Please create an account to participate in the Slashdot moderation system

 



Forgot your password?
typodupeerror
Check out the new SourceForge HTML5 internet speed test! No Flash necessary and runs on all devices. ×

Submission + - New formula massively reduces prime number memory requirements.

grcumb writes: Peruvian mathematician Harald Helfgott made his mark on the history of mathematics by solving Goldbach's Weak Conjecture, which every odd number greater than 5 can be expressed as the sum of three prime numbers. Now, according to Scientific American, he's found a better solution to the Sieve of Erasthones:

In order to determine with this sieve all primes between 1 and 100, for example, one has to write down the list of numbers in numerical order and start crossing them out in a certain order: first, the multiples of 2 (except the 2); then, the multiples of 3, except the 3; and so on, starting by the next number that had not been crossed out. The numbers that survive this procedure will be the primes. The method can be formulated as an algorithm.

But now, Helfgott has found a method to drastically reduce the amount of RAM required to run the algorithm:

Helfgott was able to modify the sieve of Eratosthenes to work with less physical memory space. In mathematical terms: instead of needing a space N, now it is enough to have the cube root of N.

So what will be the impact of this? Will we see cheaper, lower-power encryption devices? Or maybe quicker cracking times in brute force attacks?

Comment Re:The blame can be shared (Score 5, Insightful) 301

Life: Record lows in winter

e.g. If the three months of winter on average way above normal, but I can find one day over the three month period that was unusually cold, I am going to pretend the entire winter was record cold.

Life: They haven't, they aren't.

e.g. Only hurricanes that make land fall in the continental US count because they're the only ones I hear about on the news

Life: Flooding and heavy rains.

e.g. Ignore the widespread droughts, it's always raining somewhere.

Comment It's the Science News Media's Fault (Score 5, Insightful) 301

Science news is largely presented by reporters with journalism educations who don't have any background in the science they're covering and as a result don't really understand the nature of what it is they're covering.

As a result, when they report an issue like climate change, they're completely unqualified to explain the actual science and instead of covering the work that scientists do, they cover the scientists instead. Instead of explaining the research that led Dr. Jones to conclude climate is changing, we get an appeal to authority.

So the reason non-scientists deny climate change is that the argument for climate change is largely being presented to them via non-scientific arguments.

Comment White House hesitation (Score 1) 173

The White House is hesitating over making any accusations along these lines because they know full well that if you make those accusations you'd better be able to back them up and the evidence to back them up is almost impossible to get. We may know that the Russians are behind it, but I doubt we've got the evidence to actually prove it to any acceptable standard and if we go off making official accusations without being able to prove them we're going to look like fools.

Comment Re: oh, yes (Score 1) 173

The polls say otherwise...

Hillary is supposed to be running against the anti-Christ but she seems to be barely scraping by. Perhaps she shouldn't say Trump's name so much. That's a pretty rookie mistake for politics.

DNC arrogance and incompetence is far more of an influence on this election than Putin.

Comment Re:Superdistribution of Content (Score 1) 195

Generally it's from some stupid millennial, or the mouthpiece of a social networking company that offers a messaging feature that, for all intents and purposes, is email (except with centralization, censorship, advertising and data-mining). What they really mean is "we wish email were dead, so everyone would be forced to become one of our users and we could become the new defacto email".

FTFY.

Comment Re:In other news... (Score 1) 206

I tried that with an HDHomeRun. I wanted to get some DVR software running on my computer, but couldn't get it to work right.

I did that years back with HDHomerun and MythTv.

I just now switched to OTA again..this time, I priced out the hardware needed and found that the Tivo Roamio OTA unit was only about $399...and it was cheaper to do that for a 4 tuner unit than to buy the HDHomerun units (2 of them) and the computer to run it on.

Look into the Tivo OTA unit...lifetime service for $399.

I got the Tivo minis to stream from main unit to tvs in bedrooms and office..each only about $125 or so.

It works great although setup is a bit clunky for the tivo minis takes a long time for registration on them to take online and have it pushed to main unit.

You have to reboot the main one after it gets the update (up to 24 hours later)....but once it all hooks up, works flawless and great tivo guides and ease of use.

Comment Re:Eh? (Score 0) 47

Well, I'll be the first to risk Flamebait mods by saying it: this summary reads as though it was written by someone whose first language was Hindi or something similar.

Nah..Slashdot just finally outsourced their editors...or maybe just imported H-1B workers to do the work.

Seems about the same quality I've seen from most of those type of workers so far in real life.....

Comment Re:CABLE and SATELLITE (Score 1) 206

Cut the cord!

Yep, I"m just about to tell ATT Uverse to cut me off an keep their high $$ service.

I had the U200 package and it was about $113/mo.

I've set up an OTA antenna, and grab all my local channels, and have that set up with a Tivo OTA box (new version with lifetime service included) which was about $399.

I priced out building my own DVR box using HDHomerun tuners and for a 4 tuner system like the Tivo, it would have been about the same or a bit more, plus I'd have to do it.

I got 2 of the Tivo mini units for my other bedrooms, and office, so I have OTA dvr and streaming to all tvs.

For what I call the "cable channels" that I would miss...I have some amazon fireTV units at each tv, and on them I have Playstation VUE, their mid priced $35/mo package that streams 70+ channels, including all the ESPN ones, the SEC channel (the only sports I watch are college football really), I get all the cable news channels (CNN, MSNBC, Fox News, Fox Business, etc...). I also get TCM, TBS, FX, FXX...and much more.

I havne't done the HBO type channels in so long...after a week you've seen everything you need for a month...not worth it to me.

I have Netflix and Amazon Prime.

With me..my internet is a business connection and I need it for my livelihood, so I do not count it towards any cost savings or cost for my TV needs.

I had netflix and amazon before too.

SO, i'm basically dropping from $113 a month, to $35/month.

The system is sound and works...and besides having 3 remotes at each TV, I don't really notice anything the Cable gave me that I don't have now.

I'm only noticing I won't have AXS or the Velocity channel anymore....but I didn't watch them all that often.

I figured roughly on the hardware I'll break even in about 7 or so months....

Slashdot Top Deals

Save the whales. Collect the whole set.

Working...