I guess I can tell you why I am posting this question. I am a little perplexed by this article. It proposes that time may not exist.
You know, my fellow board members, I am constantly impressed by your intelligence. I’m serious. And I know it takes a very intelligent person to explain things so the common man can understand it. I think you’ll agree with me on that.
Anyways, I have to ask it in the form of a specific question. So I’ll put it this way. If time doesn’t exist, then what of time dilation then? We studied that in high school. I’ve certainly seen the equations. Seems solid enough to me. And what of hyperspheres in fourth dimensional space? Doesn’t that alone prove time is the fourth dimension? Huh?
Thank you in advance for your kindly and helpful replies
I read that article before, and I don’t even understand the explanation (is there one?) for why time may not exist (though causation without time could, which is even more confounding).
So, I’m no help, but I look forward to the responses that are.
The suggestion there is that time may not exist as a fundamental “thing”, but my actually be an emergent phenomenon arising from some even more fundamental “thing”.
The more fundamental “thing” being suggested is causation, that is, the phenomenon that one event can in turn lead to another event. We are not in the habit of thinking of “causation” as a fundamental thing in the universe, so this means we would all have to get accustomed to a new way of thinking of things.
But there’s nothing unusual about that. Einsteinian relativity forced us all to think about the fundamentals of the universe in ways nobody ever had thought before. Quantum physics likewise. And now this.
Here’s a thought: If physicists have had such an intractable trouble coming up with a theory of gravity after all these years, maybe that tells us that gravity doesn’t really exist.
I’m not sure what this has to do with it. There is all kinds of philosophical and mathematical speculation that the universe may have more than three spatial dimensions. So hyperspheres and hypercubes might be things that can exist is actual space, entirely aside from any time dimension they may have.
Hyperspheres and hypercubes can be described mathematically, as geometrical objects. So theoretically, nothing prevents them from existing. Whether they actually do or not remains to be seen.
On the other hand, if we stick to three space dimensions and one time dimension, we can define “cubes” and “spheres” that have three spatial dimensions and an additional time component. The notion that time exists only an an “emergent” phenomenon does not contradict that, as far as I can see.
@Senegoid, I acknowledge this is my own shortcoming, but I can’t get my head around causation without time. Causation to me suggests a “before” and “after.” Can you clarify, or perhaps provide a thought experiment that might provide an “aha!”?
Are you referring to the suggestion that “emergent phenomenon” requires some explanation?
I’ve seen some good explanations on-line, but now I’ll have to hunt around and see if I can find any again.
The basic idea is that some very fundamental things in the universe, things that may not even be directly visible to us, may combine in ways that form new higher-level things that we do see, that may be very different from their fundamental components.
One example is the idea that matter and energy are not two totally different kinds of “stuff”, but are both made of some even more fundamental kind of “stuff” that isn’t anything like matter or energy as we know it. Thus, when we take a closer look, we discover odd things that defy our common understanding.
For example, we find that energy is made up of “particles” as if it was tiny bits of matter, but they aren’t really particles because if you look at them right they are waves. Then we find that known particles like electrons behave like waves too. And we read about all kinds of strange quantum behavior like superposition, complex probability wave function collapse, and stuff.
So the idea is that, way down there, the universe is made up of stuff totally different than what we are accustomed to see – but those really weird building blocks combine in ways that create quarks, protons, neutrons, electrons, atoms, and bigger matter in ways that we are familiar with.
So, likewise, there could be some really fundamental thing in the universe, “causation”, the phenomenon that events can lead to other events. This may be a basic building block, and “time” may consist of that, just as protons are built of quarks which consist of some kind of quantum complex wave phenomenon.
That’s what “emergent phenomenon” means.
Now – I’ll poke around a bit and see if I can find some good explanations on-line, perhaps a bit more technically accurate.
Here’s an example of emergent phenomena, similar to something I saw explained once:
Consider the Unilever corporate logo:
What do you see? Seen close-up, it looks like a collage of a whole bunch of all-different symbols. (They are supposed to represent all the different kinds of products Unilever makes.)
But take a big step back, and look again. What do you see? Seen from a distance, it’s just the letter “U” (as in Unilever, of course).
