Quarks

[sanddbox]

Here's a mindfuck: What's the smallest unit of time?

The time it takes you to climax?

OH SNAP!

Well played.

[r-ID]

quarks are made from Preons. Preon is 1000 times smaller then a quark
Down to the preon is plank constant - a size that anyone smaller then it doesn't make any physical sence, yet

sanddbox, plank constant?

[circuitboardsushi]

preons have been postulated but no experimental evidence was ever found. It is somewhat of an outmoded concept as it they have not been included in the Standard Model.

If by some remote chance you are interested in particle physics but never visited http://particleadventure.org/ I suggest you check it out.

Quarks are hardly particles in there own right as they have never been observed individually and their existence is only possible when together they are composing a larger hadron (like a proton or something weirder).

Time is trickier. Many physicist believe that aspects of quantum mechanics suggests that time and space are discrete quantities with a smallest possible unit known a plank unit. The problem is that this is at odds with relativity.

Relativity say that measurements of space and time change depending on your reference frame. How could there be a smallest measurable unit when your measurements change depending on your reference frame?

[novalyphe]

Regarding quarks, it is currently widely accepted that quarks are fundamental particles. However, as quite a few people have pointed out that has been said before about atoms etc.

Regarding the time question heres a little thought experiment:
If time is measured in discreet quantities then for a runner to run 100 meters they must first get half way, i.e. 50m, to cross this 50m they must run another 25 to get to the next half way. If time is discreet, as there are an infinite number of half way points to cross then the runner will never cross the finish line only get infinitesimally close to it.
This for me is pretty much the best argument for time being a continuous quantity, unlike energy.

[ProjektTHOR]

That's a pretty serious fallacy in logic. Where did you hear that analogy? Yes, there are infinite discrete halfway points on a journey from points A to B, but the problem with your argument is that there is a definitive. measurable beginning and end in terms of the time and space the runner is existing and the runner hopes to go.

Speed and velocity being constant, your argument will never stand up by itself. Now if you halved the speed and velocity at each halfway point, then your point becomes a little more valid (albeit significantly less impactful).

And that's not even getting into mathematics. The halfway point of a 100m run is 50m. There are not halfway points at 50, 25, 12.5, 6.25, 3.125, etc. By virtue of being "half" there can only be "two" portions. If you arbitrarily begin further halving the halves, you end up with quarters, eighths, sixteens, et al. So the biggest fallacy is that you are not creating multiple halves of the same distance. You are constantly halving the remainder, creating the illusion of infinite halving.

[novalyphe]

Sorry, I don't think I made the argument clearly then, firstly, this is an argument for time being continuos rather than discreet, secondly I heard it during my first year of my Masters degree in Physics, It's actually just a slightly different take on Zeno's paradox involving Achilles and the Tortoise.

To cross any distance it will take you some period of time to cross the half-way. To then get from half-way to the end you must cross the 3/4 etc. this means that you must cross an infinite number of points with it taking some period of time to reach each new point. Therefore, if time was quantised it would take an infinite number of moments to reach any point, thus, it stands to reason that time is continuous so that to cross an infinitesimal distance can take an infinitesimal period of time rather than some minimum quantised amount.

[ProjektTHOR]

No, it still sounds just as fallacious. You're creating a paradox by fudging up the numbers. There's no reason to continuously divide time by half. I can just as easily say: "A runner's journey is comprised of two halves/three thirds/four quarters and they each take X/Y/Z amount of time. This is an argument for time as a discrete entity."

also csb on the master's degree.

[novalyphe]

That argument wouldn't be correct. The point is that you can split any distance into an arbitrary number of smaller distances, i.e. you can keep dividing to infinity, since to travel a given distance takes a given time if there cannot be a minimum unit of time.

If you still disagree then fair enough but I shan't be replying about time again since the thread was about quarks.

[circuitboardsushi]

zenos paradox was proven a falacy with the invention of calculus

[InCogNitO_314]

If you have such questions, you'll love to study the Standard Model in Particle Physics

Make Google your best friend! Search for the standard model..
http://en.wikipedia.org/wiki/Standard_model

Have you heard about the "Higg's Boson?
Its the something (im not saying a particle) which gives everything i.e. you, me, the atoms, electrons, quarks, leptons, et cetera a MASS

So it certainly is smaller than quarks...
Still there has been no experimental evidence of this higgs boson..and CERN, Geneva (Switzerland) are day and night searching for this Higg's Boson.. Check this out:
http://en.wikipedia.org/wiki/Higgs_boson