Question about first peak of CMB

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In summary, the conversation is about the first peak in the power spectrum of the cosmic microwave background (CMB) as measured by the WMAP experiment. The y-axis represents the temperature difference between two points and the horizontal axis represents the angle separation. The first peak is considered the fundamental frequency of the sound wave created during inflation and recombination. The speaker asks about the temperature difference measured from an overdense region that becomes underdense until the sound wave reaches a known distance of 225,000 light years, or from two points that the sound wave has reached at the time of recombination separated by a distance of 716,000 light years. They also question why there is a temperature difference in the second case, as it should theoretically be
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gluon
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Hello,i would like to ask something about the first peak in power spectrum of cmb giving by WMAP experiment.The y-axis is temprature difference between two points and the horizontal is the angle seperation.the first peak giving as the fundamental frequency of sound wave right?
if we suppose that we have a overdense region at the time of inflation and until recombination it gets underdense and the wave have propagated at known distance which is given by d=c*t ,c is the speed of sound wave 0,6c and t is the time at recombination 375.000,which giving a distance d=225.000 ly and we know that the distance from cmb surface is 41billion ly away so we get a angle which is 0,5 degree .But if i take that the wave went spherical away from overdense point we get a diameter of 716.000 ly which is giving 1 degree angle.

i want to ask which difference in temprature we measure? 1) from the initial overdence ,which became underdense,until the region which sound wave reach?or 2) from two positions that sound wave have reached at the time of recombintaion which is separated by distance 716.000 ly ? if we take the 1) case i understand why the temprature difference is so big,but the angle is 0,5 degree not 1.In case 2) the degree is 1 but i can't see why we have temprature difference between this points.should it have zero temprature difference or not?

Sorry for my English!
 
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1. What is the first peak of CMB?

The first peak of CMB, or cosmic microwave background, refers to the first and strongest peak in the temperature fluctuations of the CMB radiation. This peak represents the largest scale structure of the universe at the time of recombination, when the universe became transparent to photons.

2. What does the first peak of CMB tell us about the early universe?

The first peak of CMB provides us with valuable information about the early universe, as it is directly related to the density and geometry of the universe at the time of recombination. By studying the properties of the first peak, scientists can gain insight into the composition, expansion rate, and overall evolution of the universe.

3. How is the first peak of CMB measured?

The first peak of CMB is measured through observations made by satellite and ground-based telescopes, such as the Planck satellite and the Atacama Cosmology Telescope. These telescopes detect the faint temperature variations in the CMB radiation and use sophisticated instruments to map out the intensity and location of the first peak.

4. What is the significance of the first peak of CMB in cosmology?

The first peak of CMB is significant in cosmology because it provides evidence for the Big Bang theory and supports the idea of an expanding universe. It also helps to constrain various cosmological parameters, such as the age and composition of the universe, and can be used to test different theories of inflation.

5. How has our understanding of the first peak of CMB evolved over time?

Our understanding of the first peak of CMB has evolved significantly over time, as advancements in technology and data analysis have allowed for more precise measurements and interpretations. In the 1990s, the first peak was first observed by the COBE satellite, but it wasn't until the early 2000s that more detailed measurements were made by the WMAP satellite. Today, with the help of more sophisticated instruments, scientists continue to study the first peak to gain a better understanding of the early universe.

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