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FWIW, according to the specs the JWST starts at 600nm, which means it does at least cover the red visible spectrum. (R from RGB being 600-700nm per my understan

FWIW, according to the specs the JWST starts at 600nm, which means it does at least cover the red visible spectrum. (R from RGB being 600-700nm per my understanding) It seems a shame they didn't include the 400-600nm range as well.

dylan604 3y ago
> It seems a shame they didn't include the 400-600nm range as well. This seems to be a basic misunderstanding of the purpose of the telescope.
- hnburnsy 3y ago
  True color, visible spectrum images could help garner public support for missions like this. When I see these images, I imagine future humans enjoying a fly by, looking out a large transparent window, and seeing these amazing views.
  - wholinator2 3y ago
    What happens when the true color, visible spectrum images are exponentially less interesting and more dull? Does that increase public support? I don't think anyone in the "general public" cares or even realizes what exact wavelengths are captured and translated in every image, they care how awesome it looks. To my understand, you cannot see the rings of uranus in the visible range. And remember all those first images from the JWST, those garnered public support preeetty heavily and those were all infrared and translated. On the science side, some wavelengths just do not survive interstellar travel. You need the entire range to get the most data. Lots of times visible phenomena are just white or grey or blue anyways. When there's something that's actually more interesting in visible light, we'll see it.
    - dylan604 3y ago
      Let's also not forget that we have so many visible light telescopes already. JWST specifically needed to be a space platform way the hell away from the earth since it is essentially looking at heat. Being on earth or even in earth orbit would not be cold enough to make it worth while. Even still, we have to cool the systems because the heat from the electronics doing the science could interfere with its own readings. Once that coolant is gone, the platform will be pretty much useless. So it's not going to be wasting any time looking at things in the same spectrum that pretty much any telescope on the ground can do. Sure, we still have Hubble, but even the larger ground based telescopes with adaptive optics can see in more detail than Hubble at this point.
    - hnburnsy 3y ago
      Personally, I want reality, reality being what I would see if I fly by in a space ship.
      - xwolfi 3y ago
        Completely wrong. What you see is a product of what you need to see, adapted by evolution over millions of years, so that you can survive on Earth a bit longer than 5 minutes. We're talking of seeing a barren planet millions of kms away, flying in space ships that are thousands of years away in the making: do you really REALLY think "reality" is what your eyes see now so you don't stumble around in the bright light shower of Earth ? If we have to survive in space, we'll have to see the rings of Uranus, if only to avoid them when we fly by in your space ship :)
      - jrumbut 3y ago
        That's not an unreasonable desire, and to satisfy it there are true color pictures of Uranus including one from a space ship that flew by: https://en.m.wikipedia.org/wiki/Uranus#/media/File%3AUranus_as_seen_by_NASA's_Voyager_2_(remastered)_-_JPEG_converted.jpg https://en.m.wikipedia.org/wiki/Uranus#/media/File%3AUranus_... As the article points out, they are extremely boring to look at. A lot of space objects are that way. The mission of the JWST is to look at these other wavelengths where there is more interesting activity and where the signal from that activity survives the trip to (near) earth.
  - dylan604 3y ago
    The mirrors on this are coated with an element that is specifically good at reflecting IR wavelengths. If it was meant for visible spectrum, it would potentially be coated with a different material. Complaining about JWST not making visible spectrum light images is like complaining that a hammer doesn't really work driving in a screw. It's not meant to do that, so stop trying to do it, and definitely stop complaining about it since it's just a misunderstanding of its purpose.
    - Sporktacular 3y ago
      Chill out Dylan
    - hnburnsy 3y ago
      It can't do more than one thing?
      - dylan604 3y ago
        Because of the coating of the mirrors is gold specifically because it is designed to image in IR. "Gold just happens to reflect blue light very poorly but red and infrared light extremely well."[0] This would make visible light images extremely poor if it is not reflecting all wave lengths equally. Think of it like the *nix core belief that you design a thing to do one thing be really fast at it and do it really well while avoiding making something that does a lot of things mediocre and not nearly as fast. We have platforms that are better at imaging visible light. A lot of them. We have nothing with the capabilities of JWST. We have X-ray telescopes. We have microwave telescopes. Trying to ask JWST to be a shittier IR telescope to enable visible light imaging is just a waste of time, effort, and money. [0]https://www.jwst.nasa.gov/content/about/faqs/faq.html?linkId=142822511#gold https://www.jwst.nasa.gov/content/about/faqs/faq.html?linkId...
    - lsaferite 3y ago
      I've read about the JWST and know all about the optical path and why the 400-600nm range is not there. I simply said it was a shame that that range wasn't included so we could get Blue and Green. I hardly view that as complaining and even if it were, why the hell are you getting so bent out of shape over a simple statement? Maybe don't be an ass.
  - dandelany 3y ago
    Imagine scientists discovered colonies of ants that compose elaborate symphonies of music that they perform for each other. Two problems: they’re small, so the music is quiet. And for the same reason, it’s extremely high-pitched and just sounds like mouse squeaks. In fact, half of it is ultrasonic, above the range of human hearing. Which device is more impressive and would garner more public support for the project: an amplifier which just makes the squeaks louder? Or one which also pitches down the squeaks into a range where we can actually perceive and appreciate the tune & dynamics of the underlying music?
  - 4m1rk 3y ago
    My understanding is that if the object is far enough, the color shift towards infra red will make it perfect for JWST to see it as if a human fly by close to the object. Though the object should be huge enough to be seen from this distance so close fly by is a relative term.
queuebert 3y ago
Wavelength ranges for astronomical detectors are often tuned to the emissions of particular phenomena and for what gets through interstellar and intergalactic gas and dust the best. Unfortunately blue to green isn't very useful by these metrics.

