Talk:Tests of relativistic energy and momentum

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problems with graphs

The first graph is wrong. It shows the SR and Newtonian curves crossing, but in fact the SR value for the energy is always greater than the Newtonian value.--75.83.65.81 (talk) 17:18, 7 December 2013 (UTC)[reply]

Yes. I have reverted to D.H.'s original version of the plots of 1/2 v² versus 1/√(1-v²)-1. Don't forget to flush your browser cache. - DVdm (talk) 22:43, 7 December 2013 (UTC)[reply]

Sorry, I now corrected the former graph and uploaded it again. --D.H (talk) 09:00, 8 December 2013 (UTC)[reply]

Looks better :-) Thanks and cheers. - DVdm (talk) 10:02, 8 December 2013 (UTC)[reply]

Tests of relativistic energy and momentum First paragraph is very misleading. Suggested additional text:

No laboratory can produce sufficient force to achieve the vacuum speed of light by electro-magnetic particle acceleration. But particles falling into black holes do reach the full speed of light at the event horizon.[1] Only gravitation can force particles all the way to c, because both gravitational mass and inertial mass increase identically–by the Lorentz factor, and gravitational acceleration continues unrelenting, at least in to the Schwarzchild radius, R = 2GM/c2 . It can happen only at a black hole horizon.

Proof -- inertial frame (the massive frame): g = dv/dt = GM/ r2 ; v = dr/dt ; v dv = GM/r2 dr giving ½ v2 = GM/r ; at the horizon r = 2GM/c2  v = c .

[1] Kip Thorne, “Black Holes and Time Warps”, W.W. Norton Co. (1994) — Preceding unsigned comment added by Malicony (talk • contribs) 22:57, 18 February 2015 (UTC)[reply]

Massive particles

Only experimental evidence relates to sub-atomic particles? No experimental evidence of relativistic effects for massive particles, i.e actual matter/obects? The articles states that "relativistic energy and momentum significantly increase with speed, thus the speed of light cannot be reached by massive particles."

I think the article should make it clear that the relativistic effects which the theory of special relativity claims would affect massive particles have not been tested with massive particles at all. 101.184.63.195 (talk) 23:54, 2 September 2018 (UTC)[reply]

(Added section header)

Electrons, positrons, protons are massive particles, routinely used in particle accelerators. Check both linked articles.- DVdm (talk) 08:13, 3 September 2018 (UTC)[reply]

Should the energy-speed graph be speed-energy instead

**Kinetic energy in special relativity and Newtonian mechanics.** Relativistic kinetic energy increases to infinity when approaching the speed of light, thus no massive body can reach this speed.

I think this graph would be more pedagogical if energy was the horizontal axis. That way it would be clear at a glance that no matter how much energy you impart on a body, it only approaches but never surpasses the speed of light. @D.H: HueSurname (talk) 06:23, 24 February 2021 (UTC)[reply]