The WMAP objective is to measure the temperature differences in the

In summary, the WMAP mission aims to measure temperature differences in the Cosmic Microwave Background radiation. To distinguish this radiation from others, the spectrum is used, with the CMB having a unique black body spectrum at 2.725K. The WMAP satellite measures the sky at multiple frequencies to better differentiate the CMB from other emissions. The upcoming Planck satellite will have even more channels to further improve this distinction.
  • #1
azizlwl
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The WMAP objective is to measure the temperature differences in the Cosmic Microwave Background (CMB) radiation.

My question are,
1.How to distinguish all the radiations of 13 billion years ago from others of the latter ones.
2.How the distance of radiation source is measured.

Thanks.
 
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  • #2


azizlwl said:
The WMAP objective is to measure the temperature differences in the Cosmic Microwave Background (CMB) radiation.

My question are,
1.How to distinguish all the radiations of 13 billion years ago from others of the latter ones.
2.How the distance of radiation source is measured.

Thanks.
By the spectrum. The CMB has a black body spectrum at 2.725K, with tiny differences in this temperature from place to place at a level of about one part in one hundred thousand in temperature.

Other things we see in the sky have very different emission rates. Most are not black bodies, and tend to have temperatures very different from the CMB. So they will emit more radiation at low frequencies and less at high frequencies, or vice versa, depending upon how the radiation is emitted.

It is for this reason that the WMAP satellite measures the sky at not one but five different frequencies, from 23GHz to 94GHz. The Planck satellite, which is expected to release its first cosmological results next year, measures the sky at nine different channels from 30GHz to 857GHz, so that it is even better at distinguishing between the CMB and other stuff out there.
 

1. What is the purpose of the WMAP mission?

The WMAP (Wilkinson Microwave Anisotropy Probe) mission aims to measure the temperature differences in the cosmic microwave background radiation (CMB) in order to gain a better understanding of the early universe and its evolution.

2. How does the WMAP measure temperature differences?

The WMAP uses a specialized instrument called a Differential Microwave Radiometer to detect small variations in the temperature of the CMB. This is achieved by comparing the temperature of the CMB with a known reference temperature.

3. What can the WMAP tell us about the early universe?

The WMAP data provides valuable information about the composition and structure of the early universe, as well as the processes that led to the formation of galaxies and other large-scale structures. It also helps to test and refine existing theories about the origins of the universe.

4. How long has the WMAP been in operation?

The WMAP mission was launched in 2001 and collected data until 2010. However, the data is still being analyzed and used by scientists to this day.

5. What are some of the major discoveries made by the WMAP?

The WMAP has made several significant discoveries, including confirming the existence of dark matter and dark energy, providing evidence for the inflation theory of the universe's early expansion, and measuring the age of the universe to be 13.77 billion years old.

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