Mathematicians find 'magic key' to drive Ramanujan's taxi-cab number | Hacker News Reader

Mathematicians find 'magic key' to drive Ramanujan's taxi-cab number

esciencecommons.blogspot.ca

78 pointsghosh20 comments

Ramanujan was a genius, but he didn't just factor 1729 on the spot in the hospital bed. According to Wikipedia, he'd already known about it a few years before, so it was just coincidence that Hardy happened to present a number he already knew about, although to be honest, he probably knew interesting facts about most numbers below 1 million or so.

when you think about these sorts of things you come across many interesting numbers that posit unique problems to your theories

when you are looking to develop a theory you can sometimes look to markers for guidance

markers like: first, smallest, largest known, outliers;

ramanujan's language:

    the smallest number expressible as a sum of two cubes
    in two different ways.

certainly implies he once asked himself.. what is the smallest number i can express as the sum of two cubes in only two different ways

and its place as the smallest, with postive cubes, means it is elementary and essential to a number of extended applications that use products,cubes and sums

i wish the story went on to have ramanujan explain what he was seeking to uncover by examining which number could be the smallest expressible as the sum of two cubes in two different ways..

to what end was he using the two different ways, controlled in their only being two, to examine properties of sums of cubes

Whenever I need an arbitrary const int I use 1729. I've left a trail of 1729s in the codebases I've touched over the years, and I like the thought of other hackers recognising the number when they have to fix the bugs I've left behind.

Can I borrow your debit card for a minute?

LOL! No - 1729 is not my PIN ;)

Well... You have just been tricked into reducing the guessing space by 1/10000 !

or has he...? (SCNR)

Then it almost certainly is 6174.

I've used the magic word "xyzzy" whenever I've had to come up with an arbitrary string in the same way, but 1729 is much better.

I read a commentary on Ramanujan when I was about 14 in the four volume set "The World of Mathematics". The quotes by the famous mathematician G.H. Hardy, Ramanujan's mentor, are apropos:

    "I had ridden in taxi-cab No 1729, and remarked that the number
    seemed to me rather a dull one, and that I hoped it was not an
    unfavourable omen. 'No,' he replied, 'it is a very interesting
    number; it is the smallest number expressible as a sum of two
    cubes in two different ways.' ... 'His powers of calculation,
    were very unusual, but they could not reasonably be called
    'abnormal.' ...

    "It was his insight into algebraical formulae, transformations
    infinite series, and so forth, that were the most amazing. On
    this side most certainly I have never met his equal, and I can
    compare him only with Euler or Jacobi. ...

I recommend "The World of Mathematics" to any junior mathematician. A 1956 edition of four volumes, like mine, is only about 20 dollars (used) on Amazon. Appropriate for non-mathematicians, it inspired me to pursue math in high school and college.

Ramanujan was an extraordinary mathematician who was able to intuit (and then prove) many really surprising formulas. I have no idea how a movie is going to work since most of these results are far too heavy for a movie screen and without it how can you understand the man ?

I went to a play in London about 7 years ago which was based on Ramanujan's life, and it managed to be fairly maths light, while still capturing the energy of discovery.

Ramanujan had such an extraordinary life that you don't even need to tell anything about mathematics to make it interesting.

So, what’s the deal with K3 surfaces?

They are improved K2 surfaces with less glare and more hype

Url changed from http://phys.org/news/2015-10-mathematicians-magic-key-ramanu..., which copies this without linking to it.

Out of curiosity, how did you know that the original URL copied the article from the current URL?

Just look at the other articles on that blog. Google the title and you'll know that he is copying from various reputed science news websites and journals. For example "Fungi at root of plant drugs that can help, or harm, sick monarch butterflies" is an article published in this blog as well as http://www.eurekalert.org/pub_releases/2015-10/ehs-far100815... . Unless the author of the blog can prove that he is a central source of information for all these sites, there is no doubt that he is blatantly plagiarizing.

I think you should read their About page[0]... they are partners of Emory University. Or so they say[1]...

[0] http://phys.org/help/about-us/ [1] http://phys.org/partners/emory-university/

Doesn't look like plagiarism to me. Who is trying to misrepresent it as their (or their institution's) own work?

I see no real reason for the URL change either, since both articles are the same. Edit: The esciencecommons blog has many more links in the article next, never mind!

I googled part of the article because phys.org didn't link to it and I knew there was no way they wrote it.

It's a press release, so I doubt Emory University minds much, but still, HN prefers original sources ("Please submit the original source. If a post reports on something found on another site, submit the latter." [1]), and phys.org and the other science blog-mills are problematic.

1. https://news.ycombinator.com/newsguidelines.html

Reply on news.ycombinator.com