How the James Webb Space Telescope JWST Actually works!

RESOURCES:

CHAPTERS:
0:00 Intro Hubble vs JWST
1:38 JWST is just a digital camera!
6:25 Why Infrared is better than visible light
7:34 Instruments of the JWST
8:12 Why is Hubble located so far away?
10:12 How JWST protects itself from the sun
11:19 What will JWST "see?"
13:30 How to learn more about Astronomy

SUMMARY:
In 2021, we launched a space telescope that's 100 times more powerful than Hubble, called the James Webb Space Telescope. How does the JWST work? What makes it so powerful? And what might it see?

A space telescope is basically a digital camera, except is that it's more powerful and is built to take pictures of things very far away.

To take any digital picture you need light, optics, and a sensor or recording device. The latter records the light. It's made of millions of small pixels, which are the smallest element of the sensor that can interact with light to produce a current. The amount of light absorbed by the pixel determines its brightness intensity.

Since distant objects are very faint, space telescopes are designed to gather as much light as possible. This means that the JWST is designed with the largest folding mirror that would fit in a rocket (6.5 meters diameter vs Hubble's 2.4 m), and can have high exposure times.

The JWST can capture more than 6.5 times more light than Hubble. And it's designed to see infrared light, which is why its primary mirror is gold, since gold reflects infrared light better. Infrared has many advantages, like seeing through space dust better, and can observe things farther away and farther back in time, because the most distant objects are red shifted into infrared due to the expansion of the universe.

How it works: Infrared Light travels through space, hits the telescope's primary mirror. It's reflected onto the smaller secondary mirror then into what’s called the Aft-Optics System, which focuses and refracts the light before it goes onto the sensors (or cameras) located behind the mirrors.

Another difference between the JWST and Hubble is that it orbits the sun at about 1.5 million km away from earth instead of 547 km. Hubble orbiting so close to the earth leads to problems such as being in earth's shadow for long periods, or overexposure due to the sun.

Instead of orbiting the earth, JWST orbits the sun at the the L2 or second Lagrange point. Lagrange points are special points in space, where gravity from the sun and earth perfectly balances the orbital motion of a satellite so that it stays put in a stable orbit without using much energy.

To prevent overexposure to the sun, JWST has a large sunshield protecting it from the sun's rays, like a sun shade in your car.

We expect the JWST to see objects and light from some of the earliest history of the universe, including the formation of the first stars and galaxies. The images should be even sharper and higher resolution than Hubble not only because of the bigger mirror, but also because the JWST uses more modern and advanced instruments. For example, the camera design uses mercury cadmium telluride. It's a crystal, grown in a lab that can convert infrared light into electricity directly.
#jwst
#jameswebbspacetelescope
There is also a spectrometer on the telescope allowing us to detect that different atoms and molecules on distant planets. By looking for things like water, oxygen, methane and ammonia we may be able to detect life on exoplanets. a chance we might see something that looks like life. Yes, the JWST could detect possible alien life.

[wigglycharlie]

Arvin, great material as usual. However, the key to JWST is the MIRI instrument, which can measure infrared wavelengths out to greater than 25 microns. The detector for MIRI (Si:AS Blocked Impurity Band (BIB) is a very specialized technology that could be the subject of its own video. This is the technology that enables the red shift measurements that allow JWST to see much farther back in time than Hubble.

[syedahmed]

You are such a great teacher. I have taken graduate level computer vision classes and the professors could not explain the inner workings of a camera better than you have in this video.

[Noctifern]

it's incredible how humans built this thing

[thesublime]

Engineering genius!
And as always, great work Arvin. One of the best and simplest explanations I've seen about our JWST :)

[CJ-M]

"That's coming up.. RIGHT now!"
CHILLS every time! Never change this intro!

[Tana]

Such a well spoken informative video. You explained how photos work so clearly and i know that is NOT easy. Hearing the science behind the new telescope is blowing my mind, i was waiting for your video on it because theres sooo many false news channels out there trying to cover this subject. Thank you for your awesome work! So amazing what the human mind is capable of.

[ThestDukeDroklar]

The two things I'm most interested in are: 1- how far we can see and does what we find match up to current theories. 2- A better look at exoplanets and analyzing their atmosphere

[das_it_mane]

Incredible overview! Thank you Arvin! Pumped for the JWST era

[anacloughly]

This video has the best explanation of how the JWST is made and what is capable of achieving. Thank you. The technology is mind blowing. A real testament to what humans can do when we work together.

[farshadostadalirezania]

I am obligated to say thank you very much Arvin Ash. I really wanted to know how the James Webb Space Telescope worked, and as usual you made explained everything so well.

[diegofernandez]

One of the first Arvin Ash videos I can finally understand from start to finish! Thank you.

[steviejd]

Hi Arvin, I know the chances of you reading my comment are astronomical, (see what I did there😂)….but I only want to tell you how inspiring you are. I love science in most forms, but you help me everyday to get a better understanding. Thank you so much for your time and dedication, humanity is better for you being here…before we all turn to dust.

[Uberdubee]

Amazing engineering, inspirational really, I’ll be taking up that astronomy course now

[PAVANKUMARADURTHI]

Always great to watch your videos Arvin ! Hope to see hundreds of more informative videos from you in future. All the best and Thank you !

[johndoeofficial]

One of the best materials! Thank you Arvin!

[Turbulence]

Your videos are absolutely fantastic!! Your friendly appearance and voice make them really nice to watch but the way the information is explained and presented is just so incredibly well done!
Thank you so much!

[umami]

Can't wait to see what this will discover in the distant past. It is mind boggling that we have come this far in space exploration from just a little over 100 years from us getting into the air for the first time in a plane. I'm certain we will see things that we don't understand on how or why they happen and that is very exciting as it will mean new theories and physics. You do such a great job with these videos and along with others I watch have taught me so much that I didn't know about astrology and physics.

[manog]

Excellent useful and crucial information about JWST. Thank you Arvin.

[basavarajnandargi]

A glimpse of JWST best narrated by you. Thanks for so much of information within 16 minutes of video.

[damn_right_man]

Cool coincidence, that Cern was also restarted recently.
Research of the biggest and the smallest, both open a new era of science, tandem