[swansont]

That isn't time ticking, though, is it. It's just atomic decay.

Not decay; it's a spin-flip of the electron.  But there's nothing inherently fundamental about the choice of Cesium or that transition — that was one of utility (it's a measurement which can be realized with good precision and accuracy)

[LeeE]

The idea of zero-length objects does seem to be very counter-intuitive but they seem to be implicit in any theory that can handle n dimensions; that is, any theory that isn't limited to just three spatial dimensions, no more and no less.

If we consider a three-dimensional object, everything seems fine; that's how the universe appears to us, but then how long is that three dimensional object in the fourth, fifth, sixth etc. dimension?

The existence of 'n' dimensions is debatable, of course, but we do accept four-dimensional space-time, so it's valid to ask the question; "How long is a three-dimensional object in the fourth dimension?

Interestingly, the idea of zero-length avoids a big problem that appears in n-dimensional theory that occurs if one insists on a QM style non-zero sized object; if an object has to have some size in every dimension then every object must exist in all of an infinite number of dimensions, unless the number of dimensions is arbitrarily limited.  If you allow zero-length in a dimension though, you then don't need the object to exist in all of an infinite number of dimensions because it can have zero length and presence in them.

[DoctorBeaver]

That isn't time ticking, though, is it. It's just atomic decay.

Not decay; it's a spin-flip of the electron.  But there's nothing inherently fundamental about the choice of Cesium or that transition — that was one of utility (it's a measurement which can be realized with good precision and accuracy)

Oh, sorry. I thought it was atomic decay.

[yor_on]

LeeE that sounds like it's coming from string theory?
I guess we need the concept of zero-length to explain how we can have those 'curled up' dimensions existing simultaneously with us, presuming that an object needs to be spatially extent in all dimensions. If we look at it as some does with photons, there, but only at the moment of interaction then it seems to become another question. As photons could be said to represent a 'zero length' object.
Or a photon 'somewhere else' might be seen as only one filling up that dimension totally, perhaps?

[DoctorBeaver]

If we consider a three-dimensional object, everything seems fine; that's how the universe appears to us, but then how long is that three dimensional object in the fourth, fifth, sixth etc. dimension?

It isn't "long" at all in those other dimensions. It will demonstrate an increase in mass proportional to its motion in other dimensions.

I often wonder about the heavier types of particle in the Standard Model; the muon, for example. It is identical to the electron apart from its mass. If electrons can travel in spatial dimensions other than the 3 with which we are familiar then their motion would show as increased mass but every other characteristic (charge, spin, etc) would remain the same. Isn't that exactly what we see? (Can we for now ignore the magnetic moment anomalies of the muon? Please?)

There are 3 generations of electron in the Standard Model (electron, muon & tau). Could the disparity in their mass be a function of their motion in our normal dimensions plus 2 other dimensions of different size? For instance, the muon is travelling in the 5th dimension so its mass is increased proportional to the size of that dimension. The tau could be moving in the 6th dimension alone, which would need to be large enough to account for all the tau's extra mass, or combined motion in a 5th & 6th dimension.

[yor_on]

DB, that was real interesting. Are you sure that mass will communicate itself through all dimensions (past the ones we can see:) of an object? Do you have a good link explaining that idea?

[DoctorBeaver]

Rest mass is constant and is a measure of the amount of matter present; that is basic physics. Therefore, however many dimensions a particle can be in, its rest mass will be the same in all of them. But the particle will also have momentum. Momentum is rest mass * velocity (or, rather, rest mass times the sum of its velocities in all dimensions). We can't detect a particle's velocity in another dimension so what we see is an increase in its perceived mass. The faster the particle is moving in another dimension, the greater its momentum and, consequently, we will see it as having greater mass.

[rvt]

Hey All,

do you all saying that indeed time ticks and it not continuously?
I am trying to understand the most out of it.. and also it's very interesting to read about the zero length object....

so far it's great to see the answers and looking forward to read the 'final answer'

regards,
Ries van Twisk

[DoctorBeaver]

oops. Ik verontschuldig me, Ries. I got sidetracked  [:I]

There is no way of proving 1 way or the other whether time ticks or flows smoothly. Any ideas on the subject must be purely hypothetical. My inclination is to say that time is quantised and therefore does not flow in a linear fashion. Others here disagree with me.

Until we know what time is, we won't be able to answer the question. Don't ask me when that is likely to be; we don't even understand gravity yet and that is probably very simple compared to time.

[Burt Brinn]

Hi there.

If I can put my two cents worth in the hat, I don't think time ticks in nature.  The "tick" of time is nothing more than man's insatiable desire to measure everything.  Whether it be a planck length, a second on my watch, a year on my calendar, or a light year, it is nothing more than a measurement.  If we didn't have these "ticks" for measurement, we would have no math. 

Time flows.  Man has ticks.  []

[Vern]

I agree with Burt; time needs to flow smoothly. We have become smitten with Quantumania since we discovered that each certain frequency of electromagnetic phenomena comes in discrete bundles of action. Now we feel a great need to describe everything in terms of quanta.

