How old can radiocarbon dating go

Towards us only privileged frame problems or toward some other body with a different relativistic velocity in another direction? How can it have different elongations of the constants towards different bodies? Physics major, but in the end, I don't think this works. Or, if it does, it will take the next Einstein to explain it. I suppose this is only tangentially related, but it's a question I've been thinking about for a while now, and I don't think it's worth its own thread. I think the place to look for evidence for that the cosmic background radiation is differentiated in some way.

But, while space is largely empty, not all of it is. There's patches where it isn't so empty, just by sheer chance and volume of the universe. I think you also need to play Einstein and create some equations. While they are hard to detect precisely because they are so energetic, cosmic rays that come through the sun versus from outside the solar system that is, a place where no planets are, especially Jupiter should show, on whatever equations you posit, some sort of difference.

Or, if that creates problems due to the known issues around photons and gravity, some other near-solar incident angle that's far enough away to create the problem in an easily measured way. Versus, of course, nowhere near the sun.

Carbon Dating |

Maybe X Rays or other wavelengths would work as well. Gravitational lenses may be useful here although in this case, it would be measuring only "half" of the lensing versus something a bit "farther to the left". I suspect we'd know about it if that sort of thing was true. Astronomers do look in pretty much every direction and pretty much every wavelength we can even occasionally detect. Unless everyone was asleep possible, I suppose -- we don't always look for what we don't expect , then there'd already be people talking about the problem, perhaps trying to attribute it to gravity which is an issue, even for photons or something of the sort.

Originally posted by Control Group: If that were the case, we'd see lensing effects dramatically different than what we do see. Observable gravitational lensing pretty much agrees with relativity. You would need to give mass some kind of property that changes c. Let's say we do. Gravitational lensing is nothing like how we observe it. If c is faster away from the immediate vicinity of mass, we see less lensing. If c is slower away from the immediate vicinity of mass, we see more lensing. Objects do not follow the laws of motion anymore. We see objects either ahead if faster c or behind if slower c where they should be after accounting for the constant speed of light.

General Relativity doesn't work, ever, for anything. GR is based entirely around the immutable assertion of c being constant in all frames of reference. If that's not true, GR doesn't work. Doppler shifting goes crazy. If light slows down it shifts slightly to a higher frequency shorter wavelength to maintain the amount of energy it has. This is mandated by thermodynamics.

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If light speeds up, it shifts to a longer wavelength. The energy in the velocity as light has momentum has to come from somewhere or go to somewhere. That somewhere is in the electromagnetic field of the photon. We don't see any of that. Black holes would behave VERY differently. When slowed or accelerated, the lines added would be shifted. Light magically doubles in speed away from any mass.

We detect light from a distant galaxy cluster carrying the absorption line at We detect the hydrogen line shifted far into UV, yet the rest of the spectrum is redshifted from the galaxy cluster. To date older objects, you need to use different radioisotopes. For dating stuff that's millions of years old, you use K and Ar. As Hat and the others have explained far better than I ever could, decay rates can't have changed appreciably over the history of the universe, otherwise the very nature of matter would have changed in that time, which would be noticeable as we look farther out.

Electron capture can affect the decay rates of certain isotopes appreciably IINM, but that's not a change in the "constant" behind radioactive decay. They've just announced a big improvement in the precision of argon-argon dating. A physicist acquaintance corrected me on this about 35 years ago, as will be evident shortly , saying it's true for Special Relativity, but not GR. The two principles of GR are equivalence and relativity. Relativity is that the laws of physics are immutable over space and time.

You mean like this? It's not definite yet, but it's starting to seem likely that the fine structure constant is not, in fact, constant and possibly as a result, and I can't emphasize the word possibly strongly enough, the speed of light is not constant either. Now the variations aren't large enough on the relevant time scale to effect any radiological dating systems we currently use.

Still, the assumption that the physical "constants" of the universe have always been that way is just that, an assumption, and one that is starting to look less likely to be true. Originally posted by shread: You may have misunderstood your physicist friend. GR expands the scope of what reference frames are valid, but still requires the speed of light to be invariant between valid reference frames. Essentially reference frames that are in free fall are valid. The equivalence principle you mentioned is meant to generalize special relativity to reference frames undergoing gravitational acceleration.

Carbon dating, rate of decay, how far can we go? Ars Legatus Legionis et Subscriptor. Ars Tribunus Angusticlavius et Subscriptor.

Carbon Dating

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Researchers could then disregard the date and try other methods of dating the object. Queen's University paleoclimatologist Paula Reimer points out that measuring Carbon will often not be necessary, since archaeologists can usually use the sedimentary layer in which an object was found to double-check its age. Subscribe or Give a Gift. Brazil Dissolves Its Culture Ministry. The Plot to Kill George Washington. Science Age of Humans.

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Radiocarbon dating

In this process, nitrogen 7 protons and 7 neutrons gains a neutron and loses a proton, producing carbon 6 protons and 8 neutrons. The proportion of carbon to carbon in the atmosphere therefore remains relatively stable at about 1. One of the implied assumptions in radiocarbon dating is that levels of atmospheric carbon have remained constant over time.

This turns out not to be exactly true, and so there is an inherent error between a raw "radiocarbon date" and the true calendar date. To correct for this, scientists have compared radiocarbon dates from objects who's age is known by other means, such as artifacts from Egyptian tombs, and growth rings from ancient trees. In this way, calibration tables have been developed that eliminate the discrepancy. Despite its usefulness, radiocarbon dating has a number of limitations. First, the older the object, the less carbon there is to measure.

Radiocarbon dating is therefore limited to objects that are younger than 50, to 60, years or so.