🎓 Doc Freemo 🇳🇱 @freemo@qoto.org

These seem like accurate descriptions to me.

@funny

@stux All I know is next time we are going to the moon!

@stux you are already a pilot! I know because I recall when we hung out last time we were flying high!

@namark

As for your comment about "literally" looking up the definition of a hole anywhere. Here is the formal definition of a hole that aligns with the normal use of a hole (the only definition we can apply rigerously). I just looked it up "literally anywhere":

The genus of a connected, orientable surface is an integer representing the maximum number of cuttings along non-intersecting closed simple curves without rendering the resultant manifold disconnected.[5] In layman's terms, it is the number of "holes" an object has ("holes" interpreted in the sense of doughnut holes; a hollow sphere would be considered as having zero holes in this sense). A doughnut, or torus, has 1 such hole. A sphere has 0.

@Pat

@namark

Thats pretty much exactly what I said with different words. A cup (no handle) does not have a hole. It isnt because the hole defines the cup, there is literally no hole. A convex surface is not considered to have a hole by any reasonable definition.

Now if you want to get technical holes are very strictly and technically defined in math (though there are two major areas of math that use the term hole, both would be in agreement for these simple use cases).

What "normal people think" isnt really too important to me. Normal people have no consistent definition of a hole so its a moot point. What does matter to me is any definition of a hole which is consistent, and we can dismiss inconsistencies easily.

There are many ways to reason about the cutting of an opening into a sphere that all shows us clearly why its not a hole even by common definition... Say you cut a opening whose size is the size of the equator of the sphere, in other words you cut the sphere into two perfect halves, putting a hole in it that consumes half the material... would anyone look at what is effectively identical to a bowl, even though it is clearly a volleyball and go "that volleyball has a hole in it?

What if i cut an even larger opening in the volleyball such that 95% of the material of the volleyball is removed leaving just 5% of the original volleyball. It would look like a small patch of material approximately appearing to be that of a slightly convex disc. Would anyone in their right mind look at that little scrap of material and go "it has a hole in it"... no of course not.

Any rigorous reasoning about cutting single openings in spheres makes it quite clear there is no **consistent** way you can call that a hole and in fact in almost all scenarios most would say it isnt a hole. The rare edge cases where someone would call it a hole is arbrbitrary and so wildly inconsistent with the others we can dismiss it out of hand as being incorrect despite common usage.

Now if we want to get into formal definitions, then it is consistent with everything i just said above and extends those ideas even further and more formally.

@Pat

@Jojothegoodperson Are you saying it is telling you you arent verified? You posted once already so I figured you should be verified.

@phil_s If you werent alive to do tech or teach the next generation there would be other people around who did survive and could still fullfill that need. More over, and better yet, there would be fewer people in the next generation so less of a need for educators in the first place.

Now to be fair I was half joking in my response. Yes education is more important than healthcare to me. And no I dont want to just kill everyone off by not providing healthcare (I have actual solutions for healthcare I wont go into but it doesnt resemble universal healthcare). But that said my logic that education is more important because maintaining a too-large population isnt much of a plus anyway.

@Pat Well its not as conflated as you thin, at least not in my opinon.

If I were to "poke a hole" in a volley ball I'd have to take a long sharp stick and poke **all the way** through, in one end, out the other. This would create one hole. If you use my earlier explanation of flattening it to a disc this would be consistent with that.

If you only cut a single **opening** in it without poking a hole all the way through then you didnt create a hole at all, simple turned a sphere into a bowl or cup. Does a bowl have a hole in it? Does a cup? Most would say no. To take the analogy further I think we all agree simply scooping out a dent in something (effectively what making one opening in a hollow sphere is) isnt a hole. However if you poke all the way through a sphere you get the equivelant of a doughnut, now we would all agree there is a hole.

So in laymans terms, if you have a volleyball it has no holes. You cut an opening in it you turned a volllyball into a cup/bowl it still has no holes. You cut a **Second** opening into it, now you you have a hole.

@Jojothegoodperson I think you should be able to use a username to login. But you are required to retain access of your email to use our service since we need to prevent people from holding alt accounts here or evading bans.

@Pat

No the opening at the bottom. An opening is not a hole necceseraly... though if we want to get technical about it its a bit more complex than that. But if we ant to keep it in layman's terms then its an opening not a hole.

@twotwenty

@mc From an observational standpoint you did pick up on all the detail in the image. However technically speaking the answer is incorrect due tot he formal definition of a hole.

See here: https://qoto.org/@freemo/107296116027499260

@Jojothegoodperson I just double checked and yes its still there. Why?

@Jojothegoodperson
Yes you should. Why?

@twotwenty correct!

@twotwenty Are you so sure light can't have holes?

@Zest you are absolutely correct.. .but in a sense if you stretch your imagination a bit you can see why...

The language could be seen as saying "a hole in the surface of the ground".. if you consider the surface of the earth as a 2d plane when when you dig a hole its sort of a hole in that plain.... yes its a bit of a cop out and a stretch and your right it isnt really a hole. But it makes some sort of linguistic sense I think.

@Zest a hole does indeed to bo all the way through but even in the case of the pipe thinking of it in the same way as the shirt. Take one of the two openings ans stretch it out really big until the pipe becomes a flat disc... you will have a disc with one hold in it. One of the openings is the hole, the other is the outside perimeter of the disc.

Now do the same with your 4-way pipe. Take an arbitrary openening and stretch it out and try to flatten the whole thing into a disc again. You're 4 way pipe has 3 holes.

The reason id say its easy to reason about is because flattening out any case to a disc will always reveal the answer.

that said i do agree you can make up your own "intuitive" definition of a hole that is wrong according to the technical one. But in all liklihood such a definition will be contradictory or break apart in many circumstances.

@b6hydra analysis paralysis :)