Australian Time Scientist Says that Time "Passing" is an Illusion

[Rob Caswell]

Professor Kristie Miller, at the University of Sydney, says that the universe exists in spacetime "blocks" and the passage of time is an illusion based simply on which block you inhabit.

I'm not sure that's exactly what it says. Rather, it suggests that time is an actual dimension in the sense that height, length, and width are. It exists and has a definite limits. The problem I see with this idea is that the mass of the block universe is unimaginable large... if I read this right/ The mass of the block time universe would be TOTAL LENGTH OF UNIVERSE TIME / PLANCK TIME x THE MASS OF THE ENTIRE UNIVERSE. For all intents and purposes, that's infinity.

I'm not sure what the block universe attempts to explain/answer, aside from offering a rationale for time travel. It seems to me, on first blush, to create more problems than it answers any questions.

 

[OverTheTop]

Maybe it is a more understandable version of the tesseract, where all possible outcomes of every decision all exist at once, in their own universes (parallel universes theory)

 

[Thundercloud]

I'm not sure what the block universe attempts to explain/answer, aside from offering a rationale for time travel. It seems to me, on first blush, to create more problems than it answers any questions.

From Relativity, we know that the rate that time passes is not absolute, it is relative. From this we arrive at the relativity of simultaneity, which is a fancy way of saying that two observers moving relative to each other, will not agree on which events are simultaneous. From this we can reason that one person’s “now” is not the same as another person’s “now” if they are moving relative to each other.

In our everyday life of slow-moving objects, this difference might only be a trillionth of a second, but it is real none the less. As we travel further and further away from Earth at higher and higher speeds, this time difference will become more significant.

My “present” might be your future (slightly) and if I change directions, my present might be your past. The notion of “now” becomes almost meaningless, and the past and future both become current and real.

In the block universe, each “now” is a slice in the block perpendicular to the flow of time for that observer, and each event in that slice is simultaneous for that observer.

If I get out of my chair and start moving, my “now slice” will change to a slightly different angle, and things that would have appeared simultaneous if I was at rest, will no longer appear simultaneous.

 

[brockrwood]

What I think professor Miller is doing is simply denying that time is different from the spatial dimensions. If you get rid of the notion of space and time as two different things and just call all dimensions, including time, “spacetime”, then the Universe, past, present, and future, simply “is”.

There is no time passing because there is no “when” (time), there is only “where” (location). Why? Because “when” you are at a particular point in space, and when you are not, is part of the definition of “location”. You are located at a place in “spacetime”.

But didn’t Einstein already come up with thus concept a hundred years ago?

 

[brockrwood]

https://quotefancy.com/quote/238703...ime-flowing-or-passing-What-we-experience-are

 

[brockrwood]

 

[aerostadt]

From special relativity, paying attention to the Lorentz transformations, the relativistic invariant can be derived. This invariant being a function of the distance and time between two events is the same in "all" inertial frames. This invariant in its most general form can be expressed as a 4x4 tensor called the metric tensor. The metric tensor is the starting point of General Relativity and the mathematics get very complicated thereafter. Interestingly enough the metric tensor for the time component contains "i" or the square root of negative one (an imaginary number). One interpretation throughout mathematics is that purely imaginary numbers are on an axis perpendicular to the real numbers. I don't know about you, but I cannot imagine 4-D space, although there are many diagrams out there that are drawn on a 2-D plane claiming to describe 4-D space. In any case the fact that time is in the invariant (multiplied by the speed of light) it looks like a dimension. One could say that because the metric tensor of time has "i", it is a dimension that is perpendicular to the other 3 spatial dimensions. I think I have seen physicists in recent years talk about the first 3 dimensions and time. I like this way of talking, because it seems to say that although time is a dimension it is something different than the first three dimensions.

 

[ThirstyBarbarian]

I like the multiverse. Except for the one with hotdogs for fingers. Or the multiverse of madness.

 

[Ronz Rocketz]

Maybe God has been around so long that he knows everything.



