Time, Gravitation, Acceleration, and their effects. Or wibbly wobbly timey wimey.

[Aethon]

Ok. Time is what keeps everything from happening at once. It is effected by both gravitation and acceleration.

If I leave Earth at an appreciable fraction of the speed of light towards Tau Ceti and return at the same speed, my watch tells me the journey took say, 10 years, but my twins' watch, having remained on Earth, reports that I was gone for 50 years. So time travel into the future is relatively easy.

Near a neutron star or other bodies with escape velocities approaching c, time moves much more slowly, until near the event horizon of a black hole, time slows to a crawl and stops. (Thus my contention that we can't see any black holes because the universe is not old enough for one to have completely collapsed from our perspective. Please feel free to discuss this).

We say that the universe is 13.82 billion years old- but from where? My question is : Does the mass of the Earth have an appreciable, cumulative effect on how old we view the universe to be? Is the age of the universe 13.8 B years, but only from Earth's perspective? If I lived on a neutron star, or (even stranger) if I were closely orbiting a black hole at some incredible velocity, would I (rightfully) declare the universe to be a mere 4 billion years old and see it as it was 9.8 billion years ago, from Earth's perspective? Or If I had been sequestered from most of the mass in the universe since shortly after the big bang, would I (rightly) believe the universe was say, 16 billion years old?

If I didn't stop at Tau Ceti, my watch is never going to sync up with my twins watch. It's only going going to get further out of sync as I continue accelerating.

Edited August 19, 2015 by Aethon

[Slam_Jones]

Interesting. My question is: what would happen if the two twins opened a line of communication between them? If they spoke, would they be speaking at the same rate, or would one appear to be talking like an Ent, and the other like a squirrel? What if they looked at each other's watches? Would the second hand move at the same rate, or would it be quicker?

Is it time itself that changes, or merely our perception of it that changes?

[K^2]

Lets start with simple ones. Earth isn't massive enough to have significant effect. Neither is the Sun. So if we're measuring age of the universe from anywhere in the Solar system, we're going to be well within the error of measurement.

If you are sitting on a surface of a Neutron Star and having a chat with somebody far away, communication will appear to be coming in at a faster rate. As if someone is playing the recording too fast. And yes, that means high pitched voices, faster moving clocks, the whole deal. And vice versa, to them, it will appear that you're slow.

Now, for whether the observer on the Neutron Star will observe Universe to have the same age. The key question is when? Simultaneity isn't an obvious thing when you talk about time dilation. If you are talking to that observer, then he sees the same Universe that you do. Now, it does appear to him to evolve much faster, so if he doesn't take that into account, he'll say the Universe is much younger. But he'd also have no trouble actually making a correction for it, and arrive at the same number we do.

Thus my contention that we can't see any black holes because the universe is not old enough for one to have completely collapsed from our perspective. Please feel free to discuss this.

Lets put it this way, we cannot have seen light from anything as it was crossing the event horizon. That light hasn't reached us yet. Nor will it ever.

On the other hand, we can, at least in theory, see Hawking Radiation from a black hole. So we can actually see it. When QM mixes with GR, things get weird.

[Nikolai]

My question is: what would happen if the two twins opened a line of communication between them? If they spoke, would they be speaking at the same rate, or would one appear to be talking like an Ent, and the other like a squirrel? What if they looked at each other's watches? Would the second hand move at the same rate, or would it be quicker?

As the rocket is cruising at constant velocity, both would appear slow to the other. When the rocket accelerates to match velocities with his point of origin, though, he will be found to have experienced less time than his origin. (Don't forget that there are also acceleration effects to consider as he leaves his point of origin, and/or if he turns around and goes back home.)

Is it time itself that changes, or merely our perception of it that changes?

Time itself.

[PB666]

Interesting. My question is: what would happen if the two twins opened a line of communication between them? If they spoke, would they be speaking at the same rate, or would one appear to be talking like an Ent, and the other like a squirrel? What if they looked at each other's watches? Would the second hand move at the same rate, or would it be quicker?

Is it time itself that changes, or merely our perception of it that changes?

