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Can We Test the Speed of Light Using 'Lensing' from Supernovae? (arxiv.org)

Posted by EditorDavid on from the speed-limits dept.

Long-time Slashdot reader RockDoctor writes: One of the key assumptions of Relativity — both Special and General — is that the speed of light is a constant in all non-accelerating reference frames. As a key assumption, it is also one of the things that gets the kooks, wingnuts and fanatics all riled up, because they have proven that it's wrong, though those pesky scientists refuse to listen to their spittle-flecked presentations.

Back in the real world, real scientists also wonder if the assumption is justified, then try to work out how to test it. One idea for performing this test has just been published — that of using the gravitational lensing of distant supernovae to try to interrogate the speed of light in the distant past.

When a (relatively) nearby galaxy lenses a (relatively) distant galaxy, it is common for multiple images to be formed. If a supernova occurs in the distant galaxy, then supernova images will be seen in the different images, but typically at different times (on Earth) because the light paths from different images are of different lengths, and were of different lengths in the past.

The Chinese-Polish team of authors have studied the possibilities of making such observations and suggest that the LSST (Large Synoptic Survey Telescope, "a wide-field survey reflecting telescope with an 8.4-meter primary mirror, currently under construction, that will photograph the entire available sky every few nights") should detect several thousand gravitationally-lensed distant quasars, and so yield around 50 gravitationally-lensed distant supernovas per year. This is estimated to "produce robust constraints on the speed of light at the level of delta-c/c;= 0.005" (half a percent) in a decade of operations.

Which will shut the wingnuts, lunatics and kooks up. Not.At.All.

49 of 112 comments (clear)

  1. Since when? by magarity · · Score: 1

    it is also one of the things that gets the kooks, wingnuts and fanatics all riled

    I must be way behind on the kook news; since when was the speed of light in a given medium not constant per observer?

    1. Re:Since when? by Anonymous Coward · · Score: 1, Interesting

      Dr. Rupert Sheldrake - delusion and dogma in science: (The science delusion). https://www.youtube.com/watch?v=JKHUaNAxsTg

      Discussing the variance of "Big G" i.e. Gravity as well as the measured variance in the speed of light. Nevermind the data, it's stepping on my dogma.

    2. Re:Since when? by Anonymous Coward · · Score: 1

      The guy who thinks that science is wrong because it can't explain absolutely everything? And quite coincidentally he has a hypothesis of everything of his own? I don't think he really understands what science is about.
      Of course that doesn't mean everything he says must automatically be wrong. So please make precise references that illustrate your point and don't expect others to do that job for you.

    3. Re:Since when? by Anonymous Coward · · Score: 1

      Science is supposed to follow the scientific method. Hypothesis, test, etc. Follow the data. Today, you have scientists acting just as dogmatic as religious cult leaders. So, yes, we have a serious problem. There is data that shows anomalies with "Constants" such as Big G, speed of light... Some people start finding data that does not fit the models and they're burned at the stake for not conforming to the bullshit dogma. Questions are good. Science needs challenges. It's the only way to advance. I can think of a couple mathematicians that were murdered for challenging the establishment. Some things never change. The scary thing to me is that so many people start foaming at the mouth when you challenge the dogma! WTF over?

    4. Re:Since when? by Anonymous Coward · · Score: 2, Insightful

      Science needs evidence. Evidence that can be obtained by repeatable and independent experiments. If you can't provide that, you run into problems in science. Then it's philosophy at best.

    5. Re:Since when? by fermion · · Score: 1, Redundant
      And the kooks speak.

      Science tells us things that are useful and give us rules that appear to function under the appropriate, if sometime unspecified, assumptions,

      So we know that as long as we don't go too fast, among other things, a constant force will produce a predictable acceleration for a given mass.

      But science is new in the grade scheme of things. Until Michael Servetus in the 16th century, people believed that blood just swished back and forth in the body. Until Joseph Priestly we did not have any idea that things like atoms might exist. Galileo popularized the empiricism that is the basis of science, but much of what is done is still hunch and extreme extrapolation. Sometimes we get lucky.

