301–310 of 410 posts
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Existential dread pro-tip: The Wikipedia page on "Ultimate fate of the universe" is a fantastic way to compell the question of why anything ultimately matters. Coming up with personal answers to this is the ultimate character resolve exercise!
Nothing matters. You live for a while and then you die, but it sure can be a cool trip getting there!
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> “Cosmic Cliffs” in the Carina Nebula (NIRCam Image): > https://stsci-opo.org/STScI-01G7ETPF7DVBJAC42JR5N6EQRH.png Is this for real?! It looks like it came right out of a Sci-Fi movie/book. Could anyone explain how much of this is post-editing magic?
It's all real, but you would not be able to see it with your bare eyes even if you were relatively close to the nebula. The world around us would look very different if our eyes could perceive more of the infrared and ultraviolet spectrum. The coloring is usually done to indicate different temperatures or wavelengths detected, so it can be a bit misleading.
Not to spoil anything, but anybody else here finding these results quite underwelming?
I'm super curious how you could find these underwhelming. My mind is blown just scrolling across each of the images. What exactly were you expecting from them?
I ment more in the context of images taken by Hubble telescope - you know, all the hype. 25 years of work, 40mln hours worked, billions spent. Pictures are better than hubbles, but not by orders of magnitude, which is what I expected. That's why underwhelming.
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How does this "blueshift" compare to what we'd get if we just corrected for the relative-speed-induced redshift?
NGC3372 is inside our galaxy, just 8500 light years away. It's not redshifted by metric expansion to any appreciable degree, (A calculator I just checked gave me a z of 0.000000617) and radial velocity is a sedate ~34 km/s. (z = 0.000000115) The redshift on the other JWST images is because most of them are of objects that are much, much, much farther away. Infrared telescopes are great for observing those, but that's…
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Gravitational lensing. From the description[0]: Other features include the prominent arcs in this field. The powerful gravitational field of a galaxy cluster can bend the light rays from more distant galaxies behind it, just as a magnifying glass bends and warps images. Stars are also captured with prominent diffraction spikes, as they appear brighter at shorter wavelengths. [0] https://webbtelescope.org/contents/new…
Ah, that makes perfect sense. I guess I should have RTFM rather than just gawk at the pictures. Thanks for the ELI5!
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I’m confused.. why would we expect some other image processing software to be better than Photoshop - a software package which has been the top of its class for ~30 years?
Because photoshop it not open source, not verifiable, and not documented on a scientific level about how its filters behave.
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A GIF comparing both Hubble and JWST https://i.redd.it/9uyhwijeo0b91.gif
I made this page (posted in another thread yesterday) because I was rather underwhelmed by the .gif. I think the page shows in much better detail the difference between the telescopes' capabilities. https://blog.wolfd.me/hubble-jwst/ (If you're on mobile, you should be able to zoom in and still use the slider)
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This was also recently posted on reddit: https://johnedchristensen.github.io/WebbCompare/
Was J J Abrahams involved in Webb, because it really seems to produce nice lens flair
You could call those lens flares I guess, but commonly known as diffraction spikes when it comes to telescopes. In this case they appear because of the supporting struts in the James Webb telescope.
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I am aware. (And have been eagerly waiting for this moment for ages) It just seems “unscientific” to just use Photoshop and above all curious about the set of rules and algorithms, that enables them to decide which hue to pick for which region, levels, etc.
Photoshop is actually more complex than the JWST itself. What makes it "unscientific"? The fact that it's a consumer product?
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The difference between 'actual science' and 'some touched up version of objects in our universe' is smaller than you might think: no matter how good your eyes, if there was no frequency shift involved you would not be able to perceive the image, other than as an array of numbers. To facilitate your consumption of the data it has to be frequency shifted and the easiest way to do this is to map the IR intensity to a ra…
Thanks, but how is the sausage made then? Guess, that’s my main question. I get that the aquired data needs to be transformed in a way so we get an image that depicts a reality we can visually process. I honestly thought there’s some tools in Nasa’s imaging group that, based on scientific rules, pumps out an image that is correct - seeing Photoshop in use left me wonder… I get that the investment needs to be “sold” t…
It depends on the science of course, but generally the sausage is made with specialized software that produces contour plots with error bars and what-have-you. The actual calculations will be done using just numbers, fitting models to data without any pretty pictures at all.
This likely wouldn't have made #1 on HN without "pretty pictures" (this is what astronomers calls them). Photoshop is made for pretty pictures so it would be silly _not_ to use it. :)