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Can energy be converted into matter?


55delta
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I am sure many of you are aware Einstein's rather famous E = MC2 equation, concerning converting matter into energy. We also know that it works, given that it's the underlying basis of nuclear weapons. But I'm not interested in nuclear weapons.

Instead, I'm wondering if the opposite is true. Now, from a mathematical standpoint, it should work in reverse, a sufficient amount of energy should be convertible back into matter. But would the math be right? Is there anything known in physics that proves that this equation is reversible? Do we know if energy can be converted into matter?

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Yeah, as I understand it it's how large particle colliders work. The collision is just a means to an end, getting a lot of energy into a small space that drives the mass-energy equivalence "in reverse" to create new particles.

Indeed, it's how the universe got its matter in the first place.

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Cantab beat me to it. That c-squared term is a killer though - it takes phenomenal amounts of energy to make very small amounts of matter.

Edit. Nitpick - I'm not sure it's possible to drive an equivalence in reverse (I suspect K2 could supply the proper terminology) but Cantab's point still stands. Collide very high speed particles to get a lot of energy into a very small place and then watch all the new particles tumble out.

Edited by KSK
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The reverse, matter into energy is what fusion is about. In bombs and hopefully in power plants one day.

Edit: nevermind ... i probably misunderstood KSK's "equivalence in reverse" ... ?

 

Edited by Green Baron
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4 hours ago, Green Baron said:

The reverse, matter into energy is what fusion is about. In bombs and hopefully in power plants one day.

Edit: nevermind ... i probably misunderstood KSK's "equivalence in reverse" ... ?

According to physics, when you pedal a bicycle you are converting mass into energy.  The equation is absolute, energy *is* mass time c**2.  The reason we tend to limit it to nuclear is that such things can be measured (or at least computed.  We know the masses for the isotopes in the nuclear reaction, and they only add up if you include all the energy).  The change in mass of ATP when you bicycle is too small to measure.

The reverse (converting energy into matter) is considerably harder, as you need enough energy for at least an electron (or whatever bit of matter you are creating).  This is a huge amount of energy and it has to be concentrated enough to form a particle.  If you want something the mass of a Higgs Boson, nothing less than the LHC will provide the energy you need to create it.  If you want something significantly more massive, you will need to build a bigger collider.

There is also no known way to choose what you get (this is why it seemed to take awhile to confirm the Higgs Boson: they had to go through everything it was making to find the things).  If you want to make a "Star Trek replicator" your best bet is to start with a 3d printer* (and replace the printstock with a selection of all possible atoms.  Creating the right molecular bonds in all the right places will be even more fun), although I've heard the "official" explanation is energy-mass conversions (which simply assume that the 25th century will have a better grasp of such physics, as well as an anti-matter power source.  Right now such things are pure magic).

* I'd expect something closer to how we create chips: only instead of coating each layer with the proper atom and removing the ones we don't want (an option) charge the locations we want them and build up a layer of the right atom (then more magic happens as you convince the right chemical bonds to form, possibly in temporary conditions until all the atoms are in place).  Don't expect it anytime soon, but it should be *slightly* easier than warp drives and transporter beams.  Creating "tea: earl gray, hot" from energy is closer to the warp drives and transporter beam tech.

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18 minutes ago, wumpus said:

According to physics, when you pedal a bicycle you are converting mass into energy. 

Different thing, the mass (fat) isn't converted into energy (radiation). It's sweated out, breathed out, formed into muscles. The overall number of particles after the bicycle trip is the same as before, though a few parts and some skin may have been lost on the slope of the Cumbre Vieja down to the sea ... :-)

Nuclear fusion on the other hand really converts mass into energy at the rate of the cited formula e=m*c*c. The overall mass of the newly formed atoms is less than the mass of the atoms before the fusion. It's not much, but enough to set free a lot (!) of energy.

:-)

 

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16 minutes ago, Green Baron said:

Different thing, the mass (fat) isn't converted into energy (radiation). It's sweated out, breathed out, formed into muscles. The overall number of particles after the bicycle trip is the same as before, though a few parts and some skin may have been lost on the slope of the Cumbre Vieja down to the sea ... :-)

Nuclear fusion on the other hand really converts mass into energy at the rate of the cited formula e=m*c*c. The overall mass of the newly formed atoms is less than the mass of the atoms before the fusion. It's not much, but enough to set free a lot (!) of energy.

