Slashdot Mirror
Can We Test the Speed of Light Using 'Lensing' from Supernovae? (arxiv.org)
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.
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.
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?
https://www.wired.com/2011/05/0525arthur-c-clarke-proposes-geostationary-satellites/
https://motherboard.vice.com/en_us/article/3ked4w/scientists-find-super-earth-in-star-system-from-star-trek
L. O. L.
Am I the one?
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.
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?"
It is childish to resort to name calling when you can't prove your own position.
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'
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.
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
http://www.khouse.org/articles/1999/225/
Stop acting like a bunch of zealous retards, you're just as bad as the flat earther's with this institutional bullshit. Science will never be settled, and there's a whole fuckload of room for interpretation because the scientific method is subjective as fuck in the hypothesis forming sections. If you don't ask the right questions you don't get the right answers, if you don't look at the right things you don't draw the right conclusions, etc.
There were nearly 100 years where people thought Humans had 48 chromosomes instead of 46 - NONE of that was bad science, ALL of the results were perfectly correct, nobody thought to consider that maybe males were lacking a chromosome instead of having two X's and a Y so the experimental designs were all just a bit off.
Darwin's original theory of evolution has outright been overthrown at this point (not at all to suggest creationists are right,) and supplanted with modifications to that theory.
Now the really fucky part here: relativity (as in all that shit Einstein "came up with") was lifted from 3 scientists: Minkowski, Poincare, and Lorentz - not a single new idea was included in general or special relativity, not one. Interestingly, all the math for relativity was lifted from Lorentz and Minkowski - the vector calculus stuff stemming from Heaviside's [incorrect] simplification of Maxwell's original quaternion-form equations. What's the point of bringing that up? You don't need relativity to describe anything attributed to relativity - it's ALL just electrodynamics described precisely as it was centuries prior to Einstein - every single thing relativity predicts electrodynamics already predicted, without exception, because they're the same fucking equations. But wait, it gets better: remember that part where Heaviside decided to rejigger the equations - well, turns out he was sloppy about it and dropped all the scalar components - the things which tie gravity in, go figure.
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.
I accept that the relativistic speed of light is science fact; within the bounds of scientific error as my old school physics teacher would continuously say.
However what riles me up, is physicists seem unable or unwilling to explain away the obvious paradox in terms that can be readily understood, for example.
Why are two beams of light travelling opposite directions still equal to c and not 2c.
Quite ironic how you invoke him as a guru like authority after you've stated this as the exact problem of science.
Then challenge his findings. This is easy. You probably learned it in high school. Ad Hominem attacks just undermine your position. Challenge the data. Either his data is correct, or it isn't. That's how this is supposed to work.
So what is his data?
Rupert Sheldrake hasn't done any real science in 30 years.
Il n'y a pas de Planet B.
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 just about exactly 10 minutes.
TFTFY.
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)
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!!!
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"
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)
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.
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'
....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
A god-squad idiot. Not worth considering any further. I see that his god didn't do anything useful for him, like not preventing him from dieing. So, at a functional level she is at best, useless, if not worse than useless.
Birds are not dinosaur descendants;birds are dinosaurs, for all useful meanings of "birds", "are" and "dinosaurs"
Typical science writer error.
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)
Hold on, while I am a navigator, not a physicist, it seems that the speed of light cannot be constant in an accelerating reference frame, otherwise laser gyroscopes would not work. It certainly seems like they work.
https://en.wikipedia.org/wiki/Sagnac_effect
Maybe you don't understand the Sagnac Effect correctly?
It works on the principles of length contraction. A phenomenon that Hendrik Lorentz and George Francis FitzGerald discovered. It is based upon the assumption that the speed of light is a constant if I understand it correctly.
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).
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).
Chuck is famous for his peanut butter disproof of evilution.
Worth a watch on youtube if you haven't seen it before.
Peanut butter the atheists nightmare.
https://www.youtube.com/watch?...
Is light just bending a tiny bit every time it passes through an atom's gravity well, so it has to zig-zag in a non-vacuum?