[Burt Brinn]

Now now!  Don't blame it on the quanta.  Man has been measuring the world around him for thousands of years.  We are just getting better at measuring the quantum world in the last two centuries.

[LeeE]

I think what Doc Beaver was saying about something existing in overlapping but different dimensional sets is perfectly reasonable.  In fact, I think it must probably be a feature of any model that attempts to describe n-dimensional geometries/geodesics.  At least I think that's what he was saying  []

I'm strongly inclined to think that from our point of view, time moves in 'ticks', for the reasons given earlier.  However, what we regard as our time dimension, and which we move through in steps, could as easily be a spatial dimension for something occupying a different but overlapping set of dimensions, where they could move through that same dimension smoothly.

The same sorts of n-dimensional models seem to predict that the higher number of dimensions that something occupies, the higher the total 'quantity' of whatever it's made out of.  For example, if you consider the transformation of mass to energy, you can map it to a three-dimensional object being turned in to many two-dimensional objects, or in the case of electron/positron creation/annihilation, from two very small 3D objects to two very strong 2D objects, all in line with e=mc².

I also think it's interesting that the mathematics itself implies multi-dimensional aspects; in Albert's equation we square something to produce an area, like the length and width of a floor, and then multiply the area by the height of the wall.  You can almost see it building a three-dimensional object.

[DoctorBeaver]

I have since changed my mind about time ticking. I've posted a bit of nonsense about it in the New Theories section

http://www.thenakedscientists.com/forum/index.php?topic=21043.0

[Vern]

You may be right LeeE; but I was kinda hoping that string theory wouldn't really catch on. It is hard enough trying to figure things out in three dimensions plus time. Maybe since we've become familiar with maths and computers where adding another dimension simply requires a comma and a number, we yield to it too readily. []

[DoctorBeaver]

We seem to have been distracted into discussing dimensions rather than whether time ticks. I am as guilty of that as anyone.

[LeeE]

I don't think the issue of whether time ticks or not can meaningfully be discussed without referring to dimensions - it is precisely about the nature of movement through dimensions.

[yor_on]

Well, the idea if dimensions and what they might be defined as is worthy of a discussion on its own I think
We know that time is here, of all dimensions we have time is the one you can't take away. You can choose any optional dimension of those others, and we will still be here, well, maybe disappearing now and then as f ex. width is gone, but mostly here at least. But try to take time away and see what happens, huh...

So 'time' is a very special relation to us, like your favorite aunt perhaps? and as spacetime is a whole as I see it with time, distance, mass, acceleration and motion all being connected to each other through sliding scales, you manipulate one, the others will react / slide. I know that this is not all true, but it's true enough We may not be able to shorten a distance by our own, but we sure can do it by accelerating. And that distance will be shorter for real, no joke, as long as you are in that accelerating frame. And time outside your spaceship will seem to 'speed up'. And that's also for real. So time is not 'only' time, it's in fact  'Spacetime'.

Now if I want to have fun I would split 'spacetime' in three parts. And if I could get away with it I would name all three as 'dimensions' bur as I won't get away with it I will just call them 'states'. Those three are Space, Matter and Time. In this place created by those states we have two exceptional 'exceptions' more, namely, photons, but as I see photons as a secondary state arising from those first three its not a primary, and then gravity, as an expression of the combination of space and matter (as I see it, for now that is, things have been known to change at 'times' and not as a 'force' of its own.

So to me 'time' is the 'cornerstone' together with mass and space. But then I have this feeling that space and mass are one and the same on some strange plane, not as we experience it but there is to me a symmetry in those two, I can't imagine one of them without the other, so to speak, can you? So perhaps in the end, we are down to two 'thingies' here? Time and 'matterspace'

Well, it's just an idea. You don't need to throw things just because one gets an idea...


*Look Mummy, A taaable *

[DoctorBeaver]

I don't think the issue of whether time ticks or not can meaningfully be discussed without referring to dimensions - it is precisely about the nature of movement through dimensions.

Why do you say that? We can discuss spatial dimensions without reference to time, so why not vice versa?

[LeeE]

I don't think the issue of whether time ticks or not can meaningfully be discussed without referring to dimensions - it is precisely about the nature of movement through dimensions.

Why do you say that? We can discuss spatial dimensions without reference to time, so why not vice versa?

I'm not quite sure I understand "why not visa versa"

You can discuss milk without referring to tea, but you can't discuss tea without referring to milk.  But I don't think that's relevant.

However, although I didn't specifically refer to spatial dimensions, there really doesn't seem to be any absolute difference between the spatial and temporal dimensions; it just seems to be that way from our point of view, as the phenomenon of relativistic time-dilation implies.  In any case though, it comes down to the nature of the movement through both spatial and temporal dimensions.  What we term 'time' is the movement through the temporal dimension, and you can't talk about the movement of something without reference to the dimension that it's moving through; the definition of movement is the change of location, and location only has significance in the context of dimensions.