Well, I wanted to know whether matter can be created from nothing?
Could matter be created in pure vacuum or does it require some energy?
If energy is required, How is energy converted to matter?
If yes, what sort of matter is produced? Boon or bane.
Is there any relation between Big Bang and Energy-Matter Transformations.
How are antimatter and antiparticle related to the issue?
[These all questions popped up in my mind when I was reading Dan Brown's Angels and Demons]
Can matter be created in a pure vacuum (with no energy)?
It's a subtle question. Firstly, how do we know whether there is energy? But even if there were energy if it was a minimum of energy then you wouldn't be able to use it to make things, and the energy minimum would be considered a good vacuum. But can you make particles? If they just appeared spontaneously, we would see them (and we don't), that is unless they disappear before we look. But anything could be happening when we aren't looking, but is there any evidence?
There is a hypothetical effect called the Unruh effect where a particle detector in a vacuum can detect particles if it is accelerating. But then there must be something accelerating the detector and hence there is energy available.
Not much evidence.
What kind of matter is produced out of just energy or just acceleration?
Matter and antimatter are made equally, for every particle made, the antiparticle of that particle is also made.
Could matter be created in pure vacuum or does it require some energy?
Generally it requires energy. Energy is conserved except in General Relativity, and even then energy density obeys a differential conservation law so really it is more about the relationship between energy and energy density and that relationship determined by geometry. When a star collapses this does increase the energy of the parts as the parts rush in, but the effects on outside things outside the colkapsing matter does not change.
So to the outside it doesn't really look "like" energy changes in a way to care about number one, and number two the infalling shell changes the geometry of the region of space it falls through, and actually creates space.
used to block off an outisde and an inside when it moves if, there becomes more new outside between where it used to be and where it is now than old inside that was destroyed.
Specifically, imagine a shell of surface area $5m^2$ with some matter on it that then compresses to a smaller more compact shell of surface area of $4m^2$ with the same matter on it. There used to be a certain volume between the two surfaces when the matter was on the surface of area $5m^2.$
And then latter when the same matter is on the surface of surface area of $4m^2$ the curvature between the two surfaces is different and now has more volume between the surfaces.
So yes, the infalling matter has more energy now, but there is also more space. And to things far away (outside that surface of area $5m^2$) everything looks the same, since matter moving faster (more energy) connects up to the same type of curvature when it is on a more compact surface.
So energy can be created when the geometry changes. If you want to make energy you need to make space too. Otherwise you can't.
And if you aren't making energy then you can't make particles without using energy because the particles you make have energy.
If energy is required, How is energy converted to matter?
The energy had to be in other particles so those particles will have to give up their energy. One way is to get two or more photons to give up their energy to make pairs of charged particles. Those charged particles might be able to interact by other means, and in turns the particles involved with those interaction could make other, non charged particles. So it's about sharing through the interactions that the particles that have the energy interact with.
Another common way it to pass some nuclei together by sending them at high speed towards each other. If they get close enough then the strong force can start transferring energy to additional colored (strong charge) particles.
Another way is to send a particle and its antiparticle together which can immediately start to produce any particles that can interact with those particles.
Response to the edits
Well, I wanted to know whether matter can be created from nothing?
Matter has energy, so you must either create energy or take energy from something else.
Could matter be created in pure vacuum or does it require some energy?
The new particles would require some energy and that has to be created or come from something. If the energy is created then you need to create space and that requires some matter if you want to connect that space to our space.
If energy is required, How is energy converted to matter?
The energy from one particle can be given to another (possibly new) particle that interacts with it, via the interaction. Another example I didn't mention before is hypothetical, which is Hawking radiation. This is the equivalence principle version of Unruh radiation.
If yes, what sort of matter is produced? Boon or bane.
Electrically charged matter can be produced in equal numbers of particle and antiparticle. Hawking radiation would do this if it happens
Is there any relation between Big Bang and Energy-Matter Transformations.
The big bang created space, hence there was a possibility to create energy too, thus to make particles. However singularities are not easy to describe. A new spacetime doesn't require existing matter to connect up the newly created space to the existing space.
How are antimatter and antiparticle related to the issue?
Antimatter isn't different than matter, we just call the particles we see every day matter and also the ones most similarly related (either similar by color charge for quarks, or similar by electric charge for charged leptons or by how they interact with charged leptons if uncharged leptons). The rest we call antimatter, except for some that are their own antiparticles where we don't bother to call them either. And there might be some other particles we just don't both picking one to call matter and one to call antimatter.
Up above, every time I said matter I meant matter or antimatter or things that are their own antiparticles, things with energy.
The answer is simply yes. As long as conservation laws are satisfied.
Nothing is to be regarded as $0$ energy, $0$ mass, $0$ charge, and so on.
Keep in mind that mass is a positive form of energy, while interacting energy (like gravity) is a negative form of energy.
You can see the link for more details
https://xphysics.wordpress.com/2011/02/11/spontaneous-creation-of-matter-and-antimatter/
The small price to pay... Matter can be formed from nothing - but is does not last very long...
