To understand the answer to this slightly complicated question, it is imperative for us to understand the basic definitions of certain terms and read on a few concepts. The concepts have been illustrated in the form of a few short answers to simple questions. Read on to solve the mystery!
What does it mean that the universe is expanding?
The galaxies that we know are moving away from us. The ones who are located at maximum distances are moving fastest. Hence, it does not matter which galaxy you belong to because all the other galaxies are moving away from you.
However, the galaxies are not relocating through space, they are moving in space. It is because the space is also moving within itself. In other words, the universe has no centre. It is known that everything is moving away from everything around it. According to the generally debated and now widely accepted theory of the Big Bang, the universe has been constantly expanding ever since.
How to measure the expansion of the universe?
Initially it was Edwin Hubble who calculated the rate at which the universe is expanding. The unit that he used to measure the rate at which the universe was expanding came to be known as the Hubble constant. Since then we use this constant to measure the growing rate of the universe. The value of the Hubble constant keeps changing because the universe keeps growing or expanding at a very fast pace.
How rapidly is it expanding?
The latest studies and intensive calculations have recorded Hubble’s constant to be H0 = 67.15 ± 1.2 (km/s)/Mpc. This means that for every million parsecs of distance from the observer, the rate of expansion increases by about 67 kilometers per second. 1 million parsec can be translated to 3.3 million light years which is the unit we use to measure distance in space.
Thus, we get to know that the universe is expanding at an ever-increasing rate and leaves us with mysteries that are mind-boggling!
Contributor: Aditi Singh