Talk:2762: Diffraction Spikes
I tried to make an initial explanation, but then someone beat me to it and I made a fool of myself on the page trying to add a comment where it didn't go. I fixed it, but I am ashamed ;~; 184.108.40.206 23:31, 12 April 2023 (UTC)
- It's all good. As long as you learn from it, and we learn what useful things you want to say, nothing at all to worry about... All power to your typing fingers! 220.127.116.11 00:15, 13 April 2023 (UTC)
Exoplanets nevertheless exist because, alongside the visible diffraction spikes that chop them up, there are invisible defraction [sic] spikes that reassemble them. 18.104.22.168 00:32, 13 April 2023 (UTC)
- Pretty sure gravity causes the pieces to drift back together. 22.214.171.124 20:33, 13 April 2023 (UTC)
- Randell actually explained this in his "What if a bowling ball would have the size of the earth?". The finger holes would instantly collapse. So if a blade would actually go through the planet there would only be local destruction and a change of momentum. 126.96.36.199 16:12, 15 April 2023 (UTC)
- The spikes are stellar artifacts of distant observers, with all the mass of the star behind them. The Sun hardly moves much if you dunk the Earth into it, why should the exoplanet move the spike? At best you'd get a similar effect to karate chopping a stream of water from a hose. 188.8.131.52 04:49, 13 April 2023 (UTC)
- Please stop dunking the Earth into the Sun.184.108.40.206 08:11, 14 April 2023 (UTC)
- Adding to 172.71...'s point, the spikes are made of star, so it will be incandescent gas with plasma corona. How do you "break" a gas?
Is it inspired by some movie that features this "spike pointing on some person" effect? I remember seeing one, but I don't seem to remember its name. 2659: Unreliable Connection (talk) 02:07, 13 April 2023 (UTC)
- This comic also reminded me of fractal images. 2503: Memo Spike Connector (talk) 09:06, 13 April 2023 (UTC)
- Is there also some joke here about double vision (if you cross your eyes you will see two planets), you use lens occlusion to see expolanets? (garbled)) 10:55, 14 April 2023 (UTC+1)
From an edit comment "(Refractor telescopes (using only lenses) don't give refraction spikes, reflector telescopes (using mirrors) do.)". Yeahbut, nobuf... It's just the struts, also mentioned, that are the key. You can build pure-refractor telescopes that still have struts (probably not optimal, but a design option) and therefore spikes. And you can make one with mirrors and no struts (more complicated and less of a practical shape for most mounting/launching purposes) which would therefore be spikeless. 220.127.116.11 12:00, 13 April 2023 (UTC)
- Some telescopes get diffraction spikes from the shape of the mirror. The JWST is a notable example of this. --18.104.22.168 14:13, 13 April 2023 (UTC)
- It's the sharp, angled edges that provide interference patterns (a set of "one-sided diffractions", rather than two-sided ones around an obstruction). A full round mirror on its own would not produce any spikes. Nor if the light from the edge areas cannot possibly reach the sensors, but that would mean less use of the mirror(s) they took great pains to send up there. And the secondary mirror has struts (in a Y-shape, I think, for technical reasons), thus why there's two minor spikes (actually six, but four are aligned to be hidden within the major spikes) as well as the hexagon-edge-induced set of six. Which also helps you understand in which orientation (or which two possibilities) the JWST was, in order to make any images you see from it.
- But this is already over-explained, really. You can design a mirror set to a avoid spikes, but with other technical compromises/etc. And above is correct, in that refractive telescopes can find themselves showing spikes (struts, if so designed, and other internal angles that may intrude into the light-path's edge). 22.214.171.124 17:27, 13 April 2023 (UTC)
- Diffraction spikes are also caused by window screens, dirty or scratched windscreens, and other optical blemishes. Given the relative scarcity of telescopes these are what most people have actually encountered.126.96.36.199 00:40, 15 April 2023 (UTC)
The transcript is very long... Too long : as of now, 2055 characters. That "transcript" section is intended for people who can't see the image (blind people for example), so it should be almost as fast to read as it is for you to look at the comic. There is really no need the exact angles of the diffraction spikes or anything, just a description of what's happening so that we can get the joke. You should not try to write a vectorization of the image, there are automated tools for that. 188.8.131.52 18:04, 13 April 2023 (UTC)
- The comment speaks to the difficulty of creating a transcription of an image that is meaningful to a person who cannot access the image. It would be good to hear from such folk about this.184.108.40.206 22:15, 13 April 2023 (UTC)
Why is the asteroid belt mentioned in the explanation? 220.127.116.11 19:13, 13 April 2023 (UTC)k
- If "all stars" have diffraction spikes, then there should be no planets around Sol. We exist, so Sol must be an exception to "all stars". But the asteroid belt (chopped-up planet(s)) also exists, so perhaps Sol had diffraction spikes sometime in its history. Yes, there's a real, and satisfactory, explanation for the Solar System's Jovian asteroid belt. But, context.18.104.22.168 21:58, 13 April 2023 (UTC)
- [actual citation needed] ...are you going by solar maxima? The weak 2014 one, and the 9-14 years we can generally get between them, makes 2023 off at the earliest of expectations... Perhaps 2025 is more likely.
- And we get maybe a few days warning of "a solar storm" (CME) that might happen to come our way. Carrington Events are rare, though, and even when 3+ CMEs a day happen (slightly after sunspot maximum, and up from the low frequency of one every five days), we're such a small target that it's still more or less the same amount of total dumb-luck (15-20x a fraction of a chance with a far greater (negative) order to it). 22.214.171.124 20:42, 14 April 2023 (UTC)