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# One Hundred Years of E=MC2

#### CmdrTaco posted more than 9 years ago | from the i-still-don't-get-it dept.

408

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."

### Plagiarist? (0, Flamebait)

#### (1+-sqrt(5))*(2**-1) (868173) | more than 9 years ago | (#13350432)

"Plagiarist of the Century [nexusmagazine.com] " quoth the sensationalist headline; more credit is due, in any case, to certain now-anonymous Italian physicists: Olinto De Pretto comes to mind, et alii.

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

#### Frymaster (171343) | more than 9 years ago | (#13350544)

my question is, then, why aren't we celebrating another famous 1905 paper by a. einstein? i am, of course, talking about his work on brownian motion.

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

source:
http://www.bun.kyoto-u.ac.jp/~suchii/einsteinBM.ht ml [kyoto-u.ac.jp]

### Re:Plagiarist? (0)

#### Anonymous Coward | more than 9 years ago | (#13350640)

His paper on Brownina Motion came out much earlier in 1905, and if you were a member of the American Physical Society you would have seen many such celebrations of this work.

### Re:Plagiarist? (0)

#### Anonymous Coward | more than 9 years ago | (#13350671)

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. While Eintein definitely deserves credit for putting all this in a simple and radical form, it appeared to the Nobel committee that the matter was too controversial, especially as Poincaré was already dead by 1921 and thus could not be awarded the prize jointly. However, Einstein certainly deserved a Nobel for one reason or another and another excuse was chosen.

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

#### rk_cr (901227) | more than 9 years ago | (#13350567)

Even if it was plagiarism, the mere article itself made a much greater effect on the scientific community than did the other previous researchers. Sometimes it's not who thought of it but who pushed their point or got lucky who gets famous - that's just a fact of scientific research.

### Re:Plagiarist? (4, Insightful)

#### double-oh three (688874) | more than 9 years ago | (#13350570)

Hm. I call bullshit. The same site appears to also support UFOs and some sort of secret Nazi base in Antartica?

Seems like a scientist's National Enquirer.

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

#### Saven Marek (739395) | more than 9 years ago | (#13350625)

Nexus is a magazine devoted to printing what nobody else will publish despite glaring scientific inaccuracies and holes in logic. that is part why they publish what they do.

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 afterwards talking about the mind control use of naltrexone which was being sneaked in the back door by making drug users use it first because that wouldn't be rejected by society even though there is claimed all evidence to it being unsafe.. claims now are the whole population will be on naltrexone and under mind control within decades.

the position switch might sound like nexus is dual personality but really it just cmoes about because they feel the same information wants to be free as many other people but will work towards that by publishing information nobody else will publish.

whether that information is bollocks matters not it will be published anyway.

### Hold on there (1)

#### geoffrobinson (109879) | more than 9 years ago | (#13350597)

I don't know the details, but if Newton and Leibinitz can come up with calculus independently of each other (b/c it is true) do not assume Einstein stole the formula without proof.

### Re:Plagiarist? (2, Funny)

#### commodoresloat (172735) | more than 9 years ago | (#13350606)

now-anonymous Italian physicists: Olinto De Pretto comes to mind

This word "anonymous." I don't think it means what you think it means.

### Was it Einsteins wife? (0, Troll)

#### John Seminal (698722) | more than 9 years ago | (#13350621)

I have heard over and over and over again, that Einsteins wife is more responsible for his work than Einstein is. I wonder if any other ./'ers have heard the same?

While we are at giving credit where it is due, why not give Nikola Tesla credit for his work with electricity.

The USA has a bad habit of stealing technology and breakthroughs from other countries and then saying they invented it. There is no way that Benjamin Franklin invented everything from bifocal eyeglasses to a furnace, and still had time to fly kites and discover electricity.

### Its not E=MC^2 (1, Insightful)

#### Anonymous Coward | more than 9 years ago | (#13350437)

Its E=MC^2/(1-(V^2/C^2))

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

#### benhocking (724439) | more than 9 years ago | (#13350479)

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 (5, Funny)

#### John Seminal (698722) | more than 9 years ago | (#13350549)

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?

