4. Which evidence supports the idea that Cosmic Microwave Background radiation is a remnant of the Big Bang?
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2 points
Its mass is uniform.
Its temperature is uniform.
Its mass fluctuates greatly.
Its temperature fluctuates greatly.
The correct answer is:
Its temperature is uniform.
The evidence that supports the idea that Cosmic Microwave Background (CMB) radiation is a remnant of the Big Bang is that its temperature is uniform.
The evidence that supports the idea that Cosmic Microwave Background (CMB) radiation is a remnant of the Big Bang is that its temperature is uniform.
To understand why this is significant, let's break down how scientists arrived at this conclusion.
1. The Big Bang theory suggests that the universe began from a singularity and rapidly expanded. As the universe expanded, it also cooled down.
2. About 380,000 years after the Big Bang, the universe had cooled enough for atoms to form. This allowed photons, particles of light, to travel freely without being constantly scattered by charged particles.
3. These photons have been traveling through space ever since. Over time, due to the expansion of the universe, they have been stretched and cooled down further. Today, they exist as microwave radiation, known as the Cosmic Microwave Background.
Now, why does the uniform temperature of CMB radiation provide evidence for the Big Bang?
1. If the universe began from a hot, dense state and expanded uniformly, we would expect the CMB radiation to have a uniform temperature.
2. Astronomers have observed the CMB radiation from various directions of the sky using instruments like the Planck satellite. They have found that the temperature of the radiation is remarkably uniform across the entire sky.
3. This uniformity in temperature strongly supports the idea that the universe was once in a hot, dense state and subsequently expanded in a uniform manner, which is a key prediction of the Big Bang theory.
To summarize, the uniform temperature of the Cosmic Microwave Background radiation provides evidence for the Big Bang theory because it suggests that the universe was once in a hot, dense state and subsequently expanded uniformly. This observation aligns with the predictions of the Big Bang theory.