1. a neutrino is a en elementary particle
2. a neutrino is not a neutron - neutrons are made up of quarks, and are thus not elementary particles
3. there are three types of neutrinos: they're called electron neutrino, muon neutrino, and tau neutrino (they all also have an antiparticle)
4. the name neutrino actually means "little neutron", but I have to tell that story another time...;) (In short: Pauli proposed that there should be a particle called a neutron, before the actual neutron was discovered. Then, what we know today as a neutron was discovered before the neutrino, and by that time the term neutron was taken, and this particle became a neutrino).
5. neutrinos don't have any electric charge (so they are not at all affected by the electromagnetic force), and they're almost massless - but only almost...! They do have a tiny tiny tiny mass: the heaviest one is more than 4 million times lighter than the electron (the next lightest particle). Since they are so light, neutrinos move at a speed more than 80% of the speed of light at room temperature
6. neutrinos are created in radioactive decay (like beta-decay), nuclear reactions (like in a reactor when a heavy nucleus fission, or in the sun when light nuclei fuse), when cosmic rays hit atoms, and in supernovae. Most of the neutrinos here on Earth come from the nuclear reactions that take place in the Sun <3
7. every second, a trillion trillion neutrinos pass through your body, and since they do have (a tiiiiiny) mass, this means that there's a constant flow of matter through your body ALL THE TIME. Since their mass is so small, they don't add up to much mass - about 0.0000000000001 kg of neutrinos will pass through your body in a lifetime 😀 (If you add up the mass of all neutrinos that have passed through every single person who ever lived, over everyone's total lifetime, the sum is 0.15 kg)
8. neutrinos are extremely difficult to detect, so you need really huge detectors if you want to try... For example, the OPERA detector (a good neutrino detector) consists of 1000 tonnes of mass to try to catch a neutrino, but even if this detector was a block of lead a light-year in length, you'd only have a 50% chance of stopping a neutrino!
9. they are often called ghost particles, since they can actually change from being one kind to being another - an electron neutrino changing into being a muon neutrino changing into being a tau neutrino (this is weird: like if you went into a Mercedes and drove for a while, and then suddenly the car changed into being a BMW, and then when you arrived at your destination you were driving and Audi. W. E. I. R. D.)
10. in 2011 neutrinos were sort of detected to move faster than light - which shouldn't be possible. Of course it turned out to be an experimental mistake, and we are still very very certain that Einstein's theory of special relativity is true <3

Happy Friday!

1. Black holes are called “black” because they swallow all light, and no light (or anything) can ever escape it
2. Black holes are made when stars die and collapse (*sad*)
3. Black holes are super super super dense, and NOTHING have a higher density than a black hole
4. It's not really like what people think of as a hole, but maybe more like what we would normally think of as a sphere. But then again, it has the "traplike" properties of a hole (since you can fall into is, as if it was a hole in the ground), so you can probably think about it as a three dimensional hole 😉
5. A black hole with the size of a sugar cube weighs the same as the entire earth: 1000000000000000000000000kg (24 zeros!) - 1 septillion kilos 😀
6. We know nothing about what happens inside black holes
7. If a black hole came into our solar system it would swallow the earth. This is extremely unlikely, but it’s still more likely than for example winning the lottery ten times in a row (but less likely than being struck by lightening)
8. Black holes have a horizon (or really an "event horizon", which is the boarder of the black hole) where time stands still (at least it looks like it’s standing still if we are looking at a person who is falling into it) this horizon is the point of no return, where it's absolutely impossible to escape falling into the hole. It's really just like as a a clock runs a bit slower closer to sea level than up on a space station, a clock run really slow near black holes, and this all have to do with gravity 
9. If you fall into a black hole you would be stretched (to death) like spaghetti, since whatever part of your body that reaches the horizon first will feel soooo much more gravity (since the hole is so dense and heavy) than the rest of the body that's outside the horizon
10. When black holes collide, they make gravitational waves - which were discovered last Thursday!