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goldust
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And if so, at a rate faster or slower or the same compared to at earlier times of the universe?
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cepheid said:EDIT: Drakkith: no, not quite. A doubling of the scale factor would decrease the energy density of the radiation field by a factor of 16. See above.
goldust said:And if so, at a rate faster or slower or the same compared to at earlier times of the universe?
goldust said:And if so, at a rate faster or slower or the same compared to at earlier times of the universe?
Hornbein said:I would say that the total energy in the CMB is a constant. Its density is decreasing.
If you'll stick around the forums you'll see that it's a very common misconception.goldust said:There's another thing I don't understand now. If the Big Bang occurred in one location, then why is there CMBR all around us? All the light from the Big Bang's location would have been traveling away from that location, so why is every location in the universe getting hit by CMBR from every direction? Logic would state any location in the universe can only be hit by CMBR from only 1 side, which must be the side aligned with the location of the Big Bang. Would appreciate it if someone can shed some light on this.
Bandersnatch said:If you'll stick around the forums you'll see that it's a very common misconception.
To wit: the BB did not occur at some singular point. It "occured" everywhere at once, so there's always some CMBR passing us by from every direction.
goldust said:I think I get it now. It's because there was no space before the Big Bang, which means as space expanded, the CMBR is trapped in the expanding space and is therefore everywhere and hitting every location, sort of like water in a fish tank. Is this correct?
goldust said:Would this analogy be correct? A very tall and very slender cup filled with water is like the universe before the Big Bang filled with CMBR. The Big Bang is like pouring all the water out of the cup and onto the floor. The water spreads out on the floor, just like the universe spreads out after the Big Bang. The CMBR's intensity is like the how tall the water is. The intensity of the CMBR decreases as the universe spreads, just as the height of the water from the cup decreases as the water spreads out on the floor.
Microwave background radiation, also known as cosmic microwave background (CMB) radiation, is leftover radiation from the Big Bang that fills the entire universe. It is the oldest light in the universe and is present in all directions with a nearly uniform intensity.
The microwave background radiation provides valuable information about the early universe, as it is a remnant of the hot, dense state in which the universe was born. It helps scientists study the composition, age, and expansion of the universe.
Yes, the microwave background radiation is still decreasing, but at a very slow rate. The radiation has been cooling down since the Big Bang, and it is now only about 2.7 Kelvin above absolute zero. However, this decrease is difficult to measure and is not noticeable in our daily lives.
Scientists use specialized instruments called microwave telescopes to measure the intensity of the microwave background radiation. They compare these measurements to previous ones to determine if there has been a decrease in the radiation over time.
No, the microwave background radiation will not disappear completely. It will continue to exist in the universe as long as the universe exists. However, as the radiation continues to cool down, it will eventually become undetectable by our instruments.