Does the past exist?

Mr.Nice Guy

I was watching a documentary on time travel recently and something one of the scientists said interested me. He was talking about the past as if it was something legitimate in the universe and that it exists in some form. I am wondering what science officially makes of this? Does the past exist in the eyes of science? I hope I'm making sense.

For example, about a half an hour ago I made myself a cup of tea. Is there somewhere in our universe where this is still occurring even though as I write this I'm thirty minutes past that point?

Important historical figures from centuries ago, loved ones we have lost, obviously they are dead to us at this moment but do they exist out there in some capacity beyond our reach in the past? Are their lives imprinted on time?

Just curious what the general concensus of the scientific community is on this idea? :cool:

r3nu4l

Great question! I don't have the answer but my very limited and probably wrong!) understanding is that time is a dimension that moves 'forward' and therefore if there is a past then it can never be returned to.

I'd love to hear a physicists answer to this but I think that the biggest problem the layman has when it comes to time as a dimension is that we grow up with the idea of time travel and parallel universes where every action we take in this universe, spawns a new universe where we took the opposite action and where interfering in events of the past spawns a new reality in the present and future.

While many of the ideas we see and read in science-fiction must have come from some theoretical piece of physics I'm not sure how much and how far those ideas have been expanded on to make a good story.

If anyone has any definitive answers then come back to us last week and post about it on the forum

nyarlothothep

I have no idea about it at all but could the universe just be one big zip file which is self extracting?

Again I am a layman but I think the past must exist for there to be a present. Also if you consider space time geometrically as in minkowski space then it exists relative to the persons position in space time. Isn't it entropy and light cones which determine the arrow of time so that we cannot go back? mehfla.

Mr.Nice Guy

Another thing I can't get my head around is as the poster above says, if the past does not exist any more then how can the present exist? I would have thought the two would be interdependent. In life we go from A to B to C. If A eventually gets swallowed up, then how is B there at all?

Or is it all an illusion?

5uspect

I read once about a hypothesis that time as we experience is essentially an average of all the collapsing wavefunctions around us in much the same way as heat is the average of phonon vibrations in a mass.

More here:
http://www.newscientist.com/article/mg19726391.500-is-time-an-illusion.html?full=true

Trance

Mr.Nice Guy wrote: »

He was talking about the past as if it was something legitimate in the universe and that it exists in some form. Does the past exist in the eyes of science? /cup of tea

When you drop your cup of tea on the kitchen floor (or beam a radiosignal into space), information of that event will travel at a fixed velocity to far-living aliens on the planet Zorg. When they eventually receive that information, that which is their present will have occured in your past — Or more importantly to answer your question; before the event reaches them, that which is their future, will have happened in your past. Events that have happened in your past have yet to happen in other's futures.

When you see your friend waving at you from across the street, you're looking into his past. From his point of view however, the moment he waves, he knows your future — Time is relative to each individual.

If you and any other individual had no past, how could anyone else have a future?

Kesha

#6 Trance, I believe you are talking about the subjective perception of existence rather than the existence itself. These are two different things.
If you perceive something id doesn't necessarily mean it exists or ever has.

OP, I believe that the trend in modern science is that all past, present and future exist and even all possibilities/possible worlds do as well. However, since it is impossible to perceive anything but this one present world, it is the same to us as if they didn't.

dogbert27

OP. My thoughts on the matter are as follows: As you said, you are presently standing on point B. To get to point B you chose a future possibility at point A to go to and made your way through space and time to get to point B. At point B (the present) you are faced with future possibilities from 0 to infinity. You then make your decision and go forward you are now at point C, which now becomes your present. The future exists in the form of your possible choices. The present exists in the last chosen possibility becoming reality. The past exists in the chosen possibilites.
Or picture that you are a presently a point/dot and either side of you is a line stretching to infinity. Behind is a single line, the past. Ahead of you is an infinite amount of lines, possibilities that you choose to create your future.
So I guess what I’m trying to say is, I think yes the past exists, otherwise there would not be a present.

bonkey

Mr.Nice Guy wrote: »

Does the past exist in the eyes of science?

It depends on what you mean by "exist", really...which is more of a philosophical question.

For example, about a half an hour ago I made myself a cup of tea. Is there somewhere in our universe where this is still occurring even though as I write this I'm thirty minutes past that point?

If you define the universe in terms of space-time, then yes.

dungeon

Now I remember why I dropped Physics and Chemistry!

r3nu4l

dungeon wrote: »

Now I remember why I dropped Physics and Chemistry!

I dropped them too However, I've always had an interest in the more fanciful sides of both subjects.

m83

Everything that will ever happen, has already happened.

glaston

If you could travel faster than the speed of light then you could see the past from a different perspective. But it would be the present from where you are viewing it...
Kinda...

Rougies

nyarlothothep wrote: »

I have no idea about it at all but could the universe just be one big zip file which is self extracting?

Interesting analogy there!

As it extracts the files, the past would be "read only" and the future "hidden".
(would make more sense if the future files were encrypted though).

Gurgle

dungeon wrote: »

Now I remember why I dropped Physics and Chemistry!

This is more philosophy tbh.

Azelfafage

General Relativity informs us that we live in a "Space-Time Continuum".


What is on your left side exists.
What is above you and behind you and below you (3 dimensions) and tomorrow and today and yesterday (4th one.) exist.

The past exists.

There is no distinction in physics between space and time.

.

.

topper75

Quite amazing to look into the night sky and consider the time it takes for that starlight to reach us. Some of these stars could have ceased to exist long before I was even born.

Of course, we are not really looking into the past by looking at the stars. It is simply that our becoming aware of a past event is much delayed.

Azelfafage

"Of course, we are not really looking into the past by looking at the stars."

We are.
.

topper75

The light hitting your retina is an event in the present, is it not?

r3nu4l

topper75 wrote: »

The light hitting your retina is an event in the present, is it not?

It's our present but that light was first emitted in the past, you are arguing semantics. Much of the light we see comes from stars that may no longer exist and are no longer emitting any light so our image of the stars is based on how they were a long time ago and does not relate to how they are now.

Most people readily understand what you are saying when you say that what we are seeing now is an event from the past...as strange as it sounds

topper75

Independent of our human observation though -

The light has left the star in the past.
The light reaches our eyes in the present.

I don't know how this adds up to mean that the past is still happening.

By it's very definition, the past is not still happening. No semantics required.

r3nu4l

topper75 wrote: »

Independent of our human observation though -

The light has left the star in the past.
The light reaches our eyes in the present.

I don't know how this adds up to mean that the past is still happening.

By it's very definition, the past is not still happening. No semantics required.

No one said the past is still happening...that's what you inferred from what Azelfafage said. There is no issue here at all.

roosh

Mr.Nice Guy wrote: »

I was watching a documentary on time travel recently and something one of the scientists said interested me. He was talking about the past as if it was something legitimate in the universe and that it exists in some form. I am wondering what science officially makes of this? Does the past exist in the eyes of science? I hope I'm making sense.

For example, about a half an hour ago I made myself a cup of tea. Is there somewhere in our universe where this is still occurring even though as I write this I'm thirty minutes past that point?

Important historical figures from centuries ago, loved ones we have lost, obviously they are dead to us at this moment but do they exist out there in some capacity beyond our reach in the past? Are their lives imprinted on time?

Just curious what the general concensus of the scientific community is on this idea? :cool:

Reality is the state of things as they actually exist, not as they existed, or as they will exist.

Therefore, the present moment is all that exists, not in some kind of new age hippy kind of way, but in reality. The past is only a memory which exists in the mind and the future is also only a projection that exists only in the mind.

Also, mathematics is only an extension of the human mind, it is the manifestation of the human mind's attemtp to rationalise its experiences. Showing mathematically that the past and the future exist simultaneously with the present, is again simlpy imagination, unless of course the past is defined and observed, likewise the future.

Everything occurs in the present moment, and it is the changing nature of reality that gives rise to the illusion of time, past and future.

roosh

topper75 wrote: »

Independent of our human observation though -

The light has left the star in the past.
The light reaches our eyes in the present.

I don't know how this adds up to mean that the past is still happening.

By it's very definition, the past is not still happening. No semantics required.

indeed you are correct, and it goes back to what an earlier poster said about relative perspective.

From our perspective it can be claimed that we are seeing a past event, but in reality we are not, we are seeing the current state of reality with respect to the light.

if we were to consider it from the perspective of the ray of light (or from the perspective of sitting at the front of the ray of light) then it would be completely different. We would have been present when it was first emitted from the star, we would have travelled whatever the distance across space and would only be arriving at earth now.

The light emitted from the star was done so however many years ago, it then travelled however many light years across the galaxy and what we see is not the actual star but the light waves that were emitted.

topper75

Azelfafage wrote: »

The past exists.

r3nu4l wrote: »

No one said the past is still happening.

I think Mangeroosh cleared things up. I hope everyone else is happy.:D

roosh

A general question that I think is pertinent to this topic:

in what way can time can be said to make up the "fabric of reality", does it actually make up the fabric of reality or is the notion that it does, based purely on an assumption, that is inherent in mankind, based on a misperception of reality.

Also, is it possible that this notion is borne out in the extrememly logical mathematics that have as a starting point, this potentially erroneous "axiom".

Where:

reality
• noun (pl. realities) 1 the state of things as they actually exist, as opposed to an idealistic or notional idea of them. 2 a thing that is actually experienced or seen. 3 the quality of being lifelike. 4 the state or quality of having existence or substance.

roosh

mangaroosh wrote: »

A general question that I think is pertinent to this topic:

in what way can time can be said to make up the "fabric of reality", does it actually make up the fabric of reality or is the notion that it does, based purely on an assumption, that is inherent in mankind, based on a misperception of reality.

Also, is it possible that this notion is borne out in the extrememly logical mathematics that have as a starting point, this potentially erroneous "axiom".

Where:

reality
• noun (pl. realities) 1 the state of things as they actually exist, as opposed to an idealistic or notional idea of them. 2 a thing that is actually experienced or seen. 3 the quality of being lifelike. 4 the state or quality of having existence or substance.

A couple of articles that may be interesting to people. Could be old news but goes some way to putting the above question in more of a scientific context:
http://qd.typepad.com/17/2005/10/the_problem_of_.html
http://discovermagazine.com/2007/jun/in-no-time

Azelfafage

Ok :

The past does not exist.

Therefore the future does not exist.

So Logically.....NOW does not exist either.

(Seeing as NOW is the dividing line between the past and the future.)

Eezy Peezy.

Azelfafage

Joking aside.

The notion of past and present and future is fundamental to the theory of General Relativity.
A Black Hole can play havoc with "The River of Time",as seen by an outsider.
Explained here at this link:

http://www.cfa.harvard.edu/seuforum/bh_whatare.htm

Quote from the article:

"As you get closer to a black hole, the flow of time slows down, compared to flow of time far from the hole. (According to Einstein's theory, any massive body, including the Earth, produces this effect. Earth's gravity is so weak that the slowing of time is not noticeable, but the effect has been confirmed using sensitive instruments. For example, at sea level you age one-billionth of a second less every year than you would if you lived on top of Mt. Everest.) Near a black hole, the slowing of time is extreme. From the viewpoint of an observer outside the black hole, time stops. For example, an object falling into the hole would appear frozen in time at the edge of the hole."

Eezy Peezy.

Azelfafage

At the risk of hogging this thread I can point you to the operation of your Sat-Nav. gadget.

The satellites on which a Sat Nav depend HAVE to take into account Einsten's "Time Dilation".

GPS technology Explained here:

http://www.astronomy.ohio-state.edu/~pogge/Ast162/Unit5/gps.html

Quote:

"To achieve this level of precision, the clock ticks from the GPS satellites must be known to an accuracy of 20-30 nanoseconds. However, because the satellites are constantly moving relative to observers on the Earth, effects predicted by the Special and General theories of Relativity must be taken into account to achieve the desired 20-30 nanosecond accuracy.
Because an observer on the ground sees the satellites in motion relative to them, Special Relativity predicts that we should see their clocks ticking more slowly (see the Special Relativity lecture). Special Relativity predicts that the on-board atomic clocks on the satellites should fall behind clocks on the ground by about 7 microseconds per day because of the slower ticking rate due to the time dilation effect of their relative motion."

"Further, the satellites are in orbits high above the Earth, where the curvature of spacetime due to the Earth's mass is less than it is at the Earth's surface. A prediction of General Relativity is that clocks closer to a massive object will seem to tick more slowly than those located further away".

Won't hog this thread again...I promise
.

roosh

Azelfafage wrote: »

Ok :

The past does not exist.

Therefore the future does not exist.

So Logically.....NOW does not exist either.

(Seeing as NOW is the dividing line between the past and the future.)

Eezy Peezy.

Now is all that exists. The past is merely a mind made construct of "a former now" and the future is merely a projection of what Now will be like.

Both are man/mind made constructs and are to an extent illusory

roosh

Azelfafage wrote: »

Joking aside.

The notion of past and present and future is fundamental to the theory of General Relativity.
A Black Hole can play havoc with "The River of Time",as seen by an outsider.
Explained here at this link:

http://www.cfa.harvard.edu/seuforum/bh_whatare.htm

Quote from the article:

"As you get closer to a black hole, the flow of time slows down, compared to flow of time far from the hole. (According to Einstein's theory, any massive body, including the Earth, produces this effect. Earth's gravity is so weak that the slowing of time is not noticeable, but the effect has been confirmed using sensitive instruments. For example, at sea level you age one-billionth of a second less every year than you would if you lived on top of Mt. Everest.) Near a black hole, the slowing of time is extreme. From the viewpoint of an observer outside the black hole, time stops. For example, an object falling into the hole would appear frozen in time at the edge of the hole."

Eezy Peezy.

interesting article. Any idea where one could check out that study about aging slower under the ocean that on Mt.Everest?

The thing about black holes is that they are, by their very definition, unobservable and cannot be investigated. Almost God like if you will.

The mathematics that supports their existence is also reliant on Dark Matter and to an even greater extent Dark Energy in order to balance the equations - if I understand correctly.

Now Dark Energy is supposed to make up 70%+ of the mass (is it mass) of the universe, but that also is pretty difficult to detect is it, and can only be implied by its absence. Again, not sure if I have that fully correct.

This of course then is reconciled with Quantum Mechanics on the basis of String theory (of which there were 5), which was then unified under M theory, which lead to the postulation that the universe actually exists on a floating membrane, along with potential other parallell universes, the collision of which could potentially negate the need for a singularity, or source of a big bang.

The questions that appear to remain however, is what exactly is the floating membrane upon which we live made of, how many potential other universes are there? What are they floating in.

But I suppose, the first question that can be asked is what exactly has been observed at the subatomic level? Have Quarks ever been observed?


I apologise, I just read over the post and it comes across as a little incredulous, but as an outside observer - and it could in large part be due to a lack of understanding - it appears like a house of cards.

roosh

Azelfafage wrote: »

At the risk of hogging this thread I can point you to the operation of your Sat-Nav. gadget.

The satellites on which a Sat Nav depend HAVE to take into account Einsten's "Time Dilation".

GPS technology Explained here:

http://www.astronomy.ohio-state.edu/~pogge/Ast162/Unit5/gps.html

Quote:

"To achieve this level of precision, the clock ticks from the GPS satellites must be known to an accuracy of 20-30 nanoseconds. However, because the satellites are constantly moving relative to observers on the Earth, effects predicted by the Special and General theories of Relativity must be taken into account to achieve the desired 20-30 nanosecond accuracy.
Because an observer on the ground sees the satellites in motion relative to them, Special Relativity predicts that we should see their clocks ticking more slowly (see the Special Relativity lecture). Special Relativity predicts that the on-board atomic clocks on the satellites should fall behind clocks on the ground by about 7 microseconds per day because of the slower ticking rate due to the time dilation effect of their relative motion."

"Further, the satellites are in orbits high above the Earth, where the curvature of spacetime due to the Earth's mass is less than it is at the Earth's surface. A prediction of General Relativity is that clocks closer to a massive object will seem to tick more slowly than those located further away".

Won't hog this thread again...I promise
.

cheers for the posts. i'll check out those links. Is the Special relativity lecture very mathsy? I hope it isn't because I would love to understand it all better.

Do you know any other links to lectures and the like that would be accessible for a lay person, or documentaries that explain it relatively accurately (pun unavoidable)

Azelfafage

Gravity B satellite.

Still trying to beat Einstein.

Einstein wins.......so far.

See link:

http://einstein.stanford.edu/MISSION/mission1.html

.

.

VinnyTGM

If you think about it, everything is made of molecule's. Time is just a way of expressing when one molecule did something to another molecule. Time is nothing else, obviously human's use time to run their live's but time is not real.

So say you boiled the kettle half an hour ago, all that happaned there was that h2o got heated up to a certain temperature, there is no specific time attached to that in reality. But human's give a time to it for , as above it make's it easier to plan thing's. (How would you plan an appointment if there was no such way of measuring of when you wanted it to happen).

All that's happening in the universe is that molecule's are interacting with eachother in different way's.

Time is a man made item that is not real, only used to express when thing's happened.

r3nu4l

I just deleted some drivel a few moments ago, you know, in the past!

Back on topic please.

roosh

r3nu4l wrote: »

I just deleted some drivel a few moments ago, you know, in the past!

Back on topic please.

I'd be willing to bet that when you deleted it, you were in the present. Not "the present moment in time", but the present tense if you like.

I would have to say that the past does not exist, because all that ever exists is "the now", so that means, what we perceive as the "past" was at one stage "the now", and what we perceive as "the future", will [never really match our perception but will] materialise as "the now".


What we perceive as the past used to exist, but it no longer exists.

imstrongerthanu

Wouldn't the past be the future?
If as they say everything will end up with an increase in entropy isn't the universe going backwards?Or would it be like a gas filling a box which gets more organised and thus is going forwards in time?Increasing in entropy.Can both happen at once?

UCDEamon

The past does not exist. The past existed. The present exists. The future will exist.

UCDEamon

UCDEamon wrote: »

The past does not exist. The past existed. The present exists. The future does not exist. The future will exist.

When you conjugare the verb "to exist" in the present tense as in "Does the past exist?" definition of the work exist in that context is to exist in the present, the past is not the present so the answer is no. If however you asked "Did the past exist?" The exist there refers to the past tense so the answer would be yes. Same thing applies to the future. Except its a bit more intuitive to realise that the future does not exist right now.

Makes you think that one. I mean what is the difference between the past and the present? :eek:

roosh

UCDEamon wrote: »

When you conjugare the verb "to exist" in the present tense as in "Does the past exist?" definition of the work exist in that context is to exist in the present, the past is not the present so the answer is no. If however you asked "Did the past exist?" The exist there refers to the past tense so the answer would be yes. Same thing applies to the future. Except its a bit more intuitive to realise that the future does not exist right now.

Makes you think that one. I mean what is the difference between the past and the present? :eek:

just with regard to that [I think they are related], when the past existed it was the present, and when the future comes to be it will also be the present.


When we use the word past, we are talking about reality as it was, but no longer is, and so therefore no longer existing. Therefore the past does not exist.

Similarly, the word future refers to reality as it will be, not what it is now, and so therefore, the future does not exist either, nor will it ever, as it will always be the present.


So, the past never existed, as it always was and always will be the present.


Past and future are only human constructs, they exist only in the mind as a memory of a passed present, and anticipation of the coming present.

Turtwig

mangaroosh wrote: »

just with regard to that [I think they are related], when the past existed it was the present, and when the future comes to be it will also be the present.


When we use the word past, we are talking about reality as it was, but no longer is, and so therefore no longer existing. Therefore the past does not exist.

Similarly, the word future refers to reality as it will be, not what it is now, and so therefore, the future does not exist either, nor will it ever, as it will always be the present.


So, the past never existed, as it always was and always will be the present.


Past and future are only human constructs, they exist only in the mind as a memory of a passed present, and anticipation of the coming present.

Are you making an argument from science or are you making an argument from philosophy?

roosh

Malty_T wrote: »

Are you making an argument from science or are you making an argument from philosophy?

It was in response to the post above, and in keeping with the pre-ceding post, I felt.

r3nu4l

Science and Philosophy are closely linked. Both make excellent use of Logic and we should remember what a PhD is too

However, I'd like to leave the English grammar and tense rules out of it and stick to more scientific arguments on time and the perception thereof.

roosh

r3nu4l wrote: »

Science and Philosophy are closely linked. Both make excellent use of Logic and we should remember what a PhD is too

However, I'd like to leave the English grammar and tense rules out of it and stick to more scientific arguments on time and the perception thereof.

safe.

maninasia

UCDEamon wrote: »

When you conjugare the verb "to exist" in the present tense as in "Does the past exist?" definition of the work exist in that context is to exist in the present, the past is not the present so the answer is no. If however you asked "Did the past exist?" The exist there refers to the past tense so the answer would be yes. Same thing applies to the future. Except its a bit more intuitive to realise that the future does not exist right now.

Makes you think that one. I mean what is the difference between the past and the present? :eek:

The past can exist in many different ways depending on what is the definition of the past. For instance in some theories it is possible to visit the past but only after the invention of a time machine, time being relative so you can only go back to the point that 'time' diverged.

You can look at the past in a different light also i.e. reversing entropy or the direction of reactions which currently points to disorder e.g. how your room progressively gets messier over the weak, not tidier unless you put in energy. If you reversed entropy perfectly you could go back in the past i.e. reverse each reaction perfectly. There is a problem with this as many reactions cannot be reversed predictably due to Heisenberg's uncertainty principle..cannot predict exactly what position an electron will take.

In another case you could imagine that the universe is a collection of data that is running in a giant supercomputer. If so and if there is a central database then you could rewind the program to whatever point that you needed to go back to in the past. The problem with this idea is that you it seems you would need many times more matter in the universe to do the calculations and store the memory than actually exists.

In a further development of this idea you could copy your segment of the universe into a computer and relive the past virtually, you wouldn't know the difference (ala Star Trek Enterprise).

imstrongerthanu

What if the past, present and furure are all non concious events?Surely that would be much easier to contemplate or figure out?How much does the world around us change?
Without conciousness present;wouldn't things be easier to predict?I mean the weather is changing; the trees are growing; that can all be sorted out.
Will there be a future? Or will there just be increasing;decreasing entropy; if no conciousness was present?

Azelfafage

Tiger Woods wishes that the past does not exist!

Along with a lot more.

.

r3nu4l

Azelfafage wrote: »

Tiger Woods wishes that the past does not exist!

Along with a lot more.

.

Last warning. Stay on-topic or don't post.

Eliot Rosewater

Perhaps the most interesting fact about the universe in my opinion is that we can look at the past through a telescope as, relative to the size of the universe, light travels slowly. As far as I know this image:



was taken at the start of this decade, yet is actually a snapshot of what a part of the Universe looked like 13 billion years ago. Those Galaxies dont look like that now, assuming they even exist! Similarly, when one sees an event in the sky such as a sun exploding, its likely you are looking at something that happened when the Romans were in Britain. Because we are millions and billions of light years away from these places, we can see what they looked like then. Its quite fascinating.

Wiki source: http://en.wikipedia.org/wiki/Hubble_Ultra_Deep_Field

Incidentally, a Kurt Vonnegut novel is based on the premise that you shouldt care about people dying because they are only dead in this current moment, and they are still alive in moments passed. Another interesting thought.

The most important thing I learned on Tralfamadore was that when a person dies he only appears to die. He is still very much alive in the past, so it is very silly for people to cry at his funeral. All moments, past, present and future, always have existed, always will exist. The Tralfamadorians can look at all the different moments just that way we can look at a stretch of the Rocky Mountains, for instance. They can see how permanent all the moments are, and they can look at any moment that interests them. It is just an illusion we have here on Earth that one moment follows another one, like beads on a string, and that once a moment is gone it is gone forever.

Dublin_Gunner

Does the past exist?


Well you posted this in July, I can read it now, so yes, it does / did (depending on your opinion of 'exist'.

If you look at the sky at night, or even during the day, you're looking at things that are from the past - even the sun, 8 minutes ago.

The past MUST exist, because we have records that it exists that we can clearly see and understand. Be it a fossil, a cave writing, or the stars in the sky - all are things from the past that we can see.

What the question should be is this: Does the future exist?

Similarly, when one sees an event in the sky such as a sun exploding, its likely you are looking at something that happened when the Romans were in Britain. Because we are millions and billions of light years away from these places, we can see what they looked like then

AFAIK the Romans weren't in Britain billions of years ago

"Further, the satellites are in orbits high above the Earth, where the curvature of spacetime due to the Earth's mass is less than it is at the Earth's surface. A prediction of General Relativity is that clocks closer to a massive object will seem to tick more slowly than those located further away".

I think what this also means is, time is only relative to the observer at a particular location. I cannot measure your time, I can only measure my own.

However, if we both set our amazingly accurate atomic clocks at a synchronous time, and we are separated by a great distance (1 close to a large gravitational field, one of us further away), we will see that when we are brought together again our time pieces are no longer synchronised.

This experiment has been done by synchronising a clock on Earth, and one taken into orbit via a space shuttle, when the astronauts returned, their time piece was faster than the one on Earth.

In fact, GPS satellites have to take this phenomenon into account when deciphering a location on Earth.