0
votes
1answer
52 views

Speed=mass=time? [closed]

I was wondering why objects gain mass with speed? How can we measure speed if there is no truly stationary point to measure from? And if an object comes to a stand still will it loose its mass? ...
2
votes
1answer
71 views

If we were able to double the mass of the ordinary matter in the universe it will recollapse?

What will happen if we suppose to be able to add mass at the universe? For example doubling the mass of the ordinary matter?
3
votes
1answer
160 views

Baryon masses in Wetterich's new cosmology

Christoph Wetterich has put out a paper in which the universe isn't always expanding; it can be static or expanding just some of the time or even shrinking. And then there is an interaction which ...
1
vote
5answers
707 views

Why can't missing mass be photons?

After a star lives and dies, I assume virtually all of it's mass would be photons. If enough stars have already lived and died, couldn't there be enough photon energy out there to account for all the ...
5
votes
2answers
1k views

Why do neutrino oscillations imply nonzero neutrino masses?

Neutrinos can pass from one family to another (that is, change in flavor) in a process known as neutrino oscillation. The oscillation between the different families occurs randomly, and the likelihood ...
12
votes
3answers
2k views

If the universe were compressed into a super massive black hole, how big would it be?

I understand only a little of general relativity, but that's why I'm here! :) Consider the hypothetical situation of some extra-terrestrial intelligence pushing all the mass in the universe, every ...
4
votes
2answers
197 views

Does the recent re-count of stars in elliptical gallaxies affect our understanding of the universal mass balance?

I've seen several popular reports of a new count of low-mass stars in elliptical galaxies (here's one). Edit: Pursuant to several correct comments I've changed the title to agree with the actual ...