Steady state theory
Topic: Origin and Evolution of the Earth and the Solar System · NCERT: Class 11, Ch 2 "The Origin and Evolution of the Earth"
Meaning
The steady state theory was a rival to the Big Bang. Fred Hoyle, Hermann Bondi and Thomas Gold proposed it in 1948. It said the universe looks roughly the same at all times, and that new matter keeps being created as the universe expands, so it has no hot beginning. The theory lost support as the evidence for expansion from a hot start kept growing. Hoyle himself made up the name "Big Bang" in 1949 as a jibe.
Example
In 1965, Arno Penzias and Robert Wilson picked up a faint microwave signal with a radio antenna in New Jersey, USA. This was the cosmic microwave background (CMB), leftover light from the early universe. A universe that never changes cannot explain it, so it was the decisive blow to the steady state theory.
Don't confuse with
- Big Bang theory: this says the universe began about 13.8 billion years ago (NCERT: 13.7) from a tiny, extremely hot and dense point. The steady state theory says there was no such beginning.