Is time merely a concept?

Is time an actual entity or just a concept?We all use time to measure how long things take to move, but is there more to it than that? I thought quite a bit about this a few years ago when I was thinking over Zeno's dichotomy paradox. He states that we can never fully reach any point because to get to the point, we must first go half way to it, but before that, half way to the half way point, ad infinitum. Seeing as how we do reach points all the time (ie, I never have any problem getting to work), it seems there is no real paradox here, yet the reasoning is sound.I figured the problem with the paradox is that at a constant rate of speed, it would take a body in motion just shorter and shorter amounts of time to reach each consecutive half way point. Then I thought about how much time passes when an extremely short amount of travel occurs. So I wondered what the shortest amount of travel would be. We would have to break motion down into individual atom motions, like electron orbits (or some other subatomic motion I'm yet unaware of). How much time passes from an atom being at one distinct point to the very next possible point in motion? I labeled the first point of travel of an atom as A, and the very next possible point to travel as A prime. How much time passes as this atom travels from point A to point A prime?Then a thought struck me. Can time progress for a traveling atom, even though no real motion has taken place? On the other hand, can motion occur without any passage of time? Let me try to diagram this in text:T0 -> T1 -> T2 -> Ai -(T3)> Ap -> T4 -> T5 -> T6 -> Ap -(T7)> Ap1 -> T8
^^ Here, the smallest time units are smaller than the smallest units of motion. The implications of this occurring are that time passes even though motion does not progress. In this case, time could go on indefinitely between the smallest measurements in motion. A whole infinity of them really, and we wouldn’t know the difference. An unlikely scenario.Ai -> Ap -> Ap1 -(T0)> Ap2 - Ap3 -> Ap4 -(T1)> Ap5 -> Ap6 -> Ap7
^^ Here, the smallest motion units are smaller than the smallest time units. The implications of this scenario are that an object can be in two different spots at the same time. Quantum mechanics has shown this to occur with certain particles. I can’t recall the instance though. I’ll try to find it if I can. So this seems more likely, but one would think the evidence would be more substantial.I came to the conclusion that time is really just change and doesn’t exist as its own entity. Its how we measure change, certainly, but without motion, would time still pass? If all motion were to stop, it would be like putting the universe on pause. It would not seem possible for time to progress, or if it were possible, it would be indefinable.What do you all think?

Yeah, it is for me too. Its not an easy subject to get into without getting into high level physics, I suppose.Motion has to be a property of matter. Consider that if electons did not orbit the nucleus of an atom, just fell into it and the entire atom was stationary, it would not really be an atom. It would not be able to form molecules, and who knows what would happen to the atom itself. And any motion requires some amount of time to progress.If quantum mechanics does show that a photon or other particle can be in two places at once, is that really travel? One instance of the particle is still at its original location. If a particle DID happen to be in one location, then instantly make it to some other far off location, was it REALLY instantaneously, or just so fast that current measuring methods or brain computations cannot detect it? And it also depends on the mode of travel, whether it be interdimensional or otherwise. If the travel occurs to some place we cannot detect, it still takes time, just not that we can measure.I guess the real question is whether motion is a requirement of time, or if time is independent of motion. If motion is a requirement of time, does time actually progress? Couldn't it all just be motion, and we're using a concept of time to measure it?What would this mean for the space-time continuum? Its not the motion that takes so much time to pass, its the travel of light that is a limit to our observation. Consider a galaxy. We see it as a disk of stars deep in space, as a single entity in time, but really, the far side of the galaxy is 100,000 years or more older than the near side. Its kind of crazy when you think about it. There must be some visual distortion from that effect, yet, we always comtemplate galaxies as disks. Would they look any different if we could see the entire galaxy as it was in one moment in time?Sorry for all the questions, its just that I've been waiting so long to ask them. Thanks for all the responses.

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"Beliefs - they're the bullets of the wicked." - SOAD

fgarb:
Just to be strictly correct, I think most physicists would not say a photon is matter, yet motion is a property of the photon as well.True. I didn't mean that motion was a property of matter exclusively. If space is expanding, which is devoid of any matter at all, then that would also count as motion. It would probably be more correct to say that motion was a property of the universe in general.fgarb
I still would argue that quantum mechanics does not allow that, at least based on my interpretation of your wording. I checked in on the info from that article that I had seen, and I had either misinterpreted it, or was misled. Its not the particle itself that travels, its just that the information of the particle (in this case, photons) instantly correlates to another particle at some distance away. Quantum entanglement apparently. I don't know if this qualifies as motion or not, but a particle changes states due to received information from a distance instaneously (or seemingly so).If this is the case, then the distant particle is at one state one instant and a completely different state the next. Instants for us might be inperceivably small, but not completely T0 to T0prime, meaning: from one instant to the very next possible instant. Perception affects time interpretation quite a bit.I saw a show once, one of those mythbuster type shows, that set out to verify or debunk the myth that time slows down for people that think they are about to die. They had an LCD display that flashed a random number fast enough that it was unreadable. Then they gave the display to a guy and hoisted him up a couple hundred feet in the air in a harness, then had him stare at the display to see if he could tell what the number was while he was in freefall. Turns out he could, and even when he was off, he chose a number very close in shape to the actual number.It could just be that in a danger state, the brain picks up and interprets more information per time slot than usual, hence the perceived 'slowing' down of time. And if time, and therefore change, is simply a matter of perception, time and/or motion could seem different for any other creature. Ever wonder how bumblebees can fly such jagged patterns so quickly, or how a flock of birds can perform such pinpoint aerial manuevers without bumping into each other? They could perceive a LOT more motion and process that info much quicker than we can.

Yep. And that different brains could perceive time and motion much faster or slower than we do.Say you were a giant. A giant so big that a galaxy was about the size of your hand. When you, as this giant, look at a galaxy, would it move very slowly as it does for us here on Earth? I wouldn't think so. A brain that large would not process the visual info as fast as we Earthlings do, because it would take longer for the optic nerve to send that info to the brain and longer for the brain to fire the synapses to process it. So while this giant is watching the galaxy, its brain processes a view of the galaxy and before the brain can process the next wave of info coming in, the galaxy has moved further. Much further than it does when we normal-size beings look at it. So it takes those 2 images, interpolates the movement in between, as our brains do, and sees it has moved somewhat further than we would perceive it with our brain under that same process.On the opposite end, you have a fly. Its very hard for us to squash a fly with our hand, though we are moving very quick in our frame of reference. The fly moves because it can feel the pressure wave of air caused by the incoming hand and is able to fly away before our hand touches down. Perhaps a fly is really just perceiving so much info in that same instant that we appear to be in slow motion a bit. Ever see the first Spiderman movie? Where the bully picks on Peter Parker soon after he is bitten and the bully tries to punch him? Peter is able to easily dodge the incoming fist and watches as it slowly moves by him. I know thats a movie and not real science, but thats the point Im trying to make. Amazing! Considering that time could be fractioned down infinitely, I guess theres really no reason to think that any amount of motion could ever occur without some passage of time, no matter how small.There always has to be motion in the universe. Even though the desk in front of me is completely stationary, the atoms of the desk are moving. And perhaps since motion can never cease, this is why people feel that time is its own separate entity. Things must always move and they move constantly in succession. Like we can never sense a 'present' point in time, its all just the past and the future, because any 'present' moment has moved continually.

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"Beliefs - they're the bullets of the wicked." - SOAD