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First Experimental Evidence That Time Is an Emergent Quantum Phenomenon

Unknown Lamer posted about 5 months ago | from the quantum-machine-elves dept.

Science 530

KentuckyFC writes "One of the great challenges in physics is to unite the theories of quantum mechanics and general relativity. But all attempts to do this all run into the famous 'problem of time' — the resulting equations describe a static universe in which nothing ever happens. In 1983, theoreticians showed how this could be solved if time is an emergent phenomenon based on entanglement, the phenomenon in which two quantum particles share the same existence. An external, god-like observer always sees no difference between these particles compared to an external objective clock. But an observer who measures one of the pair — and so becomes entangled with it--can immediately see how it evolves differently from its partner. So from the outside the universe appears static and unchanging, while objects that are entangled within it experience the maelstrom of change. Now quantum physicists have performed the first experimental test of this idea by measuring the evolution of a pair of entangled photons in two different ways. An external god-like observer sees no difference while an observer who measures one particle and becomes entangled with it does see the change. In other words, the experiment shows how time is an emergent phenomenon based on entanglement, in which case the contradiction between quantum mechanics and general relativity seems to melt away."

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530 comments

Hmm (5, Insightful)

wenchmagnet (745079) | about 5 months ago | (#45211271)

First time I've seen no comments show up a few minutes into a Slashdot story going up.

Are most other people, like me, scratching their heads and trying to wrap their minds around this? :)

Re:Hmm (4, Insightful)

AbbyNormal (216235) | about 5 months ago | (#45211281)

You must be new here.

Re:Hmm (5, Funny)

Cryacin (657549) | about 5 months ago | (#45211353)

You see, the story had not yet been entangled, so to the outside observer, there was no change.

Re:Hmm (5, Funny)

cold fjord (826450) | about 5 months ago | (#45211675)

Dude, most people here have big enough egos as it is without referring to them as "god like," even if you do it indirectly.

Re:Hmm (-1)

Anonymous Coward | about 5 months ago | (#45211367)

The hardest thing about mating with an alligator is not dealing with its bite, but lifting up its tail. I then made a wallet out of its vagina.

-- Crocodile Dundee

Re:Hmm (1)

ObsessiveMathsFreak (773371) | about 5 months ago | (#45211373)

The summary mentions "God" or "Godlike" about three or four times. I think most people have figured out the "twist" in this particular quantum press release -- I mean experiment.

Re:Hmm (1)

bill_mcgonigle (4333) | about 5 months ago | (#45211391)

The aliens had to make us believe in gods so we'd eventually figure out how time works. "It was worth the price." - Darth Albright

Re:Hmm (5, Funny)

msauve (701917) | about 5 months ago | (#45211425)

The headline should be really about the creation of a Godlike observer, which was a prerequisite for this experiment.

Re:Hmm (4, Funny)

dbIII (701233) | about 5 months ago | (#45211513)

The headline should be really about the creation of a Godlike observer, which was a prerequisite for this experiment.

Let's give Mr and Mrs Norris a bit of privacy for that one.

Re:Hmm (0)

Anonymous Coward | about 5 months ago | (#45211567)

The headline should be really about the creation of a Godlike observer, which was a prerequisite for this experiment.

... sorry, what do you want me to observe

Re:Hmm (3, Funny)

Anonymous Coward | about 5 months ago | (#45211379)

Most of them are still trying to figure out the info on the relevant Wikipedia pages, ya know, so as not to sound too stupid when commenting here :-)

Re:Hmm (0)

slashmydots (2189826) | about 5 months ago | (#45211433)

I can't get over how the definition of entanglement means both particles do EXACTLY the same thing. Not one acts differently and the difference is time. Plus, all matter in the entire universe is entangled and the entanglement never fails and we cannot detect the other particle for some reason? That's an awfully big pile of nonsense.

