How do we know that the universe is infinitely expanding?
In: Physics
We can figure whether astronomical object (galaxies or stars) are moving towards us or away from us by seeing the shift in the wavelength of light coming from the objects.
It’s called a Red shift if the objects are – moving away from us
And a Blue shit if the objects are – moving towards us
Keep this concept in mind, I’ll corelate it with something you’ve experienced.
So mostly the light shift has to do with the spectrum of rainbow 🌈
VIB-GY-OR
Violet has short wavelength and red has long wavelength
So when a object is moving away from us, the Normal light from the objects takes longer to reach us and hence is stretched or elongated and appear red in color. #Red ➡️ long wavelength
The opposite happens when the object is moving towards us. The Normal/regular light from the object gets compressed or shortened. # Blue➡️ short wavelength
The same can be experienced when an ambulance 🚑 passes by you – you hear the high pich sound (whaaan) as it approaches (compressed)(corelate to the compressed short wavelength blue shift), and you hear a low pitch sound (wooon) when it travels away from us (stretched/elongated)(long wavelength red shift)
Just imagine the whole experience of an ambulance passing.
High pitch <- Whaaannnnnnnn(You)Wooooooooooo -> low pitch, long wavelength
This example with sound is called the Doppler shift
And using the former(red/blue shift) we observe the astronomical objects and find that they are red shifted and are accelerating at a tremendous rate away from us.
Hence the expansion of space/universe
The crazy part is that as the objects move away from us, more and more space is just created inbetween.
The space is expanding like how a balloon 🎈 inflates.
Gotta go and sleep. Good night people. Pardon the errors, and warm love from India
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