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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 How contrarians reconcile incompatible views. (Score 1) 2

Opponents of a theory are not required to offer a coherent alternative to demonstrate errors and fallacies in the one proposed.

What they end up doing is offering several contradictory theories in an attempt to undermine the consilience of evidence. This is a result of attacking the theory piecemeal rather than addressing the cohesive theory. A contrarian will say "Not A because Y and not B because Z" even though Y and Z are incompatible. This study examines the mechanism that allows contrarians to hold these impossible views.

The paper gives numerous examples of high profile contrarians holding several incompatible views. There are even examples where these incompatible views are expressed within a single publication. I encourage you to take a look.

You may also want to look at consilience to understand why it is a flawed question to to ask for one particular piece of evidence in favor of a conclusion or to think that undermining that one piece of evidence by whatever means necessary does not undermine the theory. The section "In history" is particularly instructive.

Submission + - mechanics of the rejection of science (theguardian.com) 2

Layzej writes: Science strives for coherence. For example, the findings from climate science form a highly coherent body of knowledge that is supported by many independent lines of evidence. Those who reject climate science often rely on several mutually contradictory ideas. Hence, claims that the globe “is cooling” can coexist with claims that the “observed warming is natural” and that “the human influence does not matter because warming is good for us.” A recent study examines this behavior at the aggregate level, but gives many examples where contradictory ideas are held by the same individual, and sometimes are presented within a single publication.

The common denominator among contrarian positions is the conviction that climate change either does not exist or is not human caused, and that either way it does not present a risk (or if it does, then adaptation will deal with the problem). In a nutshell, the opposition to GHG emission cuts is the unifying and coherent position underlying all manifestations of climate science denial. Climate science denial is therefore perhaps best understood as a rational activity that replaces a coherent body of science with an incoherent and conspiracist body of pseudo-science for political reasons and with considerable political coherence and effectiveness.

Comment Re:Hackaday Prize (Score 2) 536

Check out the Hackaday prize, over at Hackaday.io.

Actually, you don't even have to get too clever to save lives. In early 2015, the South Pacific country of Vanuatu was devastated by cyclone Pam, a category 5 storm that severely damaged almost half the country. (Full disclosure: the UNICEF photos are mine.). In spite of some islands being completely denuded of shelter, only 11 people died.

The people of Vanuatu deal with an average of 1.5 cyclones every year, but this was an unique event. There had never been a storm of this intensity measured in the country before, and certainly not one that passed directly on top of more than half the population. 3000 years of dealing with cyclones meant that people knew how to cope, but it was telecommunications that allowed us to warn people in time for them to seek shelter. Ironically, on Tanna (the worst-affected island) the majority of casualties occurred when the wall of a building designated an emergency shelter collapsed.

One national telco saw its entire national network knocked out. But within 10 days, they had better than 90% of it back in operation. I myself saw the CEO manhandling a microwave antenna into the back of a chopper during the height of the relief effort.

So yeah, it's not glorious; it's not clever. Sometimes tech just needs to be available to save lives.

P.S. The owners of a Very Large Internet Company saved a lot of lives in the immediate aftermath of the storm when they sent their superyacht to assist with relief activities. The vessel was small enough to get into the countless tiny passages, and large enough to support a helipad for medevacs. On top of that, the 40,000 litre desalination unit could keep entire villages supplied with water until barges could arrive. They don't want their names to come out because this is one of the few places in the world they can get away and just be people. But thanks guys. You rock.

Comment Re:Good, Bad And Ugly (Score 1) 194

The Good: if there are known threats that can be filtered, this is the most efficient level on which to do them.

The Bad: this will inevitably be extended to blocking torrent sites, Wikileaks and any web sites I administer.

The Ugly: it will create a false sense of security, "educating" users to be less educated about their machines.

The un-fucking-believably stupid: Ignoring the capacity for police state tactics in surveilling the domestic population, this is the same as tacking a bullseye onto the nation's internet and telling every terrorist, rogue nation and hacktivist:

DO NOT PRESS THIS BUTTON. THIS ONE. RIGHT HERE. IT WOULD BE VERY BAD. SO DON'T PRESS IT.

