Well there are many catastrophic scenarios that we already overcome. You should consider educating yourself about the great filter. A great filter is a hypothetical barrier that each civilization can or cannot overcome. From here on things get a little complex so I won't bore you with them. But there are experts in this theory called great filter and I'm sure they can tell you a lot about.
The cytoplasm in a single-celled organism and the circulatory system in a human both transport substances throughout the organism
The steeper the slope of the track the quicker the toy car will accelerate.
