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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.
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