Comments by "H. de Jong" (@h.dejong2531) on "It’s Not Just a Star! What Is In The James Webb Telescope First Images?" video.

  1. These images were made in January, the team has published more since then. This video is 4 months late.
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  2. This is easier than exploring the ocean. One telescope can view the entire sky. To view our entire ocean floor, you need 300 survey ships working for 10 years; and that's just a sonar survey.
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  3. Space is very empty: JWST will encounter micrograms of dust per year, on average. Asteroids are a potential problem: we haven't found all of them yet. But the chance of being hit by an asteroid is very low. Since the beginning of spaceflight, we haven't lost a spacecraft to an asteroid impact yet.
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  4. For the purpose of image sharpness, the mirrors act as one. The diffraction spikes are a telltale sign that it's not one physical mirror (the spikes are caused by light reflecting off the edges of the segments).
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  5. I think those were made by SOHO.
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  6.  @DadBodGaming7  Cell service is short-range radio, with a tiny antenna and a $30 receiver in your phone. The cell system is built deliberately to have short range, because the shorter the range, the more cell towers you can install without them interfering with each other, and the more users you can serve. Radio waves don't travel well through solid obstacles, so each wall between you and the cell tower reduces your signal. JWST has an unobstructed line of sight to the receiving station.
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  7. No. When looking at our Moon, JWST would have a resolution of about 50 m/pixel. So life forms would be too small to show up. JWST will look for life by doing spectroscopy: analyzing the gases in the atmosphere, checking for gases that don't occur naturally.
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  8.  @Bearzerk330  JWST will see exoplanets as a single pixel. It would be able to see if the planet was unnaturally warm, but a civilization would need to generate a LOT of heat before that happens. Humans have only started to influence Earth's temperature in the last 100 years, but we have lots of internal information (use of fossil fuels) that allow us to separate natural changes in temperature from human-induced climate change.
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  9. No, it's 930,000.
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  10. No.
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  11. We have excellent sonar systems these days. They're mostly hampered by needing to be installed on a ship, which means scanning the sea floor is painfully slow.
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  12.  @Toxxxic_  The first images were made and published before the start of mirror alignment, at the end of January. This was the image that showed 18 copies of the same star. The image shown here at 0:45 was published on March 16, after mirror alignment. At the end of April, NASA published an image that showed all of the instruments working.
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  13. We're not expecting to see the Big Bang itself. Just the first stars and galaxies that formed after the Big Bang.
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  14. Your "fact 3" is not a fact. JWST is not military. It's being operated by a university, the last place you'd use if you want to keep things secret. The target for the first year has been published. All observations will be published.  US Military satellites are run by the Air Force or the NRO, not by universities.
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  15. You heard wrong. All images will be released.
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  16. You have no idea. No, a simple camera cannot take pictures in infrared. A simple camera cannot see stars of magnitude 11 (far too faint for the naked eye), let alone the hundreds of galaxies in the background of this image. And this is just a mirror calibration image: the science images will be even better.
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  17. No. This telescope can only "look back in time" because light has a finite speed: when we look at an object 1 light-year away, we see the light that left that object 1 year ago, so we see 1 year into its past.
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  18. The STSci hasn't published full-resolution versions of the calibration images yet.
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  19. Yes, that's true. But it's that really old light we're interested in, because it can tell us what happened a long time ago.
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  20. It spent only about 30 minutes "close to our atmosphere". JWST's location orbiting L2 is empty: no space debris there.
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  21. JWST produces actual images. This channel however uses lots of CGI and stock photos in this video.
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  22.  @beta_cygni1950  Except radio telescopes.
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  23. We can't do interferometry at IR wavelengths yet. Interferometry gets harder for shorter wavelengths: your timing requirement gets tighter. We haven't gotten to the point where we can store IR observations as data in small enough timeslices to do interferometry.
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  24. JWST hasn't discovered anything yet: they're still commissioning the telescope. Alignment images have been released at several points in this process.
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  25. They're using radio, at about 8 GHz. The transmitter on JWST is nothing special. On Earth, NASA uses a dish antenna with a diameter of 34 meters and a cryogenically cooled receiver. The data rate for downlink is about 3.5 Mbit/s. The protocol is custom-made for use in space, it tolerates long delays (it takes 6-7 seconds for the signal to travel from JWST to Earth).
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  26.  @DadBodGaming7  Yes.
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  27. Incorrect. They've published 3 sets of calibration images, this is one of them.
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  28. Statistics.
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  29. Even though Canada and Europe have contributed to the mission, and science results in all disciplines are always shared freely?
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  30. It'll do 20 years of science, and you think you can predict its output from 1 calibration image?
