Quasar 'Clocks' Show the Universe Was Five Times Slower Soon After the Big Bang (phys.org) 57
Scientists have achieved a breakthrough by observing the early universe in extreme slow motion, confirming Einstein's theory of an expanding universe. The research is published in Nature Astronomy. Phys.Org reports: Einstein's general theory of relativity means that we should observe the distant -- and hence ancient -- universe running much slower than the present day. However, peering back that far in time has proven elusive. Scientists have now cracked that mystery by using quasars as "clocks." "Looking back to a time when the universe was just over a billion years old, we see time appearing to flow five times slower," said lead author of the study, Professor Geraint Lewis from the School of Physics and Sydney Institute for Astronomy at the University of Sydney. "If you were there, in this infant universe, one second would seem like one second -- but from our position, more than 12 billion years into the future, that early time appears to drag."
Professor Lewis and his collaborator, Dr. Brendon Brewer from the University of Auckland, used observed data from nearly 200 quasars -- hyperactive supermassive black holes at the centers of early galaxies -- to analyze this time dilation. Previously, astronomers have confirmed this slow-motion universe back to about half the age of the universe using supernovae -- massive exploding stars -- as "standard clocks." But while supernovae are exceedingly bright, they are difficult to observe at the immense distances needed to peer into the early universe. By observing quasars, this time horizon has been rolled back to just a tenth the age of the universe, confirming that the universe appears to speed up as it ages.
Professor Lewis worked with astro-statistician Dr. Brewer to examine details of 190 quasars observed over two decades. Combining the observations taken at different colors (or wavelengths) -- green light, red light and into the infrared -- they were able to standardize the "ticking" of each quasar. Through the application of Bayesian analysis, they found the expansion of the universe imprinted on each quasar's ticking. "With these exquisite data, we were able to chart the tick of the quasar clocks, revealing the influence of expanding space," Professor Lewis said. These results further confirm Einstein's picture of an expanding universe but contrast earlier studies that had failed to identify the time dilation of distant quasars.
Professor Lewis and his collaborator, Dr. Brendon Brewer from the University of Auckland, used observed data from nearly 200 quasars -- hyperactive supermassive black holes at the centers of early galaxies -- to analyze this time dilation. Previously, astronomers have confirmed this slow-motion universe back to about half the age of the universe using supernovae -- massive exploding stars -- as "standard clocks." But while supernovae are exceedingly bright, they are difficult to observe at the immense distances needed to peer into the early universe. By observing quasars, this time horizon has been rolled back to just a tenth the age of the universe, confirming that the universe appears to speed up as it ages.
Professor Lewis worked with astro-statistician Dr. Brewer to examine details of 190 quasars observed over two decades. Combining the observations taken at different colors (or wavelengths) -- green light, red light and into the infrared -- they were able to standardize the "ticking" of each quasar. Through the application of Bayesian analysis, they found the expansion of the universe imprinted on each quasar's ticking. "With these exquisite data, we were able to chart the tick of the quasar clocks, revealing the influence of expanding space," Professor Lewis said. These results further confirm Einstein's picture of an expanding universe but contrast earlier studies that had failed to identify the time dilation of distant quasars.
Quasars? (Score:1, Funny)
I thought they were called 2SLGBTQuasars now!
Re: Quasars? (Score:2)
What a smart take! I learned something valuable today.
This makes sense. (Score:1)
Those wacky antics of Sheldon and the gang are so funny, you just can't help but get smarter and faster. Of course the outside world would then seem slow.
When based on where (Score:5, Interesting)
Big Bang Is Time Variation (Score:2)
Time is variable anyway.
The big bang is probably an exponential variation of time, more than an explosion (whatever the reason of the variation)
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Time is relative indeed.
I've calculated, and confirmed, that it is now Independence Day in the USA.
Only quite early in the morning, but it's July 4th here as well (evening.)
Let me be the among the first to wish the USA-ians here a happy July 4.
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WHAT?? I couldn't hear you, too many firecrackers going off.
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Time is relative indeed.
I Agree. When relatives come by for a visit it always seems like they don't move on fast enough.
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>> When relatives come by for a visit it always seems like they don't move on fast enough.
That is the inverted concept: "Relatives is time"
Re: When based on where (Score:4, Informative)
We know the CMB to have traversed cyanogen clouds when it was only half its current age, cos only at the double frequency the CMB was at back then, it could have excited these CN molecules in the way it did.
And there's plenty other examples that demonstrate our understanding of redshift and "how stuff looks to other stuff" back then. The physics of expansion is very well understood, and all fits very nicely into Lambda-CDM.
The issues these days are discussing 2-3% margins of how fast that expansion happened as a function of time.
