Traveling Back In Time...

[2322]

It is extremely hard for us to wrap our heads around the fact that there is no evidence whatsoever that time even exists.... but there isn't any.

We create a variable in an equation that stands for time, and that's useful for our purposes, but time may be as illusory an idea as is centrifugal force- which also doesn't exist. ( it is a combination of inertia and acceleration, nothing more )

Einstein could not make sense of time, and so teated it rather successfully as nothing more than another dimension... But it can not be another dimension, because motion in that dimension is constrained in only one direction, which means it can not possibly be a true dimension...

Then how do you explain the existence of time dilation as proven in the Hafele-Keating experiment? If there is no time, how can we measure the effects upon it by accelerating or decelerating clocks through space? As I understand it, the clocks on the space shuttle and ISS have to be continually adjusted to synch with clocks on earth because they run faster in orbit than clocks on earth.

 

[2322]

Both you guys will love this (and thank you for that detailed explanation HG). The big brains over at GEO600 theorize that our universe may simply be a giant hologram:

Cardiff University researchers, who are part of a British-German team searching the depths of space to study gravitational waves, may have stumbled on one of the most important discoveries in physics, according to an American physicist.

Craig Hogan, a physicist at Fermilab Centre for Particle Astrophysics in Illinois is convinced that he has found proof in the data of the gravitational wave detector GEO600 of a holographic Universe – and that his ideas could explain mysterious noise in the detector data that has not been explained so far.

The British-German team behind the GEO600, which includes scientists from the School of Physics and Astronomy's Gravitational Physics Group, will now carry out new experiments in the coming months to yield more evidence about Craig Hogan's assumptions. If proved correct, it could help in the quest to bring together quantum mechanics and Einstein's theory of gravity. -New Scientist

 

[HazelGod]

Then how do you explain the existence of time dilation as proven in the Hafele-Keating experiment? If there is no time, how can we measure the effects upon it by accelerating or decelerating clocks through space? As I understand it, the clocks on the space shuttle and ISS have to be continually adjusted to synch with clocks on earth because they run faster in orbit than clocks on earth.

You actually have it backward...as relative velocity increases, time dilation becomes more pronounced. That is to say that relative to a stationary observer, time moves slower for a person traveling at high speeds. The ISS orbits the earth at ~8km/sec...and while that sounds fast to us, it's quite slow relative to light. So, its clocks run very slightly slower (microseconds) than those on the ground.

As a traveler approaches the speed of light, the Lorentz factor approaches infinity...which means that for a body moving at light speed, time would effectively stand still.

The corollary to this is length contraction. In order for light speed to be constant regardless of the observer's velocity, space and time must be dependent instead. The apparent length of a moving body along its axis of travel shrinks as its speed increases. As v approaches c and the Lorentz factor approaches infinity, so too does length contraction...meaning that for bodies traveling at light speed, they occupy zero space and time doesn't move.

 

[2322]

So that means that photons traveling at the speed of light are standing still in time? That makes me wonder if time only exists in the presence of gravity. Is gravity required for time to exist? Is time a component of gravity? Is there any way to test for this? I imagine there isn't as we're never truly ever free of gravity unless we can teleport into some kind of gravity-free dimension. I've heard that gravity sort of "leaks" out from another dimension (one of the supposed 11), whenever mass is present in our universe. Any thing we test for would have to be free of mass and the only thing free of mass I know of, are photons. Damnit! But wait. If photons can be captured and bent by gravity, then they must have some mass. Oh balls.

 

[lucky8]

So that means that photons traveling at the speed of light are standing still in time? That makes me wonder if time only exists in the presence of gravity. Is gravity required for time to exist? Is time a component of gravity? Is there any way to test for this? I imagine there isn't as we're never truly ever free of gravity unless we can teleport into some kind of gravity-free dimension. I've heard that gravity sort of "leaks" out from another dimension (one of the supposed 11), whenever mass is present in our universe. Any thing we test for would have to be free of mass and the only thing free of mass I know of, are photons. Damnit! But wait. If photons can be captured and bent by gravity, then they must have some mass. Oh balls.

