Lesson 526 of 1524
Frontiers of Physics
The earliest epochs are tied to the unification of forces, with the electroweak epoch being partially understood, the GUT epoch being speculative, and the TOE epoch being highly speculative since it involves an unknown…
Practice this chapterThe earliest epochs are tied to the unification of forces, with the electroweak epoch being partially understood, the GUT epoch being speculative, and the TOE epoch being highly speculative since it involves an unknown… The epochs of the universe are known back to very shortly after the Big Bang, based on known laws of physics
The two most important features of the universe are the cosmological red shifts of its galaxies being proportional to distance and its cosmic microwave background (CMBR). Both support the notion that there was a gigantic explosion, known as the Big Bang that created the universe
GUT epoch — the time period from 10 -43 to 10 -34 after the Big Bang, when Grand Unification Theory, in which all forces except gravity are identical, governed the universe. Hubble constant — a central concept in cosmology whose value is determined by taking the slope of a graph of velocity versus distance, obtained from red shift measurements. cosmological red shift — the photon wavelength is stretched in transit from the source to the observer because of the expansion of space itself. smoothness of the CMBR — two characteristics that are tied to particle physics.
Worked example
What does “GUT epoch” mean in Frontiers of Physics?
- 1Use the wording this chapter gives for GUT epoch.
- 2The book says: the time period from 10 -43 to 10 -34 after the Big Bang, when Grand Unification Theory, in which all forces except gravity are identical, governed the universe.
- 3Do not use the meaning of Hubble constant. That term means a central concept in cosmology whose value is determined by taking the slope of a graph of velocity versus distance, obtained from red shift measurements.
Result: the time period from 10 -43 to 10 -34 after the Big Bang, when Grand Unification Theory, in which all forces except gravity are identical, governed the universe
Why. That is the meaning this chapter gives for GUT epoch.
Do not swap GUT epoch and Hubble constant. GUT epoch means the time period from 10 -43 to 10 -34 after the Big Bang, when Grand Unification Theory, in which all forces except gravity are identical, governed the universe. Hubble constant means a central concept in cosmology whose value is determined by taking the slope of a graph of velocity versus distance, obtained from red shift measurements.
Practice margin
This chapter
A fresh set from this chapter only. Choose 10 or 20. Multiple choice and fill-in, with no repeat inside the set.