Which statement is INCORRECT about Cosmic Microwave Background radiation?
*
2 points
its temperature is uniform.
it consists of electromagnetic radiation that is a remnant of the Big Bang.
It appears uniformly across the universe.
it appeared only a few years ago
The statement "it appeared only a few years ago" is incorrect. The Cosmic Microwave Background radiation is believed to have originated around 13.8 billion years ago, shortly after the Big Bang.
The incorrect statement about Cosmic Microwave Background (CMB) radiation is: "it appeared only a few years ago." CMB radiation is believed to have originated around 13.8 billion years ago, shortly after the Big Bang, and is observed uniformly across the entire universe. It is not a recent phenomenon.
To determine which statement is incorrect about Cosmic Microwave Background (CMB) radiation, we need to understand what CMB radiation is. CMB radiation is the electromagnetic radiation that fills the entire universe and is a remnant of the Big Bang.
Now let's analyze each statement:
1. "Its temperature is uniform": This statement is correct. The CMB radiation has a nearly uniform temperature of about 2.7 Kelvin (-270.45 degrees Celsius), as observed from different directions in the sky.
2. "It consists of electromagnetic radiation that is a remnant of the Big Bang": This statement is correct. The CMB radiation is the oldest light in the universe, formed about 380,000 years after the Big Bang when the universe cooled down enough for neutral atoms to form.
3. "It appears uniformly across the universe": This statement is correct. The CMB radiation is observed uniformly in all directions across the entire universe. It fills every part of space, making it a homogeneous and isotropic radiation.
4. "It appeared only a few years ago": This statement is INCORRECT. The CMB radiation has been present since its origin, which occurred about 13.8 billion years ago during the early expansion of the universe.
Therefore, the statement that is incorrect about Cosmic Microwave Background radiation is "it appeared only a few years ago."