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  31.  @keeplookingup911  These are already proper images, and the science observations will be better still. We'll get full-color images, and we'll get images of things we've never been able to see before.
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  32. I hate to break it to you, but scientists aren't rich.
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  33. This telescope can only "look back in time" because light has a finite speed: when we look at an object 1 light-year away, we see the light that left that object 1 year ago, so we see 1 year into its past. JWST is 5 light-seconds away from Earth, so that's how far back into our history it can see.
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  34. We can already look back 13 bn years. The extra 0.5 bn isn't going to make people give up their religion.
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  35.  @jacobmartin9446  The Hubble Deep Field contained objects more than 13bn lightyears away.
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  36. No. We have lots of data from different sources that all point to the same age of the universe. By now it's highly unlikely that will change.
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  37. Cite your sources.
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  38. No. They waited 25 years for the telescope to be built. JWST's data rate is 3.5 Mbit/s, the data budget per day is 28 GB. They've taken and downloaded more than 50,000 images already.
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  39. Plenty of real images in this video though.
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  40. No. 0:05: real image, part of JWST mirror alignment imaging. So is 3:26. 3:44 is a Hubble image. 5:32 and on are made by SOHO or STEREO. 7:32 JWST mirror alignment image. etc.
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  41. We have lots of evidence that supports the universe having a finite age (and we can see how old it is) and no evidence that supports the universe being forever.
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  42. Yes. The chances of that happening are really low though. : in 60 years of operating ~10,000 satellites, we've had 0 catastrophic meteor hits.
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  43. We've seen calibration images at 3 stages of the process. You can also go over to the Mikulski Archive for Space Telescopes, and see that they've taken more than 50,000 images already. All of these will be published when calibration is finished.
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  44. Observations of various solar system objects are planned for the first year of operation. They're still commissioning the telescope at the moment, so they're imaging targets that are useful for that purpose.
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  45.  @deocyasol9406  We've already looked at every object in the solar system that possibly could have supported life at some point. They're all dead worlds now. The only remaining options are moons with an ocean under thick ice (Europa, Enceladus), and we need dedicated missions to go there to look in more detail than we can do from far away.
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  46. Don't be ridiculous. There's no way to create data that will convince future scientists without doing the actual work you say you're doing. So that money was spent on actual R&D.
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  47. No, your smartphone can't take photos in mid-IR, let alone do spectroscopy. It also can't pick up the faint targets JWST is designed for because its sensor produces far too much noise.
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  48. No. They're just not publishing the targets for the first few hours beforehand. When those observations are done, they will be published immediately (along with the raw data, and all of the 50,000+ mirror alignment and calibration images). Why? Because they want those first science images to be a surprise. That's all there is to it.
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  49. That's not skepticism though. Every single one of the items you mention are wild claims without evidence. Skeptics require evidence before they believe something.
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  50.  @jurgenroscher5777  Well, you should follow your own advice. You're claiming "We could have already spent Trillions on space", but government budgets are public, tax rates are public (so we can work out how much money the government gets), and the combination of those shows there's no room for "trillions" of classified expenditures.
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  51.  @connd9630  0:26: image from January. 0:45: image from March 16. Missing from this video: the final alignment images published on April 28 showing all 4 instruments.
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  52.  @GuitarUniverse2013  See the JWST blog.
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  53. no, 930 thousand.
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  54. That's mainly a logistics problem. To fully map the seafloor you have to travel 510,000,000 km in a boat.
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  55. They will. When commissioning is complete, all of the images made during commissioning (50,000+) will be released.
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  56. The alignment images were all taken through a single filter (so they're monochrome), they added a red filter in postprocessing - they've done this as it helps out with the contrast in the image, but any color can be used. NIRcam and MIRI each have multiple filters. They can create color images by taking multiple images through different filters (similar to a consumer camera: this takes an image through red, green and blue filters and combines the output). Whether these filters line up in a way that allows them to undo the redshift as you suggest, depends on the distance of the object.
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  57. We have photos of stars orbiting an object that's mostly invisible. From those orbits we can calculate how much mass there must be: 4 million solar masses in a tiny amount of space. The only theory that can explain those observations is a black hole. Now we've imaged that invisible object, and our observations match the theory. That means black holes are real, not theoretical, not imaginary. Welcome to science.
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  58. Stars are large and produce a lot of light. Stars are visible to telescopes even if their apparent size is smaller than a pixel in the telescope's instruments. To image the surface of a planet, you have to resolve it, with the planet spanning multiple pixels. JWST can create an image of Mars that's 1000 px wide, or 1 km/pixel, that's about the best we can do at the moment. A probe sent to orbit Mars can take images with a resolution of 1 meter/pixel.
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