### relativistic mass? (0)

#### Anonymous Coward | more than 9 years ago | (#13350704)

That's near boston mass., isn't it?

### Re:It is E=mc^2 (0)

#### Anonymous Coward | more than 9 years ago | (#13350743)

Damn, I'm getting old : I'm not even getting the leetspeak of today anymore.

too much TeX ;)

### Re:Its not E=MC^2 (1, Informative)

#### Pxtl (151020) | more than 9 years ago | (#13350501)

Ahh, the weakness of the circumsized ASCII character set. Under windows, the squared character is alt+0178, represented as: (I hope Slash doesn't eat that).

consider it ate.

### Re:Its not E=MC^2 (1)

#### ettlz (639203) | more than 9 years ago | (#13350518)

...if m is 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 (1)

#### StressGuy (472374) | more than 9 years ago | (#13350674)

Interesting...the equation is reminiscent of the equation for aerodynamic drag as you approach the speed of sound. Although i wonder if it's not backwards...i.e. mass approaches infinity as you approach the speed of light.

In any event, the aerodynamic drag equation breaks down as Mach gets much above .4. So, I can't help but wonder if there are similar "transisitional dynamics" that make this equation invalid as you approach the speed of light.

Ok, back to work now...

### Time for a physics limerick (5, Funny)

#### utopianfiat (774016) | more than 9 years ago | (#13350438)

There once was a fencer named frisk,
whose movement exceedingly brisk
so quick was his action
the Fitzgerald Contraction [wikipedia.org]
reduced his rapier to a disc

### Perent Is not OT (0)

#### Anonymous Coward | more than 9 years ago | (#13350496)

come on mods, time to get a clue.

Fitzgerald suggested that when a body moves through space it experiences a compression in the direction of the motion. Lorentz showed how such an effect might be expected based on electromagnetic theory and the electrical constitution of matter, that is, when a body moves through space its dimension parallel to the line of motion might become less by an amount dependent on its speed. If the speed of the body is v and the speed of light is c, then the contraction is in the ratio

### Re:Time for a physics limerick (1)

#### Anonymous Coward | more than 9 years ago | (#13350557)

There was a young lady named Bright,
Whose speed was much faster than light.
She set off one day,
In a relative way,
And returned on the previous night.

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

#### Rei (128717) | more than 9 years ago | (#13350605)

Q: Why did the chicken cross the road?

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 (3, Funny)

#### utopianfiat (774016) | more than 9 years ago | (#13350664)

A8: You can never definitely measure why the chicken crossed the road as long as you can definitely measure whether or not the chicken has crossed the road.

### Happy 100th (5, Funny)

#### Robotron23 (832528) | more than 9 years ago | (#13350447)

In response to this momentous occasion...I can only quote the great MC Hawking. :)

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

### Theoretical Bounds Without Implementation (0)

#### Anonymous Coward | more than 9 years ago | (#13350552)

Alas, "E=MC^2" gives a theoretical bound but provides no clue as to how to build a device that can convert mass into pure energy efficiently. If we had such a device, we could solve the energy crisis and, moreover, provide a way to power spacecraft.

The dilemma is similar to the one posed by Shannon's Capacity Theorem. It indicates the upper bound on the rate at which information can be transmitted but provides no clue as to how to build a device that can transmit at the upper bound. Consider the case of standard copper telephone cable. In the 1950's (?), the theorem told use that we can transmit at 56K baud on the cable, but 30 years elapsed before we actually figured out how to build a modem (with a little help from Viterbi) that can transmit data at that speed.

### Re:Theoretical Bounds Without Implementation (1)

#### shawn(at)fsu (447153) | more than 9 years ago | (#13350681)

Actually it does. Kind of. If I remember my Advanced Cosmology class. One of our first assignments was to figure out how much energy you would get by bringing in 1 kilogram of antimatter in to contact with its corresponding regular matter. Providing all the matter and antimatter are converted.
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 (2, Interesting)

#### Robotron23 (832528) | more than 9 years ago | (#13350702)

Exactly. Thats one of the problems scientists face with fusion power for example. Fusion as a means of an energy source was proposed back in the fifties. When old Albert was barely in the grave infact. Since then they've made modest progress, as many on /. have no doubt heard, a fusion reactor named ITER was approved for construction in France.

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 inefficient in terms of energy produced from materials used. We have a heck of a long time to go before we can even make an energy "profit" from materials put in. The most optimistic scientists predict 2040 as the crossover point. But then, only time will tell.

A second problem is that some environmentalists believe all E=MC^2 ever acheived was "The Bomb" and as such try to obstruct progress through protesting etc. It is true that fusion can pollute, but to a much lesser degree than nuclear fission. Still, perhaps in fifty, a hundred, two hundred years time when fusion becomes widely used they'll be chaining themselves to trees and whatnot.

We'll no doubt find that development in fusion and other methods of power will speed rapidly once oil/natural gas become scarce enough. And with that, hopefully, journeys to Mars, to the Centuari system, and beyond on fusion powered craft.

### Re:Happy 100th (4, Funny)

#### CrazyTalk (662055) | more than 9 years ago | (#13350586)

And to quote something I learned in high school physics,

Twinkle, Twinkle little star
Power = I squared R

### Hazzah! (2, Funny)

#### Gunny101 (894783) | more than 9 years ago | (#13350448)

#!/usr/bin/perl my $e = (mc * 2); print "$e";

### Re:Hazzah! (1)

#### serialdogma (883470) | more than 9 years ago | (#13350476)

It is 2 as in to the power of, not times by.
I think that is ** in perl.

Not if mc = 2!!

### Re:Hazzah! (0)

#### Anonymous Coward | more than 9 years ago | (#13350522)

only if c == 2 and m == 1

### Re:Hazzah! (1)

#### Drooling Iguana (61479) | more than 9 years ago | (#13350553)

c is a constant and therefore cannot be 2. This equation can only work out if m = 2/c.

### Re:Hazzah! (1)

#### Gunny101 (894783) | more than 9 years ago | (#13350600)

I'll issue a patch next the first Tuesday of next month.

### Re:Hazzah! (1)

#### Jeff Hornby (211519) | more than 9 years ago | (#13350537)

actually, since it is only c that is squared, and c is a constant (the speed of light), it is always wrong.

### Re:Hazzah! (1)

#### serialdogma (883470) | more than 9 years ago | (#13350541)

Well google informs me that c2 is "8.98755179 × 10^16 m2 / s2", you must have some really small mass.

### Re:Hazzah! (0)

#### Anonymous Coward | more than 9 years ago | (#13350494)

Incredible! From the looks of this script it looks like we've got the head of the Windows design team or possibly the lead programmer from Intuit right here in our midst. No one make any sudden movements, these beasts are timid and easily startled

*E=MC^2

### Re:You are missing an operator (1)

#### jetkust (596906) | more than 9 years ago | (#13350509)

NO NO NO. that will never compile. try this:

int getenergy(int mass, int velocity)
{
return mass * (velocity * velocity);
}

### Using ints? (1)

#### benhocking (724439) | more than 9 years ago | (#13350559)

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) {
return mass * (c * c);
}

Or:

float getenergy(float mass, float velocity) {
return mass * (speed_of_light_invacuo * speed_of_light_invacuo);
}
if you don't like using "c" for some reason.

### Re:Using ints? (0)

#### Anonymous Coward | more than 9 years ago | (#13350697)

How are "c" and "speed_of_light_invacuo" in scope in their respective examples? If they are macros, why are their names not all-caps? Why are you not lining up your braces? And, since the function is so tiny, why not inline it using a macro?

### Coral (1)

#### Saiyine (689367) | more than 9 years ago | (#13350461)

Site already slow: Coral cache [nyud.net] .

--
Dreamhost [dreamhost.com] superb hosting.
Kunowalls!!! [kunowalls.host.sk] Random sexy wallpapers.

### here goes karma... (0, Flamebait)

#### utopianfiat (774016) | more than 9 years ago | (#13350464)

Dear Slashdot. NOT A FUCKING PODCAST. [slashdot.org]

### Time to back up my assertion with facts (0, Offtopic)

#### utopianfiat (774016) | more than 9 years ago | (#13350538)

WIKIPEDIA [wikipedia.org] : Podcasting is a method of publishing audio broadcasts via the Internet, allowing users to subscribe to a feed of new files (usually MP3s). It became popular in late 2004, largely due to automatic downloading of audio onto portable players or personal computers.

### Re:here goes karma... (0)

#### Anonymous Coward | more than 9 years ago | (#13350638)

Blah blah blah, Jesus tapdancing Christ... how much of this rambling do we have to endure? It's a term used incorrectly, big deal, let's all spend lot's of time bitching about it... listening to you guys rant over something so lame is *kinda* funny, but more annoying than anything.

"Podcasting" isn't what the article was about... why don't we stick to that, more meaningful, discussion.

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

#### G4from128k (686170) | more than 9 years ago | (#13350470)

Einstein's work showed that Newton's equations were a good approximation for low velocities, but not for velocities approaching c. What if Einstein's work is an approximation, too. 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 strong.

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

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

#### hackstraw (262471) | more than 9 years ago | (#13350568)

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? (2, Funny)

#### VoidWraith (797276) | more than 9 years ago | (#13350748)

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.

Relativity, after all...

### Re:What if E = mc^2.0000000001? (1)

#### Drooling Iguana (61479) | more than 9 years ago | (#13350577)

I'm pretty sure that relativity has already been revised a few times after Einstein's initial work.

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

#### Pryon (181814) | more than 9 years ago | (#13350579)

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 strong

Interestingly, these conditions provide a good verification of 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? (2, Interesting)

#### pin_gween (870994) | more than 9 years ago | (#13350594)

What if Einstein's work is an approximation, too. ..

That's the beauty of science... Science is INQUIRY... it is not static.

Until someone does prove it was an approximation, we'll use it. Once that occurs, we will use the new figure until someone else is able to make it more accurate.

### Re:What if E = mc^2.0000000001? (1)

#### wanerious (712877) | more than 9 years ago | (#13350703)

Well, it sort of does anyway. The factor of 2 in the exponent is exact, but the entire expression mc^2 is only valid when at rest relative to the particle in question. At some relative velocity, the expression is really (gamma)mc^2, where (gamma) is 1/(1-v^2/c^2)^-1/2.

### Reaching way back into my memory,but... (1)

#### Cujo (19106) | more than 9 years ago | (#13350719)

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

### Well, actually... (0)

#### Anonymous Coward | more than 9 years ago | (#13350729)

It doesn't explain quantum effects, so the theory of relativity (both of them) is already known to be lacking for many years...

### Hey! (1)

#### Psionicist (561330) | more than 9 years ago | (#13350473)

Richard Stallman created that, not Einstein! And the current release is 21.4, not 2!

### Could someone mirror them please ... (1)

#### hritcu (871613) | more than 9 years ago | (#13350474)

... I really have a strange feeling about their web server :(

### Re:Could someone mirror them please ... (1)

#### hritcu (871613) | more than 9 years ago | (#13350573)

Here is the MirrorDot link [mirrordot.org] for the Slashdot horde.

### What did E=MC2 give us the past 100 years? (1)

#### John Seminal (698722) | more than 9 years ago | (#13350482)

I think there would be very different anwsers depending what part of the world you ask. I am sure the people of Nagasaki would have a very different anwser than the people of smalltown, USA. To some, it gave the world a horrible wepon. For others, it gave modern day comforts.

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 and there is enegery, does not ring true to me. Something more happened than we do not understand. It is like the uncertanty principle. The electron is still there. Or is it? If it is not there, where is it? How many examples are there of the opposite happening. Taking just energy, with no starting mass, and making mass?

What I think is more usefull from E=MC2 is the idea of relativity. It is true, not just for science, but for almost every field of study.

### Re:What did E=MC2 give us the past 100 years? (1)

#### jimijon (608416) | more than 9 years ago | (#13350546)

Yes I have issues with it too. But I don't believe in pure mass. Mass without geometry does not exist in our universe. This means that the equation is missing an information constant, I or such.

### Re:What did E=MC2 give us the past 100 years? (1)

#### sfjoe (470510) | more than 9 years ago | (#13350701)

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

### Re:What did E=MC2 give us the past 100 years? (4, Informative)

#### ettlz (639203) | more than 9 years ago | (#13350616)

I am sure the people of Nagasaki would have a very different anwser than the people of smalltown, USA. To some, it gave the world a horrible wepon.

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.

I don't know if I fully believe that energy equals mass.

The whole idea is a staple of Relativistic kinematics which has been verified in collider experiments, etc., etc.

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 and there is enegery, does not ring true to me.

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.

Something more happened than we do not understand. It is like the uncertanty principle. The electron is still there. Or is it? If it is not there, where is it? How many examples are there of the opposite happening. Taking just energy, with no starting mass, and making 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? (1)

#### slavemowgli (585321) | more than 9 years ago | (#13350653)

How many examples are there of the opposite happening. Taking just energy, with no starting mass, and making mass?

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 (2, Informative)

#### pin_gween (870994) | more than 9 years ago | (#13350716)

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

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

#### alispguru (72689) | more than 9 years ago | (#13350484)

By Peter Norvig [norvig.com] .

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

### Theory Of Relatively... (1)

#### creimer (824291) | more than 9 years ago | (#13350486)

I took physics in college and all I got out of it was this cool E=MC2 shirt. :P

### Thats great... (-1, Offtopic)

#### Anonymous Coward | more than 9 years ago | (#13350487)

so who are these guys?

### Timing (3, Insightful)

#### burtdub (903121) | more than 9 years ago | (#13350495)

Sadly, this comes just days after the anniversaries of the Hiroshima and Nagasaki bombings.

### Re:Timing (1)

#### Rude Turnip (49495) | more than 9 years ago | (#13350604)

People have been doing shitty things to each other since the beginning of time. Einstein came up with a formula, which amounts to a tool. It *always* comes down to people and their choices as to how a tool is used.

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

#### Anonymous Coward | more than 9 years ago | (#13350513)

"If Einstein was so smart how come people only call you 'Einstein' when you do something really stupid?" - Brian Regan

### One Hundred Years of E=MC2 (3, Funny)

#### iapetus (24050) | more than 9 years ago | (#13350516)

So what was E equal to in 1904?

### Re:One Hundred Years of E=MC2 (2, Informative)

#### capicu (880524) | more than 9 years ago | (#13350581)

So what was E equal to in 1904?
½mv^2

### Re:One Hundred Years of E=MC2 (1)

#### FlameTroll (901932) | more than 9 years ago | (#13350626)

So what was E equal to in 1904?

MC^2. Einstien discovered the relationship- he didn't invent it. What is, is, and will always be.

### Re:One Hundred Years of E=MC2 (2, Funny)

#### capicu (880524) | more than 9 years ago | (#13350666)

Whoa really? So even before Einstein, mass was proportional to energy? That really takes him down a few notches in my estimation.
Well, at least I can still look up to Newton for giving us the gift of gravity.

### Podcasting ??? (-1, Troll)

#### Anonymous Coward | more than 9 years ago | (#13350524)

It is not podcasting.

There seems to be an endless need in the Apple Kingdom to reaffirm their decisions by finding like-minded acceptance via astroturfing.

Calling "making media available on the internet" is not "poscasting".

Apple users read reviews on Apple Computers, for instance, after they bought their computer just to

This continues to happen decade after decade. Insecurity seems to be pandemic among Macphiles.
This phenomenon is the only thing that explains Mac users still getting so adamant.
If Apple had 90 percent market share you wouldn't hear a peep out of Mac users, since the
market itself would have given them the affirmation they need.

Mac users style themselves as non-conformists; in reality, they insecure and utterly intolerant.

Notice how they mod down reasonable criticism around here. Notice how they can handle being corrected.

