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Everything posted by swansont
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Citation needed.
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Is it your contention that this is new? What tests of GR have not agreed with theory?
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What would this be? Relativity has been confirmed by experiment many times, so the answer is that the effect of any new transformation must be no larger than the experimental error of the best experiments we’ve done.
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! Moderator Note Questions of this nature can be addressed with a visit to a search engine page. If you’re going to engage people, make it something requiring a human.
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Is the universe at least 136 billion years old, is the universe not expanding at all, did the universe begin its expansion when Hubble measured its redshift for the first time or was light twice as fast 13.5 billion years ago than it is today?
swansont replied to tmdarkmatter's topic in Astronomy and Cosmology
Light passing by thousands of stars describes a source on the other side of a galaxy (or the far side of a galaxy, viewed edge-on) which we can’t see, because the source is obscured. The effects would tend to cancel, since the deviations are in different directions. The stars and galaxies we can image aren’t obscured. You have yet to articulate how this deviation is a problem. It’s just a bald assertion. Andromeda, for example, has an angular size of 178x63 arc-minutes. You’re worried about deviations a few orders of magnitude smaller. -
Is the universe at least 136 billion years old, is the universe not expanding at all, did the universe begin its expansion when Hubble measured its redshift for the first time or was light twice as fast 13.5 billion years ago than it is today?
swansont replied to tmdarkmatter's topic in Astronomy and Cosmology
But they aren’t significantly further away. The deflection drops off as 1/r -
Is the universe at least 136 billion years old, is the universe not expanding at all, did the universe begin its expansion when Hubble measured its redshift for the first time or was light twice as fast 13.5 billion years ago than it is today?
swansont replied to tmdarkmatter's topic in Astronomy and Cosmology
Infinite range, but drops off as 1/r^2. Meaning that light has to pass very close to a star to have measurable deflection. How many Einstein rings have we discovered, as compared to galaxies and stars? Why is there such a disparity? Calculate what we should expect. This is just hand-waving, and shows only superficial understanding. Why don’t we see deflection for light that isn’t passing very close to the sun? ETA: I won’t wait as I suspect the wait would be very long The deflection formula can be easily found https://adsabs.harvard.edu/full/1929JRASC..23..208T#:~:text=For a light ray running,amounts to B %3D 1'. The deflection varies with mass and inversely with distance of closest approach; we know the closest approach for light around the sun - it’s about 2 light seconds The mass of the Milky Way is about 10^12 solar masses. The central bulge is about 5000 light years. or ~10^11 bigger than the sun closest approach. The ratio, which tells us the deflection, is 10x bigger than for the sun. So in rough terms, light grazing the edge of the central bulge of a galaxy similar to ours will see ~17.5 arc seconds of deflection. We can’t see that, of course, because the galaxy would be too bright. And the deflection around the spiral, which is 10x bigger, would be 10x smaller. That’s for a source behind the galaxy, which is blocked by the galaxy. For unblocked sources, there’s just empty space, which has no deflection. -
Check out our rules (specifically 2.7). You need to post material for discussion here. “check out that video” is tacit admission that you haven’t complied. If it were a continuum of energies it wouldn’t be called quantum. But to post here you have to have something of substance. This isn’t the WAG forum.
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Is the universe at least 136 billion years old, is the universe not expanding at all, did the universe begin its expansion when Hubble measured its redshift for the first time or was light twice as fast 13.5 billion years ago than it is today?
swansont replied to tmdarkmatter's topic in Astronomy and Cosmology
I didn’t mention proof. As iNow has accentuated, I said evidence, and also models, mainstream physics has plenty of evidence to support existing models. What have you got? Light is bent according to known conditions in GR, i.e. by close proximity to sources of gravity. So saying “we don’t know” is not true. Do you have evidence of light being bent under other conditions, or sources of gravity in interstellar space? (and 7 min of sun gravity? what is that?) -
It’s too bad that the GOP’s implied declaration that they have no interest in governing is viewed as an indictment against government
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Perhaps it’s terminology, but they don’t agree about the speed of light propagation in some other frame (and these are not inertial frames) even though locally they will measure it as c. The problem as framed doesn’t seem to point to any flaw in relativity.
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This notion seems to underlie some of the bad faith arguments we see in politics: “if you can’t 100% fix a problem then I won’t support it” followed by standing/voting against incremental improvements. Poverty (for example) will always be with us, but that’s not a valid excuse for doing nothing to improve the situation.
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If you built multiple atomic clocks in one location and then sent some to a location at a different elevation, the ones at a higher elevation will run at a higher frequency. This isn’t a pedagogical exercise. I’ve done it. (Some clocks near sea level, the others at more than 1 km higher in elevation. The latter ran more than 10^-13 faster at the final location) ETA: A ruler will curve in a gravitational field, but directly measuring that isn’t something we can currently do
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Is the universe at least 136 billion years old, is the universe not expanding at all, did the universe begin its expansion when Hubble measured its redshift for the first time or was light twice as fast 13.5 billion years ago than it is today?
swansont replied to tmdarkmatter's topic in Astronomy and Cosmology
The first is more of a philosophy question (metaphysics), but dark energy appears to be a property of spacetime. Any kind of “is it possible” question has to be addressed in terms of what mainstream science says. If you have a different model, you need evidence to support it. With mainstream science there’s always the possibility of some better model, but of what value is an alternative model if there’s no evidence to support it? So “is it possible” doesn’t add much to the discussion. Does it violate any known laws? If no, then it’s possible. But if you don’t have the alternative theory in place, so what? Gravity could be due to invisible fairies, but since there’s no testable model for that, we don’t waste time entertaining the notion. -
Because rulers from a factory don’t generally agree to a part in 10^15. Or anything close to that. And Alice and Bob live in different apartments I recall a discussion with a Nobel prize winner who was visiting (two of my colleagues had been postdocs in his lab) about the issues that will arise once measurement precision reaches a certain level. Like having to specify whether an electron’s mass measurement was made at the bottom of a mountain or the top. We do this with time already, because we can do the measurements with sufficient precision. I was thinking of what happens near a BH. Light can travel (orbit) but time dilation becomes infinite as seen by a distant observer
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And from that you extrapolate this into being a widespread problem. Which you interpret as “per” (despite it not making sense) but was not stated as you claimed. Your real issues are with this one author and your propensity to declare things to be a problem.
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Give an example
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Who is Swantsont?
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Observers in different gravitational potentials do not agree on the speed of light. Spacetime is not flat, and clocks run at different rates.
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Do poor people tend to buy houses (can they get a mortgage?), or do they rent? After stalling under Trump, apartment construction has increased dramatically under Biden. https://fred.stlouisfed.org/series/UNDCON5MUSA “jurisdictions participating in the American Rescue Plan’s (ARP) HOME program will produce at least 20,000 units of affordable housing and support an additional 23,000 households with rental assistance, non-congregate shelter, or supportive services” https://www.whitehouse.gov/briefing-room/statements-releases/2023/07/27/biden-harris-administration-announces-actions-to-lower-housing-costs-and-boost-supply/
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It can be as simple as somebody calling you, saying they’re coming over to your abode to kill you. Yup. An overt act, and imminent danger.
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Even if they could, we know their clocks run at different rates, owing to GR. What, precisely, is the problem?
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Which all of the republicans voted against (and IIRC, have vowed to repeal)
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That’s irrelevant to how you framed this, though. You said “the liberals are not pushing for economic improvements” rather than assessing the liberal-ness of the programs. They have definitely pushed for economic improvements. How liberal the programs are is another discussion. Democrats passed Obamacare, and that included medicaid expansion. States that have not taken advantage of medicaid expansion are run by republicans. That’s not the fault of democrats. Most congressional Democrats support increasing the federal minimum wage. The problem is there is no Republican support, so no legislation can be passed. States that have low minimum wages tend to be run by republicans. Same goes for regulation. You need better sources of information. ETA: Is this a democrat or a republican