We know matter can be converted into energy. Can energy be converted into matter?

[Hayabusa Rider]

Originally posted by: Stove
Energy to matter is happening everywhere there is energy. Pretty near nothing in the universe is irreversible (usually it looks that way coz the reverse reaction is very very improbable). BAsically anywhere there is energy (electromagnetic waves, gravity waves, whatever) there can be spontaneous generation of mass. But since the mass would only exist for the briefest of time before the particle/antiparticle annihilate each other to re-release the energy its tough to observe. It is one of the theories on how black holes could manage to radiate energy which I think is fun 🙂

Virtual particles. Yep.

Real particles can be created near extreme gravitational fields. One pair of the virtual particle falls outside the point of no return, and the other is dragged inward.

Black holes evaporate over time due to this mechanism.

 

[Loki726]

Originally posted by: The Boston Dangler
E=mc^2.

All these bright people, and I am the first to post this here?

Energy = matter at the speed of light squared.

English version:
An enormous amount of energy can be used to create a tiny amount of matter, out of nothing but energy.

Of course, the inverse is also true. A little matter turns into tons of energy. The energy released by a nuclear weapon (fission or fusion) is is from the annihilation of a few neutrons.

If we feel like stating the obvious, why not include a more complete version of the equation? E^2 = m_0^2*c^4 + p^2*c^2 . Now we can compare mass, energy, and momentum!


Think about this one. Why do we get energy when we break down heavy elements, and also when when fuse light elements together?

 

[wetcoastguy]

Look out the window........plants convert energy to mass.

 

[MobiusPizza]

wetcoastguy you didn't read the replies that had already been made.

Plants do NOT convert energy to mass.
The energy is just converted into another kind of energy which we name chemical energy.

Chemical energy in detail can be considered as electrostatic potential energy between atoms and electrons around it. Plants put in energy to separate the attraction between the oxygen and carbon atoms by working against the attraction forces by the two pair of electrons in the double covalent bond.

It has all to do with the kinetic energy of the electrons. So you can say plants convert energy to kinetic energy of the electrons to break the bonds. Whether it has something to do with mass I doubt it.

 

[MobiusPizza]

I have no idea where do people get the ideas plants make matter. To do that they would be as dangerous as an hydrogen bomb (1000 times more powerful than atomic bombs)

Yes, plant make sugar. But they don't make it out of sunlight only. Otherwise the earth would grow in size day by day because new matter is being made for the past billion years. The combine water taken from soil, and Carbon Dioxide in air; then bang the two together to give Glucose.


Chemical equation:
6H2O + 6CO2 -> C6H12O6 + 6O2

18 Oxygen atoms -> 18 Oxygen atoms
6 Carbon atoms -> 6 Carbon Atoms
12 Hydrogen atoms -> 12 Hydrogen Atoms
It is balanced.

No new atoms or anything have been made of thin air, not even electrons are made in this process

Therefore I am puzzled why people think plants make matter.

We human have trouble making matter, and plant stands no chance.
Fusion of heavy elements greater than iron currently requires too much energy and no one has done it before. This process only happen in stars.

However we are able to make some leptons and baryons in particle accelerators, albeit a tiny ammounts

 

[Loki726]

Originally posted by: AnnihilatorX
Chemical equation:
6H2O + 6CO2 -> C6H12O6 + 6O2

To be fair, some mass and energy are exchanged in any reaction where the bond strength of the products is different from that of the reactants. Its just that in most cases it is extremely negligible.

 

[MobiusPizza]

Nuclear reaction and Chemical reaction are different. In nuclear reactions usually the reactants and product have small but neligible mass difference. Chemical reaction though does not involve energy-mass equation. The energy converted to potential energy, is just chemical potential energy;

 

[Loki726]

Originally posted by: AnnihilatorX
Nuclear reaction and Chemical reaction are different. In nuclear reactions usually the reactants and product have small but neligible mass difference. Chemical reaction though does not involve energy-mass equation. The energy converted to potential energy, is just chemical potential energy;

You might be right about that seeing as I can't find any examples of intramolecular bonds causing any change of mass.

Here's why I think that chemical bonds might contribute some mass. In a nuclear reaction, the change in mass is determined by the ratio of the bond energy to the equivalent energy of the masses originally involved.

