Recent content by Gerinski

Perhaps an image is worth more than 100 words. This is my intuitive picture

I never stated that the cloud of gas could or could not radiate, that came only in some of the answers such as Anorlunda's. Personally, even now I do not see why such a gravitationally coalescing cloud of gas could not radiate to its immediate environment in the rest of the container.

Forget the ignited star then, let's consider only the collapsing cloud of gas before it has ignited. It has not yet released any huge radiation except for thermal photons.

Thanks to all, I'm just trying to improve my understanding, but I seem to receive contradictory answers. Anorlunda says such an hypothetical cloud of gas will never undergo gravitational collapse (if I understood him/her correctly, because it could not radiate heat away to any "external...

Well I was assuming a volume of space full of hydrogen and helium at stabilized pressure and temperature, in principle without any angular momentum. So, a star would never form from such a cloud of gas right? Also, and more speculatively, does that mean that stars could not form in a...

You probably meant a nuclear reaction.

Thanks, so you mean that if we took a huge space container full of hydrogen and helium gas, isolated from everything else, a star would never form by gravitational collapse? Because of the impossibility to radiate to any external environment?

Summary: Trying to understand the relationship between gravity, thermodynamics and entropy, thank you. Gravity can take a diffuse cloud of gas filling a given volume of space at equilibrium density and temperature, and turn it into a burning star surrounded by empty space. Does this mean that...

Thank you, I checked "Relativistic Doppler effect" on Wiki and it only talks about the redshifting or blueshifting of light frequency, it does not mention anything about the alteration of the perceived rate of the passage of time, so that confused me...

Let's take a star 500 light years away from Earth, let's call it Star X. To make round numbers let's say we are in Earth year 2000. We set a manned space mission to Star X, the spaceship will travel at 0.5 light-years per year (0.5 c) so it will reach there in 1000 years. Let's not worry about...

In basic physics books the standard model used to be split in 'matter' (fermions) and 'force carriers' (bosons), and there are 4 fundamental forces, gravity, weak, strong and electromagnetic. If the Higgs is a boson, why is it not considered as a force carrier and the Higgs be considered a '5th...

I may try to find where did I read that, it's in some of the popular science books I have, but I don't know if I will find it. Kindly forgive me if I don't.

There is so much discussion about what does "really happen" at the quantum level, because we can not directly observe the most minute details of quantum systems, and much is left to inference and to the "interpretations". Does the system really collapse by transferring state information to its...

I don't know how correct this is, but I read somewhere that some people interpret MWI in such a way that many (if not most) of the worlds described by the wavefunction actually cancel each other so they do not produce a physical rendering. When taken to the extreme, all of the worlds cancel out...

Thanks. Assuming hypothetically that the 3 spatial dimensions might have extended with different rates, might that have any observational clues in the present time? Of course our observable universe extends far enough in any of the 3 dimensions so all 3 of them extend beyond our observable...