https://en.wikipedia.org/wiki/Expansion_of_the_universe https://en.wikipedia.org/wiki/Expansion_of_the_universe The expansion of the universe is the increase i

https://en.wikipedia.org/wiki/Expansion_of_the_universe https://en.wikipedia.org/wiki/Expansion_of_the_universe The expansion of the universe is the increase in distance between any two given gravitationally unbound parts of the observable universe with time. It is an intrinsic expansion whereby the scale of space itself changes. The universe does not expand "into" anything and does not require space to exist "outside" it. As the spatial part of the universe's spacetime metric increases in scale, objects move apart from one another at ever-increasing speeds. To any observer in the universe, it appears that all of space is expanding while all but the nearest galaxies recede at speeds that are proportional to their distance from the observer – at great enough distances the speeds exceed even the speed of light.