Particle Accelerators and a 22 caliber bullet.

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Discussion Overview

The discussion revolves around comparing the energy levels of particle accelerators, specifically the Fermilab Tevatron, to the energy contained in a 22 caliber bullet. Participants explore how to convey these energy scales in a way that is understandable to the general public, using analogies and comparisons to familiar concepts such as atomic bombs and everyday objects.

Discussion Character

  • Exploratory
  • Conceptual clarification
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • One participant seeks to contextualize the energy of a proton accelerated to 1 TeV by comparing it to the energy of a 22 caliber bullet, suggesting analogies like the energy of a space shuttle launch.
  • Another participant calculates the specific energy of a 1 TeV proton and compares it to the kinetic energy of a bullet, noting the significant difference in energy scales.
  • Some participants propose using the energy equivalent of atomic bombs, specifically the Hiroshima bomb, to illustrate the energy contained in a proton, suggesting that it could be likened to thousands of such bombs in a bullet.
  • Concerns are raised about the clarity of these comparisons for a lay audience, with suggestions to use more relatable terms and examples.
  • One participant mentions cosmic rays and their energy levels, suggesting that comparisons to these phenomena could also be misleading or difficult for the average person to grasp.
  • There are corrections regarding the mass of the bullet, with discussions on the appropriate units and conversions between grains and grams.
  • Some participants express skepticism about the meaningfulness of scaling energy in this way, questioning whether such comparisons truly convey the intended magnitude of energy.
  • Another participant discusses the challenges of explaining complex scientific concepts to a general audience, referencing well-known science communicators.

Areas of Agreement / Disagreement

Participants express a mix of agreement and disagreement regarding the effectiveness of various analogies and comparisons. While some find the atomic bomb analogy compelling, others question its clarity and relevance. The discussion remains unresolved on the best approach to communicate these energy scales to a lay audience.

Contextual Notes

Participants note the complexity of energy comparisons and the potential for misunderstandings when using analogies. There are also unresolved issues regarding the accuracy of calculations and the appropriateness of scaling methods used in the discussion.

Who May Find This Useful

This discussion may be of interest to educators, science communicators, and anyone looking to understand or explain the energy scales involved in particle physics and their implications in a relatable manner.

cybernomad
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I’m trying to help put the energies of particle accelerators say the Fermilab Tevatron accelerator into layman’s perspective. Now if we were to scale up the energy put into say a proton and scale that up to a 22 caliber bullet, how much more energy would it require?
Also put you answer in perspective with something like “it’s like putting the energy of the space shuttle launch into a 22 caliber bullet”
Assume the 40 grain bullet to 2000 fps (rifle).
 
Last edited:
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Lets take an energy of TeV (1 x 1012 ev, or 1.6022 × 10-7 J) for a proton of rest mass 1.6726 x 10-27 kg or rest mass-energy of 938.272 MeV, gives an specific energy of
9.579 x 1019J/kg (on the basis of rest mass). Remember that mass increases with speed.
Speaking of speed, a 1 TeV proton has speed about 0.9995 c, or 2.998 x 108 m/s >> 2200 ft/s (670 m/s).

The bullet moving at 2200 ft/s (670 m/s) has a specific kinetic energy of v2/2 = 224450 J/kg which <<< 9.579 x 1019J/kg.

On an energy basis though the bullet has greater kinetic energy - 584 J (based on 40 grains/2.6 g) vs. 1.6022 × 10-7 J. On the other hand, one only needs to accelerate 6.1 x 10-19 kg of protons to 1 TeV to obtain the some KE of 584 J.

As for the Shuttle - the 3 SSME's have a thrust of 5.3 MN and let's say that thrust is applied over 200 km, which gives an energy of 1.06 x 1012J (I have excluded contribution of SRB's). Putting this into a 0.0026 kg bullet gives a specific energy of 4.077 x 14 J/kg, which is still 5 orders of magnitude less than the specific energy achieved by a 1 TeV proton.

This may help to put energy in perspective.

http://en.wikipedia.org/wiki/Electronvolt
http://en.wikipedia.org/wiki/Orders_of_magnitude_(energy)

http://en.wikipedia.org/wiki/Space_Shuttle#Technical_data

Also putting it another way using the equivalence of 11605 eV/K, a 1 TeV proton has a temperature of 11.605 x 1015 K, i.e. it is extremely hot! Compare this with about 3300 K in the SSME combustion chamber.
 
That sounds all fine Astronuc but the average Joe on the street won't get it. How about putting it this way.

The amount of energy put into a particle in the Tevatron accelerator is like putting the energy of X Hiroshima bomb(s) into a 22 caliber bullet.

Te average Joe is familiar with both a bullet and the Hiroshima bomb but not with terms like, protons, rest mass, joules etc.
 
The yield of "Little Boy" was about 13 kilotons of TNT equivalent in explosive force, i.e. 5.5×1013 joules = 55 TJ (terajoules).
from http://en.wikipedia.org/wiki/Little_Boy

Putting the equivalent energy in a 0.0026 kg bullet (40 grain (2.6 g), 22 caliber) would give 9.8 x 1015 J/kg

And a 1 TeV proton has specific energy of 9.579 x 1019 J/kg,

so a 1 TeV proton has the equivalent energy of putting 9775 Little Boy's (bomb dropped on Hiroshima) in a 22 (40 grain) bullet, or one could round it about 10,000 Hiroshima bombs.
 
