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Some Observers Perceive the Universe To Be Much Younger Than We Do
StartsWithABang writes: It's been 13.8 billion years since the Big Bang for us, and when we look out at a distant object in the Universe, we're seeing it as it was in the past. Its age — as it appears — is determined only by how long the light took for it to travel from that object to our eyes, but to someone living there, it will also appear that the Universe is 13.8 billion years old. But it is actually possible for an observer living on another planet, star or galaxy to perceive that significantly less time has passed since the Big Bang, so long as they were moving close to the speed of light relative to the CMB. Paradoxically, if they slowed their speed, they'd find that they themselves were very young, but living in a 13.8 billion year-old Universe.
Some Observers Perceive the Universe To Be Much Younger Than We [Who?] Do
Jeb Bush believes the universe to be somewhere between 4 and 5000 years old, so there's alot of diverse and nuanced opinion on this subject.
Instead of using some mythical person to determine that we live in "2015" after his birth, let's use the big bang as a time reference.
Think of all the advantages!
"I'll see you next monday at 8 o'clock *cough* +- 0.059 billion years"
Someone has just discovered relativity and feels pleased as punch.
A better way to put it is that when you are travelling nearly the speed of light, if you look behind you at the place you are heading away from time seems to stand still for it; the light from your old hometown is redshifted. But light that's coming in from in front of you (and thus, the perceived rate of time) is way higher. Time seems to be moving a hundred times faster than normal as you look at an oncoming blueshifted star. Then, the star passes you and all of a sudden it slows down... from your point of view.
So from the point of view of the fast moving observer, time is sped up in front of them, and nearly frozen behind. As they travel they pass galaxies that are growing old very fast, but leave behind them a frozen universe, that is changing imperceptibly slowly.
When they stop... they are not 'surprised' that the universe is old. They watched it grow old in front of them. Nor are they surprised that their home, now billions of light years away, has not changed much (it looks 'young') because behind them time seemed to stop. The perceived universe makes sense from the viewpoint of the traveler. Point being that there is no paradox. What happens to the fast moving universe would look really weird from inside (because of the starbow effect), but they would be used to it. You know... assuming they survived the X-Ray energy sleeting through them from impact with intergalactic matter.
"I will trust Google to 'do no evil' until the founders no longer run it." Hello Alphabet.
when Einstein published the theory of special relativity. /. is a bit behind the times.
Presuming they were able to detect the CMB - which would NOT look the same in all directions - and "correctly" identify it (i.e., presuming that that's what we've done), they would then also be able to calculate their own relative movement, and correct for it. So they'd reach pretty much the same answer that we do.
It's Medium.com spam, what did you expect?
Required reading for internet skeptics
Paradoxically, if they slowed their speed, they'd find that they themselves were very young, but living in a 13.8 billion year-old Universe.
I'm very young (compared to the universe), but I don't see a paradox when comparing myself to the universe's age.
Okay, that's just me playing with words. But there's no paradox anyway.
Paradoxically, if they slowed their speed...
...then they'd presumably be advanced enough to understand special relativity and take account for it in all their calculations.
The twin paradox has been around - and understood - for over a hundred years. What's next on Slashdot? A Starts-With-A-Bang article on how we only ever see one side of the moon?
And what would they be comparing the universe's age to, anwyay? Unless their planet or something on it had provably existed since the beginning of time and they could prove how old it was, I can't seem them getting too far.
And finally, would someone please take away Ethan's exclamation mark key?
systemd is Roko's Basilisk.
Haven't seen one on here for a while - was the guy on vacation?
#DeleteChrome
Let's try to keep them all in once place.
Could a different observer identify the universe as being much older than us, by the same argument?
Also, less seriously, if the rest of the universe is travelling away from us at light speed, but there's nobody on those planets to observe it, is it actually older?
http://www.independent.co.uk/n...
This one do? Okay, that is a fair chunk of Christians covered right there, not sure where the rest stand.
...
the universe is not all the same age. near black holes are younger because of gravitational time dilation. and even this depends on the frame of reference.
now we need to go OSS in diesel cars
Some Christians. I am not really the person to defend people whose only defense against the DSM IV definition of delusion is that they are explicitly exempt from it (because else any religion very much fits the definition perfectly), but it should be said that not all of them are THAT delusional. Only a rather tiny minority, and close to 100% of that minority residing in the USA, actually believes that.
Outside the US, new earth rubbish plays no significant role.
We used to have a Bill of Rights. Now, with the rights gone, all we have left is the bill.
A post of sound and fury, signifying nothing.
He starts out with the Yuval Ne’eman quote about how less people understand relativistic time than believe in horoscopes. Correct, it seems a lot less because as he goes on to demonstrate even someone as enlightened as he himself doesn't understand relativistic time!
