## One Hundred Years of E=MC2 408

Posted
by
CmdrTaco

from the i-still-don't-get-it dept.

from the i-still-don't-get-it dept.

Eric Ward writes

*"To mark the one hundredth anniversary of Einstein's famous equation, E=mc2, NOVA has gone live this month with a Web site that features exclusive content and podcasts from ten of the worlds top physicists. This once-in-a-lifetime gathering of top scientists such as S. James Gates, Jr., Brian Greene, Neil deGrasse Tyson and Nobel Laureate Sheldon Glashow simplify what the equation means to our world today and the effect it has had on their careers. NOVA online also details how Einstein grappled with the implications of his revolutionary theory of relativity and came to a startling conclusion: that mass and energy are one, related by the formula E=mc2. Viewers will also find lesson plans through the award-winning NOVA Teacher's Guide and a special library resource kit."*
## Time for a physics limerick (Score:5, Funny)

whose movement exceedingly brisk

so quick was his action

the Fitzgerald Contraction [wikipedia.org]

reduced his rapier to a disc

## Re:Time for a physics limerick (Score:5, Funny)

A1: To actualize its potential

A2: Unknown; the fact is, most of the poultry in the universe seem to be missing

A3: It didn't. It simply moved its legs standing still, while the road passed underneath.

A4: It didn't cross the road - it simply returned to where it started, but was momentarily moving backward in time.

A5: There exist numerous parallel universes in which the same chicken is in differing stages of crossing the road. Only when one of the chickens has concluded crossing the road do their wave functions coalesce.

A6: Chickens at rest tend to stay tend to stay at rest, and chickens in motion tend to cross the road. Given an equal and opposite reaction, clearly, it was pushed onto the road by another chicken who consequently moved away from the road.

A7: The chicken never actually crossed the road (a task impossible for a chicken of it's energy level). Instead, through uncertainties in its position, it found itself tightly clustered in with other chickens inside a coop just beyond the road, and unable to escape and return to its starting side.

## Re:Time for a physics limerick (Score:3, Funny)

A9: Scrodinger's Chicken is <blink>not</blink> dead.

## Re:Time for a physics limerick (Score:5, Funny)

A: to get to the other...uh...

## Happy 100th (Score:5, Funny)

"I explode like a bomb. No-one is spared. My power is my mass times the speed of light squared."

## Re:Happy 100th (Score:5, Funny)

Twinkle, Twinkle little star

Power = I squared R

## Re:Theoretical Bounds Without Implementation (Score:2)

While you use e=mc2, The part that a lot of people forgot was that you get twice the energy because while you get the energy of the conversion of antimatter you also get the energy from the conversion of normal mater.

## Re:Theoretical Bounds Without Implementation (Score:2, Interesting)

Thing is, though ITER is widely expected to be relatively (ha-ha) more efficient than past fusion reactors, it'll still be experimental. By that I mean it'll still be

## Hazzah! (Score:2, Funny)

## Re:Hazzah! (Score:2)

## You are missing an operator (Score:2)

## Re:You are missing an operator (Score:2)

int getenergy(int mass, int velocity)

{

return mass * (velocity * velocity);

}

## Using ints? (Score:2)

I would use floats. And make sure you note the difference between velocity (speed and direction) as opposed to just speed. And it's not just any speed, it's the speed of light in a vacuum. So, this is better:

float getenergy(float mass, float velocity) {}

Or:

float getenergy(float mass, float velocity) {}

if you don't like using "c" for some reason.

## Re:Using ints? (Score:3, Funny)

Floats? Have you never heard of quantum mechanics? Duh!God does not use rand() on the universe.

## Re:Using ints? (Score:3, Funny)

God does not use rand() on the universe.Not only does God definitely use rand() on the universe, but He sometimes confuses us by seeding it with /dev/random.

## What if E = mc^2.0000000001? (Score:3, Interesting)

Newton's 3 laws survived 239 years, I wonder how long Einstein's will last?