Thats a profound question. The precise answer is that the Time to the big-bang is not the same for everything but it would be pretty close if inflation had a relatively constant effect. I contend that this is not the case, the to a degree inflation had a larger impact on thing furter from the original center of expansion, in either case the direction of in versus outbound is unknown. This because relative to everything elses everythings speed to everythig else is a function of distance, however there is a shift between close stuff and stuff 5 billion ly from us. There are apparently really big galaxies beyond 5 billion light years and I speculate these might point in the direction of the center. If we could travel several hundred times the speed of light we might find much older universe in their time frame when we stopped. The problem is that things that are 7 billion ly light travel, they a 10s of lightyears away now and traveling away form us close to the speed of light. There is a theoretically estimated size of the universe of 92 billion years, this is based on how big the quantum singularity of infinity density and energy might have been. Its based on several fundemental constants and makes alot of assumptions. It could be way wrong, and we may be in a non-interesting part of the universe where inflation was all but constant.

Then of course, hypotheticalities fall apart with relativity, since you cannot travel faster than the speed of lihgt, there is no absolute or universal time, and the real dimension of time is space-time and space appears to be expanding relative to other space way faster than the speed of light. So then no-ones going to waste alot of bandwidth studying something so elusive, but rather come up with practical solutions, like a inertial wrist watch that automatically reports your age and the reference frame time of the beings where you are currently passing by.

[Shpaget]

If I lived on a neutron star, or (even stranger) if I were closely orbiting a black hole at some incredible velocity, would I (rightfully) declare the universe to be a mere 4 billion years old and see it as it was 9.8 billion years ago, from Earth's perspective

One way to measure the age of the Universe is by measuring the distance of distant stars (standard candles, for example). We can also measure the expansion of the Universe (Hubble constant). Using those two figures we can calculate the age of the Universe.

From your neutron star backyard observatory you would observe the rate of the expansion to be faster than when observed outside the time dilation effect. At the same time you would be slowed down compared to the outside observer, making those two effects cancel each other out and the calculation of the age of the Universe would get you the same answer as when calculated outside the gravity well.

[Slam_Jones]

Here's a rather crazy theory I've been trying to put into words for a while now. I didn't quite hit all the points I wanted to, but some of this stuff is hard to describe.

I am by no means a scientists, so I could be 100% backwards on my ideas, but here they are anyway:

So, the "Big Bang" occurs, launching matter in all directions, at just under at speed of light.

Light travels faster than the rest of the matter, so there is, outside of the "matter sphere" a "light sphere." Beyond the light sphere, there would not have been enough time for light to reach it yet, meaning we have a definable (though undoubtedly complicated) limit to the universe. Theoretically, beyond this, we would find a layer of neutrinos, which would theoretically have moved faster at the beginning, due to being able to "slip" through any other matter with little to no friction. But is it even possible to observe a neutrino in the depths of space? If so, that could theoretically be used (somehow) to get a truly accurate age of the universe.

This would (theoretically) be similar to when a star goes supernova: the neutrinos and light are released at the same time, though the former are able to move through the star at constant speed due to their nearly non-existant mass. Light waves (or particles, or whatever they really are) get bounced around by the other matter, effectively slowing them down, and causing them to not appear until after the neutrinos have already jumped ship. Once the light is outside the influence of the star, however, it's free to move at the speed of light towards wherever it may be headed.

Okay, so, the nuetrino field is basically a shell around the universe, essentially marking the outer limits. The light sphere is basically the "mantle" of the universe, in that is sits between the observable universe (all the stars, planets, etc we can see) . Unlike the matter sphere, the light sphere is (in a weird sense of the word) solid, in that there is a constant stream of new light being issued. Regular matter just clumps together and forms planets and stars and such.

I propose that it would be impossible to observe the Big Bang, unless we are at the very edge of the universe (which I theorize is impossible to reach, being unable to pass the speed of light and all). Inside the universe, the light from that time would have already passed us, and continued racing outwards. No matter how far we look, we could never truly see the beginning: only the ghost of it's existance, only the light that had been generated long enough ago that it only just now had time to reach us.

Unless, somehow, we could travel beyond the current limits of the universe, which would involve wormholes or FTL travel. But good luck getting that to work

[K^2]

Here's a rather crazy theory I've been trying to put into words for a while now.

Not even close to how expansion of the universe works.

a) Universe actually expands faster than light.

It's accelerating.

c) The UNIVERSE is expanding. Not just stuff being thrown out into the universe. There isn't an outside, or beyond, or anything of the sort. All points in space were once the same point at the moment of big bang.

