The Universe: A Planck Clock Exploration

[AndyWeb]

Hello,

I was watching watch videos lol.

I bought a new automatic watch and I was interested to see how they work, here is a nice YouTube video;


There are various types of watches / clocks. Sun dial, mechanical, kinetic, quartz and of course atomic. They all, however, measure time kinda independantly of the universe. Like, the universe ticks along and all our clocks try to measure it's ticking, but what if there was a clock that was completely locked to the ticking of the actual universe?

A clock, according to the youtube video, requires a power source and the way time is measured conventionally is that the clock measures the flow of energy.

So, taking into account the smallest measure in the universe, the Planck Length, along with Planck time (the time it takes light to travel one Planck length) can we create a clock which utilises these indivisible units and so measure time directly?

?? ? Flip, mind blow there!

 

[phinds]

There is no such thing as the "ticking of the universe". Time is by definition the thing that clocks measure.

Plank time and Plank length are not indivisible.

 

[Nugatory]

So, taking into account the smallest measure in the universe, the Planck Length, along with Planck time (the time it takes light to travel one Planck length) can we create a clock which utilises these indivisible units and so measure time directly?

The Planck length and time are not indivisible smallest possible measures. This misunderstanding of what they are is so common that we even have an Insights article about it: https://www.physicsforums.com/insights/hand-wavy-discussion-planck-length/

 

[AndyWeb]

Alright alright, go easy on me. I only got a BSc in physics. No masters! Lol.

What is the smallest unit of measure? Is there one? And is there a process which produces this tinyest unit?

 

[phinds]

Alright alright, go easy on me. I only got a BSc in physics. No masters! Lol.

What is the smallest unit of measure? Is there one?

No there is not.

And is there a process which produces this tinyest unit?

no, since there isn't one.

 

[AndyWeb]

Well holy flip I've learned something!

So what's the craic with all the quantum stuff? I thought it was all quantised down there?

 

[phinds]

Well holy flip I've learned something!

So what's the craic with all the quantum stuff? I thought it was all quantised down there?

What is it that you think is quantized? Time? Particles? What? As we have stated, time and length are not quantized but what does that have to do with whether or not particles are quantized. Do you know of any way to split an electron in two?

 

[AndyWeb]

Occ sure every man on the street knows that a lepton can't be split lol

Yes. I think length is quantised. Surely there is a particle with a wave form that's the smallest known?

 

[AndyWeb]

Well, where does the idea of the Planck length come from then?? Why's that even in my head?

 

[Vanadium 50]

Well, where does the idea of the Planck length come from then??

Same place as the idea for the foot, the meter, the mile, the angstrom, the parsec...

 

[phinds]

Occ sure every man on the street knows that a lepton can't be split lol

Yes. I think length is quantised. Surely there is a particle with a wave form that's the smallest known?

And why would that imply quantized length? Do you think that a given waveform is the same frequency in all frames of reference?

 

[Nugatory]

Well, where does the idea of the Planck length come from then?? Why's that even in my head?

That's reasonably well-explained in the Insights article that I linked to above.

So what's the craic with all the quantum stuff? I thought it was all quantised down there?

As far as we know neither length nor time are quantized. Of course it could happen that some day some experiment demonstrates quantization of length or time, but until then there's nothing in the math that suggests that they ought to be, so no reason to expect that that they are. You will have to google for "Schrödinger's equation", a topic that's out of scope for a B-level thread, to see this math in action.

Surely there is a particle with a wave form that's the smallest known?

No. The greater the kinetic energy of a particle the shorter its "wavelength" (the scare-quotes are becausethe wavelength you're talking about isn't what you think it is, but we don't need that complication here), and we can make the kinetic energy arbitrarily high just by accelerating the particle, or by accelerating ourselves relative to it. Thus, we can also make the "wavelength" arbitrarily small.

 

[AndyWeb]

"The greater the kinetic energy of a particle the shorter its "wavelength"

There's the answer! I understand now thanks lol.