Recent content by Andy DS

Wow, I really started something here. Many thanks for the insights from all contributors.

Oh right, so it's the angular momentum of the whole system which is preserved which includes the co-orbital momentum. Thanks I hadn't taken that into account. And without looking it up I can imagine that the radius of the neutron star decreases with added mass as it would help to compress the...

When we read about the mass transfer between neutron star pairs in a binary system, how is it that the one receiving the matter can increase its spin rate. Adding mass to a spinning object ought to slow due to conservation of momentum. Where does the energy come from?

What I was trying to get to the bottom of is that, do the mirrors in the LIGO experiment actually move in response to gravitational waves or is that the time it takes the light to travel between them somehow modulated.

Thanks, but I'm not sure if I explained my query correctly, if gravitational waves from merging black holes stretch space time which has let's say infinite elasticity how does it manage to stretch the earth, which is much less elastic, to show up on the LIGO experiment. In other words do changes...

How do gravitational waves in spacetime stretch and compress solid matter such as the LIGO experiment. I ask this because the expansion of spacetime of the Universe doesn't seem to have any effect on the small scale ie the solar system.

I see where all the replies are pointing and many thanks. I was thinking that during cosmic inflation there may have had some relativistic effects but if we are saying this doesn't have an effect on what we know about the age of the universe because we are all riding along on the same wave I...

"Your question is like saying, "Because clocks read different times in different cities on Earth, there is no way to know what time it is."" No phyzguy, my queasion was more like because a clock on Earth and one near a black hole run at different rates, can this effect the answer.

It's been quoted that it would take trillions of years for a white dwarf to cool so none have ever reached that point yet.

How can we know the age of the universe, with time dilation due to the mass and velocity of matter which condensed after the big bang. If time passes at different speeds depending where it is perceived, does this not make the age of the universe somewhat moot.

Once the "bubble" is completed are you suggesting that the radiation pressure would be enough to keep it inflated against gravity.

Think about the practality of constructing a DS in the first place the unconnected parts would have to be in orbit otherwise they would just fall into the star. This means you would first have to construct a ring in the orbital plane. How would you construct the rest of it as anything out of the...

Recent research puts the process that creates heavy elements down to neutron star collisions and not supernovas as the energies involved aren't quite enough. Edit... I just had another look at the periodic table above that anorlunda posted and it clearly shows which elements are produced by...

Many thanks for all your answers on this question. The reason I asked it was that the statement the prof made seemed so emphatic that there couldn't be any naturally occurring heavier elements out there, I took it to mean there wasn't even a trace of it but it that may not be quite true. I...

The statement made about there being no elements beyond uranium in space was made by Prof Brian Cox in one of his TV documentaries. To be precise he said words to the effect that we can be certain that everything out there in the Universe is made of only 92 elements. The statement about...