UHECRs tend to collide with photons of the cosmic microwave background—pervasive radiation that is a relic of the early universe.

UHECRs 往往会与宇宙微波背景中的光子相撞，这种辐射是早期宇宙的遗迹，无处不在。

youdao

Did the early universe have just one spatial dimension?

宇宙形成初期是否只有一个空间维度？

youdao

OUT of chaos comes order. Or at least it did in the early universe.

混乱过后便是秩序井然，至少这种情况在早期的宇宙中是常见的。

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The other telescope,known as Planck, will study temperature variations from the very early universe.

VOA: standard.2009.05.14

Ripples in this radiation are, in effect, fossils that reflect patterns of sound in the early universe.

ECONOMIST: Astronomy

The early universe is also thought to have produced a background of gravitational waves from quantum fluctuations.

ECONOMIST: Fundamental physics

However, the new observations do give a tantalising glimpse of what the very early Universe might have been like.

BBC: Astronomers detect 'monster star'