## Re:What if E = mc^2.0000000001? (Score:5, Insightful)

Newton's 3 laws survived 239 years, I wonder how long Einstein's will last?Einstein's _theories_ will last until evidence no longer supports them (just like all science).

Newton's _laws_ were and still are wrongly named.

And another pedantic relativity thing. The E=MC^2 was part of the _Special_ Theory of Relativity which says that measurements of time and distance vary as anything moves relative to anything else. This is where the twins where one goes in a rocket near the speed of light and the rocket twin comes back still young and the stationary twin is old (I really hope I didn't embarrass myself by reversing this, but I think this is right).

The other theory of Relativity that Einstein came up with was the _General_ Theory of Relativity that came out in 1915. This is the space-time continuum being bent by gravity.

Einstein was a little upset that he was able to join the two theories into one, but then again that is the goal of many physicists today.

Einstein was a very interesting and good person from everything I have heard and read. RIP.

## Re:What if E = mc^2.0000000001? (Score:2, Funny)

Relativity, after all...

## Re:What if E = mc^2.0000000001? (Score:4, Informative)

You can't get that backwards. However, it depends on which twin you call stationary. If you called the rocket stationary, then it would seem the twin that stayed home would be young.Bzzrt. Wrong answer. Motion is relative, acceleration is not. Rocket Twin accelerates and decellerates to leave and come back. He will always be younger at the end.

## Re:What if E = mc^2.0000000001? (Score:3, Interesting)

Bzzrt. Wrong answer. Motion is relative, acceleration is not.Bzzrt. Everyone who doesn't quite understand relativity gets this one wrong. Right answer, wrong reason. The acceleration isn't important. The velocity is.

Think of it this way. Suppose one twin went to a star 100 light years distant at 0.99995c. Assume he has a magic ship that doesn't accelerate. Just boom and it's moving....

To the twin that stayed behind, he see the ship take 100 years to get to the star and 100 years to get back, (i.e.

## Re:What if E = mc^2.0000000001? (Score:5, Informative)

Bzzrt. Everyone who doesn't quite understand relativity gets this one wrong. Right answer, wrong reason. The acceleration isn't important. The velocity is.Velocity causes the time and distance dilation yes, but the accelleration is what breaks the symmetry between the two.

While twin two is heading away from twin one, you can't say who's older - From Twin One's perspective Twin Two is aging slowly, and From Twin Two's perspective Twin One is aging slowly. It's just as legitimate to say that Twin Two is stationary and everything else is moving around him. It's the fact that he _turns around and comes back_ that breaks the symmetry between the two frames of reference and allows you to say that he is in fact the younger one.

You've covered the part about how the second twin is able to see himself covering the distance in that time, but ignored the fact that while he is not accelerating, the frames of reference are relative and that you can just as easily say the _other_ twin is aging slowly. In short, you ignored the principle of relativity. :)

## Re:What if E = mc^2.0000000001? (Score:3, Insightful)

-everphilski-

## Please learn some physics! (Score:3, Insightful)

Newton's Laws are perfectly fine, the first: an object in motion will continue in motion until acted upon by an outside force is perfectly consistent with General (and of course Special) Relativity, although it's very difficult to talk about acceleration in Special Relativity (see Newton's Second Law)Actually this is not consistent with special relativity. Special relativity allows me to convert mass into energy so suppose I start with a neutral pion. This can be travelling at a constant velocity when it

## Re:What if E = mc^2.0000000001? (Score:2)

## Re:What if E = mc^2.0000000001? (Score:2, Informative)

Perhaps we will discover that the E deviates from mc^2 when temperatures are very high or very low or m is very large or magnetic fields are especially strongInterestingly, these conditions provide a good

verificationof the relationship between energy and mass. High energy photons (no mass) in extremely strong magnetic fields (e.g. near massive stars or in particle accelerators) lead to the creation of electron/positron pairs (with mass).## What if cows could fly? (Score:3, Interesting)

What if Einstein's work is an approximation, too. ..That's the beauty of science... Science is INQUIRY... it is not static.

