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e=mc2: 103 years later, Einstein's proven right
afp ^ | nov 20 08

Posted on 11/21/2008 6:38:36 PM PST by camerakid400

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To: mamelukesabre

Yes, the bug would see the laser light moving at the speed of light.


61 posted on 11/21/2008 8:25:25 PM PST by camerakid400
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To: camerakid400

read later


62 posted on 11/21/2008 8:29:46 PM PST by LiteKeeper (Beware the secularization of America; the Islamization of Eurabia)
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To: mamelukesabre
mamelukesabre said: "In his point of view, light isn’t moving at the speed of light."

Actually, Einstein's Special Theory of Relativity deals with that exact problem and the key requirement is that EVERY observer of a beam of light in a vacuum will measure the velocity of the beam as c, the speed of light.

So, the bug riding on the laser pointer sees the light emitted from the pointer and leaving his location at the speed of light. The contribution of Einstein's theory is that this "impossible" result is made possible by changes to other observables to accomplish this.

One such change is that observers of the beam who are moving relative to each other will disagree about what the frequency of the light being emitted is. Another consequence is that observers moving relative to each other will disagree about WHEN things happened. Things that are simultaneous in one frame of reference can appear to happen at different times to a different observer, depending upon how that observer is moving.

A clock moving toward you at relativistic speeds will appear to you as running more slowly than to an observer moving with the clock.

63 posted on 11/21/2008 8:32:10 PM PST by William Tell (RKBA for California (rkba.members.sonic.net) - Volunteer by contacting Dave at rkba@sonic.net)
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To: doc1019

All sorts of nuclear interactions prove it. The kinetic energy plus rest energy is conserved when particles collide and interact to create new particles.

The idea here is that the calculations account for the rest mass of neutrons and protons in terms of the interaction energy of quarks and gluons. This is more a validation of quark theory than a proof of E = mc2, IMHO. The latter is amply demonstrated by the annihilation of a proton with an antiproton.


64 posted on 11/21/2008 8:33:25 PM PST by dr_lew
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To: William Tell

What is the formula to calculate the energy required to accelerate a mass to some speed just shy of the speed of light?


65 posted on 11/21/2008 8:35:12 PM PST by mamelukesabre (Si Vis Pacem Para Bellum (If you want peace prepare for war))
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To: SirKit

Einstein ping!


66 posted on 11/21/2008 8:37:54 PM PST by SuziQ
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To: dr_lew

And the proof of the existence of an antiproton is found where?


67 posted on 11/21/2008 8:39:18 PM PST by doc1019 (We are now an Obamanation. Palin 2012)
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To: mamelukesabre
THe effect is supposed to become more pronounced the faster you go and the farther you travel.

The famous example is the half-life of secondary particles created by cosmic rays striking the atmosphere. Some of them are detected at the ground even though they "should" decay before they have traveled a fraction of the necessary distance. The paradox is resolved by time dilation.

The formulas of special relativity are the work-a-day tools of the "ultrarelativistic regime" created in high energy particle accelerators. It's just the opposite of the "classical regime" where the kinetic energy is much less than the rest energy. In the ultrarelativistic regime, all particles behave approximately as massless particles, like gamma rays.

68 posted on 11/21/2008 8:43:51 PM PST by dr_lew
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To: doc1019
Antiprotons are easy to create. Here's a 2001 new item about measuring their properties to extreme accuracy.

Here is the famous picture of the first antiparticle discovered, the positron, which is an anti-electron. Of course, the positron is used in PET scans ( Positron Emission Tomography ) . It's every bit as weird and exotic as the antiproton, but a lot easier to produce since it has 1/2000 of the rest energy.

69 posted on 11/21/2008 8:53:14 PM PST by dr_lew
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To: mamelukesabre
mamelukesabre said: "What is the formula to calculate the energy required to accelerate a mass to some speed just shy of the speed of light?"

Well, I don't have the capability to format algebraic expressions, but I will attempt to do this.

First let's recognize that the calculation is going to be such that the energy must approach an infinite value as the velocity approaches the speed of light.

The total energy of the particle consists of the rest energy, which is the familiar E=mc2, plus the kinetic energy.

The formula for the total of these two terms is E=gamma*(rest mass), where gamma = 1/sqrt(1-v2/c2).

