2
$\begingroup$

I'm a noob when it comes to physics and most of my knowledge of physics comes from popular science; it's more likely that I'm wrong than not about this.

From what I've understood; Matter and anti-matter are opposites of each other and should annihilate each other

For every particle there apparently exists an opposite; for instance electron <-> anti-electron (or positron), proton <-> anti-proton and so on. The ability to annihilate makes the assumption that the structure of anti-matter is the same as that of matter (positrons on the outside and anti-protons and anti-neutrons in the inside).

However, if you are to invert this structure then these particles wouldn't be able to annihilate each other but instead repel each other away [anti-protons on the outside and positrons and anti-neutrons forming the core]. This would imply that anti-matter and matter repel each other. This could (maybe) explain the accelerating universe.

Have there been any theories along these lines?

$\endgroup$

1 Answer 1

2
$\begingroup$

Anti-matter atoms cannot be formed with nuclei of positrons for the same reason that normal-matter atoms can't have nuclei of electrons: the massive particles will define the effective center. The mass-ratio of anti-protons to anti-electrons is exactly the same as that of protons to electrons --- so they maintain the same structure.

$\endgroup$
4
  • $\begingroup$ Massive particles define the center, this is true of matter, but do we know why? $\endgroup$ Nov 28, 2015 at 19:41
  • $\begingroup$ @GeneralBecos Because they are massive. 2000 times more massive than the electrons/positrons. They define the center of mass, and thus the dynamical center of the system. $\endgroup$ Nov 28, 2015 at 20:02
  • $\begingroup$ Thanks @DilithiumMatrix. In theory, Neutrons + electrons, could form the center, with protons outside. A more dynamic system like standard candle supernovae could exist. That aside; I don't know for certain if standard principles of mechanics (dynamic systems) apply at the level of atoms. I could be wrong. Any references would be very welcome. Thanks again for taking the time to respond. $\endgroup$ Nov 28, 2015 at 20:16
  • $\begingroup$ @Timaeus: Thank you. I'll read up about the strong force. Also I didn't mean to be argumentative and I'm sorry it came across that way; I was given some facts that didn't add up and I did a poor job explaining why the facts didn't add up. $\endgroup$ Dec 4, 2015 at 22:47

Not the answer you're looking for? Browse other questions tagged or ask your own question.