Re:Hmm (0)

Anonymous Coward | about 5 months ago | (#45211557)

how can the entanglement fail if it is static and there is no time? such as the article proposes.

Re:Hmm (4, Insightful)

Anonymous Coward | about 5 months ago | (#45211809)

Plus, all matter in the entire universe is entangled and the entanglement never fails and we cannot detect the other particle for some reason? That's an awfully big pile of nonsense.

"Nonsense" of course meaning "I'm not smart enough to make sense of this."

Re:Hmm (1)

Chrisq (894406) | about 5 months ago | (#45211461)

First time I've seen no comments show up a few minutes into a Slashdot story going up.

Are most other people, like me, scratching their heads and trying to wrap their minds around this? :)

No - time just came to a halt as the emergent digression of entangled pairs was affected by so many observers contemplating the fact.

Re:Hmm (0)

Anonymous Coward | about 5 months ago | (#45211783)

Wait, you're saying we slashdotted quantum mechanics itself?

Re:Hmm (1)

Chrisq (894406) | about 5 months ago | (#45211799)

Wait, you're saying we slashdotted quantum mechanics itself?

yes .... what worries me is what the "God like observer" will make of it!

Re:Hmm (5, Informative)

hodet (620484) | about 5 months ago | (#45211531)

It's because the subject takes time to digest and respond to intelligently. As opposed to the usual "NSA is Monitoring My Brain" headline. It's nice to see this type of article, it's what brought me to slashdot so many years ago. I still come everyday hoping to see more stuff like this.

First Post! (5, Funny)

Fieryphoenix (1161565) | about 5 months ago | (#45211293)

But only from the point of view of an external god-like observer.

Depends on the parser (0)

Anonymous Coward | about 5 months ago | (#45211295)

It's not a 'problem of time' &mdash, it's a 'problem of validation' &mdash.

whoosh over my head (0)

Anonymous Coward | about 5 months ago | (#45211307)

does that mean if one of those fairy tale beings did create everything then he / she / it cant see a thing and nothing ever changes in its creation?

No wonder the faithfull dont get answered

Was this not obvious? (-1)

Anonymous Coward | about 5 months ago | (#45211317)

Was this not obvious to anyone with even a shred of intuition? Shoot up some DMT, fags.

Instead of likening things to rocket science (5, Interesting)

sandytaru (1158959) | about 5 months ago | (#45211347)

We need to start likening things to quantum physics. At this point rocket science is frikkin' easy compared to all this quantum stuff.

Until quantum entangled particles gets harnessed into the faster than light communications they've talked about over the years, no one will really care anyway.

Re:Instead of likening things to rocket science (5, Funny)

MadRocketScientist (792254) | about 5 months ago | (#45211437)

We need to start likening things to quantum physics. At this point rocket science is frikkin' easy compared to all this quantum stuff.

Sheldon Cooper would agree:

Missy: Yup, I’m always bragging to my friends about my brother the rocket scientist.
Sheldon: You tell people I’m a rocket scientist?
Missy: Well yeah.
Sheldon: I’m a theoretical physicist.
Missy: What’s the difference?
Sheldon: What’s the difference?
Missy: Goodbye Shelly.
Sheldon: My God! Why don’t you just tell them I’m a toll taker at the Golden Gate Bridge? Rocket scientist, how humiliating.


On a related note, maybe it's time for me to change my username...

Re:Instead of likening things to rocket science (2)

georgeb (472989) | about 5 months ago | (#45211721)

On a related note, maybe it's time for me to change my username...

Agreed. It's way too ambiguous. Are you a rocket scientist that's mad or are you studying mad rockets?

Re:Instead of likening things to rocket science (-1)

Anonymous Coward | about 5 months ago | (#45211741)

Sheldon Cooper is a fag and everyone that likes that awful retarded show is a fag as well.

I mean no disrespect towards actual homosexual people, I say this as a gay guy that actually likes to suck cock.

