It doesn't mean either one. Galaxies do not expand, nor do the planets. Only constructs larger than galactic clusters "expand" and by "expand" it just means they get farther apart. There are HUNDREDS (probably thousands) of threads on this there on PF. I suggest a forum search.Vivek Siddarth K said:We all know BigBang theory, which states that the universe is continuously expanding, my doubt is the term expanding, does it mean the expansion of galaxies as a whole or including the planets in it?.
Thanks for the link... very interesting...phinds said:It doesn't mean either one. Galaxies do not expand, nor do the planets. Only constructs larger than galactic clusters "expand" and by "expand" it just means they get farther apart. There are HUNDREDS (probably thousands) of threads on this there on PF. I suggest a forum search.
The Big Bang theory is a scientific model that explains the origin and evolution of the universe. It states that the universe began as a singularity, a point of infinite density and temperature, and has been expanding and cooling ever since.
The exact cause of the Big Bang is still unknown, but it is believed to have been triggered by a rapid expansion of space and time from a singularity. This expansion caused the universe to rapidly cool and form the first particles, which eventually led to the formation of stars and galaxies.
There are several pieces of evidence that support the Big Bang theory, including the cosmic microwave background radiation, the abundance of light elements, and the redshift of galaxies. Additionally, the expansion of the universe and the observed distribution of galaxies also support the theory.
Dark matter and dark energy are two components of the universe that are thought to play a significant role in the Big Bang expansion. Dark matter is believed to make up about 27% of the universe and is responsible for the gravitational pull that shapes the structure of the universe. Dark energy, on the other hand, is thought to make up about 68% of the universe and is responsible for the accelerated expansion of the universe.
According to the Big Bang theory, the universe is still expanding and cooling. The expansion is believed to be accelerating due to the influence of dark energy. The universe is also thought to be filled with a vast amount of matter and energy, including dark matter and dark energy, and is constantly evolving and changing over time.