A Scientific Discussion

Today, in my Physics class, we discussed the old law of how matter cannot be created nor be destroyed, and how it was "disproved" when scientists started created nuclear reactions. I've been going back-and-forth on whether I agree with that statement or not. On the one hand, when matter is converted into energy, it is, by one definition, destroyed, according to Merriam-Webster. It states that "destroy" can mean, "to ruin the structure, organic existence, or condition of; to ruin as if by tearing to shreds." Obviously, when matter is converted into energy, the previous structure of the item is not maintained, much like when water is boiled. Which brings me to the other hand. I've never known a person to consider H2O "destroyed" when it's either converted to a solid or gas. Isn't this, as a basic level, the same as converting matter to energy? I'm conflicted. Would anyone like to help clarify this matter? (Pun intended.)

Jam it back in, in the dark.

And if they are ways of turning energy into matter, would it be "creating" matter?

So, you guys say that my professors were wrong when they said that matter can be destroyed?

There's nowhere I can't reach.

Originally Posted by Cetra

Ah I think I understand the underlying problem here. It's like saying when ice metals and becomes water, the ice no longer exists. But we know this isn't true. Rather the ice exists just in a different matter state. Matter and energy share a similar concept. The problem is the Law of Conservation of Matter and Energy isn't exactly saying matter cannot be created or destroyed. The definition we get in most text books is just a simplification of the concept.

A better way to express the Law is to say something like "The sum of what you put in will always equal the sum of what you get." It's saying that in a perfectly closed reaction nothing is ever gained or lost, eg. created or destroyed.

Does that make sense?

I think the main problem with your water analogy is that the water hasn't changed, at least chemically speaking. It's H20, nom matter what phase it's in. This is why I preferred the analogy of it becoming vapor. Yes, it's still H20, but it's drifting apart from itself, essentially becoming something entirely different.

And my interpretation of how the Law should be written is, "Matter cannot be created or destroyed but can be converted into energy."

This thing is sticky, and I don't like it. I don't appreciate it.

Originally Posted by Arainach

But Matter and Energy are the same thing, so your law is redundant. The law you're looking for is the law of Conservation of Energy.

Does this same law apply to matter as well? Or would that need to be added? (Maybe it's implied...)

I am a dolphin, do you want me on your body?