YouTube - Quantum Gravity Unification of Strong Nuclear Force

Some interesting new theories coming out these days...

"the more we learn, the less we know"

 

[HazelGod]

So that means that photons traveling at the speed of light are standing still in time? That makes me wonder if time only exists in the presence of gravity. Is gravity required for time to exist? Is time a component of gravity?

:biggrin1:

These are the thoughts that bake the noodles of most physics students when they're introduced to relativity, and they're the reason that understanding of the concepts absent mathematical detail are difficult for the lay person to attain.

From the point of view of a moving photon, yes time would appear to stand still. Think about it like this: all information about the state of the universe we receive comes via photons moving at light-speed (visible light, radio waves, etc) or slower. We perceive time as a linear concept because of the ordered nature of these photons' arrival. As a person walks across our field of vision, we don't actually see him moving...we see the photons reflected off his body, and as he moves we see the apparent point of origin for those photons change. Because photons move with constant velocity regardless of the observer's speed, they arrive in the same sequence they were emitted or reflected. It's really this sequencing of light that defines our idea of time in the "real" world.

Now imagine that you're traveling at the speed of light. No photon would ever reach you, because they're all moving at exactly the same speed as you. From your POV, without the sequenced arrival of photons to convey information to you about the universe, you would appear to be frozen in a single moment in time.

Any thing we test for would have to be free of mass and the only thing free of mass I know of, are photons. Damnit! But wait. If photons can be captured and bent by gravity, then they must have some mass. Oh balls.

Photons have no rest mass, but because they're moving they possess kinetic energy...and as Einstein so elegantly pointed out, mass and energy are simply different states of the same quantity. This imparts a relativistic mass to the particles, and it's this mass upon which gravitation acts.

Gravity was a problem for Einstein, and continues to be for us today. That's why he published special relativity years before general relativity. Mathematically speaking, photons always travel in a straight line through spacetime. Any apparent change in their momentum due to gravitational force is considered due to curvature of spacetime itself.

 

[D_Kissimmee Coldsore]

So that means that photons traveling at the speed of light are standing still in time? That makes me wonder if time only exists in the presence of gravity. Is gravity required for time to exist? Is time a component of gravity? Is there any way to test for this? I imagine there isn't as we're never truly ever free of gravity unless we can teleport into some kind of gravity-free dimension. I've heard that gravity sort of "leaks" out from another dimension (one of the supposed 11), whenever mass is present in our universe. Any thing we test for would have to be free of mass and the only thing free of mass I know of, are photons. Damnit! But wait. If photons can be captured and bent by gravity, then they must have some mass. Oh balls.

Theoretically if a photon were conscious it would not perceive time passing as it is always travelling at c. In General Relativity it is shown that the presence of a gravitational field alters the passage of time; clocks run faster in weaker gravitational fields. And photons follow geodesics in space, that is they travel in direct point-to-point paths through spacetime. It's the spacetime itself that is curved by mass, the photon is actually indirectly affected. Gravity doesn't act upon the photon itself because it is massless (as you correctly stated).

At least that is according to General Relativity, which is a very very good theory but is nevertheless a classical one and so neglects quantum effects - so is not a complete explanation of the nature of spacetime.

Apologies if my spelling is guff, I'm shattered. And also after all that it was explained far better by a doubtlessly more lucid HG above. Ah well.

 

[JustAsking]

Also, photons have no rest mass.

 

[Phil Ayesho]

Then how do you explain the existence of time dilation as proven in the Hafele-Keating experiment? If there is no time, how can we measure the effects upon it by accelerating or decelerating clocks through space? As I understand it, the clocks on the space shuttle and ISS have to be continually adjusted to synch with clocks on earth because they run faster in orbit than clocks on earth.

Well, Jason... this is the thing about any theory--- its imaginary...
In recording events we THINK we are capturing something about time... but in point of fact at what point can we or do we EVER use the information captured?

Why, Now, of course. EVERYTHING happens NOW. And only now.

