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�Ƽ�Ӣ��New Pictures of an Old Universe

���ߣ�����    ������Դ����վԭ��    ����ʱ�䣺2018/7/24
�Ƽ�Ӣ��New Pictures of an Old Universe
For thousands of years humans have wondered how and when the
universe first began. Now, thanks to some photographs taken by
Wilkinson Microwave Anisotropy Probe (WMAP), scientists are much
closer to understanding, even seeing, the universe in its beginning years.
This is all possible thanks to the WMAP satellite in orbit about one
million miles above Earth. The satellite is specially designed to record
one kind of cosmic energy: microwave radiation. It can use this radiation
to show us what the universe looked like 13.3 billion years ago!��
Wait a minute ... how can this satellite show us a picture of the
universe billions of years ago? The Big Bang created the universe in a
huge explosion, and at the same time it created a specific field of
radiation��called the cosmic microwave background, or CMB. This
CMB still lingers in the universe today. What the satellite actually does is
take pictures of the CMB.��
So what did scientists learn from these new pictures? First, they
learned that stars formed very soon�� merely 200 million years�� after
the Big Bang. And they were able to confirm estimates of the universe��s
age: it was born about 13.7 billion years ago. This is the age that
scientists long suspected to be true, but now they have the birthday
pictures to prove it!��
microwave: a high-frequency electromagnetic wave, one millimeter to one meter in wavelength,
intermediate between infrared and short-wave radio wavelengths ΢����
probe: an exploratory action, expedition, or device, especially one designed to investigate and
obtain information on a remote or unknown region ̽�⣨�������ǡ�����ɴ�����
satellite: a celestial body that orbits a planet; a moon ���ǡ�
orbit: the path of a celestial body or an artificial satellite as it revolves around another body����
cosmic: of or relating to the universe, especially as distinct from Earth ����ġ�
radiation: energy radiated or transmitted in the form of rays, waves, or particles ���䡡
explosion: a release of mechanical, chemical, or nuclear energy in a sudden and often violent
manner with the generation of high temperature and usually with the release of gases ��ը��
specific: special, distinctive, or unique �ض��ģ���ȷ�ġ�
linger: to be slow in leaving, especially out of reluctance; tarry �ǻ���
suspect: to have doubts about; distrust ���ɣ��²⡡
�Ƽ�Ӣ�A Milky Way cooling its jets
�Ƽ�Ӣ�racetrack memory

�Ƽ�Ӣ��New Pictures of an Old Universe��https://kraftgear.com/syy/dxyy/201807/57127.html