Talk:2596: Galaxies

I bet this was inspired by the image from the James Webb Space Telescope after fine alignment was complete: https://www.nasa.gov/sites/default/files/thumbnails/image/telescope_alignment_evaluation_image_labeled.png. That image shows the one star that JWST was focused on, along with a bunch of galaxies in the far background demonstrating that there are a lot of galaxies. Orion205 (talk) 04:52, 22 March 2022 (UTC).

My thoughts exactly - definitely a JWST thing.172.70.218.75 07:09, 22 March 2022 (UTC)

I do not really think so. Not directly. The image is some weeks old now, and also the knowledge of the number of galaxies comes from the Hubble Deep Field. Which Randall has mentioned before, at least in his Thing explainer. --Kynde (talk) 13:43, 22 March 2022 (UTC)

Speaking of JWST, isn't the "only a few stars, and probably no planets." just a nod to the fact that one of the missions of its infrared astronomy is to "see back in time to the first galaxies forming just a few hundred million years after the Big Bang."? i.e.: given the conical shape of the sector of universe covered by the pin-hole, most of the galaxies in it will be the furthest back, thus those of which we see the "oldest" picture and thus which much earlier in their process of forming stars and planets? DrYak (talk) 09:17, 22 March 2022 (UTC)

Maybe but we cannot see them before the stars have formed and begun shining light. And by that time most of the planets would have formed. And also many many stars. So I do not think there is anything in the title text other than to make you think that what he says there is just plain wrong, and thus become even more overwhelmed! --Kynde (talk) 13:43, 22 March 2022 (UTC)

I sort of thought it might be an(other) H2G2 reference, to whit...

Population: none.
It is known that there are an infinite number of worlds, simply because there is an infinite amount of space for them to be in.  However, not every one of them is inhabited.  Therefore, there must be a finite number of inhabited worlds.  Any finite number divided by infinity is as near to nothing as makes no odds, so the average population of all the planets in the Universe can be said to be zero.  From this it follows that the population of the whole Universe is zero, and that any people you may meet from time to time are merely the products of a deranged imagination.

...but worlds-to-galaxies, by the same 'logic', rather than beings-to-worlds. But I'm not sure enough to mention it in the main article, because it disagrees on the basic 'number of planets' issue (indeed, whether the ((observable)) universe is infinite). But putting it out there because it's perfect Adamsonian logic. ;) 172.70.90.173 14:09, 22 March 2022 (UTC)

While space contains contains a vast number of things, it's still mostly empty. Like, on average, few atoms in whole square meter. Atoms of hydrogen, usually. Imagining so much of practically empty space is even harder than imagining all the stuff in it. -- Hkmaly (talk) 05:50, 22 March 2022 (UTC)

It took me half a minute to understand it: not galaxies within the circle, but within the region of the sky with the same apparent size from your position as the circle. 162.158.22.175 10:19, 22 March 2022 (UTC)

And you can move that circle anywhere you like. Also looking down at Earth surface. Then there will still be 50,000 galaxies within that circle on the other side of the Earth. As long as you hold it at arms length. --Kynde (talk) 13:43, 22 March 2022 (UTC)

Another way to consider this is that the moon is a privacy screen for 1.5 million galaxies at any one time. 172.70.131.122 16:55, 22 March 2022 (UTC)

The size of the circle could be more accurately estimated by noting that the majority of phones have between a 4.7 to 5.8 inch diagonal (https://deviceatlas.com/blog/viewport-resolution-diagonal-screen-size-and-dpi-most-popular-smartphones). While aspect ratios vary, that seems a decent approximation for the diagonal of the image, and from that, the size of the circle could more accurately estimated from its pixel size relative to the image diagonal. Overkill, though, I know. 172.70.131.122 16:55, 22 March 2022 (UTC)