77 (seventy-seven) is the natural number following 76 and preceding 78. Seventy-seven is the smallest positive integer requiring five syllables in English.

Time dilation is the difference in elapsed time as measured by two clocks, either because of a relative velocity between them (special relativity), ...

Gravitational time · Twin paradox · Gravitational potential · Proper time

The speed of light in vacuum, commonly denoted c, is a universal physical constant that is exactly equal to 299,792,458 metres per second According to the ...

Variable speed of light · Rømer's determination of the... · Hubble volume · Electricity

In physics, the special theory of relativity, or special relativity for short, is a scientific theory of the relationship between space and time.

Tests · History · Postulates · Mass in special relativity

Gravitational time dilation is a form of time dilation, an actual difference of elapsed time between two events, as measured by observers situated at ...

Physics is the natural science of matter, involving the study of matter, its fundamental constituents, its motion and behavior through space and time, ...

Branches · History · Physics education · Portal

In Newtonian mechanics, momentum is the product of the mass and velocity of an object. It is a vector quantity, possessing a magnitude and a direction.

Momentum operator · Momentum (disambiguation) · Angular momentum

If dark matter is composed of weakly interacting particles, then an obvious question is whether it can form objects equivalent to planets, stars, or black holes ...

Dark Matter (disambiguation) · Halo · Dark energy · Primordial black hole