Search Results
| Search type | Search syntax |
|---|---|
| Tags | [tag] |
| Exact | "words here" |
| Author |
user:1234 user:me (yours) |
| Score |
score:3 (3+) score:0 (none) |
| Answers |
answers:3 (3+) answers:0 (none) isaccepted:yes hasaccepted:no inquestion:1234 |
| Views | views:250 |
| Code | code:"if (foo != bar)" |
| Sections |
title:apples body:"apples oranges" |
| URL | url:"*.example.com" |
| Saves | in:saves |
| Status |
closed:yes duplicate:no migrated:no wiki:no |
| Types |
is:question is:answer |
| Exclude |
-[tag] -apples |
| For more details on advanced search visit our help page | |
Results tagged with universe
Search options answers only
not deleted
user 520
The universe refers to the cosmos; all of space-time and that which exists as part of it. Alternatively, it can refer to the observable universe, which only contains the part we can see. Questions tagged with this should ask about physics at scales the size of the universe or specific properties of the universe
21
votes
Accepted
How many times has the matter in our Solar System been recycled from previous stars?
A very qualitative way to look at it:
The Earth, and therefore you are formed of the same material that contributes to the metallicity of our Sun
Our Sun is a population I star, which means that it …
6
votes
Is the total energy of the universe zero?
In the accepted big-bang-and-inflation scenario, and before for we had evidence for the existence of dark energy, it was possible to talk about the possible fate of the universe (open or closed) in terms … Note, however that the issues are changed rather a lot by the presence of dark energy in the universe. …
- 4,690
1
vote
Questions about the Jeans length
Not really my field, but I'll take a crack at it.
I understand that if the region is smaller than the Jeans length, then pressure, which travels at the speed of sound (compared to the speed of gra …
121
votes
Am I attracting Pluto?
While the atoms that make up your body are exerting gravitational force on very distant objects you as an entity are only exerting gravitational force on objects out to about 14 light years distance ( …
3
votes
Accepted
Is every aspect (fundamental forces, periodic table) of an antimatter universe exactly the s...
Most of those can be restored however by both exchanging matter for antimatter (C) and reflecting the universe in a mirror (P, for "parity"). …
2
votes
Accepted
Expansion of the universe a thermodynamic process or not?
The universe is not currently in (or even close to) thermodynamic equilibrium, so the kind of thermodynamics we teach in a first course (often called "equilibrium thermodynamics") is right out. …
2
votes
If everything in existence were increasing in size at some rate, would we be able to detect it?
Depends.
If you simple assume matter growing we would see the distance between the surfaces of celestial bodies diminishing. Given that we regularly monitor the distance between the surfaces of the …
1
vote
Is dark matter expanding the universe, and creating the structures within it?
The dark matter is known (from galactic rotation curves and microlensing) to clump around galaxies and to mass considerably more than the visible matter.
This contradicts your hypothesis, so no.
4
votes
Accepted
Is there a universal rest frame of reference?
You've missed something important about relativity.
The rule that all (inertial) observers measure the speed of light in vacuum to be the same is really just a special case of the big rule: all inert …
8
votes
Accepted
What are the most realistic ways of high speed space propulsion?
In a lot of ways this is a technology---rather than physics---question, but lets look at some limits imposed by physics.
For rockets there are two numbers that matter: the velocity relative the spac …