Take for example 3He + n -> 4He . In this example, the bond energy is 28 MeV per bond. This only corresponds to a 0.75% change in mass. I think the strength of a typical chemical bond is of the order of 100kjoules/mol which is about .96eV per bond. This bond energy would only correspond to a .00000001285% change in mass in a HeHe molecule. This percent would be further reduced in a larger molecule. I don't know if we can detect such a small change in mass (I know we measure mass of single atoms by period of oscillation, but I don't know how accurate it is), but that doesn't mean that it doesn't exist.

Now, you might say that they are different kinds of bonds (one being due to the strong force and one due to the electrostatic), and I don't really have an answer to that. I would think that the origin of the force doesn't matter, but I really can't confirm this. Does anyone else have any idea?

 

[MobiusPizza]

Yeah the truth is we don't really understand how fundamental particles interact cause we can't really observe them inside such a small nucleus.

Breaking chemical bonds corresponding to raising the electrons to higher orbital, which means increasing its kinetic energy. Because of that there might be an increase in mass, or none at all.

Depends on how fast electrons are circling really. An atom of helium has raius 31pm Lets do the F=mv^2/r circular motion formula. Ignoring influrence of other electrons and conssidering only the outermost electron. velocity v = sqare root Fr/m. Attraction force of electron and nuclei for a He atom is, using the Coulomb's Law, (2e*3e)/4(pi)(e0)r^2 = about 4.61*10^-7 Newton
and we get v = 4040000ms-1

The outermost electron is orbiting at that speed, which is 1/74 of the speed of light
So an increase of the kinetic energy is not going to increase the electron mass much. The velocity of the electron is still magnitude lower than speed of light when general relativity kicks in.

Even the mass of electron does increase, the value would be unobsservably tiny. Not to consider it is the mass increase of only a couple of electrons when breaking a bond, not the nuclei.

 

[The Boston Dangler]

Originally posted by: Loki726

Originally posted by: The Boston Dangler
E=mc^2.

All these bright people, and I am the first to post this here?

Energy = matter at the speed of light squared.

English version:
An enormous amount of energy can be used to create a tiny amount of matter, out of nothing but energy.

Of course, the inverse is also true. A little matter turns into tons of energy. The energy released by a nuclear weapon (fission or fusion) is is from the annihilation of a few neutrons.

If we feel like stating the obvious, why not include a more complete version of the equation? E^2 = m_0^2*c^4 + p^2*c^2 . Now we can compare mass, energy, and momentum!


Think about this one. Why do we get energy when we break down heavy elements, and also when when fuse light elements together?

Why not just state the obvious: Energy CAN be turned into matter PERIOD

AnnihilatorX, I thought fusion beyond iron was only possible in a supernova. Once star's core becomes mostly iron, the lack of fusion energy causes the star to implode, then explode, possibly leaving a quasar, singularity, etc. Thus, our solar system, and us, are at least second generation matter.

 

[f95toli]

Sorry, but that calculation is completely meaningless. You can not think of chemical bonds in terms of classical physics; you need to use concepts from quantum mechanics. A term like "the velocity" of an electron doe not have any meaning, the electronic wavefunctions are distributed around the nucleus and if you image an atom (wchih we can actuually do using STM) you will just see a blurred spot; simply because the electron does not behave like a particle in this case.

Besides, breaking a bond does not mean that an electron is "raised" to a higher orbital. In free atoms the electrons are arranged (meaning the probability to find an electron has "peaks") in shells (1s, 1p, 2s etc) with two electrons in each. There are several types of bonds but they all have in common that they just lower the ground state energy of the system; if you break a bond the eletrons will just go back to their "normal" orbits.

 

[Loki726]

Classical physics only works because the frequency of classical particles is high enough that you can easily resolve velocity over the relevant area. You can't treat an electron as a classical particle because its wavelength is too long to be able to resolve both the velocity and position at the same time. For example, the uncertainty of an electron's velocity in a region the size of an atom is somewhere between -10^6 to 10^6 m/s .

 

[MobiusPizza]

hmm I see what you meant
But I wasn't trying to pinpoint exactly the position of an electron and its velocity. Even if you consider the electron to be a wide spread wave still it does orbit the atom as the atom has an attracting central force and any object under a central force would rotate around it. So consider a bulk box containing an randomly oscillating electron contained in it orbiting around an atom (To model an electron wave). Although we can't pinpoint or even know the velocity (relative to observer - us) of the electron as it's in a bulk box, we should be able to estimate using classical physics the relative velocity of the box to the atom pretty accuractly.