Others have pointed out that talking about a galaxy moving a near light speed is purely hypothetical and not particularly interesting or different from other time-bending phenomena such as black holes. But the thing that makes this all completely meaningless (and shows that he doesn't really understand it) is that relativity tells us that there is no universal "now". It's pointless to talk about how old someone at another point in space (whether 100 lightyears or 13 billion light years from us) sees the Universe as being because you're only specifying 3 of his (at least) 4 space time coordinates, assuming the forth one to be "right now", but there is no "now". The "now" is just a convenience we use when the difference is so small as not to matter to us, but when any of the dimensions gets larger you have to specify all of them to say anything meaningful. You could specify the time dimension as a specific amount of time "passed since the big bang" (instead of "now"), but then the title of Ethans little essay becomes its own answer, demonstrating the meaninglessness of the whole exercise (i.e. "is everything that exists 13.8 billion years after the big bang the same age"?)
Sounds to me like an attempt to couch the entire argument in terms of a universal preferred frame of reference, which is the foundation for many, many fallacious arguments relating to relativity.
Man, don't even defend that strawman. The ratio of actual Christian fundamentalists espousing young Earth, to those that use their existence to justify their modern progressive liberalism, is at least one in a thousand.
Here's what I notice: Generally, those fundie Christians (you have to go find them) will keep their ideas to themselves, unless pressed. They've had a persecution complex forever, and now in my old age, I'm having doubts that it is totally unfounded.
On the other hand, the people that seem to have in in for them, 'progressives' I guess, will take every opportunity to loudly proclaim the fundies' ignorance, and stupidity, and mean-spiritedness, and so on. Can't even have a thread on science without the big pile-on.
If I'm forced to take a side, which in itself seems weird to me in a modern society; well, the choice seems clear.
Check it out here:
http://gamelab.mit.edu/games/a...
Man, don't even defend that strawman. The ratio of actual Christian fundamentalists espousing young Earth, to those that use their existence to justify their modern progressive liberalism, is at least one in a thousand.
Here's what I notice: Generally, those fundie Christians (you have to go find them) will keep their ideas to themselves, unless pressed.
psst, trying to bust a strawman with a strawman. Cute
They've had a persecution complex forever, and now in my old age, I'm having doubts that it is totally unfounded.
They also have a surprisingly strong grip on one of the US' main political parties. To the point where when you ask that parties candidates if they say believe in evolution, they'll tend to answer you something like "Well, I'm not a scientist", or "There are controversies.
Back to your premise....
Well, all I have to go on is personal experience. I grew up in a town where fundamentalists held sway. Until the early 70's no stores were allowed to open on Sunday. You want the Sunday paper? You drive to another town, Eventually, they allowed newsstands to open for a couple hours so people could get papers on the way home from church. Eventually it went to normal as they lost their iron grip on the town. That was mainly a nuisance, amusing not to think back on.
School - Mandated sex education was 1 - 1 hour class saying if you have sex before marriage, you'll get VD and die.
No evolution was taught, and can you imagine - anything that might allow someone to divine an age of the universe younger than 6000 years old was not allowed. I made it the entire way through grades 1-12 without hearing the word dinosaur.
Grandparents were fundies Ever wake up in the middle of the night with your grams praying at the foot of your bed, or forced to listen to her rail on about how you are going to go to hell all day on Sunday and an hour or so every day?
My experience of all intrusive and rather scary fundies is in opposition to your apparent shy creatures, only wanting to be alloed to live the lives they choose model.
On the other hand, the people that seem to have in in for them, 'progressives' I guess, will take every opportunity to loudly proclaim the fundies' ignorance, and stupidity, and mean-spiritedness, and so on.
You don't have to be progressive (another nice strawman) to find the fundamentalists quite repulsive. Having been raised among them, ignorance and stupidity, and mean spritedness are not unreasonable assessments of their activities.
Can't even have a thread on science without the big pile-on.
If I'm forced to take a side, which in itself seems weird to me in a modern society; well, the choice seems clear.
That statement isn't completely clear. Does that mean you're aligning yourself with science, or that you're going to be trying to force schools to teach religion in science class, agitate for legislation to ban same sex marriage, declare the US a Christian nation, and tell us all that Darwin was the Devil?
Time to campaign to get the Duggars back on TV.
The shepherds did so well protecting the flock that the sheep no longer believed that wolves existed.
"It's been 13.8 billion years since the Big Bang for us..."
The guide in the science museum showed a graphic representation of the big bang to a bunch of kids with their teacher when one of them asked him how long ago that happened.
The guide replied: Well that was 13,800,000,017 years ago.
The teacher was astonished and asked the guide how he could be so sure about that very exact number.
The guide replied: When I began working here, they told me it happened 13.8 billion years ago and I began working here 17 years ago.
Time is relative.
Unfortunately I'm not at all sure that he actually got it right though because I think he has forgotten about General Relativity. He treats the entire universe as if it were a single object at rest in the CMB frame. However it isn't: it consists of many constituent components all with their own individual rest frames.
As we look further away from us galaxies are travelling closer and closer to the speed of light and so appear "slowed down" by time dilation due to the expansion of space itself which you need general relativity to account for. All that travelling close to the speed of light should do is shift which galaxies are slowed by time dilation and which are in almost the same frame and so not slowed. Hence you would see effectively exactly what we see now but it will be different galaxies which are in view because you are in a different inertial frame.
