Does having a plank length mean that time ticks forward rather then flow?

[Beamin]

I always found the plank length a fascinating idea. It kind of imply s that we live in a digital universe rather then an analog one. If the smallest unit of length is the plank length then the time it takes for light to travel it is a plank time. The light therefore cant be any unit less then at the beginning or end of the plank length. This would in turn make time tick rather then flow, since if you could divide the plank length up you would have an infinite number of fractions between 0 and 1. It kind of reminds me of super tasks: You have a two minute time scale after 1 minute you turn the light on, then in 30 seconds you turn the light off, 15 seconds you turn the light on, 7.5 light off, 3.75 light on. You keep doing that with smaller and smaller fractions, but at the end of the two minutes is the light on or off? How many steps did you preform? You just did an infinite number of steps in a finite amount of time. You do this until you reach a plank time. This is how I imagine the plank length/time(space/time) works. Is it a paradox or a real thing?

[tom66]

The Planck length is frequently misunderstood.  It does not mean that things are immeasurable below this length or that time cannot be subdivided further.  It's essentially a convenience factor for quantum mechanics.  If you use Planck constants then you can simplify a lot of the maths.

[Benta]

Are you talking about Planck Length?

Planks can be several meters long, depending on their use and on the timber they're made from.

[Beamin]

Are you talking about Planck Length?

Planks can be several meters long, depending on their use and on the timber they're made from.

Ones made from quantum ships keels

[vad]

The interpretation of Plank time is: it is not possible to measure time interval to accuracy better than the Plank time, if we rely on known laws of nature. Two points can be derived from this:

1) the statement does not mean time is discrete. Uncertainty does not mean being discrete.

2) the statement does not say anything about existence of other laws of physics that humans have not discovered yet. Maybe future theory of quantum gravity would expand our understanding of the nature of the Plank time.

[Syntax Error]

A Planck length is the shortest distance in which it is possible to discern the position of an object with any certainty; before the laws of quantum uncertainty mess up the observation. In your example, under a Planck length, your light is both on and off, depending on the observer. Maybe the 'precision' goes on forever or, some quantum foam is a granularity barrier of our universe? Either way, you will need one hell of an A to D converter to read the space time continuum on your oscilloscope

Meanwhile a 'max plank' is what you can fit in a ford transit van, without needing to cut a bit off to close the door. My builder please note.

[AntiProtonBoy]

A Planck length is the shortest distance in which it is possible to discern the position of an object with any certainty; before the laws of quantum uncertainty mess up the observation.

i.e. basically the universe is not made of discrete voxels.

[IDEngineer]

We are all living in a hologram projected onto the shell of an enormous turtle.

From there it's turtles all the way down.

It's easier if you just accept it and move on.

[Nominal Animal]

Yup; rather than discrete, it is better to think of Planck units as at this scale, general relativity, standard model, and quantum field theory do not necessarily apply (and indeed, quantum effects of gravity are expected to dominate instead), like the Wikipedia Planck units article summarizes.

Nevertheless, you could measure distances as integer multiples of Planck length, or intervals or durations as integer multiples of Planck time, but not because of any inherent "graininess" of spacetime, but because shorter distances/intervals cannot be measured with any conceivable tools – not just physical ones, but light etc. – because our current models just break down at this scale.  That does not mean they don't exist, just that we cannot measure them.

[Rick Law]

I am waiting for Quantum Gravity to become a well developed theory, but, before I get into that...

Ask dffierent physicist to define what time is, you will get various answers and not all of them will agree.  Until we have general agreement on what is time, we can't really say if it is discrete.

I would say, in all likelihood, it is quantized -- trouble is, in quantum mechanics, time doesn't exist -- ie: not a variable in the equations used in quantum mechanics developed so far.  There is a before and there is an after, that is it.  Before the wave form collapses, and after the wave form collapses.

If you accept that, that may lead to the conclusion that time ticks and the collapse is the ticking.  But then next question is, which wave form?  Yours or mine or others?  So time depends on where you are and what you are doing (acceleration for example).  What if you are observing me? or I am observing you? or no one is observing?

If you are looking at your watch on your wrist with your arm fully stretched, you are not seeing the current time on your watch.  You are seeing the time on your watch between 1ns to 2ns ago, depending on how long your arm is.  For you, the photon carried the information of time from your watch to your eyes took 1ns to 2ns to get to you -- in your time.  Yet (current accepted theory is) the photon didn't experience any time passage.  For it, it is the exact moment of it's creation.  In fact, it is the same moment for any photon between it's creation and it's death (absorb/decade) even if these two events happened light years apart.  It ticked for you, but it didn't tick for at least one something else that is the photon.

May be someone already have a paper (that resolves all these unknowns) written but not yet publish...  If not, I am waiting for Quantum Gravity.  When that is well developed, knowledge of time would/may have improved enough to gain some clarity there.  However, my gut feel is, we are in deceleration as far as pace of science advancement goes.  Theoretical Particle Physics hasn't done much in the past half century.  String theory didn't turn out to be the great leap forward that many hoped it was...  So on, and so on.  And that was when science was a more attractive field.  Now, as college graduates majored in "xyz studies" out numbered majors in Physics, Math, and Engineering, our capability of maintaining a technological society becomes questionable.  There is a fair chance we would go back to horse and buggies.   So, "what is time", along with many science mysteries, may forever be unknown to human kind.