What is actually universe? only matter or both matter and space?
2253
If the universe is expanding, what is it expanding into?
35463
How come the universe is made of matter and not antimatter?
98292
What is spacetime?
65001
Universe from nothing?
2377
Is the total energy of the universe zero?
26748
Why does matter exist in 3 states (liquids, solid, gas)?
75788
Is spacetime absolute?
130760
What are matter waves made of and what is their speed?
113659
Why was the universe in an extraordinarily low-entropy state right after the big bang?
59312
Is everything in the physical world composite?
16362
How does matter know to obey physical laws?
138161
Why is space a vacuum?
129816
Experimental observation of matter/antimatter in the universe
92937
What exactly is 'Dark Matter'?
34350
matter wave and wave function
54501
What is the entropy of the universe today?
51042
How is it possible to come to a conclusion that Universe is a result of the Big Bang while we aren't able to observe the entire Universe?