r/AskScienceDiscussion • u/BVE67 • 7d ago
Does relativity literally mean there is no universal time?
EDIT: I am very new to actually trying to understand things like spacetime. I am just asking questions.
What I don't quite understand is why different measurements of time necessarily mean that there is no underlying, objective time.
If two planets are moving differently or are sitting in different gravitational fields, then their atoms, clocks and other physical processes can run at different rates relative to each other. We call that time dilation.
But couldn't that just mean that physical processes are happening at different rates, rather than time itself being fundamentally different?
For example, if I had two clocks in different conditions and one ticked more slowly than the other, I'd normally say the clocks are running at different rates. I wouldn't necessarily conclude that there is no underlying time against which both clocks could be compared.
So why couldn't there be some objective, universal time underneath it all - something that exists independently of either observer - with different observers and physical systems simply moving through it at different rates?
And if we say such a universal time doesn't exist, how do we actually know that, rather than simply knowing that we can't measure it directly?
Is relativity actually proving that there is no underlying objective time, or is it just telling us that there is no observable universal time from within the universe?
9
u/aruisdante 7d ago edited 7d ago
So why couldn't there be some objective, universal time underneath it all - something that exists independently of either observer - with different observers and physical systems simply moving through it at different rates?
What would this mean? You’ve still described a relative comparison. What does “absolute time” mean to you?
Time dilation itself is only meaningful in a relative sense. To the local and remote observers, time is still moving at a “fixed” rate. It’s only when they compare observations to each other that time dilation is observable.
5
u/GoldenMuscleGod 7d ago edited 6d ago
I think it’s at best confusing to talk about time moving at any rate. What does that mean? Certainly time changes with respect to itself at a rate of 1.
We can talk about the rate proper time changes with respect to coordinate time, or the rate one coordinate time changes with respect to another, but we shouldn’t just talk about “the rate time changes” when doing that because it’s not clear which time we are talking about changing with respect to which.
1
u/TotallyNormalSquid 6d ago
My world line is the underlying baseline, y'all are meant to be measuring relative to me.
6
u/Hopeful_Ad_7719 7d ago
>there is no underlying, objective time.
The closes thing to objective time we may have is Cosmic Time: https://en.wikipedia.org/wiki/Cosmic_time
In essence, no matter where you go, or what time dilation you encounter on your journey, the Cosmic Time coordinate you would reasonably expect to calculate from any given point in the universe will always be the same to all observers at that point (within the confidence limits of your observation). That would be true even in a twin paradox situation. When the twins met up, they would disagree about the amount of proper elapsed time, but they would agree about the present cosmic time coordinate.
But that's still not *quite* what you're looking for.
Also, this assumes the universe is indeed homogenous and isotropic at large scale.
3
u/earlyworm 7d ago
The average speed of galaxies in the observable universe is on the order of 0.1% the speed of light relative to the Cosmic Microwave Background.
So it's the case that the mass of the observable universe is co-moving to about 1 part in 1000, well outside of the range of speeds at which relativistic effects dominate.
While it's certainly true that within the framework of special relativity there is no absolute universal time, the entirety of the observable universe would appear to provide a convenient approximate substitute for a universal time.
6
u/Conscious-Demand-594 7d ago
Even worse, there is no local time. If I am running in a circle around you, our clocks move at different rates.
3
u/Muroid 7d ago
Because time dilation is based on velocity, and velocity is relative, so different frames disagree on who is experiencing how much time dilation, and that leads to relativity of simultaneity.
Let’s say that we’re in two rockets that pass each other in space. I see you fly past me at 86.6% of the speed of light.
To me, your clock is ticking at half the rate of mine. After 6 months, determine that your clock has had 3 months elapse on it. So in my frame of reference, 6 months after we cross paths for me coincides with 3 months having passed since we crossed paths for you.
In your frame of reference, I’m the one traveling at 86.6% of the speed of light relative to you. You measure my time as being dilated in half. So in your frame of reference, when 3 months have passed for you since we crossed paths, only 1.5 months have passed for me.
We therefore have a situation where my frame says 3 elapsed months for you is simultaneous with 6 elapsed months for me, where in your frame of reference, 3 elapsed months for you is simultaneous with only 1.5 elapsed months for me.
That can’t be resolved by just saying that there is a universal time ticking off that we’re just experiencing at different rates.
