The discussion centers on the recent findings regarding "quasar clocks," which indicate that time appeared to run approximately five times slower shortly after the Big Bang. This phenomenon is attributed to the periodic variation in luminosity of certain quasars, explained by the special relativistic time dilation effect due to spatial expansion. Participants emphasize that this does not imply that time itself was slower, but rather reflects the expected behavior of objects at high redshift. The conversation also critiques the interpretation of these findings in popular science articles.
PREREQUISITESAstronomers, physicists, and science communicators interested in the implications of quasar research and the nature of time in cosmology.
Please always post links to your references when starting a new thread in the technical forums. Thank you.hkyriazi said:Regarding the new "quasar clock" data showing that time ran more slowly (~5-fold) shortly after the Big Bang: is it all based on the periodic variation in luminosity at various wavelengths of some quasars (and presumably explained by the special relativistic time dilation effect from "spatial expansion")?
I assume the researchers noticed that quasars of a certain type (which have luminosity variations of a certain period) have their luminosity vary 5-fold slower than quasars much closer to us.Vanadium 50 said:What does it even mean for a clock to run slower in the past? How do you compare them?
Here's a link to a description of the new findings:berkeman said:Please always post links to your references when starting a new thread in the technical forums. Thank you.
Yes. And this is exactly what is expected for objects at that redshift. It does not mean time was actually "running slower" back then. It is, as you propose in your OP, the same kind of time dilation as we would see in SR for objects with the same redshift.hkyriazi said:I assume the researchers noticed that quasars of a certain type (which have luminosity variations of a certain period) have their luminosity vary 5-fold slower than quasars much closer to us.
Unfortunately this is typical of such articles, even in Science News, where the writers should know better.Vanadium 50 said:I don't know what paper the Science News authors read, but it sure doesn't sound like the one they referenced.
You use standard candles, if available. Kinda hard to do with quasars unambiguously, but the authors make an effort.Vanadium 50 said:Again I ask, "What does it even mean for a clock to run slower in the past? How do you compare them?"
Yes, fair point. And given that that thread and this one both give sufficient responses to the OP's question, this thread is now closed.Bandersnatch said:It hasn't even been two months since the last thread on this.