The pinnacle of time…

 

[Thundercloud]

1. Groundhog Day is my favorite movie. I watched it over and over. How ironic.
2. I have mostly thought that time is indeed a fourth dimension, just like the other three, and it just happens be the direction that Time randomly started progressing in. I don't have much to support that viewpoint though.
3. If time is a dimension, it must somehow be perpendicular to the other three. I never heard of the imaginary number thing, but it's interesting that it might support this fourth dimension idea.
4. Time does seem to be different than the other three dimensions, but I don't know if it is intrinsically different, or just seems different because Time just happens to be flowing in that direction.

 

[aerostadt]

I tend to believe that time is unfolding and that there is a "Now". I tend to believe that General Relativity and the Big Bang points to this. To the best of my knowledge Einstein did not talk about this even though he is the one who introduced General Relativity to the world. The Big Bang is a unique explosion, if you want to call it that, because it creates the very space (3-D) that it explodes into. Not only that, but it creates the very time that it explodes into. Time did not exist before the Big Bang. An interesting book to read on this subject is "Now, The Physics of Time" (2016), by Richard A. Muller. He discusses many things throughout the book, for example, Entropy and the arrow of time. Even if you adhere to the Block Universe idea, you still need to recognize that there is an arrow of time. Finally, Prof. Muller comes out in the last chapter of this book and I think says that time is unfolding for the reason I just stated. I went back and looked at my copy of, "Time Reborn" (2013), by Lee Smolin (a well-known leader in contemporary physics). (He also shows the time-slice idea mentioned in post #26 & 33). However, with a quick perusual of the book I cannot find where he says that he tends to believe that time is unfolding, but I think he said that, too.

 

[ThirstyBarbarian]

2. I have mostly thought that time is indeed a fourth dimension, just like the other three, and it just happens be the direction that Time randomly started progressing in. I don't have much to support that viewpoint though.

Someone once told me that time is a 4th spatial dimension, just like the 3 dimensions that we perceive as space, but we are traveling through that dimension at the speed of light, so it’s compressed into nothingness. That’s why we don’t perceive it as space, and we perceive it as time.

He said we are always traveling at the speed of light, and when we move at any speed through the dimensions we perceive as space, it’s not that we’ve changed speed, we’ve just changed direction slightly so that a component of our lighstpeed velocity vector is now pointing through the spatial dimensions, not just the dimension we perceive as time.

And when you start traveling through space so close to the speed of light that you start to see relativistic effects, like space compression and time dilation, it’s because the vector has just been dramatically changed so that a very large component is pointing through space, and a much smaller component is pointing through time.

Dude seemed high to me at the time.

 

[aerostadt]

You had me going there, Thirsty, until I read the punch line.

 

[Thundercloud]

In reply to post #42, I never heard of the “compressed into nothingness” idea, I’ll have to think about that one some more! However, I think the rest was very well said, and I happen to agree with it. No punchline needed.

One reason that I like it, is that I tried using this speed of light vector idea to derive the Lorentz equation, and it worked (see attached). The Lorentz equation tells us the factor by which time slows for any given velocity.

I plotted velocity thru time on the y-axis, and velocity thru space on the x-axis, and assumed that we all travel thru spacetime at exactly the speed of light at all times. I made a right triangle in the first quadrant with the velocity thru time the horizontal leg, the velocity thru time the vert leg, and the hypotenuse the speed of light. I solved for the ratio of the hypotenuse over the vertical leg and got the equation for “Gamma” otherwise known as the Lorentz factor.

This derivation is typically done using the photon clock idea, but the speed of light vector idea worked in very much the same way.

 

[ThirstyBarbarian]

In reply to post #42, I never heard of the “compressed into nothingness” idea, I’ll have to think about that one some more! However, I think the rest was very well said, and I happen to agree with it. No punchline needed.

One reason that I like it, is that I tried using this speed of light vector idea to derive the Lorentz equation, and it worked (see attached). The Lorentz equation tells us the factor by which time slows for any given velocity.

I plotted velocity thru time on the y-axis, and velocity thru space on the x-axis, and assumed that we all travel thru spacetime at exactly the speed of light at all times. I made a right triangle in the first quadrant with the velocity thru time the horizontal leg, the velocity thru time the vert leg, and the hypotenuse the speed of light. I solved for the ratio of the hypotenuse over the vertical leg and got the equation for “Gamma” otherwise known as the Lorentz factor.

This derivation is typically done using the photon clock idea, but the speed of light vector idea worked in very much the same way.

There is a decent chance that the guy who was telling me about this stuff knew something about what he was talking about. He was well-read, but also a bit wacko. And this was about 30 years ago, so at best, I only remember the outline of what he was describing.

 

[Thundercloud]

I am impressed with your ability to recall this from 30 years ago, especially since you don't seem to completely buy into it. I was unaware of such concepts until just a couple years ago. I guess I didn't know the right wackos!

I have thought some more about the idea: "that time is a 4th spatial dimension, just like the 3 dimensions that we perceive as space, but we are traveling through that dimension at the speed of light, so it’s compressed into nothingness." I like it because it offers at least some explanation for how a fourth dimension can exist yet be invisible to us. At the speed of light, the Lorentz contraction makes length in the direction of travel zero.

 

[Daddyisabar]

What I need to know is if there is any way a liberal arts major could use this hypothesis/theory to get his oddroc easily passed by the RSO table?

 

[Thundercloud]

Funny!

 

[aerostadt]

I really don't like the idea that our reference frame is traveling at the speed of light. For the sake of argument I'll say that our reference frame is an inertial reference frame. Then within the context of Special Relativity it doesn't make sense to say that we are moving at the speed of light. You immediately have to ask yourself, we are speeding relative to "what". If you say that we are moving at the speed of light relative to some "absolute" space, you have immediately violated Special Relativity, because there is no such thing as "Absolute Space". All inertial reference frames are equivalent. None is preferred over any other. For all practical purposes if you are standing still in your inertial reference frame, your velocity is zero. Think if you are sitting in a train or plane moving at a constant speed. For all practical purposes, your velocity is essentially zero. If you say that we are moving at the speed of light or any other speed for that matter, you are going back to the old of an aether. That idea was given up over a hundred years ago.

 

[Funkworks]

All the answers are in here:

 

[brockrwood]

All the answers are in here:

Philomena Cunk is hilarious!

 

[aerostadt]

What I need to know is if there is any way a liberal arts major could use this hypothesis/theory to get his oddroc easily passed by the RSO table?

If so, there might still be hope for me.

 

[aerostadt]

All the answers are in here:

I am not sure that all the answers are there, but I love Philomena's expression after asking about the time on her watch.

The British government and Navy realized hundred of years ago that if they could keep Greenwich time on their boats, the difference between Greenwich time and local time as established by the height of the sun in the sky could give them longitude. This was invaluable naval info. So much so that the Crown offered prize money to the first person to invent a clock that could keep time on a swaying ship at sea.

 

[Thundercloud]

I really don't like the idea that our reference frame is traveling at the speed of light. For the sake of argument I'll say that our reference frame is an inertial reference frame. Then within the context of Special Relativity it doesn't make sense to say that we are moving at the speed of light. You immediately have to ask yourself, we are speeding relative to "what". If you say that we are moving at the speed of light relative to some "absolute" space, you have immediately violated Special Relativity, because there is no such thing as "Absolute Space". All inertial reference frames are equivalent. None is preferred over any other. For all practical purposes if you are standing still in your inertial reference frame, your velocity is zero. Think if you are sitting in a train or plane moving at a constant speed. For all practical purposes, your velocity is essentially zero. If you say that we are moving at the speed of light or any other speed for that matter, you are going back to the old of an aether. That idea was given up over a hundred years ago.

I am struggling to form a rebuttal. Below is a link to a very good video on this topic, but unfortunately, it still doesn't address your exact concern, which is speed thru time relative to what? In the video, I think she is saying that the math tells her that our speed through time is invariant, just light the speed of light through space is invariant. In other words, just trust the math. Not very satisfying.



Let's back up at little. If you believe in general relativity, you must believe in space-time. How can one begin to understand gravity without attempting to visualize us literally traveling thru time? Maybe we are speeding away from our own past events at the speed of light. A therapist would have a hay-day with that one!

 

[Funkworks]

I am not sure that all the answers are there, but I love Philomena's expression after asking about the time on her watch.

The British government and Navy realized hundred of years ago that if they could keep Greenwich time on their boats, the difference between Greenwich time and local time as established by the height of the sun in the sky could give them longitude. This was invaluable naval info. So much so that the Crown offered prize money to the first person to invent a clock that could keep time on a swaying ship at sea.