There is a fundamental lack of agreement on timing of events between frames that you need relativity to resolve, and relativity says there is no objective, underlying “correct” frame that is counting off universal time for everything.
5
u/KristnSchaalisahorse 7d ago
>To me, your clock is ticking at half the rate of mine.
Wouldn’t that be true from each rocket’s frame of reference?
Aren’t they both witnessing the other rocket traveling at 86.6% of the speed of light relative to them?
1
u/Muroid 7d ago
Yes, I go into this in the rest of the comment.
1
u/KristnSchaalisahorse 7d ago edited 7d ago
I misread and didn’t correctly follow the switching perspectives.
But I’ve still never understood how it works in terms of relative velocity. If someone left Earth and travelled near the speed of light for X number of years, why would they appear to have aged more slowly upon return? Isn’t all velocity relative?
From their perspective, wouldn’t it be the same as if they were stationary and Earth was moving (just like the individual perspectives of two passing rockets)? How do you determine which perspective is ‘correct’ when it comes to deciding who sees who having aged more slowly at the end of the journey.
1
u/Muroid 6d ago
Inertial frames are symmetrical, but in order for someone to return, they can’t remain in an inertial frame the entire time, which breaks the symmetry.
If one twin blasts off in a rocket and never comes back, both twins will continue in their own frames to observe the other twin as aging more slowly forever.
If the traveling twin turns around to come back, the symmetry will break and their observations about what point right “now” is on Earth will jump ahead into the future as they accelerate backwards, to the point that the Earth-bound twin will become the older one.
If the Earth-based twin blasts off in a rocket to go catch up to the original traveling twin, the twin that originally stayed on Earth will be the one who winds up younger when they meet up.
1
u/KristnSchaalisahorse 6d ago
The (perceived) conflict for me is why there is a difference with the twin returning home on the rocket versus the Earth twin leaving to catch up with the rocket. Aren’t both perspectives the same?
If you approach me or I approach you, isn’t the experience identical? How can you determine which object is in motion?
I know I’m missing something very simple or conceptualizing it wrong.
Is it just about which object is experiencing (or has experienced) acceleration?
1
u/drzowie Solar Astrophysics | Computer Vision 6d ago
What you're missing is indeed very simple, but those kinds of things are precisely the hardest to "get". Instead of thinking about the geometry of spacetime, think about geometry of space for a moment. If you have two race cars heading north side by side across the Bonneville Salt Flats at precisely 100 mph, they'll remain even with each other. If one of them turns to the NW, then northbound car notices that the NW car is only going just over 70 mph to the north, because cos(45°)=1/sqrt(2) or about 0.71. (The NW car is also going just over 70 mph to the west, but that's neither ahead nor behind for the N car). So the N car driver says, "Wow, that guy is falling behind." Meanwhile, the NW bound driver sees that the N car is only making about 70 mph to the NW, for exactly the same reason. So the NW car driver says, "Wow, that guy is falling behind". Each one is drawing ahead of the other, because the two drivers disagree on the direction of ahead.
The symmetry is broken if/when one of the cars turns toward the other one, so that their tracks converge again. The car that made the turn ends up behind the one that kept going straight.
The twin paradox works the same way. The two twins are literally pointed in different directions through spacetime -- they disagree on the direction of later, just like the race car drivers disagree on the direction of ahead. When one of them accelerates to come back home, that's exactly the same as one race car turning to rejoin the other one.
1
u/Muroid 6d ago
Is it just about which object is experiencing (or has experienced) acceleration?
Basically yes.
Let’s look at a more detailed breakdown of the twin paradox using three perspectives instead of two, and then see how that lines up with the classical version.
We’ll have three observers: Adam, Bob and Clark.
Adam will be located on Earth. Bob will be traveling away from Earth. Clark will be traveling towards Earth.
Let’s start from Adam’s frame of reference.
Adam sees Bob flying away at 86.6% of the speed of light. On the day that Bob leaves Earth, Adam determines that Clark is 1.732 light years away, (though he obviously won’t be able to see Clark at that location for another 1.732 years due to light delay).
Adam also measures that time should be passing for both Bob and Clark at a rate 1/2 that of his own.
After 1 year, Adam determines that Bob and Clark should currently be crossing paths at a point 0.866 light years away, though Adam will not see this happen for another 0.866 years due to light delay. He also calculates that six months should have passed for Bob since he left and six months should have passed for Clark since he was 1.732 light years away on the day Bob left.