      Einstein was such an intuitive scientists. The photoelectric effect, for which he won his noble prize, was not 'proven' until the 1950's when lasers allowed us to eliminate other explanations. Likewise, the effects of special and general relativity, like Time Dilation and gravity lenses, have been shown to exist and are consistent with our current theories. Black holes at the center of galaxies seem to be best explanation for celestial data.

      On the other hand, it appears that Quantum mechanics and Relativity are incompatible. It is frustrating because every test we make shows that both theories explain what we observe depending of the on the scale. Tunneling and quantum teleportation exists. Mass does warp space. But something is going to have to give. It could be that there is an assumption we made and beyond that assumption the sped of light is not constant. It could be something that no one has thought of. there has to be something.

      --
      "She's a scientist and a lesbian. She's not going to let it slide." Orphan Black
    6. Re:Since when? by novakyu · · Score: 1

      When the medium is moving relative to the observer: Fresnel frame dragging.

      Or did you mean to sound smarter and more informed than you actually were?

      P.S. This whole article is a bunk. It's a long-standing test of symmetries of nature to test if speed of light is constant (as a function of location in universe, or as a function of time). Sure, there are kooky ways to go about challenging it, but there are legitimate ways to test it that had more sensitivity than these methods. See: Is the fine-structure constant actually constant?

    7. Re:Since when? by Crashmarik · · Score: 4, Insightful

      I am kind of curious how determining if physical laws are constant over time or variable became the province of "Wingnuts and kooks".

      Sounds like Rock Doctor has issues.

    8. Re:Since when? by Crashmarik · · Score: 4, Insightful

      The guy who thinks that science is wrong because it can't explain absolutely everything? And quite coincidentally he has a hypothesis of everything of his own? I don't think he really understands what science is about.
      Of course that doesn't mean everything he says must automatically be wrong. So please make precise references that illustrate your point and don't expect others to do that job for you.

      The problem is having faith in the result before the experiment is done. There's been argument over the years about if physical constants are constant and if physical laws have been consistent over time. Anyone who asserts they are or aren't without experimental data to back up their position is equally bad, and not actually using the scientific method or in any way practicing science.

    9. Re:Since when? by Crashmarik · · Score: 1, Interesting

      Can you provide experimental data for them being "equally bad" and not actually using the scientific method or in any way practising science?

      Oh you're so funny. If you reach conclusions before the experiment is even started you are by definition not using the scientific method or practicing science. Matter of fact doing so is the experimental data that proves you aren't.

      Thanks I needed the laugh.

    10. Re:Since when? by CaptainDork · · Score: 1

      This.

      There's really nothing to get upset about here.

      Scientists are probing the universe at different times in order to determine if the speed of light has changed over the billions of years.

      It's a necessary question that we'd like to answer.

      Sure, there are spectators speculating on the outcome of the game before the fucking anthem has even started, but that's not something that's necessarily batshit crazy.

      --
      It little behooves the best of us to comment on the rest of us.
    11. Re:Since when? by Altrag · · Score: 1

      Except Einstein did have evidence. It may not have been 100% conclusive but it's not like he pulled it out of his ass either. There was getting to be an awful lot of data suggesting the prevailing wage theory of light was wrong, and Einstein provided a theory that fit all the particle-based data.

      Oh yeah, and he was wrong too. The whole idea of duality didn't come around for a couple decades after he described the photoelectric effect. And you know what he did? He arbitrarily claimed that God doesn't play nice with the universe, without even bothering to fact check with God first.. so yes, even Einstein failed at doing science from time to time.
      But his paper on the photoelectric effect was not one of those times. He wasn't doing the part of science where you "prove" things. He was doing the part where you make a hypothesis to fit the data. That's a very important step as well!

    12. Re:Since when? by DRJlaw · · Score: 1

      I am kind of curious how determining if physical laws are constant over time or variable became the province of "Wingnuts and kooks".

      The "wingnuts and kooks" were identified as those who claim to "have proven that it's wrong."

      Not those still seeking to determine the answer to the question through a rigorous experimental design and (yet to be collected) results.

