Is energy/matter a constant in the universe?

133 viewsOtherPhysics

As far as I understand energy and matter are two sides of the same coin, and I thought I knew that energy/matter could not be created or destroyed, but then a comment I read on askphysics implied that’s not true. (Something about an electron emitting photons, idk it was not targeted at a 5 year old).

So is there a set amount of energy/matter in the universe since the Big Bang, or can it be created/destroyed?

And bonus question that’s only slightly related, when an atom is broken up into quirks, will the quirks reform into an atom?

In: Physics

4 Answers

Anonymous 0 Comments

Conservation of energy only applies in a closed system, and it does not seem like the universe is a closed system. In other words yes, it does seem like more energy is entering into the universe over time.

As for your question about quarks it doesn’t really make any sense. The subatomic particles of protons and neutrons that are made up of quarks (not electrons, they seem to be fundamental) but when you try to break them apart the energy to do so creates more quarks. So you don’t really get lone quarks at all.

Anonymous 0 Comments

Energy and matter are *basically* the same thing. It is possible to turn energy into matter and vice versa.

When a plant uses sunlight, water, and oxygen to make sugar what it is technically doing is gluing the water and carbon dioxide together using that sunlight. Basically, the sunlight forms into a bond which holds the atoms together and that bond is technically a miniscule amount of matter.

When you digest sugar to move your body around, you are breaking that bond, converting the miniscule amount of matter that it contained back into energy.

There was a set amount of matter/energy in the universe when the big bang occurred. As far as anyone can tell, since that time everything in the universe is slowly getting further and further apart from everything else. What is causing this is that energy/matter is being added into the universe.

The source of that new energy/matter isn’t known and the rate at which energy is being added is too small for that energy to form into matter. Instead, that new energy just results in us perceiving a slight force that seems to repel everything in the universe from everything else.

>when an atom is broken up into quirks, will the quirks reform into an atom?

The issue with this question is that quarks are a sort of condensed version of energy. Breaking a quark out of an atom requires you to put so much energy into the atom that the energy that made up the atom is no longer condensed. If the energy inside of the atom is no longer condensed, then you no longer have quarks. Instead, you get a form of matter known as a quark gluon plasma, which is kind of made up of quarks but also kind of isn’t.

As that quark gluon plasma recondenses, it will *mostly* form into quarks which will form into the component parts of atoms. Some of it may turn into dark matter, in which case that matter will appear to be “lost” to a human observer, since dark matter is able to pass through normal matter and is also extremely difficult to detect.

Anonymous 0 Comments

Matter has energy. You can have energy without matter (e.g. radiation), but not matter without energy.

> and I thought I knew that energy/matter could not be created or destroyed

That’s something chemists teach because it’s a good approximation in chemistry. It’s not true, however.

Matter can be created and destroyed, we routinely do so in particle accelerators. The early universe was full of processes that created and destroyed matter, too.

For energy it’s trickier. Everything we can do on Earth conserves energy exactly. I don’t know what you read, but the interactions of electrons and photons doesn’t change the overall energy in any way. Energy can be created and destroyed if we look at the overall universe, however. The universe expands. Radiation in that universe is “stretched out” – its wavelength increases and it loses energy. At the same time, we end up with more space, and all of space contains dark energy – more space, more dark energy. Both processes change the total energy in the universe.

> when an atom is broken up into quirks

You can’t break up an atom into isolated quarks. Trying to do so will create additional quarks. You end up with some new particles, which new particles depends on what exactly you do.

Anonymous 0 Comments

**I got a bit carried away and this answer got a bit more indepth then expected, if you have questions you can ask them**

Yeah, so technically energy isn’t really conserved in our universe. Basically Emmy Noether discovered that all conservation laws are a result from some kind of symmetry in the universe

– So for example I can make an experiment in space and rotate it however I want and still get the same result because there is no “up” and “down” in space, and that “symmetry” is causing Angular Momentum to be conserved.

– Same with normal Momentum, if I make an experiment right here or 14 Billion lightyears away, I will get the same result, and that’s why Momentum is conserved

And then Noether found out about Energy Conservation, and for energy to be conserved we would need a “Time Symmetry” so if I make an experiment today and tommorow that needs to have the same results.

And on earth that is the case, that’s why we learn it’s conserved BUT: on cosmic scales, we know that the universe expands and so there is no “time symmetry” and that means that Energy is not conserved. (for example: a photon traveling through an expanding universe is “redshifted” and as far as we know, the energy it is losing by that isn’t transferred anywhere, so it seems like it’s geniuenly just lost)

Then later we got more evidence: Einstein wrote his theory of general relativity and nothing in that theory actually requires energy to be conserved, so we are pretty certain that energy isnt actually conserved

As for the second question, thats a bit more tricky, but hey i get to talk about my favorite fundamental force of the universe:

Basically, Quarks are held together by the Strong Nuclear Force (my favorite, yippie) and what’s cool about that is that every single time we have looked at Quarks they are always coupled (or “Color confined”) to another Quark, we have NEVER NEVER EVER seen just one singlular Quark, thats because quarks cannot be isolated because the force between them increases with distance. So normally these quarks are pretty stable, now if you were to pull at one Quark you would increase the distance, which would make the Bond stronger, so in very simple terms: The more energy you put into seperating Quarks, the more energy it uses to resist getting ripped apart.

Except: When you use a lot of energy to pull quarks apart by around 1-2 femtometers, the energy you put in simply creates new Quarks. These new quarks then pair up with the original quarks, keeping them confined together. So all this just to answer your question now:

No, generally not, Quark pairs will always form but an atom is a lot more then just some Quarks, its a lot of quarks with electrons and neutrons all having to exists at least somewhat stable, i guess, technically its not out of the question for it to happen by chance, but that chance would be astronomically low