NASA making time travel possible
The biggest and most powerful space telescope, launched by NASA, named “James Webb Space telescope”.
This is a telescope by which we can see a glimpse of the history. That is, it will be a sort of time travel.
It is not about 5 to 6 years back history. It will be millions and billions of years of history, that can be watched by this telescope.
More specifically, 13 billions years.
As we know 13.8 billions years ago, there was a huge “Big Bang”. And this telescope can see upto 13 billions of years before. That is, this telescope is capable of seeing 0.8 billion years of the formation of the earth.
But how it can be possible?
Basically, James Webb Telescope is designed to detect infrared radiation. As if we through some light on the previously build telescope or any kind of terrestrial telescope or normal telescope. It shows us the wavelength of visible light. That is the light we are able to see through our naked eyes.
The spectrum of visible light is between the red to the blue colour. And red colour has the longest wavelength. As high the wavelength , as far it can go. like if we talk about the radio waves its wavelength is the highest and it can travel through very very long distance.
The wavelength of infrared rays are bigger than that of red. But infrared radiations can’t be seen through our naked eyes.
So what is the advantage of using infrared radiations than visible?
If we se the best space telescope till now is the “Hubble space telescope”. It was also based on the visible light. Because of which a huge space dust comes in the picture(took from Hubble Space Telescope) because of which it becomes difficult to have a clear picture. But if we use infrared it will become way more clear.
As it can be clearly seen through this image.
Infrared rays are capable of passing through this dust clouds of the space and see through it. And capable of getting a better view.
Everything that radiate heat emits infrared radiations. Sun, animals, humans all emits infrared radiations. The night vision goggles that is used by soldiers also works on the principle of infrared radiations, that detect the heat source rather than capturing the actual pictures seen by naked eyes. So using the infrared radiations is best as everything in this universe weather be planets, galaxies, stars everything emits heat. So it will be possible to capture and see infrared rays.
So basically the bigger the mirror they are equipped with, the more light they will be able to capture. And the resolution of the image that we will get will be much higher. So in advanced telescopes big size of mirrors are placed to capture high resolution images.
If we talk about the mirror of James Webb Telescope, it can be seen that this mirror is completed with 24karat gold, because gold is best at reflecting red light. because of which the reflectiveness of the mirror is approx.98%.
Problems faced by this telescope.
As, already mentioned that everything that radiates heat, emits infrared radiations. So when the telescope will be working, it will also get heated up and will also emit infrared radiations too. And these radiations will interfere in the waves coming from the other source.
Because of this interference we will not be able to get high quality pictures. To solve this problem NASA came to a conclusion that, this…
Telescope will work only under cold temperatures of -223degree Celsius.
This is very cold temperature, and on earth it is difficult to get to that temperature. but it is possible to get that temperature in space, unless exposed to sunlight. This was the main problem faced by NASA. The sun’s rays was to be blocked to reach the surface of the telescope.
To solve this problem, Space telescope is equipped with sun shields that is fitted in the shape of kite. And the size of that shield is very big, bigger than a tennis court. To make this shield a special type of material is used named as Kepton. It was artificially created material in 1960s. This was the only material capable of reflecting the sunlight and keeping the telescope cooled.
5 layers of kepton was used to make the sunshield of this telescope. Each layer of Kapton is very very thin, i.e. 0.05 millimeter of the size. This is as thin as the single strand of human hair. Between each layer there is a vacuum gap present, to increase its effectiveness.
Every layer is also coated with a single layer of aluminum. As well as the layers that are closest to sun is also coated with doped-silicon.
As to get that much temperature it will be deployed 1.5 million km away from the surface of the earth. At that point in the space which is called L2 point(L2 means The second Lagrangian). This point will be the other side of the earth.
This L2 point is advantageous to us because it will cutoff the sunlight to reach the telescope. This will make the telescope cooler and will maintain that temperature at the surface of the telescope.
Also, one of the important point of this L2 point is that it is moving in the same path of the earth’s revolution.
Its orbit will be such that the shadow of the earth will always hide the Telescope.
NASA has identified more than 300 potential problems that may arise after the launch. If any of them comes true, this project will be a complete failure. And the coast spend on this project will be just become ashes.
Talking about the coast that came to make this project possible, was around USD10 billion. This huge coast cannot be easily accomplished by NASA, so many other space agency has also participated in this project. Like Canadian space agency and European space agency.
Main motive of this Mission.
The main motive of scientist is to study what actually happened after the Big Bang. How did stars and galaxies were formed? Hubble Space Telescope was able top see upto 12.8 billion years ago. But as James Webb Telescope is capable to see upto 13 billion years ago, it can be possible to see what had actually happened after the Big Bang. This is just 0.3 billion years after the Big Bang. This was the time when stars began to form.
But how can it be possible to see through past?
As we know light takes some time to travel the distance. And by the time light reaches from one place to another, a lot of time would already have passed. As sunlight takes 8 minutes to reach the surface of the earth. This means if sun disappeared from the universe it will take 8 minutes by us to recognize that sun has vanished. This means that everyday the sun we see is the 8 minutes past of the sun.
This similar logic is applied by this telescope to see in the past. This is achievable if we apply the same thing to very large distance.
Let me make you more clear my giving a similar example, like if we teleport to a kind of planet which is 100million light years away from the earth. And on that planet if we build a powerful telescope to look at the earth, we will get to see the earth as it was 100 million years ago. We can see the age of Dinosaurs.
But practically the problem that will arise is that, by the time we go onto another planet and look back at earth, it will take much longer time to reach the other planet, than the years that we can look back to. So if it becomes possible to travel by teleporting, we’ll be able to watch the history occurring on earth. And would actually be time travel.
And also it can be made possible to discover many planets in the universe through James Webb Telescope. And we must hope that this telescope will able to see such a planet where conditions like that on earth is there and where life can be made possible.