GauriVerse

The universe has went on expanding since it was born almost 13.8 billion years ago. How did it all started in first place?

We might get curious how do we actually measure age of our universe? And on what scale?

Let us understand about the unit: ‘HUBBLE CONSTANT’.

As soon as our universe was born, that guy just never stopped. It is getting faster in its speed as it is getting bigger. as of January 2018, reading from various telescopes showed that the rate of expansion of universe is different, and actually depends on which you are looking at? The measurements from Hubble space telescope (also check out James Web Space Telescope) and Gala space telescope tells us that the rate of nearby universe expansion is 73.5 kilometres per second; I mean it’s just insane!!! While the galaxies that are more away from us is expanding at a rate 67 Km per second!!

Edwin Hubble was the astronomer who was able to measure this rate using star’s brightness which we calculate every minute even today using very sensitive telescopes. There’s are many stars that vary in brightness but one is most useful for measuring the Hubble constant is called ‘Cepheid variable’. These stars keep changing their luminosity regularly between 1 to 100 days. Farther in space, Cepheid’s appear to be fainter as compared to closer ones. Hence telescope like Hubble was designed to take the observation from space itself and avoid atmosphere distractions.

 We will not dive deep into its mathematical derivation but what’s interesting is coming next!

Now we understood how this expansion is measured, but we also got to know that it differs and fluctuates. Farther the galaxies are from earth, faster they appear to be moving. So, who is controlling this then?

Here’s where the concept of dark matter comes into discussion. Scientist believes if galaxies are moving away slower then there must be dark matter that is affecting expansion of universe. Whereas even if galaxies are moving faster it can be also due to dark matter.

In the end, if we go in depth about this topic we could keep going this for a colossal amount of time. But at least now we have an idea about where our universe is heading to and will soon see what is fate of our universe? Will it burst out? Or will it collapse into a particle?

Stay tuned! Till then keep reading, keep exploring!