Here's where it gets freaky and hard to follow... you have been told that speed affects Time... that at the speed of light, time stops.
Consider that... A photon leaves the surface of a star, travels for 100 million years, and hits the back of your stargazing retina and you perceive it. Yet, from the perspective of the photon, there is no time elapsed, the moment of its creation and the moment of its impact on your retina are the SAME moment in time. And if no time elapsed, then no distance could have been traversed... the photon's perspective is that the surface of that star and your retina were the same point in space.

Sounds like malarky doesn't it? But this is perfectly true... the REASON photons have ZERO rest mass is that they have no substantive reality at all...They actually lack "being" in the ordinary sense.

Now, you call to mind that Spacecraft traveling at different speeds, in different places will all have different rates of time...

But how does that effect the NOW?

It doesn't. Even though time dilates, everything happening on the slow space ship is happening in the exact same NOW as everything happening on the fast space ship.

Dilation looks like this
TickTickTickTickTickTickTickTickTickTickTickTickTickTick versus
T i c k T i c k T i c k T i c k T i c k T i c k T i c k T i c k

Where even the letters are fatter...
And the NOW is a bar like the playhead on a UTube video. that scrubs across both at the same speed and at the same moment.
This is why Einstein proves that there is no such thing as commensurability.. Everything happens at the same time- now, but the time itself, the events themselves are not commensurate.

Here's a way to visualize it... you know those Crawls at the bottom of CNN and Fox news screens? Some of them run slow, and some of them run fast...
Now imagine adding more so that some are running so fast they are just a blur, some so slow, that you can not even perceive they are moving...

Now- imagine all those ticker tape crawls cutting across the screen at all different angles, such they they all happen to cross the center of the screen at the same point.

Those crawls, they are different dilations of time... But that point where they ALL cross... that is the NOW....

And what we experience, really and for true, is JUST that spot. Because the crawls themselves do not exist... just the single spot where all that information is coinciding at all different rates all at once.

The fact that I can record history ( in the now) and read about what the now was like before ( reading it in the now) does not lend that history any reality.

In other words, REMEMBERING an event is not the same thing as the event happening.
Our memories and ability to imagine the future create a narrative in our head that SEEMS to imply time.

But, no kidding, there is not one iota of evidence anywhere that time is anything but a conceptual construct born of imagination.

Now is never the same... always in flux. Nothing but the now has any being whatsoever.

 

[D_Tintagel_Demondong]

Um, No , we have ZERO proof of other parallel dimensions. Not even mathematically.
Its just a story made up by scientists who can not deal with the non-deterministic universe that quantum mechanics actually describes.

In point of fact, Quantum mechanics is the most accurately verified theory in physics... and it says that reality is fundamentally probabilistic.
The "multiverse" is one of the stupidest exercises in mental masturbation ever conceived, and is closer to religion than to real phenomenally based physics.

I hate to differ, Phil.

I can't insert photos here (Rob, please bring this back!), so I'll just insert the code:

Latex code: S = \frac{{Akc^3 }}{{4\hbar G}}

MathML code: S=\fracAkc34ℏG

I don't know which you prefer, but they both represent the equation for the entropy of black holes, proposed by Hawking and generally accepted by astrophysicists. It's a beautiful equation, involving thermodynamics, chemistry, physics, even quantum mechanics.

It's the quantum part that gets my attention because, in order for this equation to solve, there must be eleven universes, or dimensions, each with their own separate laws of physics. For example, time may travel 'backward'.

Decades ago, particle physicists noticed that particles never stay visible: They regularly disappear and then pop back into existance. This was a total mystery until it was suggested that they leave our universe to visit other universes then reappear into our own.

Contrary to your claim, quantum experts are accepting this 'multiverse' more each day. For your viewing pleasure.

Maybe you can explain why universal gravitaion is so much weaker than the other three forces? This theory explains it perfectly.

 

[Rugbypup]

I hate to differ, Phil.

I can't insert photos here (Rob, please bring this back!), so I'll just insert the code:

Latex code: S = \frac{{Akc^3 }}{{4\hbar G}}

MathML code: S=\fracAkc34ℏG

I don't know which you prefer, but they both represent the equation for the entropy of black holes, proposed by Hawking and generally accepted by astrophysicists. It's a beautiful equation, involving thermodynamics, chemistry, physics, even quantum mechanics.

It's the quantum part that gets my attention because, in order for this equation to solve, there must be eleven universes, or dimensions, each with their own separate laws of physics. For example, time may travel 'backward'.

Decades ago, particle physicists noticed that particles never stay visible: They regularly disappear and then pop back into existance. This was a total mystery until it was suggested that they leave our universe to visit other universes then reappear into our own.

Contrary to your claim, quantum experts are accepting this 'multiverse' more each day. For your viewing pleasure.

Maybe you can explain why universal gravitaion is so much weaker than the other three forces? This theory explains it perfectly.

YouTube - Broadcast Yourself.

I really want a doughnut now.

 

[Skull Mason]

Thank GOD for a good fucking thread in this place finally...

Why, Now, of course. EVERYTHING happens NOW. And only now.

Who woulda thunk Phil was into Eckart Tolle!!! I believe the only proof we have thus far is that everything only occurs in the now. All theories about everything else, to me, are just theories. Just like thoughts and emotions are fleeting and transient, I believe all these theories and belief systems are as well. Just as one day people had a theory that the Earth was flat, and the Sun went around the Earth. Only now the things proposed are even more ridiculous. So while things like relativity and parallel universes and dimensions etc etc are generally excepted now, I would assume that in many years time those same theories may seem archaic.

The bottom line to me is that nobody really has any fucking clue. At this point it is just the now until proven otherwise.

 

[D_Tintagel_Demondong]

YouTube - Broadcast Yourself.

I really want a doughnut now.

Heh. I guess you are referring to the Type IIA string. Does this mean that you support strings (or branes) too?

The real question is: is it 'doughnut' or 'donut'?

 

[Rugbypup]

Heh. I guess you are referring to the Type IIA string. Does this mean that you support strings (or branes) too?

The real question is: is it 'doughnut' or 'donut'?

:biggrin1:

I certainly believe in the possibility that there is more than heaven and Earth, the here and NOW.

Yesterdays theory is today's bull shit to be tomorrows normal.

I'm not able to deeply counter the argument myself, so here, I must defer to my learned betters.

 

[Phil Ayesho]

Sorry- but that is just bullshit.
Mathematically invented dimensions are precisely that.
Inventions. They are created for the express purpose of getting equations to agree with observations, and have no real relation to reality.

They really qualify as nothing more than fudge factors.
There has been not one single observation that supports other dimensions.

And the fact that many physicists can not accept the the Copenhagen interpretation of Quantum Theory is simply the result of their innate preference for a "deterministic" result. The Copenhagen interpretation of a probabilistic reality agrees entirely with all observation, thus far.


The problem with the "mulitverse" is that is serves no predictive nor useful function... It simply eliminates probabilistic results by "claiming" that ALL results occur-- and simply CLAIMS that these alternate results are forever sealed away in calved off universes of which we happen to have no access to, forever.

Sorry, but this is just someone trying to Fudge quantum theory to eliminate the fact that it plainly describes a reality that has a wave function that is not deterministic in nature.

In other words, Modern physics has two kind of folks in it... those who are cool with the idea that what happens in Shreoedingers box really is superposition... and the result really is random... and those who can not accept that and believe the BEYOND the limit of observation, there really is some hidden mechanism that, if we could figure it out, would result in perfectly deterministic results every time.

Since all experimentation supports and proves superposition to be real... in fact, Quantum computation would not even work if it wasn't real... these closet determinists have only one other stunt to pul to escape the randomness inherent in QM... and that is to spuriously and without any evidence claim that the Cat is both dead and alive, in two different universes.

Sorry... but as a true agnostic, I do not accept fabricated narrative as evidence of anything but a story.

String theory is as much a mental masturbation as is the concept of the multiverse... It is perfectly possible to come up with a very cohesive mathematical model that, nevertheless, does not reflect anything true about the world.
And just because a theory works, does not mean that the concepts it introduces to work with actually bear any relation to the real world.

For example... In aerodynamics we have a whole body of theories dealing with the force called "lift" acting on an airfoil.