Untilsomeone does prove it was an approximation, we'll use it. Oncethatoccurs, we will use the new figureuntilsomeone else is able to make it more accurate.## Re:What if E = mc^2.0000000001? (Score:2)

## Reaching way back into my memory,but... (Score:2)

If you write Newton's laws with the covariant 4-momentum, don't they still hold (pdot = Force)?

## Re:What if E = mc^2.0000000001? (Score:4, Insightful)

Which is like Newton's equations. They had known for quite a while that the orbit of Mercury couldn't be accuratly described by his theories, but they were the best avalible.

Einstein's are the best avalible now, for non-quantum events. Someday someone will come up with something that handles both. Then

they'llbe the genious hailed as the greatest.## Hey! (Score:2)

## What did E=MC2 give us the past 100 years? (Score:2)

I don't know if I fully believe that energy equals mass. The only way that makes sense if something like SuperString theory is true, that we have more than the 4 dimensions (X, Y, Z, and time). To take mass, and BANG, the mass is gone

## Re:What did E=MC2 give us the past 100 years? (Score:5, Informative)

All this business of

E=mc^2 "giving us the nuclear bomb" is another example of newspaper pap-science. There's far more to a nuke than computing the mass defect.The whole idea is a staple of Relativistic kinematics which has been verified in collider experiments, etc., etc.

You can define relativistic stuff in less than four dimensions (e.g., one of space and one of time). Take an electron-positron annihilation into two photons. A proper treatment requires quantum field theory, where mass can be understood (in one way) as a parameter constraining the dynamically allowed momentum-energy configurations of the physical ("on-shell") fields. It's [probably] not right to think of electrons as little dots of mass.

Again, you need to consider quantum field theory to [begin to] answer these questions.

## Re:What did E=MC2 give us the past 100 years? (Score:2)

Quite a bunch. IANAP, but it seems to me that the constant forming (and recombining) of virtual electron/positron pairs would be one example of this.

Admittedly, these are rather short-lived, but IIRC, you can turn them into "real" electrons (and positrons) by adding energy to the system from the outside.

## Did it in 1932 (Score:3, Informative)

How many examples are there of the opposite happening. Taking just energy, with no starting mass, and making mass?Here's the link you need to CD Anderson's 1932 experiment [physlink.com] using gamma rays

## Re:What did E=MC2 give us the past 100 years? (Score:5, Insightful)

I don't know if I fully believe that energy equals mass... To take mass, and BANG, the mass is gone and there is energy, does not ring true to me.And Newton's first law of motion didn't ring true to Aristotle—clearly objects in motion tend to come to a stop if nothing is pushing them. Our intuition about how the universe works is based on our limited experience of medium-sized objects moving at low speeds on the earth's surface, with the result that all physics post-Aristotle is more or less counterintuitive. The fact that you can't imagine it doesn't mean it isn't so.

## Re:What did E=MC2 give us the past 100 years? (Score:5, Informative)

What did E=MC2 give us the past 100 years?It's a fact (approximately) about the nature of the universe. It doesn't need to give us anything. What did the discovery of the planet Neptune do for us? Nothing practical, but I think knowledge is worth seeking for its own sake.

What I think is more useful from E=MC2 is the idea of relativity. It is true, not just for science, but for almost every field of study.If by "the idea of relativity" you mean, roughly, "there are no privileged inertial frames of reference", then I have a hard time imagining what bearing that idea has on, say, art history, or comparative religion. If you just mean that "everything is relative", then I'd say that your idea of relativity has very little to do with Einstein, and is probably too vague to be much use in any other field, either.

## Re:What did E=MC2 give us the past 100 years? (Score:2)

"Belief" has no place here. Leave that to the creationists.

## Re:What did E=MC2 give us the past 100 years? (Score:3, Informative)

## Re:What did E=MC2 give us the past 100 years? (Score:3, Informative)

In chemical reactions, the amount of mass converted to energy is very small and nearly impossible to measure, but that's not the point.

