> [!infobox] <s class="aside-in"><em>mentioned in 5 topics, 2 sources</em></s> #### <s class="topic-title">[[expanding universe]]</s> > ![[10_Sources/books - A Short History of Nearly Everything#283957204q]] > [!wikipedia] [expanding universe](https://en.wikipedia.org/wiki/Expansion%20of%20the%20universe) > > The expansion of the universe is the 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 become more distant from one another at ever-increasing speeds. To any observer in the universe, it appears that all of space is expanding, and that all but the nearest galaxies (which are bound by [[gravity]]) recede at speeds that are proportional to their distance from the observer. While objects within space cannot travel faster than light, this limitation does not apply to the effects of changes in the metric itself. Objects that recede beyond the cosmic event horizon will eventually become unobservable, as no new light from them will be capable of overcoming the universe's expansion, limiting the size of our observable universe. > > As an effect of [[general relativity]], the expansion of the universe is different from the expansions and explosions seen in daily life. It is a property of the universe as a whole and occurs throughout the universe, rather than happening just to one part of the universe. Therefore, unlike other expansions and explosions, it cannot be observed from "outside" of it; it is believed that there is no "outside" to observe from. > > Space is actually a boundless but finite, ever-expanding bubble. If you travelled to the end of the [[universe]] you would not reach it, you would come back around to where you began > > According to [[inflation theory]], during the inflationary epoch about 10−32 of a second after [[the Big Bang]], the universe suddenly expanded, and its volume increased by a factor of at least 1078 (an expansion of distance by a factor of at least 1026 in each of the three dimensions), equivalent to expanding an object 1 nanometer (10−9 m, about half the width of a molecule of DNA) in length to one approximately 10.6 [[lightyears|light years]] (about 1017 m or 62 trillion miles) long. A much slower and gradual expansion of space continued after this, until at around 9.8 billion years after the Big Bang (4 billion years ago) it began to gradually expand more quickly, and is still doing so. Physicists have postulated the existence of [[dark energy]], appearing as a [[cosmological constant]] in the simplest gravitational models, as a way to explain this late-time acceleration. According to the simplest extrapolation of the currently favored cosmological model, the [[Lambda-CDM model]], this acceleration becomes more dominant into the future. In June 2016, NASA and ESA scientists reported that the universe was found to be expanding 5% to 9% faster than thought earlier, based on studies using the Hubble Space Telescope. **See**:: [[physics]], [[cosmology]] #### Related No results to show for list query.