Mass-energy equivalence and how it relates to the content of the universe

[smulc]

I've always been interested in Physics so have finally decided to do a Physics degree. I've been reading various things to help prepare myself and have just been reading about the laws of thermodynamics and mass-energy equivalence. As I'm reading through different articles about these subjects I've been surprised at the lack of mention about how this relates to the total mass-energy in the universe.

It's my understanding that everything that exists, right down to the atoms in our bones came from the energy that was released in the big bang. Over time as the universe cooled, some of this energy became sub atomic particles, then atoms were born. So essentially through mass-energy conversion the energy that existed back then exists in everything around us. So, for example, following this keyboard back through time would show that every part of it was in existence back then but obviously in different form. Am I understanding this right? Most of what I've been reading seems to relate to things on a much smaller scale so I'm not sure if I'm misinterpreting things or if what I'm thinking about relates to a completely different theory.

It's probably a silly question but I'm still learning.

 

[Ryan_m_b]

You are correct, everything you see around you was present at the big bang. It's just the configuration that has changed.

 

[smulc]

Thanks for clarifying that.

Is this process solely down to mass-energy conversion or does it relate to any other theorys? Like I said previously I've been reading about this theory but found very little mention of how it relates to the universe. Is it just not mentioned because it's obvious or could I find more information about it in a slightly different subject?

 

[Ryan_m_b]

Thanks for clarifying that.

Is this process solely down to mass-energy conversion or does it relate to any other theorys? Like I said previously I've been reading about this theory but found very little mention of how it relates to the universe. Is it just not mentioned because it's obvious or could I find more information about it in a slightly different subject?

Thermodynamics and entropy might be good places to start.

 

[sardar]

First of all, congratulations on pursuing a degree in Physics! It's a fascinating field and it's great that you're already diving into different topics and trying to make connections.

You are absolutely correct in your understanding of mass-energy equivalence and its relation to the content of the universe. The famous equation E=mc^2, proposed by Albert Einstein, states that mass and energy are interchangeable and can be converted into one another. This means that all the matter in the universe, including the atoms in our bones, is essentially made up of energy that was released during the Big Bang.

As you mentioned, as the universe cooled, the high-energy particles present in the early universe began to form subatomic particles, which eventually led to the formation of atoms. So, in a sense, everything in the universe can be traced back to the energy released during the Big Bang.

Your analogy of following a keyboard back through time is a good way to think about it. Every part of the keyboard, even the atoms that make it up, can be traced back to the energy present during the Big Bang. This concept is not limited to just the keyboard, but to everything in the universe.

In terms of your question about the lack of mention of this in articles about the laws of thermodynamics, it could be because mass-energy equivalence is a fundamental concept in physics and is often taken for granted or assumed to be understood. However, it is an important concept to keep in mind when studying the laws of thermodynamics as they also rely on the conservation of energy.

Overall, your understanding is correct and it's great that you're thinking about these connections. Keep exploring and asking questions, that's what being a scientist is all about!