The big bang theory is a show of fags, by fags, to fags.

(also, see South Park episode "The F Word")

Re:Instead of likening things to rocket science (2)

Spiked_Three (626260) | about 5 months ago | (#45211823)

I blame KSP.

Seriously, orbit physics is now part of a computer entertainment game.

And yet, US children keep getting dumber on average, WTF?

In other words (1)

Anonymous Coward | about 5 months ago | (#45211349)

The universe is big ball of wibbly wobbly... time-y wimey... stuff.

the discoverer (0)

Anonymous Coward | about 5 months ago | (#45211355)

this is a great discovery for mdash

god-like vs. measuring observer (2)

genji_IT (3404273) | about 5 months ago | (#45211365)

what exactly is the difference?

Re:god-like vs. measuring observer (2)

bill_mcgonigle (4333) | about 5 months ago | (#45211405)

what exactly is the difference?

When people ask me why I'm a theological noncognitivist, I ask them if their God needs to be omniscient and omnipotent in every universe in an infinite multiverse or if it'd be OK if thier God is a pimply-faced youth in another.

Typically, they have no idea what I'm talking about, and probably just assume I'm nuts.

Godlike attributes (1)

Rande (255599) | about 5 months ago | (#45211507)

When they say God must be omniscient, omnipotent and omnibenevolent...I ask 'isn't 2 out of 3 good enough'?
The 3rd is a bit wishywashy anyway. What's benevolent in the opinion of some people won't be in the eyes of others.

Re:Godlike attributes (4, Funny)

Bongo (13261) | about 5 months ago | (#45211709)

He is all those three, plus one more: omnihumorous.

We just haven't got the punchline yet.

Re:god-like vs. measuring observer (5, Interesting)

lxs (131946) | about 5 months ago | (#45211497)

A god-like observer can observe without interacting. Back in reality every observation is an interaction.

Re:god-like vs. measuring observer (0)

Anonymous Coward | about 5 months ago | (#45211767)

Of course. See Fringe, for example. The damn Observers interfered and fucked everything up royally.

Re:god-like vs. measuring observer (1)

cascadingstylesheet (140919) | about 5 months ago | (#45211931)

A god-like observer can observe without interacting. Back in reality every observation is an interaction.

OK ... then what the heck is scientific about speculating about something that by definition either doesn't exist or can't practically participate in the experiment?

Re:god-like vs. measuring observer (1)

Sockatume (732728) | about 5 months ago | (#45211533)

One is used as the model for the underlying behavior, one describes the observations we would make.

What I got from the article: (4, Interesting)

Anonymous Coward | about 5 months ago | (#45211371)

From the outside, the universe looks like a photograph.

I hope we're hanging on a nice wall.

I think... (0)

Skiron (735617) | about 5 months ago | (#45211427)

After reading a lot on this is that sometimes an issue becomes a problem without reason.

Now, time is ONLY a man made measure - a measure between events. Nature/the universe doesn't know what time is nor cares about it. It is only us humans that need to try to explain time dilation and various other 'time issues' to make the maths work. Remove time, and I bet it will balance these equations.

Time cannot run backwards,as there is no such thing as time except in the human brain and the human concept of measuring changes.

Re:I think... (4, Insightful)

dingen (958134) | about 5 months ago | (#45211523)

What? Of course time isn't man-made. Why would you say only man cares about time? I'm pretty sure plants and animals are also happily perceiving the passage of time.

Re:I think... (1)

DeathToBill (601486) | about 5 months ago | (#45211535)

Wrong [wikipedia.org].

Re:I think... (2)

Rude Turnip (49495) | about 5 months ago | (#45211615)

That's entropy, not time.

It's very possible that the development of language in humans sort of locked us into the concept of time. For further reading, some of which sounds insane, look into pigeons and their homing instincts to see how other animals aren't necessarily perceiving time in the way that we do.

Re:I think... (1)

Skiron (735617) | about 5 months ago | (#45211735)

Yes entropy, but time is perceiving a measure between different states of it (but I doubt animals do anyway, I mean, does a pigeon know how old it is?). Time is just like a tape measure - just a way to measure different states between events. i.e. supposedly before the big bang, there was no time, as effectively there was no events.

Re:I think... (1)

Skiron (735617) | about 5 months ago | (#45211703)

I don't think so.... the main point is 'over the passage of time...' - but time is only a human concept. Plus I wouldn't trust wikipedia anyway with all the nonsense on there.

Re:I think... (0)

Anonymous Coward | about 5 months ago | (#45211671)

Ye I agree, time seems to be the speed of everything reacting etc, and time dilation is when something affects that speed for some reason (slower reactions means slower time)

Re:I think... (1)

Skiron (735617) | about 5 months ago | (#45211827)

No, remove time from the observer and the one doing something. Both events will happen at the same speed, but it is only the 'time' measure that is wrong because humans have to measure it.

get unentangled already (0)

Anonymous Coward | about 5 months ago | (#45211455)

time is a figment of your pitiful human imagination.

An external god-like observer? OMFG, really? (1)

itsybitsy (149808) | about 5 months ago | (#45211475)

"An external god-like observer" sounds like major woo-woo red alert all mind poop shields on full verification required.

Oh Your Fine God indeed (2)

mdsolar (1045926) | about 5 months ago | (#45211659)

Worth reading what C. S. Lewis attributed to George McDonald in "The Great Divorce" for some speculation on this same issue.

twisted article. (1)

Anonymous Coward | about 5 months ago | (#45211483)

Well there's two minutes of my life I'll never get back.

Time is dependent on observation? (3, Interesting)

Covalent (1001277) | about 5 months ago | (#45211493)

I read this essentially as saying that without an observer, time does not exist. Essentially, a "god-like" observer does not observe any change unless he or she becomes entangled in the universe he or she is observing. That universe, therefore, is without change, and therefore timeless. However, observers that are entangled within the universe (as we are), observe change and thus the universe (to them) has time.

This sounds a fair bit like some of the effects of relativity (on the train the shots appear simultaneous...on the ground they do not).

What is most intriguing to me, though, is that if the universe is both timeless (from the outside) and has time (from the inside), is it possible for us to gain the outside perspective (or any information about that timeless perspective). This shouldn't necessarily be impossible - we would need to not become entangled in the thing we are trying to observe (which we can easily do). Perhaps observing the surrounding universe would give unentangled information about the experiment in question, and thus give us a glimpse of the future?

Re:Time is dependent on observation? (2, Interesting)

Anonymous Coward | about 5 months ago | (#45211911)

I read this essentially as saying that without an observer, time does not exist. Essentially, a "god-like" observer does not observe any change unless he or she becomes entangled in the universe he or she is observing. That universe, therefore, is without change, and therefore timeless. However, observers that are entangled within the universe (as we are), observe change and thus the universe (to them) has time.

It's even sillier than that. From TF Abstract:

We implement this mechanism using an entangled state of the polarization of two photons, one of which is used as a clock to gauge the evolution of the second: an "internal" observer that becomes correlated with the clock photon sees the other system evolve, while an "external" observer that only observes global properties of the two photons can prove it is static.

So, surprise, an outside observer who can only access invariant quantities of the 'toy universe; (so that the interaction is 'non-entangling', meaning it's not breaking the existing entanglement[*]) will observe ... invariant quantities. Well, I'll be damned! It's the chicken that emerged from an egg that emerged from a chicken! Emergence ahoy!

[*'Nevermind the question of how that 'go-like' outside-the-universe observer interacts with the Universe.

The thing is, not everything that's been pushed into arxiv is publishable quality (hence their attempt with the endorsing system). Wake me up if this toy thing gets peer-review approval for publishing. If it ever does, I'll write a competing article stating that time emerges from symmetry breaking and sidestep this whole fancy-pants 'entanglement' label (should have a better shot at being published imho)

Re:Time is dependent on observation? (0)

Anonymous Coward | about 5 months ago | (#45211929)

we would need to not become entangled in the thing we are trying to observe (which we can easily do)

We can only do this for particles that we entangled ourselves. This is why they were able to be a "god-like" observer in their experiment, but they cannot apply the same trick to observe arbitrary things.

Re:Time is dependent on observation? (1)

DeathToBill (601486) | about 5 months ago | (#45211947)

The article is TL;DR (I assume...) so instead I'm going to pontificate on my own ignorance. I know, I know, call me a karma whore...

Anyway. I'm not clear how this conception of a god-like observer who does not observe time and for whom the universe remains static differs from the very old theological idea of time as a property of the created universe which then doesn't apply to the creator who, necessarily, exists apart from the creation. Is it that the god-like observer is not able to observe time? Or that the god-like observer observes the universe as a four-dimensional object, seeing all of time at once, rather than observing a three-dimensional slice at successive points on the fourth dimension?

time (0)

Anonymous Coward | about 5 months ago | (#45211529)

i know time is like a big ball of wibbly wobbly..stuff...

but this is saying that time doesn't exist until it does. that's why observing a black hole, nothing ever falls into it, until you look away. so i gues this does make sence, but i cant see how MY 4th dimension is sometimes here and sometimes not.

i wonder.. (2, Interesting)

Connie_Lingus (317691) | about 5 months ago | (#45211549)

...how this is related to the fact that the speed of light is the only true (known) constant in the universe.

for example...you are on a train going 50 km/hr north...you throw a ball 30 km/hr north and the ball is now going 30 km/hr north relative to you and 80 km/hr to a stationary observer...standard stuff.

BUT...you are on a light beam going 0.5c (half the speed of light) with a flashlight in your hand...you turn on the light...how fast is that light coming out of your flashlight going relative to you and our stationary observer?

well...relative to you its going...the speed of light...to the observer?

this is where it all gets weird...to the observer its going..the speed of light!

how can this be, slashdotters?

Re:i wonder.. (1)

green is the enemy (3021751) | about 5 months ago | (#45211795)

I think the nature of light has everything to do with our perception of time. According to this story, we perceive time by being entangled with the universe. The main way we interact with the universe is through the electromagnetic force, or basically through photons. We should be approaching your question from the point of view of the light itself and then deriving what it means for a massive object to "move." If time is emergent, then motion is also an emergent concept. The photon's wavefunction might be the fundamental concept here. I'm not a physicist, so can't take this train of thought further..

Re:i wonder.. (1)

PopeRatzo (965947) | about 5 months ago | (#45211905)

our perception of time.

That's the whole thing right there. Our perception of time might just be an evolutionary artifact, like the nail on your little toe.

Me, I'm with with the Tralfamadorians. We don't "see time" just like we don't see as many colors as geckos.

Re:i wonder.. (1)

ElectricTurtle (1171201) | about 5 months ago | (#45211815)

The mass of photons is near nothing, so they don't have the boost of inertia that the ball, being a normal material object, has. It's also worth noting that the speed of light is only constant in a vacuum. Light can be made to go slower or even faster based on its medium and other conditions (temperature, etc.).

Re:i wonder.. (1, Informative)

BitZtream (692029) | about 5 months ago | (#45211821)

Uhm, the speed of light isn't at all constant, no more than the speed of sound is. The speed of light changes depending on the medium it is in, just like everything else.

how can this be, slashdotters?

Because you utterly fail to understand what you're talking about. This behavior is also no different than sound. They behave identically.

If you turn on the flashlight while traveling at 0.5C the light would travel away from you at 1C anyway, making a difference of 0.5c and causing all sorts of blue shift. You (as are most people with a poor grasp of these physics because of some shitty analogy someone used to explain it to them) are making the common mistake that the person with the flashlight in hand would think the light is traveling at 1c away from him (total of 1.5c) but they wouldn't see any such thing.

And then there is time dilation, which makes it all work out.

Re:i wonder.. (1)

Convector (897502) | about 5 months ago | (#45211861)

Minor quibble: You cannot be on a light beam going half the speed of light because the light beam, by definition, is moving at the speed of light.

Re:i wonder.. (1)

Anonymous Coward | about 5 months ago | (#45211913)

It's worth considering that the ball thrown on the train is also subject to relativistic effects, its just that the effect is so small that the Newtonian physics that you have used to describe the motion of the ball are 'good enough' for most practical purposes.

Entangled particles everywhere? (1)

tippe (1136385) | about 5 months ago | (#45211589)

Here's a perfectly stupid question that probably does a good job of highlighting how little I know about this topic: So they are saying time is an emergent property that occurs when only one particle out of a entangled pair is observed. Does this mean that all objects in our universe must therefore be composed of particles that are somehow entangled with other particles located elsewhere (since all of the objects that we observe appear to be subject to time)? Even when we perform measurements at a particle (e.g. atomic) level, individual particles themselves appear subject to time (e.g. radioactive decay, formation or breaking of atomic bonds with other particles, change in energy levels, etc). Does this mean that there isn't such a thing as a non-entangled particle (or they must be exceedingly rare), since all particles that we've ever interacted with change or can be made to change?

"If you think you understand quantum mechanics, you don't understand quantum mechanics" --Richard Feynman

Re:Entangled particles everywhere? (1)

mx+b (2078162) | about 5 months ago | (#45211723)

Maybe the particles entangled with the ones that make up my body form my doppelganger. I see that guy everywhere. He even has the same car I do!

Objection (0)

Anonymous Coward | about 5 months ago | (#45211677)

"In the first, the observer measures the evolution of the system by becoming entangled with it. In the second, a god-like observer measures the evolution against an external clock which is entirely independent of the toy universe."

"In the first set up, the observer measures the polarisation of one photon, thereby becoming entangled with it. He or she then compares this with the polarisation of the second photon. The difference is a measure of time."

Dubious claim; "... entirely independent of the toy universe." "... then compares this with ..."

hello (-1, Offtopic)

Marry Thomas (3406973) | about 5 months ago | (#45211711)

just as Rosa implied I am dazzled that a person able to earn $8943 in one month on the computer. browse this site........ www.blue48.com

God-like observer you say? (-1)

Anonymous Coward | about 5 months ago | (#45211739)

This seems to be a fitting description of how our universe appears to an external observer:

Now, dear friends, do not let this one thing escape your notice, that a single day is like a thousand years with the Lord and a thousand years are like a single day.
https://net.bible.org/#!bible/2+Peter+3:8

Time travelling summary (1)

nitehawk214 (222219) | about 5 months ago | (#45211743)

Did the summary time travel to repeat and restate the "An external god-like observer sees no difference..." sentence?

Quantum stuff is too weird (1)

Russ1642 (1087959) | about 5 months ago | (#45211957)

Even though I trust that the scientists have a decent idea of what they're doing, any story that involves quantum mechanics just sounds like bullshit. This is simply a result of the way it needs to be dumbed down to be understood at all. It's just too weird for me so it sounds like something Data would say, just a bunch of buzzwords.

where god-like is a synonym for does not exist (0)

Anonymous Coward | about 5 months ago | (#45211975)

really poor choice of words, what they mean is a theoretical observer that can't exist which makes observations of the location of things without interacting with them in any way - this does not happen and can't happen. This observer is not god-like in any way according to the description of anyone throughout history who believes in a magical sky-fairy. It is omniscient, but not in the way any religion describes their deity. The only attribute this hypothetical observer shares with any described deity is the lack of existence.

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