There is no such force in reality. It is NOT how wings work.
However, because these formulae were created as the result of observation- that is, the math and forces were invented specifically to match exhaustive experimental results- these formulae still WORK- you can design a functional airfoil and expect it will perform as these theories say it will.
But there will be no force called lift responsible for the plane flying. In point of fact, a wing works on the principle of Thrust. The airfoil directs air downward and accelerates it. Anyone can prove this by observing any table fan. The "lift" side of the rotating airfoils has no effective suction at all.. no force is pulling the fan in that direction, rather, everyone knows that all the force is on the BLOWING side of the fan... Obviously, an airfoil generates THRUST- and its is that thrust that makes planes fly regardless of what the formulae used to design them rely on.

That is just one common example of how theory can INVENT something to solve an equation of get a result that has no bearing on reality.
Likewise, cosmologists Invented Dark matter because their formulae could not predict observation... yet even after adding in this absolutely bald fudge factor, they STILL failed to predict that expansion was accelerating... Their theory predicted precisely the opposite. SO then they added Dark Energy... to fix that failure... but this is precisely where Europeans where when they kept elaborating the geocentric model to fix the fact that observations did not match theory...
Dark energy, and multiverses are like the invention of epicycles to explain retrograde motion...
they just happen to be a LOT harder to falsify, because they are non observable.

Given the Pioneer anomaly, and the fact that it has now been verified in nearly all long term trajectories... it appears that we still have no idea how the universe works on any real long range scale... which could call for MOND, or CDT or some other theory, which will eliminate dark matter and dark energy like waking eliminates a dream.

SO, sorry... While I think all the ideas we have of Black Holes and the like are interesting and all... we still have no real observation on which to back those ideas... and as such, that means what we have is narrative, rather than knowledge.

 

[Rugbypup]

With no disrespect intended here Phil, who's opinion do you think would be more valid here to those not as deeply versed, yours or Stephen Hawking's?

It's one thing to say no, but another to have a PHD/noble prize candidate who thinks, likely yes.

 

[_avg_]

Do I have to be the one to point out the abuses of the term "universe"...???

 

[HazelGod]

Actually, I tend to agree with Phil that such constructs are no more than so much mathematical masturbation.

"Fudge factor" explanations may change in appearance, but they've been around at least as long as the scientific method...and we always find ourselves laughing about them as we look backward across a paradigm shift. Phlogiston, anyone?

Einstein himself once declared that his inclusion of a "cosmological constant" into his field equations for general relativity was one of the biggest mistakes he ever made.

 

[2322]

Aristotle was one of the most brilliant people who has ever lived. His contribution to science is incalculable. His name is engraved onto the friezes of universities, his bust graces the bookshelves of scientists. He was, however, largely wrong about a great many things. That doesn't mean he was a bad scientist, just that he was limited by the education and technology of the day.

 

[Phil Ayesho]

With no disrespect intended here Phil, who's opinion do you think would be more valid here to those not as deeply versed, yours or Stephen Hawking's?

It's one thing to say no, but another to have a PHD/noble prize candidate who thinks, likely yes.

I have read Hawking..
He doesn't actually say yes.
He has actually flip flopped on some of his ideas,... but the most important thing to note about Hawking and other scientists of his ilk is that they are perfectly capable of acknowledging that their theories are entirely provisional and unproven.
Hawking has actually written on the subject of the conceptual nature of current scientific models.


Folks who think dark matter is proven, or that Time provably exists, or that there is such a thing as the multi-verse are, quite simply, ignorant to what science actually does and does not claim.

Strings and extra dimensions are, until proven, no different than coming up with a mathematics of Pixies and sasquatches to explain the invisible universe...
If your Pixie theory actually predicts observation you can claim to have a VALID theory... but having a valid theory does not mean that theory is a true reflection of reality. It does not mean there is such a thing as Lift, nor such a thing as a pixie, nor indeed, such a thing as a particle.

Again, not all scientists are agnostics... but all the really good ones are.

having a usefully predicitve narrative about the universe is not the same as knowledge.