Holy new Mersenne prime, Batman! (M47 related)

[patrik]

I just discovered that there is another exponent that can be excluded.

36705287  70     0xDDA8BEB967041D__                23-Aug-08 07:32  dmazh          dm2

was an early double-check (since the first test had an error code of 00000002). The residues match (so the first test was good after all).

[user@zeta primestats]$ grep 36705287 2006-12-25_00_cleared.txt
36705287  68     0xDDA8BEB967041D__                13-Dec-06 15:06  mrocci         pandora
[user@zeta primestats]$

[Mini-Geek]

Originally Posted by Wacky

So 9.8 million is "OK". What about 9.81 million, 9.808 million, etc.? Where do you draw the line?

I guess that you have "contributed your 0.02 cents to the discussion".

Disclaimer: The above comment is for literary effect only. It should not be construed as a reflection of the value that I place on Mini-Geek's contribution to this discussion.

I'm not sure I have a set line, but I know that 9.8 is just fine (because it allows a quick, easy, and fairly accurate estimate), and 9.808358 is just ridiculous (because it's not an estimate, and is just as slow, and harder to read, as writing it as an integer).

[cheesehead]

Originally Posted by Mini-Geek

He said 9.808358 million, which is just ridiculous for the reasons I stated in my last post.

... and the writer is almost certainly aware that it is ridiculous, and wrote it that way for deliberate comic effect. I've done exactly that (written a number in a nonstandard way, for the sake of humor) myself many times -- though less often in this forum than elsewhere.

Just as there are, according to Cheesehead's First Law of Programming, "at least 100 (base unspecified, not necessarily decimal) different ways to write any given program", so too are there multiple ways to write an article. This time, the writer seems to have deliberately chosen a casual, folksy style rather than use the more accurate style most of us would probably use if we were in his position.

Cheesehead's Second Law of Programming says that "Some of those 100 (base unspecified ...) ways will be better for certain purposes than others." So, too, are some article writing styles better for certain purposes than they are for other purposes.

Consider that the article has more of the nature of gossip (Scientific American gossip, but gossip nevertheless) than of technical announcement. Then the casual errors or nonstandard usages may make more sense.

- - -

Edit:

Originally Posted by Mini-Geek

If we allow two words to be changed it could make the whole thing make much more sense. Change "mere primes" to "composite numbers".

Okay.

Also, later on, he seems to imply that this must be the 45th, not the 44th, and that since the 44th was so close to 10M digits, this practically must be over 10M and will get the $100,000.

< snip >

it just seems to me that throughout the article he thinks that this must be the next sequential one and it can't be smaller than M44 or just barely larger.

Yes. But isn't that what an average non-math-oriented person might expect, too? After all, it's common to rank items according to size, or to increasing value -- _is it all that big a sin_ for a non-seriously-mathematical reader (or a writer aiming for that target audience), who is unfamiliar with the realities of the order in which GIMPS searches for primes, to assume that presumably-orderly mathematicians do that, too? And thus assume that M45 is larger than M44?

[Mini-Geek]

Originally Posted by cheesehead

... and the writer is almost certainly aware that it is ridiculous, and wrote it that way for deliberate comic effect. I've done exactly that (written a number in a nonstandard way, for the sake of humor) myself many times.

I admit the possibility, the whole tone of the article isn't exactly serious (such as "... named for 17th-century French smarty-pants monk Marin Mersenne ..."
But it really doesn't seem humorous in the least to me in this context, so I'm not sure.

[cheesehead]

Originally Posted by Mini-Geek

I admit the possibility, the whole tone of the article isn't exactly serious (such as "... named for 17th-century French smarty-pants monk Marin Mersenne ..."
But it really doesn't seem humorous in the least to me in this context, so I'm not sure.

You and I are almost certainly not part of the writer's intended target auience.

[Orgasmic Troll]

Originally Posted by Wacky

So 9.8 million is "OK". What about 9.81 million, 9.808 million, etc.? Where do you draw the line?

I guess that you have "contributed your 0.02 cents to the discussion".

Disclaimer: The above comment is for literary effect only. It should not be construed as a reflection of the value that I place on Mini-Geek's contribution to this discussion.

Seriously?

9.8 million expresses the intent perfectly, that it's just a bit short of 10 million. Further accuracy in the number does not add any accuracy in the perception.

I think you've got a forest/trees thing going on here.

[Orgasmic Troll]

Originally Posted by cheesehead

... and the writer is almost certainly aware that it is ridiculous, and wrote it that way for deliberate comic effect. I've done exactly that (written a number in a nonstandard way, for the sake of humor) myself many times -- though less often in this forum than elsewhere.

I think you give the writer faaar too much credit. And even if you're right, then we're just transferring ineffective numerical sense to ineffective humor.

[ewmayer]

Originally Posted by Wacky

So 9.8 million is "OK". What about 9.81 million, 9.808 million, etc.? Where do you draw the line?

I guess that you have "contributed your 0.02 cents to the discussion".

I think you mean "0.02 dollars". But I prefer "Approximately 0.000000000002 times the U.S. GDP" in any event.

[jrk]

Originally Posted by Wacky

I guess that you have "contributed your 0.02 cents to the discussion".

Do you work for Verizon?

[jasonp]

Sigh. "Math nerds also go ga-ga for really big numbers, as we all do I'm sure"

Translation: "Math nerds are oblivious to the stupidity of things they like".

Maybe we should all take up journalism instead.

[Jeff Gilchrist]

Most of you here already know how to calculate this but for those of you that don't or for those that will be visiting this thread from the outside world, I threw together a quick program that will calculate the number of decimal digits in a specified Mersenne number (2^p-1).

There are Windows binaries available (GUI and command line), plus source code for the command line version to compile on Linux/Unix systems.

You can download the software from:
http://gilchrist.ca/jeff/MprimeDigits/

Jeff.