免费看黄色大片-久久精品毛片-欧美日韩亚洲视频-日韩电影二区-天天射夜夜-色屁屁ts人妖系列二区-欧美色图12p-美女被c出水-日韩的一区二区-美女高潮流白浆视频-日韩精品一区二区久久-全部免费毛片在线播放网站-99精品国产在热久久婷婷-午夜精品理论片-亚洲人成网在线播放

Astronomers find traces from Universe's first stars

Source: Xinhua| 2018-03-01 20:07:01|Editor: Xiang Bo
Video PlayerClose

BEIJING, March 1 (Xinhua) -- Astronomers have for the first time detected signals of light from the earliest stars in the our universe, according to a study published on Nature on Wednesday.

Scientist had long suspected the earliest stars in our universe came to be about 100 million years after the Big Bang. But they never had the evidence to back it up until now. Before this new study, the oldest stars ever found dated to about 400 million years after the Big Bang.

"This is the first time we've see any signal from this early in the Universe, aside from the afterglow of the Big Bang," said Judd Bowman, an astronomer at Arizona State University in Tempe who led the study.

Physicists believed that our universe was dark, hot and full of high-energy particles. After 370,000 years, this soup began to form neutral hydrogen atoms. Over time, they were pulled together by gravity and formed stars that ignited. This is also known as the cosmic dawn.

The earliest star lights, astronomers theorized, would have heated up the hydrogen gas permeating the universe, which would be reflected in the cosmic microwave background.

However, this is only theory. The changes on the cosmic microwave background were so subtle that they could be easily overwhelmed by radio signals produced by human activities.

Scientists have spent decades finding the evidence until Bowman's team used a relatively small antenna in an Australian dessert to pick the right signal.

TOP STORIES
EDITOR’S CHOICE
MOST VIEWED
EXPLORE XINHUANET
010020070750000000000000011100001370089751