To add to this though, Not all tori are flat. Donut isn't flat it's negative on the inside and positive on the outside. When we specifically talk about tori that are flat, we usually refer to them as "flat torus"

If the universe is infinite then it wasn't a single point, when physicists talk about a "Single point" they usually refer to the "Observable universe" which is finite. in fact when they talk about the "Universe" they usually just mean the observable part.

If the universe as a whole(including outside of the observable universe) then it wasn't a single point, infinite was always infinite and will always be infinite.

The leading idea is that there's no single point but every point in the universe is the center of big bang, a finite volume of space comes from a point and every point expands into a finite volume the size of the observable universe.

If you feel a very strong urge to drive off the road or jump off a cliff, I would suggest a meeting with a therapist.

On the topic at hand, the Human brain evolves to have these kinds of thoughts. It allows you to simulate and prepare for unexpected situations. Basically, if you are driving then there is a chance that you might lose control and go off the road, so your brain urges you to think about the situation. So in the unlikely case that you actually go off the road, you're already prepared for it.

Let's say you bought a bunch of meat, cooked it, disinfected it, and put it away somewhere. It's 100% bacteria-free(which in reality, it's probably not). If you put it in a completely sealed, sterilized container, then it's not gonna rot. it might not taste good after a while since the protein, muscle, fat, water and stuff might not retain their original structure.

but we normally don't have that kind of container at home. if you put it in....let's say...a drawer, even if the meat is bacteria-free the drawer is probably not, even if it's, some bacteria might get in through the air or airborne water droplet or even walk themselves in there.

Even if it's just a few, they will eat your meat and make more of itself(using your meat they just ate), you won't notice at first, but the number of bacteria grows exponentially, and at some point, there will be so many bacteria eating away your meat that you might be able to see a few colonies of them.

basically, nothing is producing bacteria, they produce themselves using whatever they can eat(in this context, your meat), just a few individuals can turn into billions in a few days.

This idea applies to other microbes that grow on your food as well. like Fungi, other eukaryotes, etc.

Not a physician.

It's kinda in the center but because the left ventricle is BIG makes it looks like it's off the left. Also, the left ventricle beats the hardest, it gives the feeling that the heart is on the left.