Or is the light being absorbed and re-transmitted every time it interacts with an atom?
Why has it to be one or the other. Why can't it be both? I don't see these things being mutually exclusive. Depends on the circumstances which effect is more prominent.
The former is how Maxwell's equations can answer the reduction in the apparent speed of light when it moves through matter, regardless of the wavelengths of the light and or energy levels of the electrons in the matter. Of course this doesn't tell the entire story.
This is where the latter interpretation becomes important and probably prompted Einstein to work on the inner photo electric effect. And it can be an important phenomenon when the wavelengths of the light are within the ballpark of the energy levels of electrons, leading to some more profound interactions between light and matter. But it doesn't answer for example why short wave gamma radiation can experience the very same reduction in apparent velocity as long wave micro wave radiation.
Shut the fuck up you ignorant faggot.
Why not ask a more simple question. Why does light slow down in a medium, and why does it speed up as it exits the medium?
Why is electromagnetic energy not interchangeable with kinetic energy like heat is?
What actually happens when matter becomes light and light becomes matter?
Why does gravity uniquely scale with mass?
Why is C a constant?
If you say the solution to these questions MUST exist only in the subset {what I was taught as physics facts at uni}, and the actual solution lies outside, and you physical model is wrong, then you can never fix the model because you've decided that stuff outside of {what I was taught as physics facts at uni} is wingnut land.
It just represents a closed mind.
There are serious problems with physics. The standard model is laughable. QE has a basic datamining flaw in it (filtering induced correlation), a total lack of understand of one of the most basic forces gravity....
1) FFS, you know that every dipolar force has an organization equivalent ATTRACTION ONLY force, you see it in magnets, you see it in crystals, water, everything with poles that could repel and attract, always organizes itself to attract. Gravity is likely a net organizational dipolar force. This is not wingnut, this is basic deduction screaming at you right in your face. If you don't have a new monopole force, then it will be one of the existing forces in organization dipolar form.
2) But then if its an organization force, and an existing one at that, then mass is a derived property not an actual thing.... well that's good too because light is massless, travels at c which is supposed to be impossible for mass, accelerates which would require energy in the current model, and behaves as though it has mass in pretty much every other way.
3) So it too has some of this 'mass' (which from paragraph 1 is organizational dipole force), which is also good because IT DOES HAVE A DIPOLE FORCE, it does oscillate an electric field.
We chose our math system, we chose our representation of time, all equations are in OUR system of CHOSEN measurements, and vectors are still vectors.
We could have chosen a time parameter t that is unaffected by gravity, and our parameterized equations of physics would then look different, but that is just different equations written a different way. i.e. fixups to equations don't represent any deep understanding, it does not bend time, its just our t parameter was badly chosen at the outset.
Vector math is pure math and is solid AFAIK.
In the dipole model, I ran two separating dipoles at 2c, there is no other matter in this models universe. They bind at the third harmonic (a local maximum). If you separate them at c, then they bind at 2h instead of 3h, and head apart at c. i.e. the stuff that makes up the universe is clumped around zero, c, 2c, etc. rather than c/2, 1.5c. Simply because the binding force is a local maximum at those velocities.
Dipole model (i.e. not physics model, a mathematical model of matter as two dipoles, one force, no mass, physics modelled on force deltas not mass, time as a scaleless tick tick tick independent of everything including gravity.)
I'm doing these simulations now, a photon as a clump of dipoles bound to each other at the first harmonic (=1h). Passing through a perfect slit (simulated, I don't have the computing power to run my pea soup model as a slit wall) with nothing in the middle (perfect vacuum), they don't touch the walls, it travels only through the vacuum. Fake universe is modelled around in the distance, as a low level 2h/0.5h bind.
The photon binds to the edge of the slit as it approaches at 2h and slows down as the sum of the angles of bind subtended increases (think of how the slit wells up in front of the photon as it approaches to understand what I mean), as they pass through the slit, they bind at the half harmonic in the behind/left quadrant, and behind/right quadrant, while at ahead/left quadrant and ahead/right quadrant at 2h. Pushing and pulling at an angle, which sums to a net slowing down.
