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Max
  • Member for 9 years, 3 months
  • Last seen more than a month ago
  • London
4 votes
1 answer
206 views

Why can't friction in an accretion disk radiate away enough of the angular momentum do create inward spiral?

4 votes
3 answers
4k views

Total positive energy in the (observable) universe

4 votes
2 answers
803 views

Why does the redshift formula hold true when measuring the expansion of the universe?

4 votes
2 answers
412 views

If, for outside observers, infalling matter never enters the black hole, what happens to the matter's gravity?

2 votes
4 answers
4k views

Are black holes black or invisible? [duplicate]

2 votes
2 answers
1k views

Deriving Relativistic Doppler Effect through length contraction

2 votes
1 answer
269 views

How can the expansion of space be considered a force?

2 votes
2 answers
279 views

Why length contraction and not apparent difference in relative velocity?

1 vote
2 answers
185 views

Speed of light confusion

1 vote
1 answer
332 views

Simple derivation of $E=mc^2$

1 vote
1 answer
145 views

Does a zero-energy universe imply a Big Crunch?

1 vote
1 answer
268 views

How can a black hole not be a perfect sphere?

1 vote
1 answer
281 views

How can the momentum-position Uncertainty Principle not violate conservation of energy? [duplicate]

1 vote
1 answer
435 views

Why do gravitationally bound regions not feel the expansion of the universe but the rate of expansion of the universe does depend on gravity?

1 vote
0 answers
95 views

Why does the action $S=\int L dt=\int (T-V) dt$ have to be minimised (or maximised) to produce Newton's Second Law? [duplicate]

1 vote
2 answers
416 views

What causes an electron and proton to combine into a neutron?

0 votes
2 answers
150 views

What does cosmological redshift say about speed of separation and why?

0 votes
4 answers
3k views

Why does a leaning bike not fall over?

0 votes
1 answer
158 views

Can't we obtain observational values for scale factor at different periods in the history of the universe?

0 votes
1 answer
244 views

How can the voltage in a circuit possibly be constant for different resistances?

0 votes
2 answers
1k views

How can the total amount of energy in the universe be zero? [duplicate]

0 votes
2 answers
356 views

Temperature, redshift or true colour of a star?

0 votes
3 answers
3k views

Why does relativistic kinetic energy (KE) equal to the total relativistic energy minus the rest mass energy?