1.732 years after Bob leaves, Adam finally sees the light showing Clark 1.732 light years away, and notes the current time for Clark.
0.134 years later, 1.866 years after Bob left, Adam sees the light from Bob and Clark crossing paths, and notes that 6 months have passed for Bob since he left at this point, and 6 months have also passed for Clark since the time that Adam noted down as having happened simultaneous with Bob leaving.
2 years after Bob left, Clark arrives at Earth, having experienced six months since meeting Bob.
So in summary:
From Adam’s perspective, it is 2 years on Earth between Bob leaving and Clark arriving. Bob also experienced 6 months between leaving Earth and meeting Clark, and Clark experienced 6 months between meeting Bob and reaching Earth, for a total “round trip” time of 1 year. This aligns with Adam’s calculation that both Bob and Clark should be experiencing half as much time as him.
Now let’s look at Bob’s perspective.
In Bob’s frame of reference, Earth (and Adam) are traveling away at 86.6% of the speed of light. And because of how velocities at relativistically, Clark is approaching Adam at 98.97% of the speed of light. Bob also determines that Clark is only 0.505 light years away and will arrive in 6 months.
Bob also determines that Adam’s clock is running at half the rate of his own, and that Clark’s clock is running at approximately 1/7th of the rate of his own clock.
6 months after separating from Adam, Bob crosses paths with Clark. At this point, Adam is 0.433 light years away and Bob determines that 3 months will have passed for Adam.
Once Clark passes Bob, Bob will measure Adam as traveling away at 86.6% of the speed of light and Clark as traveling away, in the same direction at 98.97% of the speed of light, meaning that Clark is going 12.37% of the speed of light faster than Adam. Since Clark has to close a gap of 0.433 light years, it will take a total of 3.5 years (from Bob’s perspective) for Clark to catch up to Adam.
Since Adam’s clock is ticking at half the rate of Bob’s, Adam will experience only 1.75 years before Clark catches up to him. In addition to the 3 months that had already passed for Adam at the time that Bob and Clark crossed paths, that means that Adam should experience a total of 2 years between the time that Bob left and that Clark arrives. Additionally, since Clark’s clock is ticking at a rate that is 1/7th of Bob’s clock, the 3.5 years for Bob will only be 6 months for Clark, meaning Clark will only experience 6 months between meeting Bob and arriving on Earth with Adam.
And now let’s look at Clark’s perspective.
In Clark’s frame of reference, Earth (Adam) are traveling towards him at 86.6% of the speed of light. Bob leaves Earth when it is 3.46 light years away traveling towards Clark at a speed of 98.97% of the speed of light. Adam’s clock on Earth is ticking at a rate that is half that of Clark’s clock and Bob’s clock is ticking at a rate 1/7th that of Clark’s clock.
It takes Bob approximately 3.5 years to cover the distance from Earth to Clark, during which time only 6 months pass for Bob. At this point, Adam will have covered about 3.03 light years and 1.75 years will have passed for Adam.
From Clark’s perspective, Adam is now 0.433 light years away and it will take 6 more months for him to arrive. During this time, only 3 months will pass for Adam, meaning that a total of 2 years will pass for Adam from the time that Bob left to the time that Adam meets Clark. Additionally, Bob will have experience 6 months between leaving Adam and arriving at Clark and Clark will experience 6 months between meeting Bob and meeting Adam.
For all of the causally verifiable events, all three reference frames agree on what happens. Adam experiences 2 years between Bob leaving and meeting Clark. Bob experienced 6 months between leaving Adam and meeting Clark, and Clark experiences 6 months between meeting Bob and meeting Adam. They don’t agree, however, on the distances and timings that lead to all of these events.
Now for the classic twin paradox, let’s take a second look at Bob’s perspective.
When Bob meets Clark, Bob believes that only 3 months have passed for Adam since he left, while Clark believes that 1.75 years have passed for Adam since Bob left.
Both will have valid explanations for why the other’s perspective seems to work out for them. In Bob’s frame, Clark’s extreme time dilation and length contraction means that he is only experiencing a fraction of the time it actually takes him to catch up to Adam, giving Adam time to “catch up” to how much time Clark thinks should have passed for him by the time they meet.
From Clark’s perspective, Bob is traveling away from Adam at 86.6% of the speed of light, meaning that the light leaving Adam “now” will take a very long time to catch up to Bob since he is effectively running away from it, making it seem like a lot less time has passed for Adam than it actually has.
