e=mc2

[thermidorthelobster]

I was just emailed a question from a student asking me to tell him what e=mc2 was all about.

I explained that it says that energy and mass are two different aspects of the same thing.  So you can change energy into mass, or mass into energy;  matter is basically just concentrated energy.

Then I worked out that if the student's body mass was converted entirely into energy, it would release enough energy to power the earth's energy needs completely (transport, heat, electricity, the lot) for 3 days  :shock:

Or to put it another way, if you exploded him into pure energy, he'd release about as much energy as 20 of the world's most powerful atomic bombs.

Interesting when you look at it that way...  And probably a good reason to steer clear of neutron sources  8)

[datalas]

Alternatively a good reason to use chavs to cure the worlds energy crisis :)

[skip]

Considering the lack of energy and the massive density some chavs seem to exhibit perhaps they might be put to better use as control rods for our new neuclear power stations :lol:

[Bulli]

hmmm, i once had a heated debate with a guy doing an astrophysics PHD and he couldnt prove it was right. My (drunken) reasoning was that nothing else in nature follows such nice rules, Beech trees for instance dont all have the same number of branches let alone leaves.
So how come the energy released is exactly the massXthe speed of light squared....seems quite strange i think Einstein was just trying to think of a nice big number and hey preston speed of light. Anyway he got very frustrated.

Therm surely there would be an awful lot more energy released as we are 70% water and each water molecule contains 2 hydrogen atoms....

[thermidorthelobster]

How come it's exact?  I don't think there's an answer for that.  We don't know.  Odd isn't it?  But nonetheless it works, exactly, ie the rule has passed every test we've been able to throw at it.

It doesn't matter how many atoms we have because it's the mass that counts.  We are made up of water each containing 2 H and 1 O but the total mass in the hydrogens and oxygens isn't any more than if you look at the whole molecule.

[Bulli]

yes but  splitting more(increased mass) atoms creates more energy...hence energy = massX the speed of light squared. And im sure the average student contains more than 20 X the destructive force in little boy.If you could trigger the hydrogen into fusion.

My logic is simple: you cannot contain the reaction so you cant measure it accurately so to say its right is pure guess work...but if someone can show me different then im listening

[thermidorthelobster]

But more atoms doesn't mean increased mass...

1 H2O molecule has exactly the same mass as 2 H atoms PLUS 1 O atom, apart from a very, very tiny difference indeed due to the energy the bonds hold when it's bonded (according to E=MC2).  It doesn't matter how far you pull everything apart, the mass is still the same.  If you were pulled apart into all your constituent atoms, your mass would still be the same as you whole.

It's not guess work at all.  You can't easily measure the energy released by nuclear fission of a student, but you can measure it very accurately indeed for small particles.  Put energy into particles in a particle accelerator, look at what's produced when you smash them all together, and you'll find the energy you started out with is the energy you end up with, minus the amount of mass you've created x the square of the speed of light.  You can work out the mass & velocity (hence energy lost to speed) of the resulting particles very accurately by measuring how they're deflected in an electric field.

There are other implications of E=MC2 as well - such as the amount of energy needed to accelerate things to very high velocities - which can be tested, and have been, in thousands of experiments.  Each time it's tested, the results are as they would be if the formula was accurate.  This doesn't mean it's right;  but it means it's not wrong yet.

[Wolfie]

MIT have done some detailed research into the validity of the theory, http://web.mit.edu/newsoffice/2005/emc2.html seems to be pretty accurate. But there again it does still remain only a theory.

[diggerdog36]

But iwas it not Einsteins wife that came up with the Theory of Relativity. What does HE know???

[thermidorthelobster]

Here's an article from New Scientist which describes how it's been tested to be accurate to 5 parts in 10 million.

Science can't actually PROVE anything, as yer man Popper quite correctly pointed out.  You can say all swans are white, and you can be fairly damn sure that's the case, but one black swan blows it all apart.  We can't "prove" that the sun will rise tomorrow morning;  all we can do is be pretty sure that it will, by making up theories, testing them and finding they're not disproven.