    13. Re:Since when? by Gr8Apes · · Score: 1

      The problem is having faith in the result before the experiment is done. There's been argument over the years about if physical constants are constant and if physical laws have been consistent over time. Anyone who asserts they are or aren't without experimental data to back up their position is equally bad, and not actually using the scientific method or in any way practicing science.

      So far as I'm aware, those physical constants have held up to all experimental evidence we have today. So accepting them as constants is reasonable for all other work. Until someone provides repeatable proof that they're not constant, this will not change. Kind of like the expansion of the universe and the fact that space itself is expanding. That one blew a lot of assumptions out of the water. So it's not that science is wrong, it's that people who assume that alternate facts can explain something with no basis is equally valid to experimentally derived theories that are delusional.

      --
      The cesspool just got a check and balance.
    14. Re:Since when? by Crashmarik · · Score: 1

      The problem is having faith in the result before the experiment is done. There's been argument over the years about if physical constants are constant and if physical laws have been consistent over time. Anyone who asserts they are or aren't without experimental data to back up their position is equally bad, and not actually using the scientific method or in any way practicing science.

      So far as I'm aware, those physical constants have held up to all experimental evidence we have today. So accepting them as constants is reasonable for all other work. Until someone provides repeatable proof that they're not constant, this will not change. Kind of like the expansion of the universe and the fact that space itself is expanding. That one blew a lot of assumptions out of the water. So it's not that science is wrong, it's that people who assume that alternate facts can explain something with no basis is equally valid to experimentally derived theories that are delusional.

      Tell it to the guy who submitted the article with a rather obvious axe to grind. Personally just on cosmology's version of eschatology, I have seen heat death, big crunch, endless expansion, quantum fluctuation cycle and big rip (steady state was alreadyon the way out when I got interested). I may be leaving something out it's not my field. The one thing they all have in common is how remarkably belligerent their supporters have been.

    15. Re:Since when? by Crashmarik · · Score: 1

      I am kind of curious how determining if physical laws are constant over time or variable became the province of "Wingnuts and kooks".

      The "wingnuts and kooks" were identified as those who claim to "have proven that it's wrong."

      Not those still seeking to determine the answer to the question through a rigorous experimental design and (yet to be collected) results.

      That's one way to read it. I read it as the author thinks anyone who disagrees or has an opinion on the matter different than his, is one or the other perhaps both. It was hard to get past his fuming especially since there had been experimental evidence that purported to show alpha (fine structure constant) had variance in the past, currently there's results from a team at Los Alamos claiming to show the variance. Others have indirect isotope evidence claiming to constrain it. Personally given the sheer complexity and possibility for unaccounted events, the isotope work isn't as compelling as its champions would like people to believe.

    16. Re:Since when? by Gr8Apes · · Score: 1
      My main gripe with your comment was regarding

      Anyone who asserts they are or aren't [constant] without experimental data to back up their position is equally bad

      There is no data to prove a constant, only a preponderance of evidence. However, we have no data disproving the constant, and it only requires 1 repeatable test, so the one saying they aren't constants need to come up with some proof.

      TL;DR the naysayers in this case are the ones that need to step up.

      --
      The cesspool just got a check and balance.
    17. Re:Since when? by Crashmarik · · Score: 1

      I don't have a horse in this race except perhaps a desire to see new and interesting physics but it didn't take much effort find papers.

      https://arxiv.org/abs/astro-ph...

  2. Go find out by Bite+The+Pillow · · Score: 1

    Why not go find out and then let us know? It's not like you're crowd funding here, just wait until you have news.

    1. Re:Go find out by RockDoctor · · Score: 2

      The point is, someone is proposing a method of using a in-construction tool to test this point, as their "card on the table" in the competition for observing time on the scope when it achieves first light. Or, considering it'll be a zenithal scope, whose viewing schedules are dictated by the rotation of the Earth, they'll be bidding for time to observe (and get spectra of) the supernovae that get caught by the LSST, using other steerable scopes that can accumulate the tens of hours of observation needed to get a spectrum of adequate signal-to-noise level.

      --
      Birds are not dinosaur descendants;birds are dinosaurs, for all useful meanings of "birds", "are" and "dinosaurs"
  3. No we can not... by Kenja · · Score: 1

    Perhaps YOU can, but I'm too busy.