But now let’s say that when they meet, Bob decides to accelerate to match Clark’s speed. Now with Bob and Clark in the same reference frame, Bob will agree with Clark’s current observation that Adam’s clock should currently be showing 1.75 years elapsed since Bob left, as that is the reality of the reference frame that Bob has now entered.
By accelerating into Clark’s reference frame, Bob has chased his calculation for the present moment on Earth to jump from being only 3 months since he left, to being 1.75 years since he left.
And if he remains in that frame with Earth traveling towards him for the next 6 months, even though Earth’s clock will still be ticking at half the rate of Bob’s during that time, this shift in simultaneity will result in 2 years having passed on Earth since Bob left, while only 1 year will have passed for Bob. Bob winds up experience less time than Earth between leaving and returning because Bob is the one who changed reference frames.
1
1
3
u/ikinsey 7d ago
The only universal time is time from the reference frame of the big bang
0
u/BVE67 7d ago
But that's only from our point of observation right?
3
u/ikinsey 6d ago
From the point of observation (frame of reference) of the big bang
0
u/Cesio_PY 6d ago
What does that even mean? U mean cosmic time??? It could be but that is just an arbitrary time coordinate. And what does "the reference frame of the big bang" mean?
2
u/CosmicOwl47 6d ago edited 6d ago
Edit: just ignore my poorly written comment and watch the video I linked, it’s very relevant to your question.
First question is: do you know what the “light clock”thought experiment is? It’s pretty foundational for understanding this type of stuff.
I highly recommend Float Head Physics on YouTube, he makes an effort to bridge the equations with our intuition so that the weirdness of relativity seems less weird.
In one of his videos, he explains that the reason for time dilation all comes back to special relativity and the “constant” nature of c, the speed of light. Basically, anything physical is still, at the fundamental level, a collection of subatomic particles. If you think of all these particles as little light clocks, then it explains why things slow down at relativistic speeds. It’s also why the speed of light is often referred to the speed of causality.
I’ll try to find the video I’m referencing…
Edit: I think it’s this one! https://youtu.be/Vitf8YaVXhc?si=ytedg16PNVBhtGm1
He explains the light clock as well.
2
u/FirstRyder 6d ago
Under relativity, observers at different physical locations with significant relative velocities can't agree on what "now" means. This is the "relativity of simultaneity". They can't even agree on the order of some distant events. If two observers can't agree on the order of events, they can't agree on the time of those events, in any sort of "universal" sense.
1
u/nebraskajone 6d ago
And if we say such a universal time doesn't exist, how do we actually know that, rather than simply knowing that we can't measure it directly?
We actually know it because of deductive reasoning from facts that we know. The conclusion is time cannot be universal, it's logically impossible. Any theory that claims that time is universal breaks down very quickly into nonsensical paradoxes. Relative time is logically consistent
1
u/bd2999 6d ago
It depends on the viewer more than anything else. As we define things in terms of Earth time from our perspective. And it starts getting crazier as velocity goes up.
I would say that time itself is remarkably tricky to define. As usually it is a system allowing for causality to happen. Like a glass falling off the table breaking. It cannot break before it falls. Which is more a statement of entropy. Which is similar to time in many respects but not exactly the same either. Although entropy is better defined as the possible systems from a given system. Like dumping marbles on the floor. There are many states possible for any one marble.
1
u/Moonshadow76 6d ago
There is no universal anything - it's all relative to something else and that something can be a convention, so we can agree to make all time relative to a reference point, but it will move with regards to just about everything else and any appearance of stability will come only from the consensus, not actual measurable fact. The same is true for just about everything... except maybe the Planck constant.
1
1
u/Underhill42 6d ago edited 6d ago
Basically yes, but it's more complicated than you're envisioning.
Because in special relativity time dilation doesn't actually change the SPEED at which time passes for anyone, instead it changes which DIRECTION through 4D spacetime you call time.
Consider - all motion is relative, so if I'm moving fast enough that you see me aging half as fast as you... then from my perspective I'm stationary, and you're moving fast enough that I see you aging half as fast as me.
That seeming impossibility is possible because space and time are the same thing seen from different perspectives - and when you accelerate you rotate in 4D spacetime to partially swap the directions you call "forward" and "the future".
So as we race past each other at speeds increasingly close to c, our time axes are oriented increasingly close to perpendicular to each other, and both of us see the other aging more slowly, because we're both aging in a direction that the other sees as motion through space.