[QuesoExplosivo]

Interesting. My question is: what would happen if the two twins opened a line of communication between them? If they spoke, would they be speaking at the same rate, or would one appear to be talking like an Ent, and the other like a squirrel? What if they looked at each other's watches? Would the second hand move at the same rate, or would it be quicker?

Is it time itself that changes, or merely our perception of it that changes?

The communication would be subject to a relativistic Doppler shift, so yes, the messages received would be distorted (Ent/squirrel, but in this case red/blue).

[vger]

Not even close to how expansion of the universe works.

a) Universe actually expands faster than light.

Why doesn't that break relativity? I've heard the metaphor of being like you're running on a track and the track is stretching as you run, but because the track is simply "space" it doesn't count as matter breaking lightspeed. But if it's literally "nothing" that is doing this, how is it expanding? Or a better question would be, exactly WHAT is expanding?

[K^2]

Why doesn't that break relativity? I've heard the metaphor of being like you're running on a track and the track is stretching as you run, but because the track is simply "space" it doesn't count as matter breaking lightspeed. But if it's literally "nothing" that is doing this, how is it expanding? Or a better question would be, exactly WHAT is expanding?

In General Relativity, speed of light is a strictly local limit. Two "proximate" things can't travel faster than light relative to each other. (There is a way to put it into precise mathematical terms.) It's not a violation for two "sufficiently" distant objects to move at faster than light speeds relative to each other. But it indicates that space-time between two objects is not your basic flat space-time.

[PB666]

Not even close to how expansion of the universe works.

a) Universe actually expands faster than light.

It's accelerating.

c) The UNIVERSE is expanding. Not just stuff being thrown out into the universe. There isn't an outside, or beyond, or anything of the sort. All points in space were once the same point at the moment of big bang.

At the moment of the big bang begins space-time are rather difficult to define. And i should point out that K2 is presenting one explanation, there are others in which the universe we are expnding in is one of many expanding in empty space.

this is where i dive into the evasive visible universe that every Tv program likes to use. Visible universe on average is becoming less dense due to a wider expansion. but that does not mean energy is distributed according inflation. And i should point out that there has been open debate whether the higgs field precede the big bang, inflated the universe itself.

But technically speaking if the universe is everything light cannot be beyond, and it is poosible that feilds that travel at the speed of light in a strait line define the edge of the universe. As for his neutrino stuff, IIRC, inflation places the energy capable of generating light also sufficient for light to creat matter and anti matter, so light would not be alone, high energy gamma intersects can also create matter. The question would be if the matter also looks like matter in our visibke space. We get back to the core thing is we see a rather unifirm visible universe and conclude that it is the same everywhere, its no more than an educated guess.

The honest answer is that we do not know, and unless someone creates a big bang to test the hypothesis we would never know, and testing the hypothesis itself would destroy all knowledge as we know it, including ourselves, a possible hypothsis for the origin of our universe (sinister grin).

Time in my opinion is a fascination of sentiency. Light has no concern of time, its only mass that creates a sense of time, without inertia the universe expands and nothing transpires. Our electrons zipping around our atoms, causing synapsis create a sense of time and space, these are ways of characterizing the universe that make 2-dimensional sense out of a three dimensional universe. In a way the universe has come of age, but if we go back to the moment inflation ends, every bit of space is inflating away form ever other bit of space at speeds at event horizon deltas and time in our sense is virtually useless, its only now that things are pretty spread apart and there is a consistency of time form place to place, we actually have to look hard to find evidence of it. Newtons Mercury observation was the first in all earths history that someone detected the effects of dilation and it wasn't realized for 400 more years.

Edited August 20, 2015 by PB666

[Slam_Jones]

In General Relativity, speed of light is a strictly local limit. Two "proximate" things can't travel faster than light relative to each other. (There is a way to put it into precise mathematical terms.) It's not a violation for two "sufficiently" distant objects to move at faster than light speeds relative to each other. But it indicates that space-time between two objects is not your basic flat space-time.

So in order to travel fast than light, you have to be far enough from everything else. Or accelerate the stuff "proximate" enough to you to not break any laws. Would it be possible then?

[K^2]

So in order to travel fast than light, you have to be far enough from everything else. Or accelerate the stuff "proximate" enough to you to not break any laws. Would it be possible then?

