My interest is in dark matter mostly and its affects on our universe aswell as the galaxies that float around in it. What its gravitational properties do to these objects and what not? And on anti matter i have very little understanding of that too. Thank you.
Antimatter is matter that has equal mass and opposite charge to normal matter. If it comes into contact with normal matter it causes mutual annihilation. Examples of antimatter are positrons, anti protons, anti neutrons etc. Here is antimatter (positrons) coming off a block of Potassium as protons decay into neutrons.
As for dark matter.
Dark matter is matter we don’t understand and can’t see. It is speculated the vast majority of the universe is made of Dark matter, which remember is a generic term for any matter we can’t see. We know it exists by the gravitational influence it has on matter we can see. As for the galaxies, we have observed that galaxies rotate in a strange way, namely the stars on the outer arms of the spirals orbit the centre of the galaxy roughly as fast as the stars close to the centre. This is not how gravity is supposed to work. Look at our solar system Mercury orbits the Sun every 88 days or so, Earth every 365 days and Neptune every 185 Earth years. So we expect the stars in the outer reaches of the galaxy to take longer to complete their orbits than those close to the centre. Since this is not the case there must be a heck of a lot more matter in this and every other galaxy than we can see with our telescopes.
Just remember dark matter simply means “we don’t know the heck it is”, the same goes for dark energy and dark flow, these are just words to describe something astronomers have observed that cosmologists and theoretical physicists can’t yet explain.