### From the i-still-don't-get-it dept. (1)

#### HishamMuhammad (553916) | more than 9 years ago | (#13350527)

It's because you're doing E=MC2, not E=MC^2. Redo your calculations and you'll see everything makes sense now. ;)

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. (1)

#### ettlz (639203) | more than 9 years ago | (#13350670)

It's because you're doing E=MC2, not E=MC^2.

That's dimensionally inconsistent.

### Ok guys... educumacate me (1)

#### EnronHaliburton2004 (815366) | more than 9 years ago | (#13350530)

Ok everyone, let me proclaim my utter ignorance. I have been trying to understand E=MC^2 for years, and I don't get.

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 understand why.

Are there any good, visual examples of these ideas?

I'm listening to these Physicists [pbs.org] . But again, most of these people are talking about the legacy of the equasion-- they talk about how the equasion impacted society. (Although Janet Conrad has a good brief description of why it matters)

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

#### drxenos (573895) | more than 9 years ago | (#13350584)

Well, one example of where Netwon fails is explaining the rotation of the planet Mercury around the Sun. Since the gravity is so strong that close, Netwon fails, and we must use General Relativity. I believe the planet's orbit (someone correct me) actually spirals.

### Re:Ok guys... educumacate me (1, Insightful)

#### CrazyTalk (662055) | more than 9 years ago | (#13350598)

Ummm - a good visual example? Ever seen photographs of the ruins of Hiroshima? I don't think it gets much more visual then that! A few grams of matter (Ok, not sure exactly how much) converted to enough energy to level a city.

### Re:Ok guys... educumacate me (0)

#### Anonymous Coward | more than 9 years ago | (#13350663)

As stated in some other posts, it is the rest energy of a body. The total energy of a particle is given by this equation E^2=(p*c)^2+(M*c^2)^2

E = Energy
p = Reletivistic Momentum
M = rest mass

p = gamma * M * v

gamma * M is the relatavistic mass, an objects mass depends on it's velocity. Gamma is 1/sqrt(1-v^2/c^2)

This is important becasue as v->c the body's mass and energy approach infinity, hence why you can never travel at v = c (Unless you're massless, when M = 0 (eg: a photon) you can travel at c)

Other wierd things occur when massless particles travel at c: they have momentum, but no rest mass.

The E=MC^2 is relvent for atomic energy, our understanding of stars, radiation, and most of modern physics.

It's quite simple really... you have to thorw out you bais to what you this is "intuative" These things only seem odd becasue we don't encounter these situations (at least in any observable senario) in out day to day lives. However I'm about to enter my third year as an undergad Physics major... so perhaps my idea of what is 'easy' and 'simple' are a bit skewed.

### Re:Ok guys... educumacate me (1)

#### slapout (93640) | more than 9 years ago | (#13350690)

Well, there's your problem....you're watching PBS...you're probably falling asleep halfway thru....

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

#### Unequivocal (155957) | more than 9 years ago | (#13350713)

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!

### E=MC^2 (0)

#### Anonymous Coward | more than 9 years ago | (#13350554)

But only in the rest frame.

### NO.. (0, Offtopic)

#### E IS mC(Square) (721736) | more than 9 years ago | (#13350571)

I am not 100 yrs old!

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

#### suitepotato (863945) | more than 9 years ago | (#13350590)

If you have it that the values are irrellevant and only the geometery matters, then for E to be conserved and still change c...

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

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

...which only means that as the speed of light changes, mass must change where it does so that E does not change and violate conservation. And if t is related to c then quite possibly as c approaches infinity m drops towards 0 and the distance between any two points drops towards zero and the speed of time climbs towards infinity and at c=infinity everything happens at once and all distances are zero.

Conversely if c drops toward zero then mass heads for infinity and when c=0 then mass is infinite, nothing happens, and all distances are infinite.

It looks like reverse time dilation and one wonders if you can warp space to create a faster local c, can you accellarate normally at such a rate as to counter it and have dilation=0? It doesn't look so much like Star Trek's integral warp speeds as there being a curve on which normal dilation can match warp dilation. Would be interesting to have a high-speed zero dilation trip to the next system and back to check it out with chronometers.