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for a photon travelling at the speed of, well, photons, there is no time. hence there isn't distance either.
it's us observing the path of photons who experiment the illusion of time. given the distribution of mass in galaxies, that map would typically be a strong gradient starting at the center (where black holes hang out) but quickly fading out towards the edges. so just like a blanket decorated with swirls. again, this is all about perception, no area is actually "ahead" and all matter in the universe is
Its just the way we are observing it.. (Score:3, Informative)
Time wasn't slower back then, but we are seeing photons that are red-shifted to hell because of the expansion of the universe.
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Yeah, but by a factor of five!? That's bloody impressive dilation!
If the universe appears that distorted at great distances then can't a small inaccuracy in our understanding of this distortion explain dark energy?
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Yes, it's a redshift of 5 (or 6, I can't remember). We have measured redshifts up to over 10, possibly over 11 (I haven't done a survey of "the literature" today).
Surprisingly, this factor of 1930s cosmology has been taken into account in 1990s, 2000s, 2010s and 2020s cosmological interpretations
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What makes you say times wasn't slower back when the universe was denser.
Did you not understand the story or am I misreading it?
Redshift is due to expansion and not anything time related.
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Which thing is more surreal: time going slower, or the universe inflating? Both concepts are equally mind-bending to me.
No, Real Physical Effect (Score:4, Informative)
Time wasn't slower back then, but we are seeing photons that are red-shifted...
It's more than just a trick of the light it is a real, physical effect. Compared to our passage of time the passage of time in the universe is slower the further away you look. If you had a light that was flashing once a second a great distance away to us it would be flashing much more slowly. This is not just an optical trick. Indeed, the reason the photons are red-shifted is that, relative to us, time was passing more slowly for whatever emitted them and so it emitted photons with a lower frequency.
Indeed, due to the accelerating expansion of the universe the distant universe will gradually get dimmer and more red shifted as well as becoming slower and slower in time until its faded image is frozen in time - it's exactly the same thing you would observe for an object falling into a black hole if it were not ripped apart by tidal forces.
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This. A good visualization is to imagine recording audio on a strip of rubber. Presumably you would use an optical reader to play it back. Now stretch the recording to double it's length but don't change the speed of the playback head.
Given that the universe is still expanding, the further back in time the event is, the more it gets stretched.
New early-universe clock (Score:4, Insightful)
This is excellent news. As the article says, our other measures of time are redshift and SN1a's time stretching at those high redshifts.
To establish and have a new independent type of clock in the distant, young universe offers great opportunities for a variety of reasons, and can probably give new insights to the current Hubble tension.
I'm looking forward to more measurements and integration of this new clock into existing theories and issues!!
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If time was 1/5th speed (Score:3)
Doesn't that mean the expansion was running at 1/5th the speed we thought too? Unless its somehow outside time. Either way, doesn't it rather mess up any calculations of how the early universe evolved?
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True ... but that's not what the research actually says. Phys.org is pretty much the Daily Fail of science reporting: they get things wrong with a monotony that makes you wonder if it's on purpose.
From the summary of the research paper: "observations of the distant cosmos should be time dilated and appear to run slower than events in the local universe.". Appear is the key word here. Time did not run any slower then than now. It's just that when we observe the light that has travelled across the universe fo
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No, it only appears that way to us because of the speed difference. It tells us how fast those quasars were travelling away from us. I didn't know it was such a large factor though.
Basically, there won't be much that is faster that hasn't already fallen outside the visible universe.
It seems to me that gravity from beyond the visible universe will be indirectly detectable by deducing it's far-reaching motion effects into our visibly most distant objects. Maybe that's an explanation for Dark Energy.
Bah, humbug! (Score:5, Funny)
Young universes always think that they have all the time in the world, us older universes know that time flies.
If only (Score:2)
The men in the early universe would help with more of the chores and checking for all the doors being locked, the stove and oven off and the toilet not running before leaving the house, time would run more quickly.
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Or, as Roger Waters put it ...
"Every year is getting shorter / Never seem to find the time"
What's really alarming is that it was 50 years ago that Dark Side of the Moon was released - and to this old fogey it just seems like last year that I was listening to it for the first time as a student!
Now THAT is time dilation!!
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Let's PARTY like it's 1999,000,000. BCE.
Acceleration and time dilation (Score:2, Interesting)
For some reason I have this intuition that time dilation only occurs after an object has experienced acceleration. Also, I have this more reasonable intuition that objects accelerating apart due to the expansion of the universe (Hubble's law) do not experience any acceleration. So, these two combined would mean that if we look back at highly red-shifted objects that move away from us at relativistic speeds, we should find that there isn't any time dilation.
Also, let's do a thought experiment:
H
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TFA and comments (yours included) remind me of the old Slashdot days. I guess congrats to BeauHD for that one. I hope the trend will continue.
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Just like me after 12 tequila shots (Score:2)
Not only time seems to get distorted but also space itseld seems to get warped in every direction.
Time cannot be slower (Score:3)
That is just nonsense. Time has no speed. All that can happen is that matter and energy behave differently on the time-axis.
