Now the expansion of the universe is accelerating, indicating that there is repulsive force in the universe, which can
Enough to resist gravity, expand space and keep galaxies away from each other. Scientists use cosmological constants
To express this repulsive force.
According to quantum theory, vacuum is not completely nothingness, it also has energy, which is called vacuum.
Zero point energy, it is this energy that provides the repulsive force of the cosmological constant. However, theoretical calculations
The obtained cosmological constant is very large, which is larger than the actually observed cosmological constant by the power of 10/20.
Time magazine.
In other words, in theory, there should be a strong repulsive force in the universe, so that particles will not work.
Combine to form atoms, not to mention stars, planets and life. Cosmic constant theory
The huge difference between numerical values and observed values is a major problem that puzzles physicists, which is related to the fact that.
Why we can exist. It has been suggested that the cosmological constant will increase with the age of the universe.
However, the calculation results show that the cosmological constant decreases from the theoretical value to the observed value.
This is much longer than the age of the universe.
Paul steinhardt is a physicist at Princeton University and a professor at Cambridge University in England.
Neil turok put forward a new view that the universe does not exist only once, but
Is in the continuous cycle of the big bang (birth) and collapse (destruction), every time.
Passing through a ring, the cosmological constant will contract.
Steinhardt and turok published a paper in the latest issue of the American Science magazine, saying that
Every cycle of the birth and destruction of the universe will last about 1 trillion years. Every time a big bang happens,
The mass and radiation in the universe will be reset, but the cosmological constant will not be reset.
But gradually decreases through a series of quantum transformations in multiple cycles. Because this universe
"Samsara" is infinite, and the cosmological constant has enough time to shrink to its present value.
The two scientists said that their theory could be tested. According to the forecast, the big bang
Gravitational waves are generated in space, and the attenuation of zero-point energy in vacuum will produce new elementary particles.
By detecting gravitational waves and such elementary particles, it is possible to detect them compared with theoretical expectations.
Check whether the circular universe model is correct.