To calculate the energy required to accelerate to a given velocity v, calculate the total energy at that velocity and then subtract the rest energy.

One can also calculate the energy required to accelerate from velocity v1 to velocity v2 by calculating the total energy at each velocity and then subtracting.

70 posted on 11/21/2008 9:12:35 PM PST by William Tell (RKBA for California (rkba.members.sonic.net) - Volunteer by contacting Dave at rkba@sonic.net)
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To: mamelukesabre
Oops. I should have proof read one more time.

The statement:

The formula for the total of these two terms is E=gamma*(rest mass), where gamma = 1/sqrt(1-v2/c2).

Should be:

"The formula for the total of these two terms is E=gamma*(rest energy), where gamma = 1/sqrt(1-v2/c2)."

71 posted on 11/21/2008 9:17:03 PM PST by William Tell (RKBA for California (rkba.members.sonic.net) - Volunteer by contacting Dave at rkba@sonic.net)
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To: mamelukesabre
Oops, again. The copy and paste function doesn't copy and past superscripts properly.

The statement:

"The formula for the total of these two terms is E=gamma*(rest mass), where gamma = 1/sqrt(1-v2/c2). "

Should be:

"The formula for the total of these two terms is E=gamma*(rest energy), where gamma = 1/sqrt(1-v2/c2). "

72 posted on 11/21/2008 9:32:16 PM PST by William Tell (RKBA for California (rkba.members.sonic.net) - Volunteer by contacting Dave at rkba@sonic.net)
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A very disappointing outcome. I had come to believe, over the years, that e might actually be equal to something, anything, else. My life is now without meaning.


73 posted on 11/21/2008 9:32:26 PM PST by KarinG1 (Opinions expressed in this post are my own and do not necessarily represent those of sane people.)
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To: MyTwoCopperCoins
"If the apparent movement is faster than the velocity of light, can’t information be sent from point A to point B, faster than that velocity? Why, or why not?"

Seems possible!

http://en.wikipedia.org/wiki/Superluminal_communication

http://query.nytimes.com/gst/fullpage.html?res=940DE5DE123BF931A15754C0A961958260

74 posted on 11/21/2008 9:49:38 PM PST by blasater1960 ( Dt 30, Ps 111, The Torah is perfect, attainable, now and forever)
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To: MyTwoCopperCoins

Apparent movement is not real movement so there is nothing to carry information. Just like you can’t send an apparent letter to carry a message.


75 posted on 11/21/2008 10:36:05 PM PST by count-your-change (You don't have be brilliant, not being stupid is enough.)
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To: yarddog

Briane Greene had a great book, that if you expland space enough, time also changes.

IE, if you could see someone across the universe 13b light years away, you’d be able to fast forward and rewind by moving towards and away from them. Basically, if you’re far enough, motion towards and away causes time to contact/expand.

Amazing stuff, and very important to understanding of the universe.


76 posted on 11/21/2008 10:39:17 PM PST by MartinStyles
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To: CaptRon

Actually, with is the opposite of without. Nice try, but you learn that in high school.

P.S. It’s Saturday.


77 posted on 11/21/2008 11:56:24 PM PST by Disciplinemisanthropy (III III IV)
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To: yarddog
...you would arrive instantaneously.

From the Photon's point of view, there is no journey. And that's where it gets WEIRD for most people, but it explains a lot from a quantum mechanical point of view (think: 2 slits).

78 posted on 11/22/2008 5:24:30 AM PST by ImaGraftedBranch (...And we, poor fools, demand truth's noon, who scarce can bear its crescent moon.)
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To: TheZMan; Ingtar
There is some work at Livermore (I think) that is indicating c is indeed not constant and is influenced by gravity and possibly other forces. If this turns out to be true it will turn physics on their ear. The other little tidbit is that it means Roddenberry style warp drive in probably possible if you can find the power to do it. My college physics went to his grave trying to prove that the "science" of Star Trek was all bunk. More and more it looks like he was wrong. Interesting.

So if M is fixed and the other two move around - -well that is just a mind blowing thing.

79 posted on 11/22/2008 5:35:18 AM PST by mad_as_he$$ (Nemo me impune lacessit.)
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To: camerakid400

Wow, that article is written so badly it’s almost like babelfish.


80 posted on 11/22/2008 5:35:30 AM PST by Straight Vermonter (Posting from deep behind the Maple Curtain)
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