181–190 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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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…
For example, some algorithm might filter the raw images and extract objects matching some properties, fit them, and then run every reasonable manipulation of that filter to give the fit an error bar. Or they will compare spectra from many galaxies to understand their composition, again running every reasonable variation of the calculation to get some kind of uncertainty.
The end science result will be a graph of some kind in a paper, but it costs very little extra to make these beautiful images on the side.
Watching the livestream i was more than surprised, that color correction actually happens in Photoshop. Also, there seem to be multiple layer-masks involved for specific regions and objects. I get that you can shift and composite color, based on hue, apply filters etc, but: Photoshop? Curious if anyone can explain, that what we see is actual science or some touched up version of objects in our universe. p.s.: What st…
Webb's primary camera is infrared, so there is by necessity a choice to be made with how to present the data for humans who can't see in infrared.
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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…
No, there's none of that. These pictures aren't being used for any kind of science. They're 100% PR pieces, made to look pretty - which is fine!
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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…
So, would that mean that the gravitational lensing over how-ever-many-light-years is ALSO coupled with the convex/cave aspect of the pico-adjusting of the JWT 'lens' such that even our JWT's pico-adjustments affect the NORMAL of the photons to the image? Can this be adjusted for? Wouldnt the pico-arc of the overall array affect the image output due to the distances involved such that we receive "false gravitational l…
Dumb question. Why can’t we focus on a single exoplanet, look for mountains, grass, buildings? Why am I so stupid but isn’t this the obvious thing to do?
There is a fundamental physics limit at play here: the diffraction limit is linear with the aperture diameter and gives an upper bound on the resolution of a telescope. Having a longer exposure doesn't help - that's for resolving very faint objects (more light collected -> higher signal-to-noise). To resolve a building-sized object on an exoplanet, regardless of its intensity, we'd need a telescope the size of the so…
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Yes, it's a combination of both the primary mirror and struts. The JWST website has a very helpful infographic explaining: https://webbtelescope.org/contents/media/images/01G529MX46J7...
That's quite exhaustive, but it makes me wonder why isn't anything done to correct for that. Like for example instead of taking one 15h exposure, why not take three 5h exposures and roll the telescope 5 degrees in between, then median filter out the artefacts?
What's resonating with me today: As a web dev, I cannot imagine the feeling of so much dedication and effort from so many people finally unfolding to release after 30 years. One moonshot longer than full careers. Some of those responsible (hundreds? thousands?) retired or no longer with us. What a sacrifice, and what an achievement.
James Webb Telescope First Images – Livestream - https://news.ycombinator.com/item?id=32070531 - July 2022 (8 comments)
Deepest infrared image of universe - https://news.ycombinator.com/item?id=32062849 - July 2022 (334 comments)
James Webb Space Telescope White House Briefing - https://news.ycombinator.com/item?id=32062139 - July 2022 (91 comments)
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So, would that mean that the gravitational lensing over how-ever-many-light-years is ALSO coupled with the convex/cave aspect of the pico-adjusting of the JWT 'lens' such that even our JWT's pico-adjustments affect the NORMAL of the photons to the image? Can this be adjusted for? Wouldnt the pico-arc of the overall array affect the image output due to the distances involved such that we receive "false gravitational l…
The gravitational lensing matches exactly how it looked in Hubble's deep field overlay, so I would guess no the JWST lens is not causing any "false" gravitational lensing? If that's what you are asking.
I worded that poorly ;
Wouldn't one be able to adjust the perceived path of the photon after time, to adjust for re-normalizing the path of the photon based on the understanding of the gravitational arc imposed on such -- meaning the astro equivalent of "ZOOM. ENHANCE!" :-)