Talk:James Webb Space Telescope

Replacement needed
"SMACS 0723 [...] 4.6 billion light-years from Earth" should be replaced by "SMACS 0723 as it appeared 4.6 billion years ago", as in "Webb's First Deep Field" article. This is a common confusion between the time-of-travel  of light to reach us, and  distance expressed in light-years, which ignores Universe Expansion. This is why it is best to speak of redshift z,  when referring to such large distances, keeping the use of "light-years" distances to very small values of z. Another solution, as mentioned in the article Webb's First Deep Field, is to speak of time of emission of the signal detected.

Similar modifications should be made each time such errors occur in the article(s). Pverlain (talk) 11:08, 5 December 2022 (UTC)


 * In the interests of preventing edit wars, do we all agree that this web page used as one of the references for the 4.6 billion number, is incorrect? So 4.6 billion light years is the current distance and 13 billion years the light travel time?  Perhaps it would be best not to use that reference, at least in this location, if it directly contradicts the content of the article.  Lithopsian (talk) 16:25, 4 January 2023 (UTC)
 * Surely the image is not "How it appeared 4.6 billion years ago". it is, quite literally, how it appears today. it could be described as "How it would have appeared 4.6 billion years ago to an observer there at the time" or even "how it was 4.6 billion years ago". it is however, how it appeared at the time the photograph was taken. Moons of Io (talk) 16:34, 4 January 2023 (UTC)
 * @Pverlain. Agreed.  It's not 4.6 billion light years from Earth, since the universe has expanded in the time it took to get here.
 * @Lithopsian: No. The source, which uses "as it appeared 4.6 billion years ago", is correct.
 * @Moons of Io: Also no. "As it appeared 4.6 billion years ago" implies "to an observer there at the time". If it's good enough for NASA  and ESA, it's good enough for Wikipedia. Dan Bloch (talk) 19:35, 4 January 2023 (UTC)
 * Then the article is currently incorrect, despite an attempt to fix it. Lithopsian (talk) 19:57, 4 January 2023 (UTC)
 * True. I've put back the recently reverted change which fixed this. Dan Bloch (talk) 00:04, 5 January 2023 (UTC)
 * It is always true that when you look at distant objects you are looking into the past. From reading the comments, I understand that the light captured in the photo was emitted 4.6 billion years ago and subsequently the objects have retreated so that they are now 13 billion light years away. So light emitted now (whatever now means in this context) won't reach our location for another 13 billion years. However saying the picture shows the objects as they appeared 4.6 billion years ago is sloppy writing.
 * 4.6 billion years ago the objects would have appeared very differently. They would have been very much nearer for a start and the red shift would have been far less. This is not just pedantry because it is important to say what we mean. (Please note that saying this is what they looked like if we had been at that location 4.6 billion years ago opens a can of worms as to what is the meaning of simultaneity over cosmic distances.) It is true that we rely on organizations such as NASA for the factual basis but we don't have to copy their wording.
 * That this discussion has taken place is the proof that the wording is not good. OrewaTel (talk) 00:37, 5 January 2023 (UTC)

Largest in “space” superlative
I get that Wikipedia has an earth centric audience, but isn't it a little presumptuous to claim that the James Webb is the largest telescope in "space"? That's not provable, regardless of each of our own held beliefs. Could it be edited to say instead something like the "largest telescope in low earth orbit" (I might be wrong claiming it's in LEO?) regardless, there's a more appropriate, demonstrative framing for the James Webb deserved significance that's not claiming a presently unknowable fact. Dvlpmnt (talk) 03:45, 23 March 2023 (UTC)


 * If someone verifiably from elsewhere complains about it, we could change it then. Until then, it's probably not worth bothering about. And no, it's not in low Earth orbit, but at the Sun–Earth L2 Lagrange point. BilCat (talk) 05:40, 23 March 2023 (UTC)


 * FWIW, I offer the following, if anyone feels strongly enough and wants to make the sentence more neutral: "As the largest optical telescope orbiting Earth..." DonFB (talk) 21:11, 23 March 2023 (UTC)
 * Technically, it doesn't orbit the Earth, but the Sun. BilCat (talk) 00:06, 24 March 2023 (UTC)
 * "... launched from Earth" is a possibility. Dan Bloch (talk) 01:40, 24 March 2023 (UTC)
 * Kinda like '...launched from Earth', but '...in the solar system' would be pretty safe'. Agree it is not in Earth orbit and certainly not in LEO. Ex nihil  (talk) 09:51, 24 March 2023 (UTC)
 * Or just add "known" to what we have there now. Theoretically, someone from Earth could have larger telescope in the Solar System that we don't know about. BilCat (talk) 09:57, 24 March 2023 (UTC)
 * Being that it's the second lead sentence, adding "known" (or actually anything else) would just confuse some readers. Best to leave it be until a larger telescope is detected or announced. Randy Kryn (talk) 10:35, 24 March 2023 (UTC)
 * Exactly! BilCat (talk) 11:03, 24 March 2023 (UTC)
 * I had a go, change at will. Ex nihil  (talk) 12:32, 26 March 2023 (UTC)
 * Strongly disagree. The addition of "known" will be confusing to most users. The idea that there might be undiscovered extraterrestrial civilisations and that some might have telescopes is amusing, but it's self-indulgent for an encyclopedia. I support its deletion.
 * TowardsTheLight (talk) 12:52, 26 March 2023 (UTC)
 * An editor has already deleted it, and I support that decision. TowardsTheLight (talk) 12:54, 26 March 2023 (UTC)


 * oppose change, that's just stupid. By this logic we can add "known" to almost any article, because yes, who knows what's there in the galaxy far far away? Maybe they have a larger particle collider, or larger telescope, or even larger Russell's teapot orbiter some planet? And the earth centric audience is the only known audience unless you have proofs that they read wiki on Tau Ceti. Artem.G (talk) 13:10, 26 March 2023 (UTC)


 * oppose on these grounds. If you consider ETs,  you will also need first 'known' to all mathematical proofs, as well as the discovery of any rules of physics.  If we really need to recognize this, a better place is at some top level description of Wikipedia, where we could state that unless otherwise specified, superlatives such as 'first' and 'largest' are Earth civilization relative.  LouScheffer (talk) 15:05, 27 March 2023 (UTC)


 * oppose I thought the consensus was clear but an edit was made. OrewaTel (talk) 21:34, 26 March 2023 (UTC)

Lazy English
Why use "surfaced" to describe a discovery. Webb surfaced a new ... Submarines surface. 2A00:23C6:F680:2C01:60F9:4DDC:935B:E1C2 (talk) 14:42, 11 December 2023 (UTC)
 * Where is the word 'surfaced' used? OrewaTel (talk) 09:55, 12 December 2023 (UTC)
 * No longer used. I changed it to "revealed". DonFB (talk) 10:00, 12 December 2023 (UTC)

Great images in a preprint
Please see figures 1, 2, and 5 in https://arxiv.org/html/2405.21054v1#S5

Is the threshold for image inclusion such that we can use those? 141.239.252.245 (talk) 05:27, 13 June 2024 (UTC)