You just need sufficiently curved space between you and everything else. Which is possible in theory. That's how Alcubierre Warp Drive works. The problem is that there no known configurations that don't require negative energy, which is hard to come by.

[YNM]

In my opinion, time (and means of temporal application, like actions, movement etc.) is governed mainly by light (and gravity, but we'll talk about this later, or if someone have a better understanding about it), and the fact that their speed are finite.

Now, consider the equivalence principle. People knew that abberation happens when you're going at speed, and light path shall be curved when you're accelerating (mind you it's in classical sense). Equivalence principle further push this along gravitation - as you can't differ between gravitational acceleration and linear acceleration, light shall bend under gravitation - and because light always follows the shortest path between two object, it means space is not flat as previously thought.

Knowing that light is affected out by gravity and acceleration, and space is big, now, you shouldn't expect that simultaneity is really simultaneous. A far away galaxy for sure haven't aged as old as you. The surface of a neutron star doesn't age as much as you do. Fast moving muons gets extra time from your position due to their speed.

Why light ? Simple - everything emits them, means the only way to know what happens far away is by their light. You can't tell what's inside the black hole due to absence of light from them, the same as big bang (because back then it's very opaque). You also can't tell what a galaxy 20 million light-year away looks like, because their light haven't reach us.

For how we can tell an age of 13.8 billion years for our universe, it's out of light as well. Due to universe's expansion (velocity !), light is redshifted (and time shall be dilated as well, redshift derrives out of this). Knowing how our universe redshift go (hubble law), the farthest light we get indicate a redshift that equals a distance only can be travelled by light for 13.8 billion years. So that's how we know them for sure.

Edited August 20, 2015 by YNM

[PB666]

So in order to travel fast than light, you have to be far enough from everything else. Or accelerate the stuff "proximate" enough to you to not break any laws. Would it be possible then?

Convert yourself to pure energy and place yourself on an inflating quantum bubble. The traveling faster than light was the result of the initial state of the material universe and the apparent addition of some dark energy hence. Its not so much a function of distance as a function of trigonomrty and time elapsed since the big-bang. As stated space is expanding. If two dots sat next to each other and space started expanding at the beginning the dots would not notice that all dots are in on the surface of a baloon, but each dot would begin separating from the next closest dot and each dot no matter which direction is moving away from the next closest dot. finally the dots look at each other and they are red shifted, and some dots finally dissappear over the event horizon.

that inflation occurs seems certain, recreating the state of inflation is not trivial. But at 92 bly span and 45 bly over 13.8 bly means roughly some things are expanding away form each other at 6C, but this is not really a cogent argument since their space and our space are so far removed and inflated there is no observable value.

[PB666]

In my opinion, time (and means of temporal application, like actions, movement etc.) is governed mainly by light (and gravity, but we'll talk about this later, or if someone have a better understanding about it), and the fact that their speed are finite.

CMBR - in our age 13.7 billion years old - in its age , less than plancks time.

Neutrino's form the first galaxies, a few seconds in age. There universe is a few million years old

Cosmic rays from the first super nova the universe is a 20 million years old.

A neutron in a black hole in a super massive galaxy 7 bly away. Universe is a couple of billion years old.

So basically we are the lighter elements, a couple of times thrown from supernova and alot of slow sedentary, non-radioactive atoms with electrons filling thier lowest energy state orbitals occasionally getting excited. And we bid our time and look to see how frequencies of light from stars, with absorption and emmision lines in expected patterns are shifted and we denote times passage in a interval that takes an object 100 billion mter from a star that weighs 2x10E30 kg to orbit that star. A rather passive spectators sport, stop that ole CNBR and ask him whats been going on

"well" dazed and confused "thats just great, who stole all the anti-matter" looking around "and where did all these solid dense cold things come from" "Jeeze, I take off for a plancks moment and everything changed and got boring".

90+ % of our universe is dark something, so far as yet we don't know how time ages with these.......so yeah I would say time is an artifact of the observer, not really a universal clock we can identify.

[YNM]

Safe to say that there's a lot of things inside our knowledge that needs to be ironed out. Or modified with some additional cloth and strings. Or cut away and replaced with something else. Or, it might be just the wrong garment that you need to replace fully. Choose one, and you'll soon face the same issue.

[Rune]

The space-time thingy and inflation always weirded me out. I mean, I know the talks, I've read (some) books. I still can't wrap my mind around the whole concept of space-time expanding, much less the boundary, or a conceptual "beyond" not making any sense. I guess my human perception just doesn't work here. I just recite the things as gospel, not fully interiorizing them like say, orbital mechanics (thanks to KSP, among other things), where I can model things in my head easily. Wouldn't any of you guys have some kind of awesome explanation of the current best-est model for the edge of that expanding bubble of space-time we call universe?

Rune. I promise cookies!

[theend3r]

Near a neutron star or other bodies with escape velocities approaching c, time moves much more slowly, until near the event horizon of a black hole, time slows to a crawl and stops. (Thus my contention that we can't see any black holes because the universe is not old enough for one to have completely collapsed from our perspective. Please feel free to discuss this).

I'm not exactly well-versed in this topic but I don't think that "time" slows down near an event horizon considerably. Afaik the effect of gravitational time dilatation is rather minuscule and gravitational forces get stronger still further beyond the event horizon. Space at the event horizon and beyond is just very compressed / gravitation too strong to let things escape, nothing more.

[SAI Peregrinus]

The space-time thingy and inflation always weirded me out. I mean, I know the talks, I've read (some) books. I still can't wrap my mind around the whole concept of space-time expanding, much less the boundary, or a conceptual "beyond" not making any sense. I guess my human perception just doesn't work here. I just recite the things as gospel, not fully interiorizing them like say, orbital mechanics (thanks to KSP, among other things), where I can model things in my head easily. Wouldn't any of you guys have some kind of awesome explanation of the current best-est model for the edge of that expanding bubble of space-time we call universe?

Rune. I promise cookies!

I suggest B.H. Arnold's "Intuitive Concepts in Elementary Topology", especially the last chapter. But of course that builds on the previous chapters, so read the whole thing, it's not very long. It should help, once you can understand how to think about spaces (in the topological sense) it becomes pretty intuitive to think about a space not contained in any other space that still expands.

[PB666]

The space-time thingy and inflation always weirded me out. I mean, I know the talks, I've read (some) books. I still can't wrap my mind around the whole concept of space-time expanding, much less the boundary, or a conceptual "beyond" not making any sense. I guess my human perception just doesn't work here. I just recite the things as gospel, not fully interiorizing them like say, orbital mechanics (thanks to KSP, among other things), where I can model things in my head easily. Wouldn't any of you guys have some kind of awesome explanation of the current best-est model for the edge of that expanding bubble of space-time we call universe?

Rune. I promise cookies!

1. Plank Epoch (of the Universe or of new instances within the multiverse)

https://en.wikipedia.org/wiki/Planck_epoch

-zero to approximately 10^{−43} seconds

-quantum universe composed of energy only quantum gravity physics persist.

-unmeasurably hot and dense

-space-time have very little meaning - however unstable this state its longevity is not known or subject to measurement, the definable space is also meaningless because

-it was a quantum singularity with an apparent infinite density, given the events that followed time passed during an expansion of the energy, although not exactly clear if that has meaning.

! if we knew how quantum gravity defines relativistic gravity then we would know the rusles that operate during the Planck epoch, but to us gravity is still an approximation.

2. Grand Unification Epoch. While gravity had meaning in our modern sense, no other force has meaning. For about 10^-36 seconds.

-Some aspects of spacetime are present, but quantum mechanics still dominates

-Energy density is above 10²⁴ eV with temperatures over 10²⁷

3. Inflationary Epoch. to 10^{−32}

-space-time can be made sense of - scalar fields can be applied to explain the universe.

-uncertainty is loosing its stranglehold

-universe is symmetrical and the inflation is uniform between scalar fields,

-inflation initially opens up the flood gates of energy flow into our universe that was not acting in the grand unification epoch. This causes the accelerative expansion of space, it also dilutes any variances in the structure from that period.

-"Cosmological inflation has the important effect of smoothing out inhomogeneities, anisotropies and the curvature of space"

4. Early Baryogenesis, (pre CMBR) . . . . . . to a fraction of a second.

To understand the problem of the Quantum age of the universe, I think take off the physics cap and pretend you are the Cheshire cat. Quantum physics does to things that make classic thought difficult. 1. It allows everything to be in a singularity and 2. It allows that singularity to have its will with space-time as we know it. Thus there is nothing to really constrain it, and even if there were, over infinite times, the improbable becomes probable. Or to give this a little humor, If god plays dice with our universe, then the Quantum Universe is all performance enhanced gods at a dice throwing tournament, the die of space-time become blurry apparitions at all scales (which of course resolve into very tiny scales).