Example: To heat your house, you use on order of 1000kWh

## Albert Einstein's performance review, 1905 (Score:5, Funny)

Don't miss the rest of his site [norvig.com] while you're there.

## Theory Of Relatively... (Score:2)

## Timing (Score:3, Insightful)

## Re:Timing (Score:3, Informative)

I don't personally use the word "accuse", but he bears some responsibility for the events of 60 years ago, and for the nuclear arms race that followed.

## Re:Timing (Score:3, Informative)

It's important to note that Einstein's 1939 and 1940 letters of introduction and warning to Franklin D. Roosevelt can be reasonably called the primary stimulus of the Manhattan Project. I don't personally use the word "accuse", but he bears some responsibility for the events of 60 years ago, and for the nuclear arms race that followed.The fact that the letter itself was essentially a warning that the

Germanswere probably already pursuing it (which they were)indicates that the events were already in mot## Re:Timing (Score:3, Informative)

I don't want to get all Voltaire on this, but all things considered it worked out better than it might have. If Heisenberg hadn't botched slow-neutron diffusion path (and hence, critical mass), the Nazis might have had a practical U235 or PU239 warhead before anyone else. As you say, no one was going to un-invent nuclear fission as a weapons explosive; Einstein's own words [aip.org] indicate that the

## If Einstein Was So Smart... (Score:5, Funny)

## One Hundred Years of E=MC2 (Score:4, Funny)

## Re:One Hundred Years of E=MC2 (Score:5, Funny)

e = 2.71828 18284 59045 23536 02874 7135... [wikipedia.org]

Or are we being case-sensitive?

- shazow

## From the i-still-don't-get-it dept. (Score:2)

Now seriously, I don't get it either.

(Another thing I don't get: why isn't <super> allowed HTML?)

## Re:From the i-still-don't-get-it dept. (Score:2)

That's dimensionally inconsistent.

## Ok guys... educumacate me (Score:2)

Honestly, I don't even understand many of the basics.

Sure-- it's the formula for "Energy to matter" or something. But why does this matter? How does this relate to Einstein's theories about gravity wells, speed of light, etc.

And I understand the legacy-- E=MC^2 changed how the world was viewed by theoretical physicists. It's different from the Newtonian models of the Universe. I just don't und

## Re:Ok guys... educumacate me (Score:3, Interesting)

## Re:Ok guys... educumacate me (Score:2)

But e=mc^2 is special relativity, and you can derive it with high school math (they still teach math in high school, right?). Historically, it broke down the wall of separation between matter and energy, and was a major conceptual hurdle that we had to get over to proceed into modern physics.

## Re:Ok guys... educumacate me (Score:2, Insightful)

## Re:Ok guys... educumacate me (Score:2)

## Re:Ok guys... educumacate me (Score:2, Informative)

Relativity : The Special and the General Theory

By Albert Einstein

This is written for the technically inclined layman. I read it and since then I've been life of the party. It really did make things much more clear - like what does flexible of spacetime have to do with the speed of light? It's all in there!

## Re:Ok guys... educumacate me (Score:3, Interesting)

Sure-- it's the formula for "Energy to matter" or something. But why does this matter? How does this relate to Einstein's theories about gravity wells, speed of light, etc.First thing to realise is that there are two theories of relativity - special and general. Special came first, is much easier to get your head around, and concerns motion, energy and that equation. The second, general theory came after, concerns gravity and is a complete pig to work with (Riemann curvature tensors [wikipedia.org] anyone?)

As to why do

## Re:Ok guys... educumacate me (Score:3, Insightful)

Einstein noticed that there's a discrepancy between Newton's laws and Maxwell's laws of electricity and magnetism (E&M). To patch this, most physicists assumed special treatments for E&M like ether. Einstein went backwards and decided Newton must be wrong.

The most amazing conclusion he reached was that the speed of light is a constant in any reference frame. ANY reference frame.

## Of course, a minor change points to warp physics (Score:2, Interesting)

E=(m/(n^2))*((n^2)*(c^2))

where n is the factor by which the speed of light changes.

