Is energy/matter a constant in the universe?

237 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

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.

You are viewing 1 out of 4 answers, click here to view all answers.