Let the electron inside the bulky box doing random motion all over the place, but since motion is random; its velocity rarely affect the relative velocity to the central nucleus. I agree my answwer might be an underestimate due to the fact that I am relating to kinetic energy wwwhich means speed instead of velocity. But well

Originally posted by: The Boston Dangler
AnnihilatorX, I thought fusion beyond iron was only possible in a supernova. Once star's core becomes mostly iron, the lack of fusion energy causes the star to implode, then explode, possibly leaving a quasar, singularity, etc. Thus, our solar system, and us, are at least second generation matter.

Sorry my bad baffling without thinking. You are absolutely correct.

 

[f95toli]

No, because the the idea of an electron somehow "orbiting" an electron is entirely classical. You can e.g. look a the shape of the wavefunction, only the s-wave looks like a real "shell" (isotropic), shells with higher angular momentum (p-,d- etc) have lobes and nodes; meaning that fyou calcutate the probabiltiy density it will not look at all as any classical "orbit".

There are relativistics effects in atoms which you need to consider if you e.g. want to calculate the g-factor with high accuracy; but in most cases ordinary quantum mechanics works just fine.

 

[Loki726]

actually, in a hydrogen atom, you can use classical physics to estimate the radius of orbit and energy levels of an electron as long as you consider the restraints that the wave nature of the electron imposes on the system, look at page 3 on this site http://www.physics.gatech.edu/academics.../Lecture%20Notes/L11%20Bohr%20atom.pdf . The only thing is when you calculate the energy you have to consider both the potential of the electric force as well as the kinetic energy. Of course this doesn't work very well in complex systems.


In any case, I don't see how this is relevant to this discussion.

This was my basic argument. Take a system of particles (elementary or otherwise) in which there is some total energy divided between the individual masses of the particles and what we would traditionally consider energy (kinetic energy of the particles and potential between the particles).

If you observe the mass of the entire system, you are observing the contributions to mass from the individual masses of each particle as well as contributions from the energies of the particles interacting with each other.

If you observe the particles as seperate systems, the sum of the masses of each individual system will be different from the mass of the combined system because the individual systems no longer have the same potential and kinetic energies as they did in the combined system.

Electron interactions are only one piece of the picture.

 

[unipidity]

Absolutly.

The distinction between a chemical, or nuclear, or whatever potential energy and the mass change between the unbonded and bonded systems is artificial. Its the same thing. Plants DO 'make' mass... because they absorb energy.

 

[The Boston Dangler]

Plants do not make matter. They absorb chemical and solar energy, and through chemical reactions, process absorbed matter into more plant material. Any statement to the contrary is blatantly wrong.

 

[unipidity]

But the output weighs more than the input (at rest, if there were such a thing for a photon). It 'makes mass' because we think of some things in terms of mass and other in terms of energy when we shouldnt.

 

[harpy82]

Originally posted by: unipidity
But the output weighs more than the input (at rest, if there were such a thing for a photon). It 'makes mass' because we think of some things in terms of mass and other in terms of energy when we shouldnt.

no it doesn't... please don't think so highly of plants....

anyway... all these should end with just E = mc^2.... if this is background/ common sense knowledge... why is someone asking this question anyway?? any high school students can see wat is going on with tat equations from decades back... it is easy to understand....

haha... no hurt to anyone kay !!! dun bomb meeeeeeeeeeeeee

 

[The Boston Dangler]

Originally posted by: harpy82

Originally posted by: unipidity
But the output weighs more than the input (at rest, if there were such a thing for a photon). It 'makes mass' because we think of some things in terms of mass and other in terms of energy when we shouldnt.

no it doesn't... please don't think so highly of plants....

anyway... all these should end with just E = mc^2.... if this is background/ common sense knowledge... why is someone asking this question anyway?? any high school students can see wat is going on with tat equations from decades back... it is easy to understand....

haha... no hurt to anyone kay !!! dun bomb meeeeeeeeeeeeee

please see my above posts, and please see the crap i got for saying the obvious, when others want to extend their e-penis in a flagrant manor

 

[Changlinn]