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Perhaps that's true from a single point of reference. But when you compare the passage of time between two places, there certainly can be differences. We see this in a very practical way in the GPS satellite system. https://www.astronomy.ohio-sta... [ohio-state.edu]
Motion itself is relative. With only one point of reference, that point is "motionless." The only way to consider something to be "moving" is compared to another object.
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"Time running slower" is an absolute statement. And that does not make any sense. Sure, if you have two things happen "simultaneously" (which is a questionable concept by relativity), one can have time working faster than the other. But that is not the situation from the story.
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The word "slower" literally compares two things. The words "slower" and "faster" have no meaning unless you are comparing two or more things.
The story asserts that time was "slower" long ago. This again compares two things: observations of quasars long ago, and observations of more recent quasars.
These comparisons are by definition relative, not absolute.
It's all relative (Score:4, Interesting)
That is just nonsense. Time has no speed.
No, but it does have a direction and when we look at things a long distance away in the universe their direction of time is at an angle to our direction of time. Hence, when one second passes for us we only see the component of that second for the distance object which is parallel to our direction of time. Thus the passage of time appears slowed, relative to us, for the distant object.
It's perhaps easier to think about the special relativistic case of a train going by you at close to the speed of light. If you measured it the train would be shorter because part of its physical length is pointing along your direction of time. This also means that if, in the train's frame of reference, it had two synchronized clocks at each end of it, you would see different times on those clocks because part of its time direction is pointing along your direction of space. This would also mean that a flashing light on the train would appear to be flashing more slowly for you than it would for someone on the train.
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I am just objecting to the dumbing-down expressed in "time running slower".
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How would you rephrase it in a way that carries the idea forward in an understandable manner while only slightly sacrificing accuracy? "Close enough" without being impenetrable is how you communicate with the layman.
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I am just objecting to the dumbing-down expressed in "time running slower".
Well, technically time is running slower from our point of view. The only dumbing down they did was to omit saying that it does depend on looking at it from our frame of reference. I'm usually pretty sensitive to dumbing physics down but even I would tend to forgive them that omission here because otherwise, they would have to get across the concept that if you were in either location time would pass normally for you and it's only when you look at the other location that time is actually passing more slowl
Re:Time cannot be slower (Score:4, Interesting)
Of course it has a speed, as the joke goes, "we are all traveling at the rate of 1s/1s into the future (given we all more or less have the same point of reference)
When you factor in relativity, it varies... Einstein's famous twin thought experiment posits that given 2 twins, one traveling at the speed of light going on a ride across the galaxy & the other at a standstill will experience time speeds at different orders of magnitude. On a more pragmatic scale, differences between clocks at different altitudes, including required adjustments for GPS have demonstrated that numerous times.
Some have postulated that antimatter universes with anti-planets/stars/galaxies... time could even go the other way, ie negative. Feynman/Wheeler have even postulated the universe is made of a single electron going back and forth in time (Personally not a big fan of that idea but who am I to argue with Feynman :p )
You don't even have to use 2 different time references/observers... Arguably, Time is a positional element like any other dimension. As one speeds up/slows down and other matter goes in and out of focus, it affects time relatively. Sure, you can ignore it locally, but arguably the same could be said of altitude... in your daily life it doesn't really matter when you go from home to work, to the supermarket.... but that doesn't mean altitude does not exist
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While true, that is meaningless. Time _always_ runs as 1s/1s. i.e. 1 (no unit) in any place.
I am aware of these theoretical models where time could run backwards, but let's face it, they are not more than a mathematical trick. They are meaningless because without working causality you cannot have an observer in there. Sure, mathematical tricks are useful, but they do not explain the universe, they merely make things easier to model. Confusion between model and reality is a curse of our times and many people
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"While true, that is meaningless. Time _always_ runs as 1s/1s. i.e. 1 (no unit) in any place... Obviously that flies right over most people's heads..."
It's kind of funny that they said it was a joke, and that it still flew right over your head. :)
Pity, I am not a charlatan ... (Score:2, Flamebait)
Does this explain dark matter? (Score:1)
Unlike normal matter, dark matter does not interact with the electromagnetic force. This means it does not absorb, reflect or emit light, making it extremely hard to spot. In fact, researchers have been able to infer the existence of dark matter only from the gravitational effect it seems to have on visible matter, depending on the distance from the center of a galaxy.
Arxiv (Score:4, Informative)
Einsteins theory (Score:3)
Einstein's theory of an expanding universe? Einstein proposed no such theory. In fact, I believe he thought it unlikely. However, the theory he did propose is useful in the context of an expanding universe. Journalists.
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Relative Time (Score:1)
This is objectively true. (Score:2)
I can observe it directly. The older I get, the faster the years go by.
Old Age (Score:2)
"the universe appears to speed up as it ages": Yeah, life's like that. When I was young, summer lasted 3 months, now it only lasts 90 days.
I don't know why they need to do all that work... (Score:2)
I can say that time definitely goes quicker now than when I was young, and while that is anecdotal, it does appear to be pretty much universal among human observers.