dylan604 3y ago

> It seems a shame they didn't include the 400-600nm range as well. This seems to be a basic misunderstanding of the purpose of the telescope.

hnburnsy 3y ago
True color, visible spectrum images could help garner public support for missions like this. When I see these images, I imagine future humans enjoying a fly by, looking out a large transparent window, and seeing these amazing views.
- wholinator2 3y ago
  What happens when the true color, visible spectrum images are exponentially less interesting and more dull? Does that increase public support? I don't think anyone in the "general public" cares or even realizes what exact wavelengths are captured and translated in every image, they care how awesome it looks. To my understand, you cannot see the rings of uranus in the visible range. And remember all those first images from the JWST, those garnered public support preeetty heavily and those were all infrared and translated. On the science side, some wavelengths just do not survive interstellar travel. You need the entire range to get the most data. Lots of times visible phenomena are just white or grey or blue anyways. When there's something that's actually more interesting in visible light, we'll see it.
  - dylan604 3y ago
    Let's also not forget that we have so many visible light telescopes already. JWST specifically needed to be a space platform way the hell away from the earth since it is essentially looking at heat. Being on earth or even in earth orbit would not be cold enough to make it worth while. Even still, we have to cool the systems because the heat from the electronics doing the science could interfere with its own readings. Once that coolant is gone, the platform will be pretty much useless. So it's not going to be wasting any time looking at things in the same spectrum that pretty much any telescope on the ground can do. Sure, we still have Hubble, but even the larger ground based telescopes with adaptive optics can see in more detail than Hubble at this point.
  - hnburnsy 3y ago
    Personally, I want reality, reality being what I would see if I fly by in a space ship.
    - xwolfi 3y ago
      Completely wrong. What you see is a product of what you need to see, adapted by evolution over millions of years, so that you can survive on Earth a bit longer than 5 minutes. We're talking of seeing a barren planet millions of kms away, flying in space ships that are thousands of years away in the making: do you really REALLY think "reality" is what your eyes see now so you don't stumble around in the bright light shower of Earth ? If we have to survive in space, we'll have to see the rings of Uranus, if only to avoid them when we fly by in your space ship :)
    - jrumbut 3y ago
      That's not an unreasonable desire, and to satisfy it there are true color pictures of Uranus including one from a space ship that flew by: https://en.m.wikipedia.org/wiki/Uranus#/media/File%3AUranus_as_seen_by_NASA's_Voyager_2_(remastered)_-_JPEG_converted.jpg https://en.m.wikipedia.org/wiki/Uranus#/media/File%3AUranus_... As the article points out, they are extremely boring to look at. A lot of space objects are that way. The mission of the JWST is to look at these other wavelengths where there is more interesting activity and where the signal from that activity survives the trip to (near) earth.
- dylan604 3y ago
  The mirrors on this are coated with an element that is specifically good at reflecting IR wavelengths. If it was meant for visible spectrum, it would potentially be coated with a different material. Complaining about JWST not making visible spectrum light images is like complaining that a hammer doesn't really work driving in a screw. It's not meant to do that, so stop trying to do it, and definitely stop complaining about it since it's just a misunderstanding of its purpose.
  - Sporktacular 3y ago
    Chill out Dylan
  - hnburnsy 3y ago
    It can't do more than one thing?
    - dylan604 3y ago
      Because of the coating of the mirrors is gold specifically because it is designed to image in IR. "Gold just happens to reflect blue light very poorly but red and infrared light extremely well."[0] This would make visible light images extremely poor if it is not reflecting all wave lengths equally. Think of it like the *nix core belief that you design a thing to do one thing be really fast at it and do it really well while avoiding making something that does a lot of things mediocre and not nearly as fast. We have platforms that are better at imaging visible light. A lot of them. We have nothing with the capabilities of JWST. We have X-ray telescopes. We have microwave telescopes. Trying to ask JWST to be a shittier IR telescope to enable visible light imaging is just a waste of time, effort, and money. [0]https://www.jwst.nasa.gov/content/about/faqs/faq.html?linkId=142822511#gold https://www.jwst.nasa.gov/content/about/faqs/faq.html?linkId...
  - lsaferite 3y ago
    I've read about the JWST and know all about the optical path and why the 400-600nm range is not there. I simply said it was a shame that that range wasn't included so we could get Blue and Green. I hardly view that as complaining and even if it were, why the hell are you getting so bent out of shape over a simple statement? Maybe don't be an ass.
- dandelany 3y ago
  Imagine scientists discovered colonies of ants that compose elaborate symphonies of music that they perform for each other. Two problems: they’re small, so the music is quiet. And for the same reason, it’s extremely high-pitched and just sounds like mouse squeaks. In fact, half of it is ultrasonic, above the range of human hearing. Which device is more impressive and would garner more public support for the project: an amplifier which just makes the squeaks louder? Or one which also pitches down the squeaks into a range where we can actually perceive and appreciate the tune & dynamics of the underlying music?
- 4m1rk 3y ago
  My understanding is that if the object is far enough, the color shift towards infra red will make it perfect for JWST to see it as if a human fly by close to the object. Though the object should be huge enough to be seen from this distance so close fly by is a relative term.

queuebert 3y ago

Wavelength ranges for astronomical detectors are often tuned to the emissions of particular phenomena and for what gets through interstellar and intergalactic gas and dust the best. Unfortunately blue to green isn't very useful by these metrics.