Early photographs of the James Webb Space Telescope have raised a lot of hope in astronomy. Scientists also think that with this telescope billions of years old celestial bodies will also be able to see which could not been seen yet. It can also detect faint light waves coming from far away from the telescope. That is, we can see more distant objects which are so far away that it takes thousands to billions of years for their waves to reach us. That is why scientists say that this telescope can make us travel in time.
Look back in time
The possibility of seeing those faint objects with this telescope has increased, which until now were very faintly visible even with the Hubble Space Telescope. It seems strange in general that we can look back in time, but this is actually what astronomers do every day. The universe is so vast that the distances between the objects in it are so great that it takes millions of billions of years for the fastest moving light to travel the distance between many objects.
Speed of light and travel
It takes more than 8 minutes for light to reach the Earth from the Sun itself. The speed of light is three lakh kilometers per second. In such a situation, if we are seeing a body whose light takes millions of years to reach us, then in fact we are looking at a body that is millions of years old and not its present form. That is, the Sun we see on Earth is 8 minutes 32 seconds old.
Too long distance
The distance of celestial bodies is so much that scientists have kept the unit of these distances as light year which is the distance covered by light in a year. The stars being born in the Carina Nebula recently photographed by the Webb telescope were actually born 7.5 thousand years ago because this nebula is located at a distance of 7500 light-years.
History of the universe
Whenever we look away from the earth, we are looking at the time behind us. Through this we can get information about the history of the universe and solve many of its mysteries. And the Webb Space Telescope can help us better in knowing this because it can detect waves that have been blurred due to too long travel.
Difference between Hubble and Webb
Where the Hubble Space Telescope can capture ultraviolet rays and the visible part of the electromagnetic spectrum, ie visible light. The Webb telescope is capable of capturing wide waves of infrared light. That is, he is more capable than Hubble to look back in time.
Cosmological redshift
Galaxies emit a range of gamma radiation to radio waves, including visible light in the electromagnetic spectrum. When galaxies are near us, the waves coming from them do not change, but when they are very far away, the wavelengths of the waves coming from there become larger due to the rapid expansion of the universe. That is, millions of millions of years ago, the body we could see with our eyes close by. Now only infrared telescopes can see it. This change of waves is called cosmological redshift.