It's odd, it slows down IN THE VACUUM, and it begins slowing down as it approaches the slit, and speeds up as it exits the slit.
It's a bit odd. You can pass it through simulated 'glass' to understand refraction, and it bends. You can cut away the glass it doesn't travel through and the bend changes as you cut it away.... it isn't the glass it passes through that bends it, it's binding to that ahead and behind at 2h and 0.5h, it's not the glass normal to the direction of travel either, left and right cancels out, it's the stuff ahead/left behind/right ahead/right behind/left that's bending it. It doesn't actually interact with the matter in the simulated glass either, its assumed to be made of zero sized points dipoles which have such a low probability of hitting they never hit in this simulation. It just binds to them depending on their spin.
Odd. And that would make electromagnetic wavelength spin radius not spin frequency. Since dipoles even out their spin frequency, all photons would likely be spinning at the same frequency but with different spin radii. Which means longer wavelength photons occupy more physical space since their spin radius must be bigger.
Or perhaps this is shit and a filter it wrong somewhere or a line of code is buggy.
Typo, 1.5c is correct, c/2 is not (half harmonics are also local maxima, c/3, c/4.....)
i.e. if you add up all the stuff in the universe (including photons) and plot it against velocity relative to us, you'll notice its clumped by velocity at the harmonics. It's not evenly spread out by velocity.
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.
Presumably they're referring to the postulates of special relativity but instead of saying 'inertial' they've said 'non-accelerating'.
Cognitive Dissonance occurs when you look at the universe (or any science really) and do not realize that all of us look through our culture, and knowledge. On an absolute measure none of us can be unbiased.
However we have a charter to examine the world and discover how it works - "The honour of God is to hide a thing, And the honour of kings to search out a matter."
So well documented - reproducible experiments are a necessity to counter the bias of observers, paper reviewers, and publishers.
Constants are - well constant, but can we tell the difference between a constant, and a relatively stable variable?
It would be interesting to compare this model using the case of propagation delay along a length of Coax cable. The phenomenon the parent describes sounds similar to the effect of impedance on propagation velocity.
If the model result is similar to reality in a number of situations it becomes a useful engineering tool. Engineers do not require theoretical correctness, just usefulness, and the boundaries at which a model becomes invalid.
If the boundary limits expand to the entire set of possible cases, the engineering model becomes the functional equivalent of a physics axiom.
"He was among the top 100 Global Thought Leaders for 2013, as ranked by the Duttweiler Institute, Zurich, Switzerland's leading think tank."
Like hell it is. The Gottflieb Duttweiler Institute is a Kook Factory, funded by Chain Stores, and primarily interested in Alternative Economics, Public Relations and Marketing, something they are quite up front about, and you are not.
Oh, and the "British Scientific and Medical Network" doesn't appear to exist outside of its connection to Sheldrake and a couple of other quacks, promoting among other things, Homeopathy.
"His most recent book Science and Spiritual Practices is about rediscovering ways of connecting with the more-than-human world through direct experience". Oh crap, Goethe's Phenomenology again. (Just a recap: Goethe rejected Newton and all succeeding Instrumentalist Science because Goethe was lazy and inept and incapable of reproducing Newton's "Opticks". Oh, and "The Sorrows Of Young Werther" was also crap...) Science is not Perfect, but it is getting better with Time; in other words, Science is, and probably always will be, Incomplete. Something about Godel would be appropriate here, but as the old edifices of Metaphysics are torn down to be replaced with More Complete understandings of how Things really are, the less need we will have for all that Spiritual Practices shit.
Sheldrake is a Kookbiscuit, who attracts other Kookbiscuits, like the dude that stabbed him because he thought Sheldrake was doing Mind Control experiments on him.
You too are a Kookbiscuit, and a disingenuous one at that. I do hope that you are kept away from sharp objects.
I see that you have not read any of Sheldrake's academic or popular works.
He's advocating for science. In particular, he advocates for science in the public interest. That is, science that explores the questions people have about their everyday experiences.
