The steady state theory of the universe was proposed by:

In 1948, these three British astronomers proposed the steady state theory of the universe.

Main idea of the steady state theory:

The universe has no beginning and no end in time.

It looks the same, on the large scale, at all times and from all places. This is called the "perfect cosmological principle".

The universe is expanding, but new matter is continuously created to fill the gaps, so that the average density of the universe stays constant.

The rate of creation needed was extremely small, about one hydrogen atom per cubic metre every few billion years.

The rival view:

• Opposed to this was the idea that the universe began from an extremely hot, dense state and has been expanding and cooling ever since.
• Ironically, Fred Hoyle is believed to have coined the popular name of that rival theory during a BBC radio talk in 1949, while trying to make fun of it.

Why the steady state theory was abandoned:

In 1965, Arno Penzias and Robert Wilson discovered the cosmic microwave background radiation, a faint glow of radiation filling the whole universe. It was strong evidence that the universe had a hot, dense beginning.

Observations of distant quasars and radio galaxies showed that the universe looked different in the past, against the idea that it never changes.

The amounts of light elements, such as helium, also matched the predictions of the rival theory.

Contribution of Fred Hoyle:

• Hoyle, along with others, explained how heavier elements are formed inside stars, a process called stellar nucleosynthesis.
• He also supported the idea that life may have come to Earth from space (panspermia), with the Indian astrophysicist Jayant Vishnu Narlikar.
• Narlikar and Hoyle together developed the Hoyle-Narlikar theory of gravity.

Why not the other options?

• ✗Einstein, Planck and Bohr were pioneers of relativity and quantum theory.
• ✗Newton, Halley and Hooke were 17th-century scientists.
• ✗Eddington, Jeans and Chandrasekhar were known for work on the structure and evolution of stars.