity...

The inflation model is apparently needed to explain why the universe is homogeneous at large scales as there would be not be enough time for photons to travel between points if inflation had been constant.

Feynman's QED series says that there are small probability amplitudes for photons travelling faster than the usual speed of light.

In the early universe where space was small in each dimension, wouldn't the Uncertainty Principle have caused photons' velocity to fluctuate wildly and be above the general speed of light much more often than normal, thereby allowing signals to move from one part of the early universe to another very quickly and removing the need for an exponential inflation theory? Please can someone inform me what is wrong with this logic =)

O.K, so the universe stared life as a primeval atom, or a similar object??Well what was that object in?Answer: well... it could be dark matter (or a substance unknown to us...which dark matter is)What if dark matter acted as normal matter, the large 'vacuum' which was 'outside the universe' is actually eternal dark matter and the grouping of this into a central point due to a gravity type force, if not gravity itself, could lead to collisions of dark matter.This in turn could transform energy and may create 'matter' as we know it today. The transformation of dark matter to normal matter could be what we would perceive as an expansion of matter, which could link in with theories of inflation and thus the continued transformation of dark to normal matter could explain why the universe is expanding.Therefore the expanding universe could be a result of a far greater infinite (perhaps) expanse of dark matter.Only a theory, not very well explained or backed up in anyway, but thought I could lay it out on the table for you all to prod and jab at the concepts that could make it work.

I was profoundly struck by some images of Saturn that Sir Patrick Moore was presenting on TV and I had a revelation..The Rings of Saturn have fascinated me from Cradle to Dole Queue and on studying them tonight, strike me as a valid and viable form of data-stream, akin in many respects to the grooves on a vinyl LP or the digital binary spiral track of a DVD or CD.THIS IS WHERE YOU CAN HELP.! I would love to hear any thoughts on the possibility of setting about attempting to create a musical analogue, accurately interpreted from Hi res images taken of Saturn’s rings; We have all at one time or another had scratched or messed up Vinyl discs or cds.. etc. Right.? And we all know it still always at the very least sounds like SOMETHING, no matter how distorted or random the damage or distortion.My bet is:- That if someone is prepared to stamp a scaled down image of Saturn’s rings and join each rotation to it’s sub neighbour on a piece of black vinyl and I pop it into my Granddad’s gramophone we are going to hear either the secret of the genesis of life in our universe or The Colonel’s secret recipe - in Saturn-Ian. Or, at the very worse something better than, anything from the pop 90s Charts.I know this sounds a little ‘April fool!’, buts that’s just how I roll.Who’s with me?

PS. it doesn’t need to be the vinyl idea it will in all probability have to be digital..Sincere Musical and Scientific Hugs Big G.

I have heard that black holes have a finite mass but no size and they most likely contain singularities which have infinite mass. How can a finite mass object contain infinite mass? Or am I thinking the question wrongly?

Hello Scientists

I am currently working on my final school exam paper about Relativity and Astrophysics and these questions came up. Can anyone give me definite answers to them?

1. Is it possible for an Object (excluding light) to travel at the speed of light? Maybe even faster?

2. If an Object theoretically travels at the speed of light, will its length contract infinitely small or will it converge to a certain number? Does the starting length matter?

3. Do Black holes attract one another?

4. Do black holes die? If yes, after how long? What comes next?

5. Do black holes accumulate mass?

6. Is the Universe infinite? If no, what comes after it?

7. What is the biggest Object in the universe?

8. How far can light travel?

9. Could there be other elements in the universe that we don't know of?

10. Are there radiations other than Light/Sound/Radiowaves..Etc that we can't perceive?

Alexander Campbell

Hochalpines Institut Ftan

Ftan, Switzerland.

poolkill@hotmail.com