Edited August 21, 2015 by PB666

[Aethon]

So then, we're back to The Dancing Wu Li Masters and Hesiods' Theogony?

"...first there was Chaos, but next...the deathless ones who hold the peaks of snowy Olympus, and dim Tartarus in the depth of the wide-pathed Earth, and Eros (Love), fairest among the deathless gods, who unnerves the limbs and overcomes the mind and wise counsels of all gods and all men within them. From Chaos came forth Erebus and black Night; but of Night were born Aether (5) and Day, whom she conceived and bare from union in love with Erebus. And Earth first bare starry Heaven, equal to herself, to cover her on every side, and to be an ever-sure abiding-place for the blessed gods.

[PB666]

So then, we're back to The Dancing Wu Li Masters and Hesiods' Theogony?

"...first there was Chaos, but next...the deathless ones who hold the peaks of snowy Olympus, and dim Tartarus in the depth of the wide-pathed Earth, and Eros (Love), fairest among the deathless gods, who unnerves the limbs and overcomes the mind and wise counsels of all gods and all men within them. From Chaos came forth Erebus and black Night; but of Night were born Aether (5) and Day, whom she conceived and bare from union in love with Erebus. And Earth first bare starry Heaven, equal to herself, to cover her on every side, and to be an ever-sure abiding-place for the blessed gods.

They don't call it the Opaque Epoch without reason. Think of it like this, if you are doing statistics and you have 1 thing, and that one thing can switch its feel to anything else, you are going to have horrible sample statistics. In fact with one thing you can't do variance because the equation has n-1 in the denominator. That is the pre-inflation phase, statistics of a small number of things, really chaotic at the scale it operates. Then the inflation phase comes along and all kinds of energy is pouring into space time, much better statistics the events become the laws of mass action, the result is a smooth CMBR. I should point out however, the CMBR is a sphere surface of space time that exited inflation relatively close to our ancestral space-time, and most (the overwhelming majority) of the universe is not represented in our view of CNBR. Its better than that, because astrophysicists can make assumptions about the galaxies that are between us and that CMBR space-time acts like it should if CMBR is uniform (unfortunately they observe 2-state acceleration). But the universe that we see gives the outward appearance that the inflation was perfectly so. Its kind of a shame in a sense, because if there was something non-uniform about CMBR we might know something. Our guestimate of the size of the universe could be way off, and if it is so we would not be able to distinguish local appearance of uniformity in CMBR from a uniform Opaque Epoch.

BY the way the equations on how they estimated the size of the universe in ly is not to different from your myth, we have to take it on reason that Compton's limit and the universal constants also work when space-time inflation is accelerating at some super-relativistic rate, and much of the forces today can't exist because of the energy density.

[PB666]

Ok. Time is what keeps everything from happening at once. It is effected by both gravitation and acceleration.

If I leave Earth at an appreciable fraction of the speed of light towards Tau Ceti and return at the same speed, my watch tells me the journey took say, 10 years, but my twins' watch, having remained on Earth, reports that I was gone for 50 years. So time travel into the future is relatively easy.

Near a neutron star or other bodies with escape velocities approaching c, time moves much more slowly, until near the event horizon of a black hole, time slows to a crawl and stops. (Thus my contention that we can't see any black holes because the universe is not old enough for one to have completely collapsed from our perspective. Please feel free to discuss this).

We say that the universe is 13.82 billion years old- but from where? My question is : Does the mass of the Earth have an appreciable, cumulative effect on how old we view the universe to be? Is the age of the universe 13.8 B years, but only from Earth's perspective? If I lived on a neutron star, or (even stranger) if I were closely orbiting a black hole at some incredible velocity, would I (rightfully) declare the universe to be a mere 4 billion years old and see it as it was 9.8 billion years ago, from Earth's perspective? Or If I had been sequestered from most of the mass in the universe since shortly after the big bang, would I (rightly) believe the universe was say, 16 billion years old?

If I didn't stop at Tau Ceti, my watch is never going to sync up with my twins watch. It's only going going to get further out of sync as I continue accelerating.