I can't believe no one brought up the big bang Theory, the whole universes matter was pre-big bang a ball of pure energy, it expanded according to the theory to about the size of a grapefruit about 10 1000ths of a second before the big bang, cooled slightly, blah blah, exploded, matter and anti-matter formed, but only primitive matter, and possibly only light elements like hydrogen. Hence why hydrogen is so common me-thinks.
Oh dear, photo sythesis is just a chemical reaction to combine, elements from the earth, water and oxygen or carbon dioxide into other chemicals. It'd be like saying fire destroys matter, it destroys stuff, not matter it is just another chemical/thermal process.
It is also a two way street, e=mc^2 means that matter can be converted to energy using the same amount of energy you can convert it back. As someone has already said however, there is a lot of energy in one atom, a lot, have a look at the minute amount of mass that is converted to energy in an atom bomb and you will see what I mean, I heard a good example once, if all of the petrol in a cars tank was converted to pure kinetic energy with 100% efficiency, you wouldn't need to fill the cars tank again for around 10,000 years of constant running. Now were can I get me one of them 🙂

 

[MobiusPizza]

Originally posted by: Changlinn
As someone has already said however, there is a lot of energy in one atom, a lot, have a look at the minute amount of mass that is converted to energy in an atom bomb and you will see what I mean, I heard a good example once, if all of the petrol in a cars tank was converted to pure kinetic energy with 100% efficiency, you wouldn't need to fill the cars tank again for around 10,000 years of constant running. Now were can I get me one of them 🙂

The only known 100% efficient energy conversion right now though is matter-antimatter annihilation. That is really what E=mc^2 about. Pure mass -> Pure energy

 

[cquark]

Originally posted by: AnnihilatorX
The only known 100% efficient energy conversion right now though is matter-antimatter annihilation. That is really what E=mc^2 about. Pure mass -> Pure energy

Actually, matter-antimatter annihilation is only 100% efficient in cases which don't involve the strong force, such as electron-positron annihilation. The moment you begin dealing with the nucleus, events become more complex. For example, hydrogen-antihydrogen annhilation is only about 40% efficient, which is still quite impressive.

 

[Gibsons]

Originally posted by: cquark

Originally posted by: AnnihilatorX
The only known 100% efficient energy conversion right now though is matter-antimatter annihilation. That is really what E=mc^2 about. Pure mass -> Pure energy

Actually, matter-antimatter annihilation is only 100% efficient in cases which don't involve the strong force, such as electron-positron annihilation. The moment you begin dealing with the nucleus, events become more complex. For example, hydrogen-antihydrogen annhilation is only about 40% efficient, which is still quite impressive.

What happens to the other 60%? The reaction products from the hydrogen-antihydrogen would be some really high energy photons and.... ? Also, if the strong force is important here, would the efficiency change as we look at higher atomic number atom-antiatom pairs?

 

[cquark]

Originally posted by: Gibsons

Originally posted by: cquark

Originally posted by: AnnihilatorX
The only known 100% efficient energy conversion right now though is matter-antimatter annihilation. That is really what E=mc^2 about. Pure mass -> Pure energy

Actually, matter-antimatter annihilation is only 100% efficient in cases which don't involve the strong force, such as electron-positron annihilation. The moment you begin dealing with the nucleus, events become more complex. For example, hydrogen-antihydrogen annhilation is only about 40% efficient, which is still quite impressive.

What happens to the other 60%? The reaction products from the hydrogen-antihydrogen would be some really high energy photons and.... ? Also, if the strong force is important here, would the efficiency change as we look at higher atomic number atom-antiatom pairs?

99% of the energy comes from proton-antiproton annhilation, which produces a variety of pions, including pi+'s, pi-'s, and pi0's. (NB: at high energies, you'll get a variety of more exotic particles, like we see in Crystal Barrel and other accelerator experiments, but that's not what we'd use to produce power and there are hundreds of possible reactions depending on the energy.)

Pi0's can decay into photons, but charge conservation forbids the pi+'s and pi-'s to do the same. As they're the lighest mesons, they can't decay into other mesons, so they decay into leptons: muons and muon antineutrinos. A few microseconds later, the muons decay into electrons, muon neutrinos, and electro antineutrinos. Conservation of energy and momentum require that most of the mass energy released be carried away by the neutrinos.

As neutrinos only interact through the weak force, they readily pass through normal matter (billions passed through you and the Earth beneath you as you read this sentence.) It would take several light years of lead to capture half the neutrinos in a beam, and as that would collapse into a black hole under its own weight, it's clear that you're not going to capture them for power production.

Increasing the atomic number would add proton-antineutron and antiproton-neutron interactions to the mix, along with pion-nucleon interactions, but none of them are noticeably more efficient, so I don't think that would help. It's also very difficult to construct antiatoms heavier than antihydrogen.