2 may be the only even prime - that is it's the only prime divisible by 2 - but 3 is the only prime divisible by 3 and 5 is the only prime divisible by 5, so I fail to see how this is unique.
this post was submitted on 09 Aug 2023
552 points (95.4% liked)
Memes
44073 readers
2182 users here now
Rules:
- Be civil and nice.
- Try not to excessively repost, as a rule of thumb, wait at least 2 months to do it if you have to.
founded 5 years ago
MODERATORS
Exactly, "even" litterally means divisible by 2. We could easily come up with a term for divisible by 3 or 5. Maybe there even is one. So yeah 2 is nothing special.
"Threven" has a nice ring to it now that I think of it.
Here is an alternative Piped link(s): https://piped.video/watch?v=BRQLhjytJmY&
Piped is a privacy-respecting open-source alternative frontend to YouTube.
I'm open-source, check me out at GitHub.
Gtfo! 😅
2 is a prime though isn't it
Yes, but it's the only even one. Making him the odd man out
It is but if feels wrong
It pretends to be prime and we all go along with it to avoid hurting its feeling.
Even vs odd numbers are not as important as we think they are. We could do the same to any other prime number. 2 is the only even prime (meaning it is divisible by 2) 3 is the only number divisible by 3. 5 is the only prime divisible by 5. When you think about the definition of prime numbers, this is a trivial conclusion.
Tldr: be mindful of your conventions.
Yes, but not really.
With 2, the natural numbers divide into equal halves. One of which we call odd and the other even. And we use this property a lot in math.
If you do it with 3, then one group is going to be a third and the other two thirds (ignore that both sets are infinite, you may assume a continuous finite subset of the natural numbers for this argument).
And this imbalance only gets worse with bigger primes.
So yes, 2 is special. It is the first and smallest prime and it is the number that primarily underlies concepts such as balance, symmetry, duplication and equality.
The meme works better if it's 1 instead of 2. 1 is mostly not considered a prime number because a bunch of theorems like the fundamental theorem of arithmetic would have to be reworked to say "prime numbers greater than 1." However, just because 1 is not a prime number doesn't mean it's a composite number, so 1 is a number that is neither prime nor composite.
2 is a prime number, but shit ton of theorems only apply to odd prime numbers, and a lot of other theorems treat 2 as a special separate case, because it behaves weirdly.
I don't get it, why does adding a hand move to the next prime?
🚨 NERD ALERT🚨
Go define a vector space, nerd.
Go compute the p value of you being cool
Go integrate f(x)= 1/x on the domain (-1,1)
This is meme-ville population: me
Take a hike.
Spoiler: p < 0.05
load more comments
(5 replies)
Pretty sure that when we plug in a correction factor for the relative age of the Fediverse userbase, "today's lucky 10,000" becomes more like "today's lucky 10 million"
It's just the way the power rangers combined their forces
2 is a prime number though…..
Is it Just because it’s the only even one?
Often things hold true for all primes except 2. You come across things like "for all non two primes"
Any examples? Sounds like you mean the reason why one is excluded from the primes because of the fundamental theorem of arithmetic.
No, he's right. "For any odd prime" is a not-unheard-of expression. It is usually to rule out 2 as a trivial case which may need to be handled separately.
https://en.wikipedia.org/wiki/Fermat%27s_theorem_on_sums_of_two_squares
load more comments
(1 replies)
load more comments
(2 replies)
Like what? Genuine question, have never heard of this.
In the drawer in the living room in the house in my town in my state in my country.
And how is "even" special? Two is the only prime that's divisible by two but three is also the only prime divisible by three.
load more comments
(4 replies)
Oh yeah? What about 0? And 1?
They're not prime. By definition primes have two prime factors. 1 and the number itself. 1 is divisible only by 1. 0 has no prime factors.
Commonly primes are defined as natural numbers greater than 1 that have only trivial divisors. Your definition kinda works, but 1 can be infinitely many prime factors since every number has 1^n with n ∈ ℕ as a prime factor. And your definition is kinda misleading when generalising primes.
Isn't 1^n just 1? As in not a new number. I'd argue that 1*1==1*1*1. They're not some subtly different ones. I agree that the concept of primes only becomes useful for natural numbers >1.
How is my definition misleading?
It is no new number, though you can add infinitely many ones to the prime factorisation if you want to. In general we don't append 1 to the prime factorisation because it is trivial.
In commutative Algebra, a unitary commutative ring can have multiple units (in the multiplicative group of the reals only 1 is a unit, x*1=x, in this ring you have several "ones"). There are elemrnts in these rings which we call prime, because their prime factorisation only contains trivial prime factors, but of course all units of said ring are prime factors. Hence it is a bit quirky to define ordinary primes they way you did, it is not about the amount of prime factors, it is about their properties.
Edit: also important to know: (ℝ,×), the multiplicative goup of the reals, is a commutative, unitary ring, which happens to have only one unit, so our ordinary primes are a special case of the general prime elements.
Oof, I remember why I didn't study math 😅
But thanks for the explanation
Yeah, higher math is a total brainfuck :D You're welcome.
I was never able to wrap my head around quaternions.
There is multiple things wrong here.
-
1 is not a prime number because it is a unit and hence by definition excluded from being a prime.
-
You probably don't mean units but identity elements:
- A unit is an element that has a multiplicative inverse
- An identity element is an element 1 such that 1x =x1 = x for all x in your ring
There are more units in R than just 1, take for example -1(unless your ring has characteristic 2 in which case thi argument not always works; however for the case of real numbers this is not relevant). But there is always just one identity element, so there is at most one "1" in any ring. Indeed suppose you have two identities e,f. Then e = ef = f because e,f both are identities.
-
The property "their prime factorisaton only contains trivial prime factors" is a circular definition as this requires knowledge about "being prime". A prime (in Z) is normally defined as an irreducible element, i.e. p is a prime number if p=ab implies that either a or b is a unit (which is exactly the property of only having the factors 1 and p itself (up to a unit)).
-
(R,×) is not a ring (at least not in a way I am aware of) and not even a group (unless you exclude 0).
-
What are those "general prime elements"? Do you mean prime elements in a ring (or irreducible elements?)? Or something completely different?
load more comments
(2 replies)
0 has all the factors. Itself and any other number.
Put them in a sieve of Eratosthenes and see what happens.
Spoiler, they aren't.
Yo what about my man 9
7 ate them
9 isnt prime, it's divisible by 7
just not very well...
Two is the oddest prime of them all.
view more: next ›