<<< Date Index >>>     <<< Thread Index >>>

[IP] more on Brian Greene: That Famous Equation and You





Begin forwarded message:

From: "David P. Reed" <dpreed@xxxxxxxx>
Date: October 2, 2005 11:57:04 PM EDT
To: dave@xxxxxxxxxx
Cc: Ip Ip <ip@xxxxxxxxxxxxxx>
Subject: Re: [IP] more on Brian Greene: That Famous Equation and You


Dave:

Non-physicists ought not to pontificate on physics. They end up looking foolish. [JUST LIKE PHYISICS NOBELS SHOULD NOT PONTIFICATE ON EVERY THING ELSE :-) DJF]

Standard relativity theory, as invented by Einstein, asserts that mass and energy are equivalent, and that E=mc^2 merely describes the equivalence.

To talk about "conversion" in a relativistic model is absurd. There is no "conversion" - mass is energy, energy is mass. They are just two views of the same thing.

The distinction only becomes possible when one is trying to describe how one corrects classical physical descriptions (in which mass and energy are distinct) to explain violations of the conservation of energy and conservation of mass, which are unified in relativity theories, so there is a single conservation law.

Classical dynamics is what most engineers use, and it is quite useful, so we don't teach children that mass and energy are the same thing. But perhaps we should, now that 100 years of testing suggest that relativity theory is a much more apt description than classical theories that treat mass and energy as distinct.

"mass-energy conversion" is like the "epicycles" needed to explain the trajectories of planets in a model where orbits are presumed circular rather than elliptical.


-------------------------------------
You are subscribed as roessler@xxxxxxxxxxxxxxxxxx
To manage your subscription, go to
 http://v2.listbox.com/member/?listname=ip

Archives at: http://www.interesting-people.org/archives/interesting-people/