It's different only quantitatively. The products of respiration will have a lower total mass than the reactants, in the exact same way the products have lower total mass in a fusion reaction. E=MC2 isn't something that applies in some circumstances, it's a fundamental statement about the nature of mass and energy.

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15 hours ago, Kryten said:

It's different only quantitatively. The products of respiration will have a lower total mass than the reactants, in the exact same way the products have lower total mass in a fusion reaction. E=MC2 isn't something that applies in some circumstances, it's a fundamental statement about the nature of mass and energy.

Yes, however it would be pretty hard to measure, Its also a bit irrelevant as no matter is broken down, its just that an water molecule is a tiny bit lighter than two hydrogen and one oxygen atom, probably less than the weight of an electron.
An nuclear reactor on the other hand will loose mass who should be measurable even if its just an tiny fraction. 

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To give you a rough idea how energy is transformed into mass...

Take a spring. A common metal spring, made to such specs, that when you hang a 1kg weight on it, it expands by 20 centimeters.

spring-rod-square-section-250x250.jpg

Measure its mass. Then hang that 1kg mass on it, and now measure the mass of the spring. (obviously substracting that 1kg).

It will be heavier by 11 femtograms - 11x10^-14 grams. The smallest of bacteria weigh ten times as much.

This is the mass equivalence of the energy of 1 Joule, which was the energy stored in the spring by expanding it.

No atoms or other particles were created or destroyed. But as bonds between atoms got stretched, the atoms themselves grew heavier.

 

Edited by Sharpy
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The reason why chemical reactions change mass is simple.  Chemical reactions that release energy form more stable chemical bonds.  This means the electrons clouds are more compact - the electrons have a smaller distance to cover.  That means the electrons travel at a lower velocity, which in terms means their relativistic mass is smaller.  So the electrons are very slightly lighter for the products of chemical reactions that release energy.  

The example of the spring above, given by sharpy, is similar.  The unstrained metal spring, the cloud of electrons that tend to travel around metals has slightly less distance to cover and thus they each weigh a little bit less.

 

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On 8/31/2016 at 0:01 PM, Kryten said:

It's different only quantitatively. The products of respiration will have a lower total mass than the reactants, in the exact same way the products have lower total mass in a fusion reaction. E=MC2 isn't something that applies in some circumstances, it's a fundamental statement about the nature of mass and energy.

Well, that's the theory, and while I expect to indeed lose some infinitesimally small mass while biking, I think we should be a little more careful about extending an equation far, far longer than it can ever be verified.  There might be other, much smaller bits hanging off that equation that we are yet to find.

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18 hours ago, Sharpy said:

 

It will be heavier by 11 femtograms - 11x10^-14 grams. The smallest of bacteria weigh ten times as much.

[snip]

No atoms or other particles were created or destroyed. But as bonds between atoms got stretched, the atoms themselves grew heavier.

 

Physics. So beautiful. 

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On 8/31/2016 at 1:39 AM, Bill Phil said:

Matter is a property of energy, so, yeah. Don't expect high efficiencies though.

Matter is not a property of energy. Matter and energy are two interchangeable forms of whatever (I don't know the higher hierarchy word in English).

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1 hour ago, lajoswinkler said:

Matter is not a property of energy. Matter and energy are two interchangeable forms of whatever (I don't know the higher hierarchy word in English).

That's more of a simplification. If something has more energy it's more massive. E/c^2=m was the original equation, which algebraic ally becomes E=mc^2. 

Actually it was mass that was a property of energy, my bad. Matter is energy in a certain form.

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Energy is a property of matter. The difference between matter and other energy is that in matter the energy is tied up in feilds that interact and stabilize each other, and/or the whole.  If you were to pluck just one of these out, the rest would become energy of various sorts. 

Energy added to matter in any form increases the mass. Energy in the form of photons can create matter de Nova at high enough energy 

https://en.m.wikipedia.org/wiki/Pair_production

This general requires a perturbance such as a nucleus, but in the early universe there was a plethora of exotic particles running around that suffice tonprovide the impetus. 

 

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