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.
Quasar clocks are astronomical objects that emit powerful bursts of energy, known as quasars. They are believed to be powered by supermassive black holes at the center of galaxies. These objects are used as a reference point for measuring time and distance in the universe.
Quasar clocks are used to measure the time it takes for light to travel from the quasar to Earth. By studying the light from quasars, scientists can determine how much time has passed since the light was emitted. This allows us to understand how time has evolved in the universe and how it may have been different in the past.
According to Einstein's theory of relativity, time is relative and can be affected by gravity. As the universe expands, the gravitational pull on objects decreases, causing time to run slower. This means that time may have run slower in the past when the universe was smaller and more compact.
By analyzing the light from quasars, scientists can determine how much time has passed since the light was emitted. This allows us to look back in time and study the conditions of the early universe. Quasar clocks also provide a way to measure the expansion rate of the universe, which can help us understand its history.
While quasar clocks can provide valuable information about the past, they cannot be used to predict the future. This is because the universe is constantly expanding and changing, making it impossible to accurately predict what will happen in the future based on observations of the past.