Comment The Conspiracy Theory Detector (Score 1) 448

You're way in over your head and you don't even know it.

XD

Looks like they're removing stuff now.

What, every single group that does temperature reconstructions is "removing stuff" and just happen to end up with the exact same answer? That's one hell of a conspiracy theory! It's item 4 on the conspiracy theory detector.

In my humble opinion, his successor is lying a lot more. That's why every month this year has been a "record."

So, nothing to do with the El Nino? That's item 10 on the conspiracy theory detector.

Even featured here on slashdot it's so suspicious,

That one's off the chart.

This site has actual photos of newspaper articles.

But isn't discussing global temperatures so is not really relevant to our discussion...

Those stubborn facts again-

Well, yeah :)

Yet another analysis:

Also not discussing global temperatures...

I understand you're not a scientist. However for God sakes, look at the data! Go into the distant past to present! Analyze it! Come up with a theory!

We've already got one, and as I've shown, the data fits quite well!

Another clue is they want to put people in jail that disagree with man made GW.

Yes. Clue #7

What's very frustrating to me is I've predicted this for 20 years that their models wouldn't hold up

Yes. That's got to be frustrating given how well they have!

Wonder why I haven't been responding? I

Because you're losing our bet so badly and because of how cocky and condescending you were when you entered it and because you're not particularly fond of the taste of crow?

Comment Re:GPS Pilot, right-wing wanker (Score 1) 448

we're really returning to where we were about 1000 years ago.

We've blown past where we were even 6000 years ago at the peak of the current inter-glacial. And FAST! It's all occurred since industrialization.

There is the fact that the 1930s was the hottest decade of the 20th century

Not even close.

Did you look at their last graph from 1880 on? That doesn't line up with the CO2 levels worth a damn.

The cyclical variations from PDO/ENSO/etc on top of the secular warming from CO2 explain each peak and valley in the temperature record quite well. It is naive to think that you would have a monotonic rise in temperatures that matched the monotonic rise in CO2. This is certainly not what the models show.

Here's a neat tool you can use to explore this. Set CO2 to 2.4 and PDO to 0.13 and you already have a pretty good match to the temperature record.

Comment Re:modus operandi doesnt seem to make any sense. (Score 1) 61

There is much to like about the Trump campaign if you are Russian.

Trump has promised to look into lifting the sanctions that the U.S. has imposed against Russia for its military incursions in Ukraine.

The Trump campaign worked behind the scenes to make sure the new Republican platform won’t call for giving weapons to Ukraine to fight Russian and rebel forces, contradicting the view of almost all Republican foreign policy leaders in Washington.

He questioned whether the U.S. would defend its NATO allies in the event of a Russian attack and claimed that the alliance is “obsolete.”

An isolationist America would pose less of a threat to Russia’s ambitions in Europe and the Middle East.

On top of this, Putin likely holds a grudge against Clinton for this.

Comment Re:This is the year of the extreme climate (Score 1) 412

From the records that we all have access to it's clear CO2 is a symptom and not the cause. You always see an incresae in heat before the CO2 rises.

Wow. It must be getting really hot because atmospheric CO2 levels have shot through the roof ever since the industrial revolution. I wonder why?

Even a high school student, no even an elementary school student can conclude CO2 doesn't cause warming.

Errr. Yes, but radiative physics.

By the way, If every month this year has been the hottest in recorded history then you must be starting to doubt your chances at winning our bet. Earlier this year you had said: "I figured when I pointed out that 2015 was a high water mark, you'd realize it would be very close to a fools bet to bet this year will be warmer than 2015. You either have no clue what you're doing (one might say you drank too much of the cool aid) or I have a feeling you think you know something I don't."

Well, I'm not a big fan of cool aid.

Comment Climate data has been available for a decade... (Score 1) 64

The code is available here. Papers here. NASA uses station data compiled by NOAA GHCN v3 (meteorological stations), ERSST v4 (ocean areas), and SCAR (Antarctic stations),

According to the Director of the NASA Goddard Institute for Space Studies "Anyone can download it, run it for themselves and get the answer before we update our website every month."

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