Just thinking out loud is all...

### If c is the speed of light... (0)

#### Anonymous Coward | more than 9 years ago | (#13350599)

...and nothing is faster than the speed of light, how can we square c ???

### Re:If c is the speed of light... (1)

#### becauseiamgod (559722) | more than 9 years ago | (#13350676)

when we sqaure c, we aren't getting another speed, we are just getting a number that is fastest speed ever, multiplied by itself.

### Re:If c is the speed of light... (1)

#### Le Marteau (206396) | more than 9 years ago | (#13350708)

nothing is faster than the speed of light

That's not what special relativity says. Special relativity says nothing can travel AT the speed of light. It says nothing about FASTER.

### Re:If c is the speed of light... (1)

#### mopslik (688435) | more than 9 years ago | (#13350710)

> how can we square c?

.__
|
|__

That ought to do it.  Pesky formatting seems to insist on the period, but it looks *far* more squared to my eyes than "c".

### Re:If c is the speed of light... (1)

#### Skiron (735617) | more than 9 years ago | (#13350720)

...how can we square c ???

Get c to marry Bush or Blair or some other 'trendy person'.

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

#### Michael.Forman (169981) | more than 9 years ago | (#13350687)

E = mc^2 is Not Einstein's Discovery

Robert A. Herrmann

1. Introduction

Michael. [michael-forman.com]

### These dudes all have smart sounding names. (1)

#### RandoX (828285) | more than 9 years ago | (#13350689)

You don't usually hear of a genius physicist named "Chuck Miller"...

### 2 years too late (1, Informative)

#### Baldrson (78598) | more than 9 years ago | (#13350693)

Einstein's E=mc2 'was Italian's idea' [guardian.co.uk]

Rory Carroll in Rome
Thursday November 11, 1999

Guardian

The 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 Pretto's insight in a major paper published in 1905, but De Pretto was never acclaimed, said Professor Bartocci of the University of Perugia.

De Pretto had stumbled on the equation, but not the theory of relativity, while speculating about ether in the life of the universe, said Prof Bartocci. It was republished in 1904 by Veneto's Royal Science Institute, but the equation's significance was not understood.

A Swiss Italian named Michele Besso alerted Einstein to the research and in 1905 Einstein published his own work, said Prof Bartocci. It took years for his breakthrough to be grasped. When the penny finally dropped, De Pretto's contribution was overlooked while Einstein went on to become the century's most famous scientist. De Pretto died in 1921.

"De Pretto did not discover relativity but there is no doubt that he was the first to use the equation. That is hugely significant. I also believe, though it's impossible to prove, that Einstein used De Pretto's research," said Prof Bartocci, who has written a book on the subject....

### serious question (3, Insightful)

#### frovingslosh (582462) | more than 9 years ago | (#13350698)

I, of course, learned this famous equation back in grade school. And I understand the relationship between matter and energy (at least as well as most physics students do and better than most lay people, if anyone really understands 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?

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

#### CompuSwerve (792986) | more than 9 years ago | (#13350699)

As my mass has gone up, my energy has gone down. What more proof do you need?

### Quantum debugging (4, Funny)

#### stengah (853601) | more than 9 years ago | (#13350717)

Another interesting fact, derived from empirical analysis : in a Windows field, light speed is negative.This explain the interesting "expanding copy time" (aka "30 seconds left... 4 centuries left...") experienced by most Windows users.Another explaination would be a schrödinger-like effect induced by closed source.

### Hacks with books (0)

#### Anonymous Coward | more than 9 years ago | (#13350723)

Why do they get all the hacks with books to explain these things? The real people doing the real work are never on these shows. I guess Michio Kaku, Alan Guth, and Brian Greene are all more suitable for public consumption even though their work sucks.

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

#### plehmuffin (846742) | more than 9 years ago | (#13350726)

100th anniversary? Yeah, but it's all relative

# Slashdot: News for Nerds

Mathematics deals exclusively with the relations of concepts to each other without consideration of their relation to experience. -- Albert Einstein