Is Time Only an Illusion?

0:00College football is back. So, Hilton called to me the superstition concierge to make your fan rituals a reality. Need a room to match your lucky number? We got you. Want to make sure our team doesn't wash your lucky jersey? Oho, that smells lucky. Hilton's unmatched hospitality can keep up with any superstition. Even a marching bandwink up call it 555 and 55 seconds. Hit it! When you need a team that will do whatever it takes on game day, it matters where you stay. Hilton, for this day. Good things come in force. Like ukulele strings, boy band members. Oh yeah! And PayPal payin' for. No fees, no interest, no impact on your credit score. Just the flexibility to pay the way that works for you. Strum it, hum it, pay it in for. Download the PayPal app to get started. Subject to approval. Learn more at paypal.com slash payin' for. Paypalling. NMLS 910457. To tease Spooky season October for this year, here's one of the great questions I have regarding physics.

1:04And in some ways, the implications of it are spooky, in that it would mean a fundamental reality that we live by every day might in fact just be an illusion. The subject here is time. And I have found that the definition of time and physics varies by what scientists you ask. Because there are so many unknowns regarding it. Is it a dimension? Is it a process? Doesn't exist at all. It used to be, and in fact was a major assumption made by Sir Isaac Newton, the time was separate from us, and ticked at the same rate everywhere in the universe, no matter where you went. That perception changed in one way within physics. But to us, in everyday life, it did not. We still live in the phenomenology of time, planning our days, counting the minutes of the clock until the workday is finished, what month it is, and so on. Our life very much is intertwined with how we see time in everyday life. When awake at least, we are always conscious of the passage of time unless something is wrong.

2:08But Albert Einstein changed all of this with relativity on the physics count. It turns out here, Newton was wrong. Because as assumption about time was incorrect, and it turned out crucial to a better understanding of the universe. This problem first reared its head with the planet Mercury. Mercury was not behaving according to Newton's laws. The same scientists are Bain Leverier, that calculated the discrepancy in the orbits of the outer solar system planets, that led him to discovered Neptune, noticed a discrepancy in the procession of the perihelion of Mercury. Say that ten times fast. Basically, Mercury was misbehaving, and it still is. You can still measure this with modern telescopes, even amateur ones if you want to. Leverier did this in 1846. This led Leverier to suggest that there must be another planet inside the orbit of Mercury, or a ring of debris, tugging on Mercury.

3:09This fabled planet was fraught with claims of observations that could not be repeated, and many other things. And it frankly turned out that it simply isn't there. That left a real mystery that lasted decades that no one had any idea how Mercury was doing this. And then the answer came from nowhere in 1915. It was doing that from our perspective, but it isn't actually doing anything out of the ordinary inherently, because of an effect of general relativity, and provided one of the first confirmations of general relativity. Mercury's behavior is functioning in lockstep, with the prediction of it in general relativity. It's not functioning in lockstep with Newton from our perspective, though in its own form of reference, it is, hence relativity. It's actually a surprisingly simple concept. Einstein found that space and time are linked, hence the term space time. Think of it like this. If you walk across a space, say a football field, that takes time.

4:12You can go faster and contract that time, but it will still always take time, even if you were near the speed of light. It would take a tiny amount of time to cross it. That is a gross oversimplification and not the best analogy admittedly, but at least an understandable one. Time and space are linked. Well, we know that to be the case for this reason. So special relativity deals with speed. The faster you go, time ticks at a different rate. General relativity deals with gravity. There, the greater the gravitational field, the more time ticks at a different rate from the space outside the well. This is time dilation. We know this is real because the GPS system in our cars must compensate for relativity with its clocks or it ends up wrong. If you correct for it exactly according to relativity, you get the right answer and the correction works. Do it according to Newton and the system very quickly goes haywire. This is just one of the many proofs of Einstein, but this is the one we use every day.

5:14And if you have a GPS in your car, you are using relativity as an applied science. In short, speed and gravity do not just affect space, they also affect time. That would seem to suggest the time is, in fact, a something. It exists, but more on that in a bit. What never appears in any of this, however, is the fundamental human perception of now. It simply doesn't exist in physics. There is only the future in the past, there is no now. It cannot be expressed as we perceive it as humans in physics and simply doesn't exist there. Think of it like this. Your brain perceives now, but it actually doesn't. It takes time for signals to cross your synapses, just as it does for light input into your eyes. The present is, in fact, an illusion, but it gets worse. You see the world as it was when that light left the table across the room, but you don't see the table as it really is at the moment you are looking at it. Instead, you see it in the past, even though it is the extremely recent past, tiny fractions of a second.