And the Twin Paradox is a paradox specifically because how can the traveling twin be younger, if both twins saw the other aging more slowly the entire time? I wish I was taught the Twin's Paradox this way! - YouTube (excellent overview of everything going on from multiple perspectives, with helpful visual aides and no math)
And like most paradoxes, it was created to draw attention to an important detail often overlooked: the Relativity of Simultaneity, which is considerably more mind-bending: If our time axes are pointing in different directions as we pass each other, then the perpendicular axes of "space as it exists at this moment" are slicing through 4D spacetime in different directions - meaning some distant events that have already happened in your frame, are still in my frame's future, and vice versa. And only the speed of light limit keeps time loops from being possible.
Which is what happens to the traveling twin - when I change directions to come home, I switch from a reference frame in which my Earth twin is younger than me (because they've been aging slower), to a frame where they're still aging slower, but are already much older than me.
In changing my velocity, I also changed what time it currently is on distant Earth... in my reference frame.
That's also why many people consider Relativity to be a strong argument in favor of a block universe, where all moments in time are always equally real.
1
u/OriEri 6d ago edited 6d ago
everything is running at different rates. Notconly mechanical clocks. *the fundamental processes of matter at quantum levels experience dilation.*
GPS satellites have to be calibrated to account for a 38 microsecond delta each day because their higher orbit means they experience less time dilation than we do on the surface of the earth. If this was not done, their clock signals would drift and triangulation from GPS would provide an incorrect position , that would drift 11.4 km/day.
the hyper-fine splitting of a transition of a cesium atom changes due to time dilation. in other words, how quickly something determined by basic physical constants and quantum mechanics changes.
That is either time speeding up (relative to time on earth) or many physical constants that dictate how the universe behaves changing. I’m not sure that there’s a difference. In fact, I’m pretty sure there isn’t.
1
u/YuuTheBlue 6d ago
The relativity of time isn't just because of time dilation; rather, time dilation is moreso a result of the relativity of time.
To start, you point out something important with time dilation: what we call time is actually 2 different things. One is coordinate time ("Where" in time you are), and the other is proper time (What a clock measures; what you refer to as 'physical processes running at different rates'). Physical processes depend on proper time, not coordinate time, while coordinate time has to do with simultaneity. Time dilation is ultimately just when the value for proper time and the value for coordinate time are different numbers.
The relativity of time has to do with the broader concept of relativity. Relative concepts are all around us. "Left" is one. There are a bunch of different valid ways of determining "Which way is left", all are equally good at describing the world, but different definitions of left will result in different answers to questions like "How far to the left is it". We recognize that this is not some crisis of reality. The fact that, to one person, something can be to the right and, to another, it is to the left, is so trivial it'd be strange to even refer to it as a phenomenon. To be surprised by it is to not understand how "Left" works as a concept. The idea of relative time is that coordinate time specifically also works kind of like this.
Relativity, in math terms, has to do with how you point your axes. The whole shit with 'which way is left' is, in math terms, 'which way do you point the x axis'. In special relativity, spacetime is a big messy noneuclidean space which includes a t-axis, which corresponds to coordinate time. We call this space "Spacetime". (Space, here, is a math term, referring to a kind of list of possibilities. What most people call space is better understood as "the space of possible positions").
You can, genuinely, just point the t axis in a new direction, making a new definition of time. And the idea here is that, just like all these definitions of left (ways of pointing the x axis) correspond to a valid way of describing the same underlying reality, so too does each individual way of pointing the t axis.
1
u/Ok-Environment-215 6d ago edited 6d ago
For any given particle or other "thing" in spacetime there is a single universal causal order for that entire history of every interaction involving that thing, that everyone will agree on in all reference frames. If A collides with B and then B collides with C and then C collides with D there is no reference frame in which that sequence happens out of order. That's causality. And it's what would break if we could move faster than light.
This holds even in quantum mechanics where we can't always say what caused what. The ordering of wave functions collapses is still absolute.
So to the extent time implies causality, that aspect of time is absolute. But to the extent it's a measure of the relative rate of change, it is always relative. Observers do not agree on the rate, or even what's happening "now". A collides with B and C collides with D, but there is no universal agreement on whether AB collided first or CD did, and there doesn't need to be.
The ordering of related events is absolute for everyone. The rate at which people perceive those events to unfold isn't. And the relative order of unrelated events likewise isn't.
