Can matter really be created or destroyed?

[mauriceb]

Everytime you type on a keyboard a pixel is created on a screen you have created something out of thin air. Everytime you delete a word, that pixel and bit on a platter is destroyed. perplexing isn't it?

I have been a computer guru for many years and it still perplexes me, that a single electron can come and go out of thin air.

 

[willem2]

Your computer doesn't create any electrons, it just moves them around. Electrons in a cathode ray tube display come from the heated cathode.

Because of conservation of electric charge, it's not possible to create single electrons anyway, but you'll create an electron and a positron from nothing, or you create an electron a neutrino and a proton from a neutron.

 

[alxm]

Everytime you type on a keyboard a pixel is created on a screen you have created something out of thin air. Everytime you delete a word, that pixel and bit on a platter is destroyed. perplexing isn't it?

Uh, no? "Things" are not matter. "Matter" has a specific meaning in physics, and it does not extend to everything that is a "thing". "Blue" (noun) is a 'thing', "five" is a thing, but neither of them are physical objects, nor matter. The 'things' you describe are actually just states of matter. The amount of physical matter does not change.

(Although as it were, matter can be created and destroyed. E=mc^2 and all that. Energy, however, cannot be created or destroyed.)

I have been a computer guru for many years and it still perplexes me, that a single electron can come and go out of thin air.

In the cases you describe, they don't.

I don't really see why being a "computer guru" would imply any understanding of this. Computer science is not a natural science. Being an expert on computer software doesn't imply knowledge of the physics behind computers any more than having a degree in Literature implies knowledge of paper chemistry.

 

[Dremmer]

Uh, no? "Things" are not matter. "Matter" has a specific meaning in physics, and it does not extend to everything that is a "thing". "Blue" (noun) is a 'thing', "five" is a thing, but neither of them are physical objects, nor matter.

Yep. Also energy, gravity, space and time are things, but are not matter.

 

[Robot B9]

A pixel is just a tiny light. In a CRT a bunch of electrons get converted into photons and that is the pixel you see.

But the electron is not really converted into a photon! The energy it is carrying is. After the electron hits the inside of the CRT screen it gets recycled, at a lower energy state, back into the CRT circuit. So all the electron is doing is dumping energy to the screen that then shines out as light. Energy into energy, nothing fancy.