Jump to content

Smallest measurable unit of time

Winter Man

By Winter Man
in Science & Spaceflight

 Share

Recommended Posts

Winter Man

Winter Man

Posted
Posted

Anyone know what the smallest unit of time currently measurable is by any means? I don't mean the absolute smallest theoretical unit like the Planck time or Chronon, I mean the smallest you can actually read by actual experimentally possible means.

Link to comment
Share on other sites
Ralathon

Ralathon

Posted
Posted
The Planck time is the shortest measureable time, and is I think 5.4x10^-44 seconds. It's the time it takes for light to travel one planck length in a vacuum. The planck length in turn, is the smallest measurable distance.
I don't mean the absolute smallest theoretical unit like the Planck time or Chronon, I mean the smallest you can actually read by actual experimentally possible means.

At least read past the first 15 words :P

Link to comment
Share on other sites
NASAFanboy

NASAFanboy

Posted
Posted
Anyone know what the smallest unit of time currently measurable is by any means? I don't mean the absolute smallest theoretical unit like the Planck time or Chronon, I mean the smallest you can actually read by actual experimentally possible means.

There is no such thing as the smallest distance or smallest unit of time. They can just keep getting smaller and smaller and smaller by mere perception.

Sure, the Planck length is the smallest...but what do you call half of a Planck length?

It matters by perception, and that can vary from person to person. There is no such universal thing of "time" perception felt by everyone, and it can always keep getting smaller and smaller. There is NO limit to human perception/view of time-space, and it should best remain that way. Who knows? Maybe time could be a illusion, and you-or me, don't exist, or I'm really in the future and I'm just doing this out of memory...who the hell knows? I don't.

Link to comment
Share on other sites
Holo

Holo

Posted
Posted
There is no such thing as the smallest distance or smallest unit of time. They can just keep getting smaller and smaller and smaller by mere perception.

Sure, the Planck length is the smallest...but what do you call half of a Planck length?

It matters by perception, and that can vary from person to person. There is no such universal thing of "time" perception felt by everyone, and it can always keep getting smaller and smaller. There is NO limit to human perception/view of time-space, and it should best remain that way. Who knows? Maybe time could be a illusion, and you-or me, don't exist, or I'm really in the future and I'm just doing this out of memory...who the hell knows? I don't.

I mean the smallest you can actually read by actual experimentally possible means.

You've quoted the OP, and yet ignored it in your own post. Whether time is discrete or not doesn't change that our equipment is only sensitive to a certain degree.

According to this, scientists are able to measure time to 500 zs.

We also know that the lifespan of a W or Z boson is 0.3 ys. You'd have to ask someone more qualified than I how we know that, but it looks like a lower limit on how far we can currently measure time.

Link to comment
Share on other sites
TheDarkStar

TheDarkStar

Posted
Posted
Anything that is less than a planck length or planck time is not physically relevant.

I agree with this; from what I've seen, while it is possible to talk about a shorter distance, that smaller distance does not matter and has no effect (but correct me please).

Link to comment
Share on other sites
K^2

K^2

Posted
Posted
The Planck time is the shortest measureable time, and is I think 5.4x10^-44 seconds. It's the time it takes for light to travel one planck length in a vacuum. The planck length in turn, is the smallest measurable distance.

We don't actually know that. What we know is that physics we know breaks down at these time/length scales. Whether it's actually a unit of time/length or if we simply have completely different physics governing shorter time/length scales is currently unknown.

Link to comment
Share on other sites
rkman

rkman

Posted
Posted
While I don't think the Planck time is measurable currently by instruments, that will change in the future. So yeah, planck time.

The question is about what *is* the smallest measurable unit of time.

"Is" as in present tense, not 'will be in the future' (which a speculative claim anyway).

I'm not sure if this is actually the fastest measurement of time but it's pretty fast and rather cool:

propagation of light filmed at one trillion frames per second

http://youtu.be/-fSqFWcb4rE

Link to comment
Share on other sites
Winter Man

Winter Man

Posted
  • Author
Posted
propagation of light filmed at one trillion frames per second

http://youtu.be/-fSqFWcb4rE

I remember seeing that when they announced they'd done it. Pretty awesome stuff. Anyone know the methods of measuring such short time? Does it involve damn fast electronics or do they generally employ some kind of cheat, like using several measuring devices harmonically?

Link to comment
Share on other sites
Yourself

Yourself

Posted
Posted
I remember seeing that when they announced they'd done it. Pretty awesome stuff. Anyone know the methods of measuring such short time? Does it involve damn fast electronics or do they generally employ some kind of cheat, like using several measuring devices harmonically?

They sort of cheat kind of. What they actually have is a camera that can take a picture at a very precise moment in time. They then simply repeat the experiment a bunch of times taking pictures at slightly different time offsets. These pictures are then composited into a single video.

Link to comment
Share on other sites
NASAFanboy

NASAFanboy

Posted
Posted
There is no such thing as half a planck length. For all intents and purposes, it's undividable. Anything that is less than a planck length or planck time is not physically relevant.

So, the Planck length will get smaller and smaller?

What do you call a quarter of a Plack length? A new updated definition of a Planck length?

What defines physical relevance? What is the minimum for an object to physically exist? What even is physical existance?

Once we answer these questions, we can find the shortest length.

For now, no.

Link to comment
Share on other sites
NASAFanboy

NASAFanboy

Posted
Posted
You've quoted the OP, and yet ignored it in your own post. Whether time is discrete or not doesn't change that our equipment is only sensitive to a certain degree.

According to this, scientists are able to measure time to 500 zs.

We also know that the lifespan of a W or Z boson is 0.3 ys. You'd have to ask someone more qualified than I how we know that, but it looks like a lower limit on how far we can currently measure time.

"Not physically relevant" means, that things can happen within that ammount of time/that distance, and have no effect what so ever on the system. They are thus not measurable, and hence, there is no "quarter of a planck length".

Things can happen in half a Planck length of time.

Move.

Something is happening. Galzillions, maybe more half Planck lengths has passed. Your movement, something is happening, is it not? And thus, it is still relevant. Besides, what defines "something happening" anyways?

Link to comment
Share on other sites
Person012345

Person012345

Posted
Posted
No, "something happens" means, there is a change in the state of a system.

Anything that "happens" in less than a planck time, or moves less than a planck length, has no influence on the system.

And importantly, by extension, doesn't "exist" within that system (the system in this case being the universe).

Although K^2 is probably right also.

Link to comment
Share on other sites
Albert VDS

Albert VDS

Posted
Posted
There is no such thing as the smallest distance or smallest unit of time. They can just keep getting smaller and smaller and smaller by mere perception.

Sure, the Planck length is the smallest...but what do you call half of a Planck length?

It matters by perception, and that can vary from person to person. There is no such universal thing of "time" perception felt by everyone, and it can always keep getting smaller and smaller. There is NO limit to human perception/view of time-space, and it should best remain that way. Who knows? Maybe time could be a illusion, and you-or me, don't exist, or I'm really in the future and I'm just doing this out of memory...who the hell knows? I don't.

Our current understanding of the universe doesn't allow you to calculate anything smaller than Planck length,time,etc.

Asking what "What do you call half a Planck length?" is like asking "What do you call half a pixel?". Like pixels they can't be divided.

Also, human perception of time boils down to how fast your neurons can send impulses. Which is is around 80m/s to 100m/s and not limitless.

Link to comment
Share on other sites
This thread is quite old. Please consider starting a new thread rather than reviving this one.

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
 Share
Go to topic listing
×
×
  • Create New...