    --

    "Have you ever thought about just turning off the TV, sitting down with your kids, and hitting them?"
  4. Wait, in all *NON*-accelerating reference frames? by mark-t · · Score: 1

    What about accelerating ones? Moving along a circular path at some constant velocity has a constant acceleration towards the center of the circle, for instance... is the speed of light any different? I wouldn't have thought so, but if it's only constant in non-accelerating reference frames, I don't know....

    --
    File under 'M' for 'Manic ranting'
  5. Insults by Anonymous Coward · · Score: 5, Insightful

    I guess insults are part of science now? Or is this just someone with an expensive speech comm degree writing about science who has been radicalized to hate anyone who disagrees with current theory. As another poster suggested go test the hypothesis and let us know without resorting to insults. If you can manage that.

    1. Re: Insults by jd · · Score: 5, Insightful

      When insults are the only things listened to, expect to listen only to insults.

      Sorry, you can't blame science writers for copying a broader trend. Blame the trend, or better still fix it.

      --
      It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
    2. Re: Insults by jd · · Score: 1

      Scuse me whilst I laugh. Isaac Newton drove a colleague to madness and suicide. Boltzman fared little better against Mach's fans.

      Besides, science has never been about Truth. If you want Truth, theology is down the corridor. There are no treasure maps and X never, ever marks the spot. Science is about finding out why you're wrong. It's a heuristic, not an algorithm. It's about progress, not perfection. It's about prediction and falsification, not truth.

      --
      It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
  6. Re:Spittle??? by meglon · · Score: 4, Informative

    I can't tell if you're being sarcastic, or if you're really so stupid as to think Sheldrake is anything more than a psuedo science conman.

    https://newrepublic.com/articl...

    He's as much of a conman as those dipshits who spout the electric universe bullshit... which i'm sure we'll be seeing on this thread in no time.

    --
    Fascism: An authoritarian and nationalistic right-wing system of government and social organization. See also: NAZI's
  7. Re:Spittle??? by Anonymous Coward · · Score: 1, Informative

    Ok, So you're the one calling a Cambridge University researcher and seasoned, highly published professor a conman. He's simply found data and asked the question. Why doesn't it jive with our models of how the universe works????? hmmmmm???? It's a worthy question. Instead of sending ad hominem attacks, why don't you take a more erudite path of considering the question?

    Rupert Sheldrake is a biologist and author of more than 85 scientific papers and 13 books. He was among the top 100 Global Thought Leaders for 2013, as ranked by the Duttweiler Institute, Zurich, Switzerland's leading think tank.

    He studied natural sciences at Cambridge University, where he was a Scholar of Clare College, took a double first class honours degree and was awarded the University Botany Prize (1963). He then studied philosophy and history of science at Harvard University, where he was a Frank Knox Fellow (1963-64), before returning to Cambridge, where he took a Ph.D. in biochemistry (1967). He was a Fellow of Clare College, Cambridge (1967-73), where he was Director of Studies in biochemistry and cell biology. As the Rosenheim Research Fellow of the Royal Society (1970-73), he carried out research on the development of plants and the ageing of cells in the Department of Biochemistry at Cambridge University. While at Cambridge, together with Philip Rubery, he discovered the mechanism of polar auxin transport.

    The Science Delusion in the UK and Science Set Free in the US, examines the ten dogmas of modern science, and shows how they can be turned into questions that open up new vistas of scientific possibility. This book received the Book of the Year Award from the British Scientific and Medical Network. His most recent book Science and Spiritual Practices is about rediscovering ways of connecting with the more-than-human world through direct experience.

  8. Re:Spittle??? by Zontar+The+Mindless · · Score: 4, Informative

    Rupert Sheldrake hasn't done any real science in 30 years.

    --
    Il n'y a pas de Planet B.
  9. Re:Riled up and not a kook. by crunchygranola · · Score: 2

    So, what you are saying is - "Why can't you explain this to me using a car example?".

    --
    Second class citizen of the New Gilded Age
  10. Re: Wait, in all *NON*-accelerating reference fram by jd · · Score: 3, Informative

    The speed of light is a constant, time and space change under the Lorenz contraction in a way that keep light fixed.

    (Technically, light only happens to travel at C in a perfect vacuum. C is not otherwise related to light.)

    --
    It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
  11. Re:Spittle??? by Anonymous Coward · · Score: 1

    Which study? He took measurements from the British government scientist findings and plotted them. There was variance. He asks the question why. Then people attack him. I don't know the answer to his question. But the data seems sound. It pokes holes in some of our scientific models. Maybe we need new models to take account for these data variances? I don't know, but it's a damn good question!!!

  12. Re:Spittle??? by RockDoctor · · Score: 1

    Please reference the work of Dr. Rupert Sheldrake et al.

    Why? I wasn't thinking him important enough to be worth mentioning. Indeed, until he got mentioned here, I thought he'd died, or gone onto breakfast TV, or some horrible fate of unbeing.

    --
    Birds are not dinosaur descendants;birds are dinosaurs, for all useful meanings of "birds", "are" and "dinosaurs"
  13. Re: Riled up and not a kook. by jd · · Score: 2

    This has been explained countless times.

    Vectors aren't additive that way.

    http://hyperphysics.phy-astr.g...

    http://hyperphysics.phy-astr.g...

    https://opentextbc.ca/physicst...

    In a nutshell, relative velocity alters space and time. It's the Lorenz Contraction. This throws in the extra term into the equation.

    --
    It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
  14. Re: Spittle??? by jd · · Score: 4, Insightful

    He's a biologist. I don't get my astrophysics from biologists any more than I get my biology from astrophysicists.

    --
    It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
  15. Re:Spittle??? by Anonymous Coward · · Score: 1

    Maybe? Without knowing exactly what data we're talking about and what scientific models are challenged in their validity I can't say more about it.
    That scientists can be assholes is not a new thing. They're humans after all and these things are well within the capabilities of humans.
    For example Albert Einstein himself was quite the asshole, endlessly debating quantum physics with other scientists like Niels Bohr, asking questions after questions, with the intention of Reducio Ad Absurdum, that Bohr could not answer. Could not answer, mostly because we did not have the technical capabilities to answer these questions at that time. But in the end, when we finally could conduct proper experiments, Einstein was mostly proven wrong.

  16. Re: Wait, in all *NON*-accelerating reference fram by mark-t · · Score: 1

    Well yeah, that's what I figured... so what's this about so-called non-accelerating reference frames then?

    Why bother saying that if it isn't equally true for any reference frame, whether it is accelerating or not?

    --
    File under 'M' for 'Manic ranting'
  17. Re:Spittle??? by meglon · · Score: 4, Insightful

    ....and Dr. Andrew Wakefield was an actual doctor, until he started falsifying research results in his bid to con the UK government out of money by selling an "alternative" vaccination drug. I guess when people start caring more about making money than honesty and integrity, shit goes sideways: hence - conman.

    You're sucking the dick of his dogma,while complaining about people preferring reality to bullshit. Grow the fuck up, use that wilted brain you supposedly have in your head, and clean the bullshit out of your eyes.

    --
    Fascism: An authoritarian and nationalistic right-wing system of government and social organization. See also: NAZI's
  18. Re:Science Isn't a Religion by RockDoctor · · Score: 2
    What was the title of Einsten's SR paper?

    Oh yes, ""Zur Elektrodynamik bewegter KÃrper" (in English, "On the Electrodynamics of Moving Bodies", in which he refers extensively to Maxwell's work and the asymmetries "which do not appear to be inherent in the phenomena" (Perrett and Jeffery's translation of 1923). Einstein cited his sources perfectly adequately in the form of the time, even if subsequent writers haven't been so careful in their commentary on his work.

    --
    Birds are not dinosaur descendants;birds are dinosaurs, for all useful meanings of "birds", "are" and "dinosaurs"
  19. Re:Riled up and not a kook. by RockDoctor · · Score: 1
    Because the "ready understanding" that you seek is based on your experiences at low velocities (far, far less than the speed of light). Your understanding may be al that you have, but if that is the case then you have no real choice but to work through the maths.

    Of some relevance - at around the time that Maxwell was generating his work on electrodynamics, the problems of travelling faster than the transmission speed of longitudinal waves in a medium - sound wave in air or water - were also starting to become clear as ships started digging into their own wakes and bullets started to travel supersonically. When peculiar things started to happen. The analogy is far from perfect, but it's about as close as you're going to get to a car analogy.

    Is that "supersonic car" thing still over-budget, behind schedule, undelivered, or all of the above?

    --
    Birds are not dinosaur descendants;birds are dinosaurs, for all useful meanings of "birds", "are" and "dinosaurs"
  20. Or determine the elemental composition of bodies. by technosaurus · · Score: 1

    It would be possible to calculate the reflected/refracted high energy pulse trajectories and when each known space body's signature would make it to earth. Given sensitive enough equipment, we could use the energy spectrum distribution to figure out what elements are in each one. As a side experiment we would just note how far off from the calculated time and duration the signals arrive... (this reminds me of a similar thing with Mercury, but on a much larger scale).

  21. Same question as everyone else by Brett+Buck · · Score: 1

    Uh, what? Whick kooks have "proven" that it's false? And why is anyone paying any attention to them, even to debunk it? There's something very big missing from TFS (and the TFA, which I uncharacteristically read).

  22. Re:Riled up and not a kook. by tinkerton · · Score: 1

    Actually the problem you describe was raised by a a few experiments in the second half of the 19th century which showed that the speed of light did not change if you moved towards or away from the source. Then Lorentz came up with a mathematical formula which allowed light opposite directions still equal to c and not 2c. But it was difficult to give meaning to it. Poincare went quite far in making a coherent 'traditional' model while Einstein made a revolutionary model, even if a lot of the math was the same. The concepts were different.
    So the first explanation of your problem was given in 1892 but the first decent explanation was given in 1905.

  23. Re:Riled up and not a kook. by Potor · · Score: 1

    BRAVO!!

  24. Re:Vectors are pure math by jd · · Score: 1

    Wouldn't work.

    Time and space don't exist, and even spacetime is just an emergent phenomenon.

    You can't eliminate the terms, even if you hide them inside other terms.

    --
    It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
  25. When idiots revel in ignorance... by Martin+S. · · Score: 1

    When idiots revel in ignorance, what is left?

    It is increasingly common to hear people spouting nonsensical pseudo science, or phrases such as "I'm entitled to my opinion" that flys in the face of well proven science, Flat Earth, water powered cars, creationism and such nonsense is common place.

    When somebody will not listen to reason arguments, actual facts, resort to abuse, murder and even terrorism. They are kooks, idiots and morons. If that accurate description offends then change, learn the scientific method, learn the facts and stop whinging over an accurate description of your failure.

    Frankly we've had enough of it.

    1. Re:When idiots revel in ignorance... by DNS-and-BIND · · Score: 1

      There is no objective truth, only the powerful trying to dominate us with their version of events. Go read Foucault.

      --
      Shutting down free speech with violence isn't fighting fascism. It IS fascism!
  26. Re: Wait, in all *NON*-accelerating reference fram by SqueakyMouse · · Score: 1

    Presumably they're referring to the postulates of special relativity but instead of saying 'inertial' they've said 'non-accelerating'.

  27. Re: Wait, in all *NON*-accelerating reference fram by mark-t · · Score: 1

    My point is that it was my understanding that the speed of light is constant, period. and bringing up any notions of frames of reference is superfluous at best, outright misleading at worst, because it suggests that two different frames of reference could measure two different speeds for light, which isn't true.

    --
    File under 'M' for 'Manic ranting'
  28. Re: Wait, in all *NON*-accelerating reference fram by SqueakyMouse · · Score: 1

    We assume as little as possible to deduce as much as possible. This is the general principle we follow. In special relativity, Einstein started by assuming the velocity of light, and the laws of physics generally, are the same in all inertial reference frames. At this point, he is not trying to produce an exhaustive list of when it is OK to say the speed of light is the constant 'c'. He wants to make the absolute minimum of assumptions to make his conclusions.

    So can we say the speed of light is absolute? Here are some links: