No, relativity makes sense out of relativity. From what I read of those philosophers, they’re making nonsense out of it.
Quoth DSeid:
The Planck units get way overhyped. We don’t know whether spacetime is quantized, and even if it is, it may well be in a manner much more subtle than a simple grid. And even if spacetime is quantized in a simple manner, we don’t know what scale it’s quantized on. All the Planck time (or Planck length) is, is a plausible back-of-the-envelope guess for what the quantization scale might be in the general vicinity of, if spacetime has a quantization scale at all.
And Douglas Adams had the Whole General Sort of Mish Mash (if I quoted that correctly), within which different beings perceive different bits. (Oh, so you see time as going THAT way, kind of thing.) It may be time for me to read that again. There’s good news and bad news about having a bad memory. The good news is that when you read it again, you get to discover it all over again.
Philosophers are aware of planck time and quantum physics. I’m not sure why you (or DSeid?) believes that this changes anything in the argument. It’s a measurement of how far light travels during this period.
The interesting thing is that DSeid suggests that some some theoreticians believe that any event shorter than a Planck length does not exist, which would support the A theory (presentist theory):
Ahh, but if time is illusory then can any of time’s derivative works be real? I think not. Therefore, tempo is also an illusion and the commas were used for no reason.
A hologram’s three dimensional, yet it’s carried on some two dimensional substrate. For certain meanings of ‘illusion’, one could well say that the third dimension is one in this case.
Very good discussion on that in Brian Greene’s The Fabric of the Cosmos, p. 49*.*
A good chunk of the book is devoted to the discussion about the flow of time. The entire book* From Eternity to Here* by Sean Carroll also addresses the subject.
It means that to describe an exact location you must give coordinates, in x, y, z, and t. If you leave out t, then then you can’t specify the location of a point-sized object. So a physical dimension is one of these four. Other conceptual dimensions exist mathematically but we don’t know of any other physical, macroscopic dimensions required to describe our world.
It’s nice analogy, just I think you got to be careful because Brian Greene does a bit of a switcheroo with his definitions when describing an objects ‘speed in spacetime’
That depends on your definitions. One often has call, for instance, to work in phase space, where there are three dimensions for an object’s position, and three more for its velocity or momentum. And the momentum in such a case is certainly physical, and can be macroscopic.
Okay that’s fair enough, I would say that the number of dimensions of an object defined as the number of ordered scalars needed to continiously parametrize it is a fairly decent working definition.
but relatvity has been mentioned. In relativity one t coordinate is not necessarily the same as another t cooridinate. Further still you can have weird coordinate systems were the basis vector fields can’t be grouped nicely in to 3 spacelike vector fields and 1 timelike vector field.
In the context of relatvity itt doesn’t even mean anything to say time is a dimension except in a vague sense. So perhaps it isn’t such a great description.
You can’t move through space if the passage of time is an illusion. I think the question in the OP is: is what we perceive as the continual unstoppable progress though the dimension of time (assuming time IS a dimension) actually what happens, and/or do the past and the future exist in some objective way and is “the present” an illusion?
On the other hand, I may have just confused the matter even more.
I also recommend this book, that is where most of my ideas on this topic come from. Here is a summary of what I remember (combined with my own ideas):
Time itself is real of course, it’s one of the dimensions of spacetime. What is an illusion is the following set of ideas:
The past is over and done with
The present is happening right now
The future is still to be determined.
Everything we know about physics tells us that spacetime as a whole simply exists. The future is no more changeable than the past. There is nothing special about any point in time, just as there is nothing special about any particular point or direction in space. However, one unique thing about time is that entropy increases in one direction and decreases in the other. The perception of the flow of time hinges on entropy. We remember the past and do not remember the future due to the effect of entropy on the brain. This makes the future impossible for us to predict, whereas the past can be remembered. What we interpret as the “present” is then the boundary of what is remembered at a particular point in spacetime.
At the end of the day, while the flow of time is not occurring in an absolute sense, the effect from our perspective is that it might as well be. But this explanation leaves the door open for finding a region of spacetime where entropy increases in the opposite direction, or building a machine to affect entropy.
Not arguing with what you say in general, but the past is determinate, and the future isn’t. And we remember the past because it has changed our brains through our experiences, while we haven’t experienced the future yet. That’s how we percieve the flow of time.
You may not think you’re arguing, but your statement directly contradicts the idea that spacetime as a whole exists. Either it’s true or it isn’t, but as I said, the math behind the currently accepted theories of physics suggest that it all exists. If the future exists then it is determined just as much as the past. Predicting the future and remembering the past are equivalent operations in the two different directions of time. Why can we do one and not the other? The same reason that eggs regularly get smashed to bits, but a bunch of egg fragments never seem to converge into a solid egg. Entropy.