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Astronuc said:
so a 1 TeV proton has the equivalent energy of putting 9775 Little Boy's (bomb dropped on Hiroshima) in a 22 (40 grain) bullet, or one could round it about 10,000 Hiroshima bombs.

thanks,


what prompted me to pose this question was a popular media news clip a few years back where they stated a extreme cosmic ray or was it a gamma ray burst:? had an estimate energy equal to an 40 mph or so "fast ball" (baseball). I felt they did an injustice in their comparison for a layman to grasp the magnitude of energy inputted into the particle. Now if my memory is correct they also stated that it was about 50 million times more energy than the Tevatron accelerator.

Now imagine trying to explain that!
 
Astronuc said:
a 0.0026 gram bullet (40 grain, 22 caliber)

please check your calculations

1 grain = 0.065 grams
40 grains = 2.6 grams
 
I corrected the typo. I was originally writing 2.6 grams, then intended to write 0.0026 kg, but instead wrote 0.0026 gram.
 
cybernomad said:
what prompted me to pose this question was a popular media news clip a few years back where they stated a extreme cosmic ray or was it a gamma ray burst:? had an estimate energy equal to an 40 mph or so "fast ball" (baseball). I felt they did an injustice in their comparison for a layman to grasp the magnitude of energy inputted into the particle. Now if my memory is correct they also stated that it was about 50 million times more energy than the Tevatron accelerator.
Now imagine trying to explain that!

Yah, those are cosmic particles that are rather curious because their energies dance around this GZK limit. We aren't suppose to be observing such high energy particles unless their is a high energy source nearby (which there isn't unless we're REALLY missing something about our solar system...). I did a quick and crude calculation based on the speed those particles go and if you got a kg of material and you wanted to accelerate it to the speeds those protons come at... it would take something like 90,000,000,000 Tsar hydrogen bombs (Russian thermonuclear weapon, largest ever built with an energy equivalent to 50 megatons of tnt)
 
cybernomad said:
I’m trying to help put the energies of particle accelerators say the Fermilab Tevatron accelerator into layman’s perspective. Now if we were to scale up the energy put into say a proton and scale that up to a 22 caliber bullet, how much more energy would it require?
I'm not sure scaling this way is meaningful or impressive. For example, the electrons in a TV picture tube travel at about a tenth the speed of light. If bullets went that fast, they would each have as much energy as a bomb.

Re the Tevatron, your average Joe or Jill understands neither how incredibly fast nor how incredibly tiny the protons are. But consider this: The tevatron can accelerate 10^13 protons to 1 TeV. That is an energy of a million joules circulating in the vacuum chamber. A million joules is the amount of energy it takes to bring a 3000 pound car to the top of a 30 story building. Think of it: If you shove this car off the building, the amount of energy it has when it hits the ground is the same as the amount of energy stored in this skinny 6km vacuum tube. Let it out all at once and this energy gets deposited in 21 millionths of a second. If it happens in an unprotected area, it's quite a catastrophe.
 
  • #10
Pengwuino said:
Yah, those are cosmic particles that are rather curious because their energies dance around this GZK limit. We aren't suppose to be observing such high energy particles unless their is a high energy source nearby (which there isn't unless we're REALLY missing something about our solar system...).

I don't read up on it much but I suspect some as of yet undetectable particles are involved, perhaps having to do with dark matter? well that's a different discussion.


I did a quick and crude calculation based on the speed those particles go and if you got a kg of material and you wanted to accelerate it to the speeds those protons come at... it would take something like 90,000,000,000 Tsar hydrogen bombs (Russian thermonuclear weapon, largest ever built with an energy equivalent to 50 megatons of tnt)

!
 
  • #11
krab said:
I'm not sure scaling this way is meaningful or impressive. For example, the electrons in a TV picture tube travel at about a tenth the speed of light. If bullets went that fast, they would each have as much energy as a bomb.

Well, how much of a bomb? I'd bet an average Joe or Jill would gain some perspective from such an comparison that may be indeed impressive into the nether world of the subatomic. What if that was your task; to try to explain it to your average Joe or Jill or a class of middle school students for that matter.


Re the Tevatron, your average Joe or Jill understands neither how incredibly fast nor how incredibly tiny the protons are.

Have you considered such scientists as Brian Greene, Michio Kaku or Carl Sagan who have to some degree able to explain to some deep scientific concepts to the common audience?


But consider this: The tevatron can accelerate 10^13 protons to 1 TeV. That is an energy of a million joules circulating in the vacuum chamber. A million joules is the amount of energy it takes to bring a 3000 pound car to the top of a 30 story building. Think of it: If you shove this car off the building, the amount of energy it has when it hits the ground is the same as the amount of energy stored in this skinny 6km vacuum tube. Let it out all at once and this energy gets deposited in 21 millionths of a second. If it happens in an unprotected area, it's quite a catastrophe.

Indeed.
 

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