## E = mc^2 is Not Einstein's Discovery (Score:3, Informative)

E = mc^2 is Not Einstein's DiscoveryRobert A. Herrmann

1. Introduction

It appears that some scientists have not received the proper credit for significant discoveries for which they have priority. However, without specific and irrefutable information, it is not possible to give convincing reasons why these individuals have been denied recognition and why others have been given credit for their scientific discoveries. In 1996, I was asked whether certain aspects of General Relativity were originally formulated by Einstein or Hilbert. (Hilbert presented the gravitational equation(s) prior to Einstein.) The questioner said that he knew very little about Einstein's achievements except for such things as "E= mc^2." I answered his question relative to the Hilbert verses Einstein controversy but I neglected to discuss the more easily explained E = mc^2. What follows in this short article shows exactly who developed the idea that "radiation" can be characterized as having an apparent mass and that it was not Einstein in his 1905 paper. Except for the last remarks on Olinto De Pretto, this article is concerned mostly with "radiation" and its relation to E = mc^2.

read more... [serve.com]

Michael. [michael-forman.com]

## It's too bad, because he's probably right (Score:3, Interesting)

Which all points to the dangers of mixing science with politics and religion. You can piss away a lot of credibility that way, and luckily Einstein never claimed to be an expert at either.

## Re:Another nutbar ... (Score:3, Interesting)

Michael.

## 2 years too late (Score:2, Informative)

Rory Carroll in RomeThursday November 11, 1999GuardianThe mathematical equation that ushered in the atomic age was discovered by an unknown Italian dilettante two years before Albert Einstein used it in developing the theory of relativity, it was claimed yesterday.

Olinto De Pretto, an industrialist from Vicenza, published the equation E=mc2 in a scientific magazine, Atte, in 1903, said Umberto Bartocci, a mathematical historian.

Einstein allegedly used De Pre

## serious question (Score:4, Insightful)

reallyunderstands it).But I have a few nagging question about this famous equation. People just tend to explain c^2 by saying something like "a little matter represents a lot of energy, and c is a big number and so c squared is even bigger". Well, that certainly is true if c is measured in meters per second or any other common unit. But it's all about the units. If c is expressed in light-seconds/second rather than meters per second, or worse yet light-years/second then the "logic" of that argument is exposed as just hype. So the real issue comes down not to the equation e=mc^2 itself, but the selection of the units that e, m and c are expressed in. Use a different unit and, as I try to show above, the whole thing breaks down.

Al himself made a pretty famous point of saying that c was a constant. So c^2 is also a constant. So the equation boils down to expressing an important relation between e and m. But it all depends on the units of measure. So here's the question:

Is there some science behind the selection of the units involved that allows this equation to be so simple, or are we to believe that some serendipitous magic just allows this to be an exact equation and the units somehow just happen to match up? After all, I certainly don't know of any reason why a meter is any more of a valid unit to do this calculation with than a furlong, or a foot, or a parsec. And I am under the impression that the units of both mass and energy were determined before the equation, not as a result of it. So should I believe that this equation is just a serendipitous chance match up of units, that Einstein made some sort of deal with God, or that the equation just might be a bit over simplified?

If a meter were and inch shorter or an inch larger, there would still be an equation that could show the relation between e and m, but a conversion number would have to be added to the equation to make up for the slight difference in the size of the meter. How is it that this equation works out with the current rather arbitrary length of a meter to such whole numbers?

## Re:serious question (Score:3, Informative)

it is in m^2kgs^-2

Speed is also a derived unit.

it is in ms^-1

So when you pick a definition for time and distance, everything matches up.

## Re:serious question (Score:5, Informative)

But it's all about the units. If c is expressed in light-seconds/second rather than meters per second, or worse yet light-years/second then the "logic" of that argument is exposed as just hype. So the real issue comes down not to the equation e=mc^2 itself, but the selection of the units that e, m and c are expressed in. Use a different unit and, as I try to show above, the whole thing breaks down.I think you are making the mistake that, for example, a 4-slice pizza is smaller than an 8-slice pizza, because, as everyone knows, 4 is less than 8. However, the pizzas are exactly the same size, it is just that the slices are larger in a 4-slice pizza.