6:18But when you do see it, your brain has to process what it's seeing, and as a result, even though it feels like now to us, the present is actually a trick of the brain and perception. It isn't real. It's an amalgam of times, depending on your distance from objects, delayed and processed by your brain into an aggregate that you believe is the present. One thing we do know in all this is that time seems to have a definite direction. It's called the arrow of time and physics, and it always points forward in the universe. You are always moving into the future. To this day, it's unclear why, but it is perhaps telling that everything in the universe is running on entropy, and cause always comes before the effect. But in physics itself, it could go either way. The math works backwards and forwards, but nature isn't doing that, but we don't know the reason why. But then there is entropy, which suggests time itself is real if not the present. That's thermodynamics and does not run backwards.

7:18If you drop an egg, it will not unbreak itself, no matter how long you stare at it. You can't make it do it. Everything goes from an ordered state to a disordered state, eventually, including basically the universe itself. Here though, there is often a tendency to define time as a fourth dimension, especially within the framework of string theory. After all, space has three dimensions, and may be more according to some ideas, but time is a fourth. But it may not actually be an accurate way to describe time. It may not be a dimension at all. Rather, just a measure of entropy. But that is where we leave what we know, and for time, that is very little. All we really know is that through relativity, space and time are locked together, and you can move around space in its dimensions, but at the same time, well, time responds, and you can move around within it through time dilation, but there are limits there, only forwards. You can't go back. There doesn't seem to be a way to go backwards in time, so it's limited in some way, as a dimension, if it is one.

8:23It does not let you back out of its driveway. There is also another aspect of time that is sometimes brought up. What if you were able to stop every particle in its tracks, every moving atom, and just freeze it there? Would time stop? The answers that, while it would look, like it stopped, at least at the atomic scale, it hasn't stopped at the quantum mechanical scale. Say you had an unstable atom in the mix, just sitting there, say it's uranium. At some point, no matter what, it will spontaneously decay, marking time. The quantum world stops for no one, suggesting again, perhaps that the idea of time as a mark of entropy is very much real, even if it sometimes appears to be an illusion. But also, no matter what, the expansion of the universe also continues even if you stop everything. And there is no known way to stop that, it will mark time. So in the end, basically all you can say about time as we perceive it is that it is what a clock reads.

9:23It's a measurement useful for us, one of the most useful things we do, really. And we've done it ever since early man watched the sun to mark the day, but oddly, it may not be useful to aliens. In fact, they may have a very different conception of it entirely, if any at all. The only reason we set time the way we do is the scale we work on. We tend to work on a day, as in Earth's 24 hour cycle, but that cycle is unique to Earth. What does an alien species with a circadian rhythm that works on 200 days look like? Or how about a species native to a tidally locked world, at the equator that world in permanent twilight? How do they perceive time? Is it timeless without a day? Or do they understand entropy and measure it directly from that? The bottom line, it would be impossible to explain our version of understanding time to them. And likewise, they may not be able to explain theirs to us.

10:23Especially if their view of time is greatly sped up compared to how the human brain sees it, or very much slowed down. This very basic difference is probably worse than trying to figure out alien communications, or even their math. Because the commonality of time is crucial for how fast you could determine any kind of information from an alien. If they only send one bit of data every 400 years, it's going to take many, many thousands, if not millions of years, just to figure out they are saying hello. Because their timing is off from ours. Still no matter what, if time stopped there would still be something happening because of the rules of quantum mechanics. Time stops for no one, and importantly, the universe continues to expand. And that tells us that time is something rather than nothing, and that it warps and speeds up and is linked to space. Which also is something rather than nothing, that at least some dimension of the concept of time probably is not an illusion.

11:24But I leave you with this. If time is only an illusion, or something superficial, does that mean the idea of time travel is an illusion as well, a red herring? That does seem to be what nature is saying to us, food for thought. Thanks for listening. I'm science fiction author and futurist John Michael Goedea complaining that I never have enough time for anything. Life would have been so much easier and more productive if Earth had chosen to have a longer day. And be sure to check out my books at your favorite online book retailer and subscribe to my channel, Cirregular, Inteth Explorations, and of the interesting, weird and unknown aspects of this amazing universe in which we live. It's football season, and you can now get almost anything you need for game day delivered with Uber Eats. What do we mean by almost? You can't get a running back delivered, but you can get baby back ribs delivered. A strong defense? No. A strong deodorant? Yes. The six pack of abs? No. Six pack of beer? Yes.

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