Suppose you build a solid object made like this. Stand back and toss a tennis ball at it. How does the tennis ball bounce off? When a bouncy object hits a flat solid surface, it bounces back at an angle equal to the angle at which it hit. The Unilever logo, from a distance, behaves rather like a flat surface, at least when hit by an object of roughly the same size.
But look again up close. The “surface” of the logo has lots of little gaps in it, and the pieces of the logo are all different shapes and sizes and their surfaces are at all different angles. So suppose you shoot a tiny object – like a BB or an electron – at it. It may hit one of the solid pieces and bounce off at an irregular angle. Or it may go into one of the gaps, and eventually hit some interior surface, only to get lost somewhere inside the logo.
The behavior as a flat surface only emerges when the object is seen at a distance, or when relatively large objects interact with it. Seen up close, there is no flat surface there at all.
Likewise, fundamental thingies like quarks may combine to form protons and neutrons that don’t behave at all like simply a bunch of quarks. And these may combine into atoms and molecules, from which we can build things like “tables” (mentioned in the OP’s link), that don’t behave much like individual protons and neutrons. That’s what “emergent phenomena” or “emergent properties” are all about.
The idea in this thread is that time itself may be some kind of phenomenon in the universe that does not exist as a basic thing itself, but arises out of the effects of something more basic.
That may require a whole new way for us to think about such things. But that’s the whole point of the OP’s article: To our usual way of thinking, it’s weird.
I know nothing about this so this may not be at all what they are saying, but here is a way you could have causation with time only existing as an emergent phenomenon. Imagine I drop a ball and time it with a stop watch.
The classical view would be that there is a number line and events are placed at various points on the line. So my dropping a ball occurs at time equals zero when I turn on my stop watch on the number line and it hitting the ground occurs when my stop watch says 1.
But an alternative view would be that there is no number line and events are just stacked up like a deck of cards. One of those cards is my dropping the ball, which happens between the card of my of my starting to press the button on the stop watch and my taking my finger off it. Another card is the ball hitting the ground which occurs between the card of the stop watch saying 0.999 seconds and the one saying 1.001 seconds.
So I say that it took one second for the ball to hit the ground, but there really isn’t any time number line just a series of ordered events but we can define time intervals in terms of reference events and so it feels as though its a continuous line with an associated distance.
Ideas that time might be emergent rather than fundamental are part of the decades-long attempt to go beyond the current formulation of GR (where both space and time are fundamental) and to reconcile it with QM in a unified theory of quantum gravity. For what it’s worth, Lee Smolin has also proposed theories where it’s the other way around - time is fundamental, and space is emergent.
You can’t make a leap from high school physics to the most advanced physics that the greatest physicists in the world can’t figure out. I’ll bet that nothing that got taught in high school decades ago was anything more than the most general approximations of what back then was cutting edge science and today is old hat. Why people believe they can apply one to the other has always mystified me.
The article you cite is a pretty good popular science explanation of one current approach to a subject that has baffled people since Einstein. Time is a problem. Things seem to take place over time periods, but the way things seem to us has proven over and over not the way there are when examined at the deepest levels. One possible answer is that time is a property that makes equations work but is not itself fundamental, or maybe even an illusion.
How does that work? Through math. Not through popular science articles, even those written by a philosopher who “is currently investigating the role of non-causal explanation in the indispensability argument for the existence of mathematical objects, as well as timelessness in theories of quantum gravity and timelessness in metaphysics more generally.” They didn’t teach that in high school.
I subscribe to New Scientist. They regularly run articles about the efforts to try to describe time. Have for years, decades. Nobody’s cracked the mystery yet. We probably won’t know what time is in our lifetimes. I wonder how many lifetimes will need to elapse before some simplified explanation is taught to high schoolers.
(to the OP): I’m a sucker for these kinds of articles too, but you have to appreciate just how tentative such propositions are. We have been trying to come up with a quantum theory of gravity for decades now, and in that time there have been hundreds of pop sci articles like this one.
Plus the need to jazz these things up.
As far as I can understand the article (and it’s likely I haven’t got this completely)…if the decades-old theory of loop quantum gravity is true, then one implication is that one aspect of time (the flow of time?) is not necessary as it is not part of the model. Not ruled out, just not necessary.
Put that way it’s not an exciting headline.
…and of course validating the model will probably happen after the model has been improved or refined. And who knows whether such refinement might involve changing the relationship of time in the model?