Is there some science behind the selection of the units involved that allows this equation to be so simple, or are we to believe that some serendipitous magic just allows this to be an exact equation and the units somehow just happen to match up?Yes, there is a very challenging derivation of this simple relationship. It is just math, and it is not magic. I won't do the derivation, but I will show that the units do, indeed, make sense:

Energy is a force acting through a distance: F x d

Force is a mass undergoing an acceleration: F = m x a

Acceleration is a change in velocity over a change in time: A = deltaV/deltaT, whose units are length/time x 1/time. Let's use metric. That would be m/s x 1/s.

Substituting the units back into the general energy equation, we get:

E = F x d = m x A x d = kg x (m/s x 1/s) x m. If we pair the 1/s with the meter from "Force acting over a distance" The units are:

E = kg x (m/s) x (m/s), which are the same units as Einstein's famous relation. So, yes, the units do make sense, it is not serendipitous that this works out, and the reason it is so famous is because it is so simple.

## Re:serious question (Score:5, Informative)

E = mc^2 holds true no matter what units c is expressed in - as long as the units for energy, mass, and c are consistent.

If you say c is expressed in meters/second, and m in kilograms, then energy must have the units of [kg*m^2/s^2] which we also call Newton-meters or Joules.

Just to confuse you further: sometimes we choose our units such that c=1! In this case, E = mc^2 becomes just E = m. Energy is mass.

Numbers in physics are just convenient ways to express a measurement; they are not of numerological significance (well, maybe the fine structure constant...).

Check out http://en.wikipedia.org/wiki/Physical_unit [wikipedia.org] if you have more questions on the units.

## Re:serious question (Score:3, Informative)

If E is in Joules and m is in kg, c would have to be in m/s for the equation to work. Otherwise you'd need a conversion factor. That's all units are, attached labels that assume you're being consistent throughout the equation.

## Re:serious question (Score:3, Insightful)

Whats really impressive is google can convert those two fine

1 lightyear per femtosecond in microns per millenium [google.com]

## Einstein was so wrong (Score:5, Funny)

## Quantum debugging (Score:3, Funny)

## Obligatory lame physics joke: (Score:4, Funny)

## Re:Obligatory lame physics joke: (Score:3, Funny)

in this frame of reference.## Plagiarism is at least better than bullshit (Score:4, Informative)

To begin: Wolfgang Pauli postulated the neutrino, not Einstein.

Next: Whatever one concludes about the validity of Eddington's solar eclipse experiment, the predictions of General Relativity have been tested and proved out in hundreds, if not thousands, of repeatable and rigorous experiments since then.

And Next:

This quote falls somewhere between the irrelevant and a

non-sequitur. Thanks for sharing man--but what does it mean? No physicist takes cold fusion seriously, and autodynamics is a competing theory to General Relativity, for which Richard Moody, Jr. is clearly a shill.At the end of the day, it doesn't matter whom it was that provided the first, or the first accurate, derivation of e=mc^2. It could have been Einstein, Poincare', or William goddamn Shakespeare, for all I care. What matters is that both Special and General Relativity have withstood an awful lot of testing over the last century, and stood up well under that onslaught.

The autodynamics camp also seems to believe that Special Relativity is used in radioactive decay calculations, and I could have sworn that Quantum/Statistical Mechanics holds sway there....

## Heaviside's Equation (Score:3, Interesting)

Oliver Heaviside is one of the forgotten men of science, much like Philo T. Farnsworth (inventor of the electronic television) is one of the forgotten men of engineering.

As well as casting Maxwell's equations in their modern (vector) form, he contributed to work in relativity, and if memory serves first wrote down E=mc^2 in 1892. David Bohm's book on special relativity covers this in considerable detail.

