Go Back   Physics Help Forum > College/University Physics Help > Special and General Relativity

Special and General Relativity Special and General Relativity Physics Help Forum

Like Tree10Likes
Reply
 
LinkBack Thread Tools Display Modes
Old Feb 21st 2018, 05:20 PM   #11
Junior Member
 
Join Date: Feb 2018
Posts: 7
I heard of something called Einstein's box which could yield the equivalence without working with the gamma factor. Is it true?

Last edited by Ziang; Feb 21st 2018 at 05:28 PM.
Ziang is offline   Reply With Quote
Old Feb 21st 2018, 06:39 PM   #12
Senior Member
 
Join Date: Aug 2010
Posts: 372
No, 'Einstein's Box' has to do with quantum theory, not relativity.

It is mentioned here: https://en.wikipedia.org/wiki/Bohr%E...#39;s_argument
topsquark likes this.
HallsofIvy is offline   Reply With Quote
Old Feb 22nd 2018, 03:09 AM   #13
Senior Member
 
Join Date: Oct 2017
Location: Glasgow
Posts: 258
Originally Posted by Ziang View Post
Is there any way to modify Newtonian mechanics so that the equivalence can be derived from classical concepts in absolute space and time?
Just nope.
topsquark likes this.
benit13 is offline   Reply With Quote
Old Feb 22nd 2018, 07:47 AM   #14
Pmb
Physics Team
 
Join Date: Apr 2009
Location: Boston's North Shore
Posts: 1,570
Originally Posted by Ziang View Post
I heard of something called Einstein's box which could yield the equivalence without working with the gamma factor. Is it true?
Einstein used more than one boxes in his writing. You're thinking of the one where he deduced the equivalence of mass and energy of electromagnetic radiation. There is no gamma factor in that derivation since there's no gamma factor when E = mc^2 relates the mass and energy of EM radiation.

You can follow the derivation at my website at
Einstein?s Box

In this page I derived the equivalence of mass and energy for tardyons (particles that move at speeds v < c)
Mass Energy Equivalence

Caution: There are a few mistakes in that page which I haven't corrected yet. I referred to equation numbers which aren't in that page. I'll eventually fix hem.
Pmb is offline   Reply With Quote
Old Feb 23rd 2018, 07:46 AM   #15
Junior Member
 
Join Date: Feb 2018
Posts: 7
Originally Posted by benit13 View Post
Just nope.
I found some educational links and textbooks which use the box to derive the equivalence.
Ziang is offline   Reply With Quote
Old Feb 23rd 2018, 08:02 AM   #16
Junior Member
 
Join Date: Feb 2018
Posts: 7
Originally Posted by Pmb View Post
Einstein used more than one boxes in his writing. You're thinking of the one where he deduced the equivalence of mass and energy of electromagnetic radiation. There is no gamma factor in that derivation since there's no gamma factor when E = mc^2 relates the mass and energy of EM radiation.

You can follow the derivation at my website at
Einstein?s Box
So the equivalence can be derived without dealing with gamma factor or relative spacetime, right?
Ziang is offline   Reply With Quote
Old Feb 23rd 2018, 08:14 AM   #17
Senior Member
 
Join Date: Oct 2017
Location: Glasgow
Posts: 258
Originally Posted by Ziang View Post
I found some educational links and textbooks which use the box to derive the equivalence.
Okay, but I doubt very much that the derivation came from classical mechanics.

Can you please provide the links and textbook details so I can investigate?
topsquark likes this.
benit13 is offline   Reply With Quote
Old Feb 23rd 2018, 04:38 PM   #18
Forum Admin
 
topsquark's Avatar
 
Join Date: Apr 2008
Location: On the dance floor, baby!
Posts: 2,468
Originally Posted by Ziang View Post
I found some educational links and textbooks which use the box to derive the equivalence.
Originally Posted by Ziang View Post
So the equivalence can be derived without dealing with gamma factor or relative spacetime, right?
Again. No.

As with benit13 I would like to see what sources you are using to say this.

-Dan
__________________
Do not meddle in the affairs of dragons for you are crunchy and taste good with ketchup.

See the forum rules here.
topsquark is offline   Reply With Quote
Old Feb 24th 2018, 08:51 AM   #19
Junior Member
 
Join Date: Feb 2018
Posts: 7
This is a link
galileo.phys.virginia.edu/classes/252/mass_and_energy.html
Ziang is offline   Reply With Quote
Old Feb 24th 2018, 10:12 AM   #20
Pmb
Physics Team
 
Join Date: Apr 2009
Location: Boston's North Shore
Posts: 1,570
benit13, Dan - Have you read Einstein's 9105 paper on mass-energy equivalence.? Einstein didn't use the gamma factor because the derivation was for a slowly moving body. When he later derived the same result for EM radiation there too the gamma factor is absent. Its only for a particle moving at a speed comparable to the speed of light that gamma comes into play. In that case it cannot be avoided.
topsquark likes this.
Pmb is offline   Reply With Quote
Reply

  Physics Help Forum > College/University Physics Help > Special and General Relativity

Tags
formula, mc2, proved



Thread Tools
Display Modes


Similar Physics Forum Discussions
Thread Thread Starter Forum Replies Last Post
formula of energy ling233 Advanced Mechanics 0 Jan 20th 2016 05:11 PM
Need help rearranging formula. Xp96 Atomic and Solid State Physics 1 May 28th 2013 08:33 AM
Need a formula for this question.. jonbrutal Kinematics and Dynamics 0 Feb 14th 2010 07:57 AM
how to use lens formula?? kenny1999 Light and Optics 1 Sep 3rd 2009 12:48 AM
Which formula do I use? kdaaa Advanced Mechanics 1 Mar 11th 2009 01:48 AM


Facebook Twitter Google+ RSS Feed