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 incorrect statement is: it appeared only a few years ago.
To determine which statement is incorrect about Cosmic Microwave Background (CMB) radiation, let's examine each option.
1. "Its temperature is uniform." - This statement is correct. The CMB radiation is known to have a remarkably uniform temperature across the entire observable universe. It is measured at around 2.7 Kelvin (-270.45 degrees Celsius).
2. "It consists of electromagnetic radiation that is a remnant of the Big Bang." - This statement is correct. The CMB radiation is indeed the afterglow of the Big Bang. It originated about 380,000 years after the Big Bang when the universe cooled enough for protons and electrons to combine and form neutral hydrogen atoms. This allowed the radiation to travel freely through space.
3. "It appears uniformly across the universe." - This statement is correct. The CMB radiation is observed to be nearly uniform in all directions in the sky. The precise measurements from various satellites and experiments, such as the Planck satellite, have confirmed this isotropy.
4. "It appeared only a few years ago." - This statement is incorrect. The CMB radiation has been present since about 380,000 years after the Big Bang occurred, which is approximately 13.8 billion years ago. It has been continuously propagating throughout the universe since then.
Therefore, the statement that is incorrect about CMB radiation is: "It appeared only a few years ago."