Sheldrake starts with "lot's of people say that ______" and immediately follows that up with "let's use science to evaluate those claims".
You come along and say "Sheldrake is investigating _____? Pseudoscience! Burn him!"
One of those is dogmatic, the other in the spirit of scientific inquiry. Can you guess which one is which?
> Peanut butter the atheists nightmare.
And it goes so perfectly with jelly. It's like they were designed to be together. That could not have happened by chance.
Checkmate, atheists!
Should read "The China polishing team".
As an industrial geologist you are not qualified to diagnose someone as an idiot.
Therefore by your own logic/standards you are one, although I would never diagnose you over the internet.
I suppose you might be able to characterize someone's post as "idiotic" although that is unnecessarily vague, insulting, likely incorrect, and not very useful. If someone is wrong, using poor logic, explaining things badly - you can point those things out. Or ignore. Or state the post is not deserving of your time and rebuttal. Or a million other choices.
Calling someone an idiot may make you feel good and superior, but that is your problem.
> As an industrial geologist you are not qualified to diagnose someone as an idiot.
You can't diagnose such, because "idiot" is not a classified disorder in DSM-V or whatever the latest book-o'-crazy is.
It's like Penn & Teller said on "Bullshit!" - they can call out something as "bullshit" and it's not libel, because it's an opinion and nobody can determine legally what constitutes "bullshit."
If I say you're a liar, that can be proved or disproved. If I say you're an asshole, well... no litmus test for that!
Wow how old are you like 12? I did not post this but it is a report on work by two physicists.
Dr. Joao Magueijo, a Royal Society research fellow at Imperial College, London
Dr. Andreas Albrecht, of the University of California at Davis.
Interesting line
"It wasn't until 1677 that a Danish astronomer named Olaf Roemer announced that the anomalous behavior of the eclipse times of Jupiter's inner moon, Io, could be accounted for by a finite speed of light. It took another half century for that notion to be accepted."
I know which side you would have spent hours insulting.
That is what the equations predict. C will probably remain a constant. But does it have the same value everywere?
Why is c the value we know it to have? Because of the relation to all other natural constants. Are they all really constant, across in space and time? If yes, how do we know?
If the speed of light changed would it even be possible in principle to know? Speed is distance/time. The meter is defined as the length of the path traveled by light in a vacuum in 1/299,792,458 of second. So if the speed of light "changed" then the meter would change accordingly such that the speed of light would remain the same. For that reason I thought scientists were more interested in trying to detect changes in dimensionless constants, such as the Fine Structure Constant. See this PBS Spacetime episode for more details on that if you are interested.
Given the preceding, my question for any physicists out there is then what are these scientists actually trying to measure?
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'
It's been a long time since I studied physics, but if I remember correctly, Einstein started with the assumption that the speed of light is constant in all reference frames, and derived his theory from that.
So far all the experimental data supports relativity, so it's pretty safe to accept the assumption of constant c until some revolutionary observation contradicts it?
Purely from memory here.
There was a very distant supernova, billions of light years away. IIRC, ground detectors received neutrinos, and light of all detectable wavelengths.
There was a gap that separated detection of just a few hours. Scientists were able to show that the time differential was caused by the neutrinos able to escape the bulk of the star immediately while the light took a couple of hours to breach the surface, and that accounted (100%) for the time difference in detection.
I remember this being roughly 10 or more years ago.
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:
I think this is one of those experiments that is meant to validate the constant nature of the speed of light.
Science does this all the time, even with accepted and tested theories. When they can confirm the theory, or test it under unusual circumstances, or increase the accuracy of a measure, they tend to do the experiment. It's one of those situations where the outcome is expected. If the experimental result conforms to General Relativity, it's received as, "No Biggie, General Relativity Confirmed". If the experimental result contradicts, the sh*t really hits the fan.
Then everyone comes out of the woodwork to either challenge the experimental result (most scientists), a few claim they suspected that General Relativity was wrong all along, and a few more attempt to hook the result into a Theory of Everything and how GR still hasn't been reconciled with Quantum Theory.