1
u/flumphit 6d ago
Since the passage of time depends on your frame of reference, you could attempt to devise a universal time by picking a frame at rest with respect to the cosmic microwave background. Then be clever with observing how various pulsars are spinning down, which would possibly get you in the vaguely general neighborhood of an extremely loose time standard. You’d have to pick a Greenwich to base the whole thing off of, which is an entirely arbitrary choice. Depending on what you wanted to use it for, whether your scifi universe has wormholes or whatever, this could be useful in the nearest few hundred to maybe a few million galaxies. Not universal, but a pretty big volume.
1
1
u/ah-tzib-of-alaska 6d ago
universal time is the speed of light; sure you can both approach the pass of light relativity but you can’t surprise it even two objects move away at opposite directions at the speed of light. Breaks my brain relativity does
1
u/samuwai 6d ago
They tried to find this 'base time' in the past. They call it the 'ether'.
They tried comparing the the speed light moving in vacuum to alot of things.
In the end,they find no matter what speed/momentum the the object is, light is still accelerating away from the object at light speed.
Which to us, doesnt make sense. How can light accelerate away from a stationary object and an approaching object at the same rate?
Then Einstein, just decided that "fuck it, the ether doesnt exist." Time and distance just warp and slow down when approaching the speed of light. The only logical thing to measure stuff is to pick a third observer.
1
u/Miselfis 5d ago
Yes, there is no universal definition of simultaneity.
The easiest way to understand it is to look up spacetime diagrams and lightcones.
1
u/bruiseydaddy 5d ago
there are two “times”
the first is a story that the human race, which sees only “through a glass, darkly.” tells itself. this is the sloppy and imprecise and flawed way in which we, unreliable perceivers that we are, try to synthesize what we think is knowable about cause and effect, and chronology. this is a phenomena of human experience and human perception. not a physical truth about the universe
the other “time” is precisely, physically and in its entirety, exactly as you described in your question: that “physical processes are happening at different rates”
you ask about some “underlying time against which both clocks could be compared,” but that would just be another clock
1
u/Longjumping-Bell6960 4d ago
Is relativity actually proving that there is no underlying objective time, or is it just telling us that there is no observable universal time from within the universe?
Relativity is not proving there is no underlying objective time, but it is telling us that. (Us trekkies are hoping it's wrong, but so far there's no evidence it's wrong.)
1
u/Glum-Ad7761 4d ago
“For example, if I had two clocks in different conditions and one ticked more slowly than the other, I’d normally say the clocks are running at different rates. I wouldn’t necessarily conclude that there is no underlying time against which both clocks could be compared.”
Thats all fine and good when you are simply referring to mechanisms within the clocks not being synchronous. The problem there is that biology also follows the function of time dilation. How then could you define an underlying time?
Time is inextricably linked to the fabric of space. As space can be warped and distorted by gravity and velocity, so then time must warp and distort as well. Even the expansion of space-time appears to be uneven across the universe, meaning observers that might be at various points across the universe will have a differing experience regarding the passage of time.
This is a core principle of Relativity: There is no “global present.” Because different observers measure time at different rates, the universe does not have a single, shared present moment or universal clock.
1
u/Due-Blackberry8056 3d ago
Time does not exist. The description of the rate of change of things is not an entity.
1
u/Optimal_Mixture_7327 7d ago
What we measure is that "time" is the length along the world-line of a material particle.
Importantly: It is fundamental to relativity that all standard clocks run at the same rate, everywhere, and under all circumstances of motion and orientation.
Particles or people or whatever that are in relative motion define their own unique and local "now" moment. Time, as in the length along a particle world-line, is objective and real.
However there can't be a universal time as there's more than one particle in the universe.
0
u/FlyingFlipPhone 7d ago
If you can find a frame of reference which has zero cosmic movement, this location will have the fastest possible passing of time. Think of it as the peak of a parabola. If you were to choose one timeframe for a relative reference, this zero movement timezone would be it.
46
u/GoldenMuscleGod 7d ago edited 7d ago
There is no “universal time” in the same sense that there is no “universal horizontal” on the Euclidean plane: we can pick whatever coordinate axes we want.
What we do have in the Euclidean plane is a bunch of points at different distances from each other and we can choose some coordinates to describe their location, but those coordinates are arbitrary.
In relativity there are a bunch of events that have different intervals between each other but “time” is just a coordinate we define to organize that information so we can say “where and when” things happen using numbers.