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Why do prime numbers make these spirals? (2019)

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Re: Why do prime numbers make these spirals? (2019)

#31

What's the commentary on prime numbers currently? Is it expected that there is some unfound pattern to them? Or will they always remain elusive?

Prime numbers are important for cryptography - if there is a pattern to them it might have an effect on what we think is secure or not.

https://www.abc.net.au/news/science/2018-01-20/how-prime-num...

Re: Why do prime numbers make these spirals? (2019)

#33

I’m hardly a math genius, but isn’t this basically because he’s using polar coordinates, where nearly any trend is going to look like curves and spirals?

Hence, the video...

Hence the video what? It's polar coordinates making the spiral, not prime numbers.

Re: Why do prime numbers make these spirals? (2019)

#34
One of the thrills of studying the primes is the discovery that all primes greater than 3 are of the form 6k+1 or 6k-1. And for primes greater than 2, all primes are of the form 4k+1 or 4k-1. It is something that is commonly rediscovered by students, and that new independent finding was quite exciting for me.

The reasoning, which is in the article here, is that you can make any whole number you wish if the number is of the form 6k+1, 6k-1, 6k+2, 6k-2, 6k+3, or 6k-3. But you cannot make primes with the numbers of the form 6k+2, 6k-2 (they would always have to be divisible by 2), and you cannot makes primes with numbers of the form 6k+3, 6k-3 because they are always divisible by 3. So what are you left with? All primes >3 must of the form 6k+1 or 6k-1. And that factor 6 is just a bit less than 2 pi (a full turn in radians) so you get spirals from the offset. They are also a pixel or two off, but that is imperceptible.

The same logic is a nice exercise to apply to the problem of why primes >2 can only be of the form 4k+1 or 4k-1. Apply the same logic as above.

Re: Why do prime numbers make these spirals? (2019)

#35

One of the thrills of studying the primes is the discovery that all primes greater than 3 are of the form 6k+1 or 6k-1. And for primes greater than 2, all primes are of the form 4k+1 or 4k-1. It is something that is commonly rediscovered by students, and that new independent finding was quite exciting for me. The reasoning, which is in the article here, is that you can make any whole number you wish if the number is…

Yes, it was such a thrill to discover this in college (not a math major). I formulated it as all primes >2 are “factors” of 1 and 5 in a base 6 notation.

Re: Why do prime numbers make these spirals? (2019)

#36

Earlier quoted context omitted.

Hence, the video...

Hence the video what? It's polar coordinates making the spiral, not prime numbers.

The primes >3 are all of the form 6k+1 or 6k-1, so they are close to 6k. As k increases, the resulting marks on the polar coordinate system form nearly complete turns because 6 is close to 2 pi. Hence, spirals. See my other comment for a clearer explanation of why primes >3 all must necessarily be one more or one less than a factor of 6k where k is an integer. That is the crucial piece that the author did not make totally clear.

Re: Why do prime numbers make these spirals? (2019)

#37

One of the thrills of studying the primes is the discovery that all primes greater than 3 are of the form 6k+1 or 6k-1. And for primes greater than 2, all primes are of the form 4k+1 or 4k-1. It is something that is commonly rediscovered by students, and that new independent finding was quite exciting for me. The reasoning, which is in the article here, is that you can make any whole number you wish if the number is…

[deleted]

Re: Why do prime numbers make these spirals? (2019)

#38
post #6

It could use a (2019) in the title. Interesting, but not recent.

Does it matter for math articles? It’s not like the math has changed in 4 years.

> Does it matter for math articles

It matters for all the articles, so yes.

Re: Why do prime numbers make these spirals? (2019)

#39
post #6

It could use a (2019) in the title. Interesting, but not recent.

Does it matter for math articles? It’s not like the math has changed in 4 years.

It has less to do with math, and more to do with the conventions of posting to HN where people expect dates for non-recent links. There's nothing wrong with them otherwise.

Re: Why do prime numbers make these spirals? (2019)

#40
post #2

Bit of a let down when they reveal that plotting integers in general results in the same spiral pattern as primes. So naturally primes as a subset of integers also produce spirals. Seems the title is a bit misleading!

I found it insightful, not a let down. It says a lot about human nature and our biases towards spotting patterns that may be incomplete or inaccurate.
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