[Bulli]

intresting reading,
 Therm i know there are no more atoms i was mearly saying that surely a student contains more atomic material than in 20 atomic weapons.
Certain theories are established as laws though, like gravity, which in our universe works in a manners which can be calculated and does not vary.
Sorry for being the eternal sceptic it just seems that nature rarely throws anything finite into the mix. PI for instance 22/7 yeah nice and neat but in decimal....

[thermidorthelobster]

Certain theories are established as laws though, like gravity, which in our universe works in a manners which can be calculated and does not vary.

Well, there's no way of proving this (any more than we can prove anything else - we can merely say we haven't disproved it yet), and there are actually a few theories knocking around that suggest maybe gravity ISN'T constant!  They can help explain things like accelerating expansion of the universe, which is what dark energy is also hypothesised to explain.

Sorry for being the eternal sceptic it just seems that nature rarely throws anything finite into the mix. PI for instance 22/7 yeah nice and neat but in decimal....

Ah, but pi isn't 22/7.  It just happens that 22/7 is close enough to make it quite a useful approximation sometimes.

Being sceptical is absolutely right;  it's only by challenging the received wisdom and striving to test our theories until they break that we make progress.

New Scientist also ran an article about 13 things in modern science that do not make sense. If anybody can't access the full article and wants to, then pm me with your email and I'll send you a PDF.

[beast5680]

13 things in modern science that do not make sense

there is another one they missed on that list :?

why when the door bell rings does the dog always think its for him? :lol:  :lol:

[Lord Shagg-Pyle]

E=MC2 featured in a song called 'Einstein a go-go' by an 80's band called Landscape.
That is the extent of my input! :D

[landy4x4xfar]

13 things in modern science that do not make sense

there is another one they missed on that list :?

why when the door bell rings does the dog always think its for him? :lol:  :lol:

from your link to 13 things in modern science that do not make sence

2 The horizon problem
Nothing can travel faster than the speed of light
wrong wrong wrong with bells on and a cheery on top doing a lap dance

their is the speed of dark that will take you from one side of the universe to the other intently how very 1960's of the clap trap some prat with a PHD will write  



 :twisted:  :twisted:  :twisted:  :twisted:  :twisted:  :twisted:  :twisted:  :twisted:

[datalas]

There are some things that travel faster than the speed of light...

money traversing through my bank account, that's pretty damned rapid

[Sheddy]

Gossip on Canvey Island ... that travels faster than the speed of light too.

[Evilgoat]

13 things in modern science that do not make sense

there is another one they missed on that list :?

why when the door bell rings does the dog always think its for him? :lol:  :lol:

from your link to 13 things in modern science that do not make sence

2 The horizon problem
Nothing can travel faster than the speed of light
wrong wrong wrong with bells on and a cheery on top doing a lap dance

their is the speed of dark that will take you from one side of the universe to the other intently how very 1960's of the clap trap some prat with a PHD will write  



 :twisted:  :twisted:  :twisted:  :twisted:  :twisted:  :twisted:  :twisted:  :twisted:

You Also forgot Astramax vans and Gossip in a Tesco store (where the subject of the roumour she is leaving hadnt actually told anyone yet)

[thermidorthelobster]

2 The horizon problem
Nothing can travel faster than the speed of light
wrong wrong wrong with bells on and a cheery on top doing a lap dance

their is the speed of dark that will take you from one side of the universe to the other intently how very 1960's of the clap trap some prat with a PHD will write

Eh?  Speed of dark?  Is that Terry Pratchett?

If I understand it correctly, Einstein actually said you can't transmit INFORMATION faster than the speed of light, which is different, and still holds true at the moment (despite quantum entanglement etc).

[datalas]

The speed of dark concept is that if you open a door slowly you can see the light flood into the room,  but you don't see the dark leave, ergo dark must be faster than light...

[BigSi]

I’ve always wondered what is the difference between the scientific challenge to Darwinian evolution and the theory of intelligent design?  :shock:  :shock:  :shock:  :shock: