What Sets Chronon Apart from Planck's Time?

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Discussion Overview

The discussion centers on the differences between a chronon and Planck's time, exploring their definitions, historical context, and the variations in their perceived values. Participants examine the implications of these time units within theoretical frameworks, particularly in relation to string theory.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • Some participants note that while some sources equate chronon and Planck's time, others suggest that Planck's time is smaller than a chronon, indicating a lack of consensus on their definitions.
  • Nim provides historical context, stating that Planck time, proposed in 1899, is approximately 0.539 E-43 seconds and has been consistently defined for over a century.
  • Participants discuss the ambiguity surrounding the term "chronon," suggesting it varies by author and is not a well-established concept, particularly in the context of string theory.
  • Nim explains how to derive Planck time from fundamental constants, emphasizing the relationship between area, length, and time in Planck units.
  • There is a technical exchange about formatting floating-point numbers in posts, indicating a shift in focus from the physics discussion to the forum's formatting capabilities.
  • Participants inquire about the meanings of symbols like E and G, with one clarifying that E45 refers to 10^45 and G is the gravitational constant.

Areas of Agreement / Disagreement

Participants express differing views on the definitions and values of chronon and Planck's time, with no clear consensus reached regarding their relationship or significance.

Contextual Notes

The discussion highlights the variability in definitions and the potential for confusion regarding the terms used in theoretical physics, particularly with respect to the chronon and its context in string theory.

Who May Find This Useful

Readers interested in theoretical physics, particularly in the concepts of time measurement and the implications of Planck units in modern physics discussions.

Nim
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What is the difference between a chronon and Planck's time? A few websites said they were the same thing. But other websites showed Planck's time as being smaller than a chronon. And those websites didn't always agree on how small Planck's time or a chronon is.
 
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Originally posted by Nim
What is the difference between a chronon and Planck's time? A few websites said they were the same thing. But other websites showed Planck's time as being smaller than a chronon. And those websites didn't always agree on how small Planck's time or a chronon is.

One way to approach this question is to ask what has traditionally usually been meant by "Planck time"

Planck proposed a set of natural units in 1899 to a meeting of the Prussian Academy and the time unit he proposed was
for practical purposes the same as what is called "Planck time" today----about 0.539 E-43 second.

For over 100 years the Planck time unit has been this.

What the "chronon" is must depend on whatever writer is talking. It is not a well-established traditional thing, so could mean anything someone wants it to mean. The basic string theory scale is not solidly nailed down so if there is a "chronon" in that context it could be drifting around changing from author to author.

Here is how to remember Planck units:

Memorize what the area is and get all the rest from that.

The area is hbar G/c3

Therefore the length is sqrt(hbar G/c3)

The unit time is how long light takes to go unit length so it equals unit length divided by c. Or you can divide by c2 inside the square root and get

Planck time unit equals sqrt(hbar G/c5)


Since Planck time is 0.539 E-43 second, if you multiply by E45 you get 53.9 seconds which is on same scale as a ordinary minute.

So next time someone on telephone says "please wait a minute. I put you on hold for a minute" remember that this means

E45 Planck time units, or maybe you like it better written

1045 Planck time units
 
Thanks for the answser.

This isn't a physics question. But how do you make those floating numbers like that 45 you have by the 10?
 
Originally posted by Nim
Thanks for the answser.

This isn't a physics question. But how do you make those floating numbers like that 45 you have by the 10?

A2 is written like this (but with the spaces removed)

A[s u p]2[/s u p]


subscripts are written like superscripts except you say "sub"
instead of "sup"

if you want to see how anyone made a math symbol they wrote in their post, click on "quote" below their post AS IF you were going to reply and wanted to quote them in your reply-----you can look at how they typed stuff and you don't have to reply unless you want----you can just back away
 
marcus said:
about 0.539 E-43 second.
The area is hbar G/c3
marcus said:
Therefore the length is sqrt(hbar G/c3)
What are E and G?
 
E45 just means 10^45
G is the gravitational constant
 

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