Hence I am not at all sure that he got it right. Certainly I'd like to hear it from a cosmologist before I believe it since GR is far more complex than SR and it is easy to get stung applying SR to a situation which requires GR and hence my cautiousness about whether he is wrong since I'm not a cosmologist. This would far from the first thing that he has got wrong...but it would be the first truly spectacular failure.
No they don't. Your belief is far more ridiculous than that of most Christian's.
and we are in it. We know that gravity slows time, and we know that the distribution of matter in the universe is into filaments and the surfaces of 'bubbles'. In those places, like where we live, gravity slows time down unlike 'in' the bubbles and other voids between the filaments. So how much slower are we perceiving time with respect to 'universal' time?
There is a dipole anisotropy observed in the CMB as observed from our local observations, which can be attributed to our local motion in reference to the CMB. I'll quote/steal the paragraph from Wikipedia (https://en.wikipedia.org/wiki/Cosmic_microwave_background#CMBR_dipole_anisotropy),
"From the CMB data it is seen that our local group of galaxies (the galactic cluster that includes the Solar System's Milky Way Galaxy) appears to be moving at 627±22 km/s relative to the reference frame of the CMB (also called the CMB rest frame, or the frame of reference in which there is no motion through the CMB) in the direction of galactic longitude l = 276±3, b = 30±3. This motion results in an anisotropy of the data (CMB appearing slightly warmer in the direction of movement than in the opposite direction). From a theoretical point of view, the existence of a CMB rest frame breaks Lorentz invariance even in empty space far away from any galaxy. The standard interpretation of this temperature variation is a simple velocity red shift and blue shift due to motion relative to the CMB, but alternative cosmological models can explain some fraction of the observed dipole temperature distribution in the CMB".
I haven't done any more reading on this but it does appear that there may be something to a preferred rest frame in the CMB.
I'm a creationist, a Christian. I believe the universe is somewhere around 13.5 billion years old. A true reading of Jewish and Christian bibles will reveal this to be the truth. I'm not here to debate the existence of God, rather to say that as a Christian, God is the one who gave us science. Judaism/Christianity and science are partners not or/or.
... moving close to the speed of light relative to the CMB...
What does this mean? Isn't the CMB a kind of standing wave that fills the universe? a bunch of photons going off in all directions?
Here is my take. I am not a cosmologist or astrophysicist. I know about as much math as the fetal Einstein.
The universe began in a singularity with maximum separation distance of zero, and no meaningful earlier time. Next thing we know it is a dense space full of energy with the maximum separation (or the measurement thereof) increasing. It is like a plasma, opaque since the world line of any photon is very short.
Eventually the expansion lowers the energy density so that photons begin to have noticeable world lines. Let there be dark. The universe has become transparent, life and baryons and such can happen. And we get protons and galaxies and astronomers, who detect the CMB.
But the universe is not dark/transparent. At CMB frequencies and below the universe is still hot and opaque. ...everywhere.
You may now choke on your coffee and tear my karma to shreds.
--
If you believe everything you read, you are a fool. Believe me.
Creationists need to produce an alien witness who is from a world with a very different time dilation than ours
And this alien might have gone by the name Joshua while on earth, which the Greeks misheard as "Jesus".
Some Christians. I am not really the person to defend people whose only defense against the DSM IV definition of delusion is that they are explicitly exempt from it (because else any religion very much fits the definition perfectly), but it should be said that not all of them are THAT delusional. Only a rather tiny minority, and close to 100% of that minority residing in the USA, actually believes that.
That definition was changed in DSM-V. Significantly. The delusion no longer has to be demonstrably false. Now, they can believe that it is true, and still be diagnosed with a mental illness, if their behavior warrants it. But it also means that it is up to the clinician making the diagnosis. Parents who sincerely think praying is going to heal their child should not be penalized for holding that belief if the clinician determines there is no danger to the child. As long as their delusions are doing no harm in the opinion of the clinician, they fit the exemption. But it will be harder to ask for an insanity defense -- they will have to face their crime for what it is if the child dies.
Outside the US, new earth rubbish plays no significant role.
Ahh, yes. But it does play a significant role in the U.S. It is perhaps unlikely, but it is certainly possible, especially if any one of the current GOP candidates for president actually win, that somebody that (emphasis yours) delusional could achieve the highest office in the land. You really, really don't want an American president, a man who can call down a nuclear strike if he thinks it is necessary, to believe the earth is only 6000 years old, and to believe there is an invisible man in the sky telling him to do it... .
You will all be cows in 10 billion years. Practice for it, say MOOOOO!
Table-ized A.I.
Oh, oh. He's on to us. Shut it down!
Have gnu, will travel.
An observer moving faster, but compared to what point?
I don't know about you but I travel through time regularly. In fact, I'm planning on travelling 24 hours today!
Guns don't kill people; Physics kills people! - John Lithgow as Dick Solomon on Third Rock From The Sun
It's like the Truman show. The UN flag is the actual map. There's a top, as well as sides. That's why we can't go to Antarctica: https://en.wikipedia.org/wiki/...
I feel fantastic, and I'm still alive.