this post was submitted on 25 Nov 2024
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Showerthoughts

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A "Showerthought" is a simple term used to describe the thoughts that pop into your head while you're doing everyday things like taking a shower, driving, or just daydreaming. A showerthought should offer a unique perspective on an ordinary part of life.

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[–] [email protected] 4 points 13 hours ago (1 children)
[–] [email protected] 2 points 12 hours ago (2 children)

Does this mean the concept of infinity requires an infinite number of infinities?

[–] [email protected] 2 points 4 hours ago

Informally, yes. Formally, no. There is no cardinal sufficient such that every cardinal can fit in a set with that cardinality. Isn't that fascinating? There's too many infinities for us to mathematically express how many infinities there are.

[–] [email protected] 1 points 10 hours ago

I believe so. I wonder what is the ordinal of the set of ordinals.

[–] [email protected] 2 points 17 hours ago (1 children)

A circle has an infinite number of corners.

[–] [email protected] 2 points 16 hours ago (2 children)
[–] [email protected] 0 points 9 hours ago

therefore ∞ = 0 😀👍

[–] [email protected] 2 points 14 hours ago* (last edited 14 hours ago) (1 children)

Probably More accurate to say it has an infinite number of edges

[–] [email protected] 3 points 13 hours ago (1 children)

A circle has one edge/side, that is grade-school geometry. There is no reason to engender confusion by trying to make it into a polygon or introducing infinity. Your model of shapes does not seem to account for curved edges.

Consider a stereotypical pizza slice. One might plainly say that it is a "like a triangle but one edge is curved" without falling into a philosophical abyss. :)

[–] [email protected] 2 points 10 hours ago* (last edited 10 hours ago) (1 children)

It's quite useful, though, to understand a curve or arc as having infinite edges in order to calculate its area. The area of a triangle is easy to calculate. Splitting the arc into two triangles by adding a point in the middle of the arc makes it easy to calculate the area... And so on, splitting the arc into an infinite number of triangles with an infinite number of points along the arc makes the area calculable to an arbitrary precision.

[–] [email protected] 2 points 4 hours ago

Or you could just enjoy your π

[–] [email protected] 8 points 20 hours ago (1 children)

Imaginary numbers have a specific value, just like all the normal numbers we use on a daily basis. Infinity is not a specific value. Instead, it’s a qualitative property like “flat”, “periodic”, or “symmetric”.

[–] [email protected] 2 points 5 hours ago* (last edited 5 hours ago) (1 children)

I think of it this way, infinity is an action. It’s not a “thing.” This is why it’s not countable. It doesn’t stop to be counted.

[–] [email protected] 1 points 3 hours ago

What do you mean by action? Like, how running or writing are actions people can take? So maybe infinity would be an action a group of numbers can take?

[–] [email protected] 10 points 1 day ago

The imaginary numbers and real numbers cross at infinity (on the Riemann sphere).

[–] [email protected] 9 points 1 day ago (1 children)

I find this all to be very irrational. I need to have some pi and think about it.

[–] [email protected] 1 points 1 day ago (1 children)
[–] [email protected] 3 points 20 hours ago

Let’s be real, it’s a complex topic.

[–] [email protected] 1 points 1 day ago* (last edited 1 day ago)

Infinity is a placeholder for uncountable large numbers and is used for stuff like either functions to describe the the craps behavior towards the "end" wich there is none.

[–] [email protected] 1 points 1 day ago* (last edited 1 day ago)

A set is infinite exactly when there exists a proper subset whose cardinality is that of the set.

[–] [email protected] 19 points 1 day ago (2 children)

Why? What does it mean for something to be real?

I believe pure mathematics isn't concerned with its correspondence with reality.

[–] [email protected] 13 points 1 day ago (3 children)

I recall hearing a quote from the guy that coined the term "imaginary number", and how he regretted that term because it conveys a conceptualization of fiction. IIRC, he would rather that they would have been called "orthogonal numbers" (in a different plane) and said that they were far more real that people tend to hold in their mind. I think he said "they are as real as negative numbers" along the same lines of one not being able to hold a negative quantity of apples, for example.

The stray shower thought (beyond simply juxtaposing the discordant terms of 'imaginary' and 'real') was that infinity by contrast is a much weaker and fantastic concept. It destroys meaningful operations it comes into contact with, and requires invisible and growing workarounds to maintain (e.g. "countably" infinite vs "uncountably" infinite) which smells of fantasy, philosophically speaking.

[–] [email protected] 1 points 2 hours ago

So Descartes coined the term specifically as a dig because he didn't see any geometric possibilty to the concept. The concept seems to have roots going back to ancient Egypt, but the modern inquiry goes to the Renaissance. I think Gauss wanted to call them laterals.

[–] [email protected] 2 points 9 hours ago

It destroys meaningful operations it comes into contact with, and requires invisible and growing workarounds to maintain (e.g. “countably” infinite vs “uncountably” infinite) which smells of fantasy, philosophically speaking.

This isn't always true. The convergent series comes to mind, where an infinite summation can be resolved to a finite number.

[–] [email protected] 9 points 1 day ago

Furthermore, it is meant to highlight the fact that people gleefully embrace the concept of infinity, but try their hardest to avoid and depreciate the concept of imaginary numbers. It would appear to me that the bias ought to be reversed.

[–] [email protected] 4 points 1 day ago (1 children)

I mean, complex numbers are important for quantum mechanics. In that sense, they are closer to reality as they are used to describe the underlying blocks of reality to our current best understanding

[–] [email protected] 3 points 1 day ago (1 children)

You don't even have to go into quantum mechanics. I vaguely recall using a real/imaginary plane with a rotating vector to do something about electricity in first year engineering?

Don't worry I'm not actually an electrical engineer.

But my point is that there are applications for imaginary numbers with very practical engineering applications. Foundational, even.

[–] [email protected] 4 points 1 day ago

something about electricity

It's a usefull technique to model the symmetry between magnetic and electrical power.

[–] [email protected] 10 points 1 day ago (2 children)

Amazing. Your shower thought is incorrect on both counts. Perhaps you meant to say "conceivable?"

[–] [email protected] 11 points 1 day ago* (last edited 1 day ago)

I'm guessing they maybe mean that they have a more trivial practical resolution to real numbers, in that i^2=-1?

Kinda like "yeah they're imaginary but I understand that if I hit them with a certain stick they become real"