This is not to diminish the contribution of Einstein, who worked mostly independently of previously known results, but to make it clear that there were others who set the stage for Einstein's great performance.

The fundamental contribution of Einstein was his ability to show that results that had previously been derived by people like Heaviside and Lorentz with great difficulty from an electro-mechanical dynamical model of the electron could be generalized and proven very simply as a result of a purely kinematic invariance.

## It is E=mc^2 (Score:5, Insightful)

But m = \gamma m_0, where \gamma = 1/sqrt(1 - \beta^2), and, of course \beta = v/c.

I.e., E = mc^2 = m_0 c^2 / sqrt(1 - (v^2/c^2))

Oh, m_0 is rest mass, in case you didn't know that, and m is the relativistic mass.

## Re:It is E=mc^2 (Score:5, Funny)

But m = \gamma m_0, where \gamma = 1/sqrt(1 - \beta^2), and, of course \beta = v/c.I.e., E = mc^2 = m_0 c^2 / sqrt(1 - (v^2/c^2))Oh, m_0 is rest mass, in case you didn't know that, and m is the relativistic mass.Do you get laid much? I can just imagine the bar talk.

So, ladies, did you know that if. wait. I need my blackboard. Would you mind pushing the pints down a little, I need more space to show you this. Screw it, lets just go back to my TA office. I sure hope professor Greennuts is not there. He steals all my women with his theory of relativity- they're not related to him. bada-boom-bang.

I admit it, I am crazy and my mind entertains me.

BTW, I am shocked you would put a link on slashdot to your picture. You will have to let us know if this has brought you any nerd on nerd love?

## Re:It is E=mc^2 (Score:3, Informative)

People like it because many equations in mechanics are nonrelativistic, such as p=mv, F=ma, and ironically, E=mc2, and the concept of "relativistic mass" makes them work out again if you interpret the "m" as being a function of v: m="m0"/sqrt(1-v2/c2). In fact that is how the concept of "relativistic mass" historically became popular and stayed popular. People wanted to extend the Newtonian laws of mechanics that they were already familiar with, and since we still teach Newtonia

## (E^2) = (m^2)*(c^4) + (p^2)*(c^2) (Score:4, Informative)

[PEDANTIC]

For things like photons that have zero rest mass

E = m0*c^2 / sqrt (1-(v/c)^2)

Doesn't work so well... By using the following:

(E^2) = (m0^2)*(c^4) + (p^2)*(c^2)

Now photons (which by definition are moving and have momentum) can have kinetic energy associated with them without having to divide zero by zero (since photons travel the speed of light v/c = 1 and the denominator is zero in your equation).

[/PEDANTIC]

## Re:Its not E=MC^2 (Score:2, Informative)

## Re:Its not E=MC^2 (Score:2)

mis the invariant mass,m/ sqrt(1 --v^2) gives the total dynamical energy.E=m(c= 1) is a statement of unit conversion --- the energy "worth" of mass in Relativistic kinematics.## Re:Its not E=MC^2 (Score:2)

In any event, the aerodynamic drag equation breaks down as Mach gets much above

Ok, back to work now...

## This story is a dupe (Score:5, Funny)

## So that's it!! (Score:3, Informative)

A few years ago the National Library in Canberra had an extremely popular exihbition called "National Treasures" or something like that. It was a collection of many historical and influential works like ancient maps, the original lyrics to "Yesterday" by Paul McCartney, and other incredible things I've forgotten about. Included amongst them was Einstein's original paper on relativity open at the famous equation E=mc^2.

A German friend of mine went and saw it, and when he read

## Re:Plagiarist? (Score:5, Interesting)

einstein was awarded the nobel prize for his brownian paper. relativity, published the same year, was all but ignored.

source:t ml [kyoto-u.ac.jp]

http://www.bun.kyoto-u.ac.jp/~suchii/einsteinBM.h

## Re:Plagiarist? (Score:3, Informative)

I guess its just

## Re:Plagiarist? (Score:5, Informative)

Ummm, no. Einstein's NP was for his paper on the photoelectric effect. Read your source again.