Philomena is a character played by an actress. The video is 100% comedy.

However, I disagree with "we know it's possible to travel into the future just by travelling very fast."
... It may appear to you that you've jumped to the future, but to others not really.

To others, it would appear that you're from the past. Travelling near light speed and coming back to where you started would indeed bring you to the future.

... If you believe in general relativity, you must believe in space-time. How can one begin to understand gravity without attempting to visualize us literally traveling thru time? Maybe we are speeding away from our own past events at the speed of light. A therapist would have a hay-day with that one!

According to GR, light curves in a gravitational field, and this is the 1919 observation showing that star light curves in the Sun's gravitational field. GR is simply the only explanation we have for that observation (and others).

Lately, the definition of time I go by, and that works for me, is that a unit of time is what distinguishes one cycle from another cycle, where a cycle is an event repeating in a vacuum. Example A of a cycle: one rotation of the Earth. Example B of a cycle: one cycle of an electromagnetic wave in a vaccum. Sort of consistent with the beginning of this video:

 

[aerostadt]

I am amazed Thundercloud that you found this video. Examining this critically I do not learn anything new. Speed or v= dx/dt ,which she states early in her video. Defining a new quantity ds/dt or the invariant divided by dt can be done, but it does not tell me anything new. I would write the invariant as

(ds)^2 = (dx)^2 + (dy)^2 + (dz)^2 - (ct)^2

If this is written with the metric tensor like what the vast majority of physicists would do, you get the following:
ds = dr + ic dt with dr = sqrt( dx^2 + dy^2 + dz^2) (I and others disagree with her signs in this equation, but let's move on. Yes, Physicists often drop the i and the c in this equation when discussing with each other, but the terms are really still there.)

If you write this in the most general way with the metric tensor assuming coordinate systems that are tilted with respect to each other, we get off-diagonal components, but we won't go there. Ds is the invariant. The invariant between two events is the same in all inertial reference frames. Peter Bergman shows in his book, "The Riddle of Gravitation" (1992) Appendix 3 that the invariant is consistent with the Lorentz transformations. The Invariant squared between events can be negative, zero, or positive. Physicists assign the description of time-like, light-like, or space-like, depending on the value of the Invariant squared. This is nothing new. Likewise, if the Invariant between two events is zero it is called light-like. This is nothing new. Dividing ds by dt doesn't really tell me anything. One paradox comes to mind right away. As I recall if I take off from Earth and travel to Alpha Centuri at an appreciable fraction of the speed of light and land back on earth. And then I calculate my velocity based on the known distance as measured on Earth by my elapsed time. I will find that I have traveled faster than speed of light. That is because I am using "my" elapsed time. You have to be careful here, there are definitions in Relativity for "proper" time and "improper" time.

 

[aerostadt]

Someone can always come up with new ideas to replace Relativity. If something is really good you might want to rush off and submit a technical paper to the next big national or international physics convention for peer review. However, before you spend a lot of work doing so, I would note that there has been many "alternative theories for special relativity" (some are discussed in Lee Smolin's book, "The Trouble with Physics" (2006) or you can Google the subject on the internet), but after over a 100 years the vast majority of physicists agree that no other theories fit the measured data as well as Einstein's Relativity.

 

[rcktnut]

I don't spend much time thinking about time or gravity, waste of time!!

 

[Thundercloud]

Things that I learn about Time and Gravity don't affect how I live my life, so you could say that they don't matter. I guess I am just curious, and it is a hobby. I am not trying to invent new theories, just trying to understand the ones that are well supported, and the ones that can be understood by a non-physicist like me. I am trying to be somewhat careful not to fall into giant rabbit holes which would frustrate me to the point of not having fun anymore. I suppose, if I find myself trying to answer questions that still puzzle the pros, that should serve as some sort of sign. If I am learning and having good conversations about it, it's not a waste of time to me.

 

[Funkworks]

On a related note, I recently watched this video which really helped me visualize how standing waves relate to electron orbitals. It's probably just a crude analogy for a professional physicist, but it was just my speed!

For what it's worth, I've taught the subject matter of that video (introductory QM) and everything about it sounds great. Using a circular wire (instead of a linear string) to demonstrate standing waves is a great idea. All it's missing is a semester's worth of equations supporting the ideas.