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21:57
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Q: How do we know the expansion of space is happening "now" and isn't an illusion?

Ask QuestionsSome time ago there was an article published by an astronomer who's last name was "Gupta" I believe. I wish I could find it, but I haven't been able to so far. In that article, they alleged that the fundamental forces of nature were "weaker" in the early universe than they are today. So, this con...

I think you have to come up with a specific scenario that can be discussed, or rather you have to say exactly what it is you want to vary and what you are holding constant.. All we can do is look for variations in dimensionless constants like the fine structure constant - the variations of which could be due to variations of several constants with units.
Please link to the article by "Gupta"
I understand that this concept is new and therefore you have not had much time to think about it, but the burden of proof is not on me, a non-astronomer. The burden of proof is on astronomers, who claim space-time expands. When astronomers claim that space-time is expanding, how do they know space-time is expanding at the predicted rate "currently" and not in the past? How do they know it is universal and global, rather than an alternative scenario where physics is not as constant as Einstein claimed?
The burden of creating a sensible question IS on you though. Your assumptions are not valid, so your post is not a real question. Your posts appear to be a conglomeration of ideas an AI chat bot may spout out. Please put in a bit of research before posting.
Your 3rd sentence, for example, is entirely incorrect. There is nothing contradictory about it.
I'm asking a reasonable question and you're being weirdly defensive. This suggests you feel your...I don't know...intelligence is being questioned? I'm not saying you're not a hard working astronomer with a Ph D, I'm asking how astronomers know the universe is CURRENTLY expanding at its projected rate, given that we can only see galaxies red-shifting to the speed of light only in the past. Can you measure the expansion of space here and now between two atoms on Earth? Probably not, we don't have the technology to confirm or deny, hence my question.
@RoryAlsop But there is potentially a contradiction if you make all your inferences based on data from the past, not the present. Now, I'm not saying there is, I'm not assuming that conjecture is true, but I'm saying there's the potential to be. That potential is now why I ask the question. Again, can you measure the expansion of space between two atoms here on Earth? This isn't a "gotcha" question, this is a real inference of real data. When we measure galaxies, we measure them from the past. That brings up another question: how do we know the expansion of space everywhere is uniform?
@RoryAlsop Despite your hostility, which undermines DECADES of hard work by countless scientists by the way, I've just formulated a conjecture on how we might suggest the expansion of space is assumed to be uniform. In a VERY, VERY, VERY, VERY NON-TRIVIAL task of measuring SHIT TONS of galaxies at various distances, then and only then might we be able to suggest that the expansion of space appears to be a function of distance. Your hostile, negative, arrogant attitude has done absolutely nothing to avail this research to me though. This still does not address the issue of time.
21:57
No, the concept isn't new. But what do you mean by "old light" - light does not experience any proper time. If you mean "tired light", then that tired idea has been argued to death and there is oodles of evidence that show it is not a viable explanation for Hubble's law. What is the "force" that you think causes the redshift of light? I think there is a reasonable question in here, but I'm struggling to see what it is. Are you just asking whether there is any direct evidence for expansion? i.e. Seeing something get further away with time, rather than simply inferring a speed from redshift.
@ProfRob I'm not saying "old light" as a rigorous concept, I'm saying old in the sense that, relative to our interpretation of reality under the standard model, those photons must have existed for millions of years, and traveled millions of lightyears to get to us, therefore when we destroy them with equipment to make measurements, the information our brains infer from them says we measured those galaxies as they were in the past, not the present. I'm not referring to "tired light", though it is good to know your opinion that it is not a viable explanation for Hubble's law.
When I say "forces", well, unfortunately until I track down that article, I don't know for sure, but I might mean Maxwell's laws themselves, that, over time (and possibly space), physical equations like Maxwell's laws and light cones are not necessarily constant, and allow for different cosmic speed limits as you go further back in time.
I think you need to go and re-read our tour and How to Ask pages. It looks like what you want from this site is not what it is for. You don't need to be an astronomer to follow the guidance around structuring a question that makes sense and isn't predicated on fallacies you present as facts. When folks here comment that your question isn't currently reasonable, the best action you can take is to edit it to make it make sense, to take on board the comments, rather than be defensive and hostile.
@RoryAlsop Sorry, but I'm not violating guidelines, you're straw manning. If I knew how to ask the perfect question that arbitrarily pleased you, well, then I'd have enough knowledge to answer my own question, because I would then be a Ph D physicst, wouldn't I? But I don't, I'm a layman, it is impossible for me to magically know in advanced how to ask the perfect question that pleases you. Frankly, it's entirely hypocritical, without doubt you once started off not knowing a lot about astronomy either. It's completely elitist to require me to be a Ph D graduate in order to simply "ask".
No. Go and read and follow the guidance. You don't need any qualifications to ask a good question (see any number of laymen who already have.) Asking a question that is well structured can be done by anyone. Take commentary on board and please go and edit your questions, instead of taking comments on your questions' quality as some sort of attack against you.
"Well structured" is still arbitrarily defined, particularly by a small consortium of mainly Ph D educated folks on this particular site. To me, the question I asked was good. To you, it was bad. This is a textbook sign your standard is subjective either way. Regardless, you made absolutely no effort whatsoever to help me ask a better question, you're just ranting, and, hypocritically, failing to provide scientifically verified evidence on the truth or falsehood of various claims you've made or that I've made. After ranting, you then tried to mask your ranting with citing guidelines.
As for a layman asking a good question, that's called "statistics". You never know what string of words is magically going to be well received by random people, and you never quite know entirely whether your outside cultural tendencies will coincide with every interpretation of another group. If you do know, you stand to make LITERALLY trillions of dollars. So why are you on this site instead of making trillions of dollars? Unless, you're just being hypocritical, and you're inappropriately conflating being educated with being correct about subjective disputes.

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