## Re:Plagiarist? (Score:3, Informative)

The Nobel Prize is not awarded for a single act or document, but for a collection thereof. Books do not win Nobel Prizes, for example. Authors do.Not really. In the Nobel prize for physics is almost always given for something specific that a person did. In Einstein's case [nobelprize.org] it was awarded for "for his services to Theoretical Physics, and especially for his discovery of the law of the photoelectric effect".

Most of the other physics prizes are just given "for his discovery/demonstration/development of X"

## Re:Plagiarist? (Score:3, Funny)

## Re:Plagiarist? (Score:5, Informative)

Einstein was not awarded the Nobel for special relativity because much of it was in fact unveiled by the great mathematician Henri Poincaré. Poincaré found the key point, i.e., everything stems from defining time as being obtained by synchronizing clocks with electromagnetic signals.Not really. Poincare did do a lot of the interesting math, following on from Lotentz, that provides a lot of the mathematical foundations for relativity, but what he didn't do was redefine time. Poincare still viewed the different time in the calculations as a sort of "local time" which was in a sense merely a mathematical fiction required to make the calculation go through. Poincare still believed in the ether, and thus an absolute referene frame and an absolute time. It was Einstein who, with his observations about the very nature of time being relative, did away with a ficntional "local time" and an absolute reference frame. In Einstein's view there was no true reference frame and all time was "local time" - local to the observer. The effects on time were thus not a mathematical fiction, but a physical reality. It was this observation and new conception of time that Einstein is highly regarded.

That does not, of course, in any way diminish Poincare's work - and he did a great deal of work besides just that relating to relativity (he is the father of algebraic topology for instance). Certainly Poincare deserves a little more recognition for his great achievments than he gets outside of the mathematics community. Misrepresenting Einstein's achievements is not the way to give Poincare his due credit however.

(As a side note, more recognition should probably also be given to David Hilbert, who did a lot of the pure maths required to lay the foundations of General Relativity).

Jedidiah.

## Observations vs Posulates (Score:3, Interesting)

Poincare still believed in the ether, and thus an absolute referene frame and an absolute time. It was Einstein who, with his observations about the very nature of time being relative, did away with a ficntional "local time" and an absolute reference frame.No if anyone "observed" that time was relative it was Michelson-Morley [virginia.edu]. Einstein postulated this observation as the basis of a formal system which yielded new testable hypotheses.

## Re:Plagiarist? (Score:2, Insightful)

## Re:Plagiarist? (Score:5, Insightful)

Seems like a scientist's National Enquirer.

## Re:Plagiarist? (Score:2, Informative)

years ago they were pushing naltrexone for blocking the effects of drugs like opioids and many stories talked of its completely safe use and ability to fix drug users in just days or weeks and prevent any relapses, and was an immune system miracle drug that beat HIV and AIDS.

then after naltrexone was approved nexus printed many articles

## Re:Plagiarist? (Score:3, Funny)

now-anonymous Italian physicists: Olinto De Pretto comes to mindThis word "anonymous." I don't think it means what you think it means.

## Re:Plagiarist? (Score:4, Funny)

"When you are a student, it's called plagiarism; when you are a professor, it's called scholarship."

But for all I know he ripped that quote off from someone else . . .

## Re:Was it Einsteins wife? (Score:2)

so tell me again why

## Re:If c is the speed of light... (Score:3, Insightful)

## Re:E=MC^2 roadblock (Score:3, Insightful)

When I talk to "scientists" (I'm not one either), and even hint that Einstein's theory might be wrong, it's as if I've shouted out a stream of profanities at church.it's not because they thought you shouted profanities in church, it's because you're showing remarkable lack of understanding of the scientific method and how science is done. if you want to be taken serious, propose your model, show how it explains an observable fact that current theories don't.

being a physicist, i can't believe your po

## Re:E=MC^2 roadblock (Score:3, Insightful)

claimthat. The reality is, he's memorised a lot of fairytales.