20180914

Fri Sep 14 09:15:16 EDT 2018 Slept from ten to six-thirty. Woke briefly around midnight. High of seventy-nine and partly sunny today. Stopped at Starbucks on my way to work. Work: - Directory data entry, photos Done. - Prep for Monday IT review meeting Done. - Continue brainstorming about office remodel Not much. Ten-minute walk at lunch. Hot. Saw several little white butterflies. Home: - Play with _Mormo_ D&D zine Done. - Register for U-Con events? Still not open. Stopped at the grocery on my way home. https://www.schneier.com/blog/archives/2018/09/quantum_computi_2.html > At its core, cryptography relies on the mathematical quirk that some things are easier to do than to undo. Just as it's easier to smash a plate than to glue all the pieces back together, it's much easier to multiply two prime numbers together to obtain one large number than it is to factor that large number back into two prime numbers. Asymmetries of this kind -- one-way functions and trap-door one-way functions -- underlie all of cryptography. > Quantum computers promise to upend a lot of this. Because of the way they work, they excel at the sorts of computations necessary to reverse these one-way functions. For symmetric cryptography, this isn't too bad. Grover's algorithm shows that a quantum computer speeds up these attacks to effectively halve the key length. This would mean that a 256-bit key is as strong against a quantum computer as a 128-bit key is against a conventional computer; both are secure for the foreseeable future. > For public-key cryptography, the results are more dire. Shor's algorithm can easily break all of the commonly used public-key algorithms based on both factoring and the discrete logarithm problem. Doubling the key length increases the difficulty to break by a factor of eight. That's not enough of a sustainable edge. > There are a lot of caveats to those two paragraphs, the biggest of which is that quantum computers capable of doing anything like this don't currently exist, and no one knows when -- or even if - we'll be able to build one. We also don't know what sorts of practical difficulties will arise when we try to implement Grover's or Shor's algorithms for anything but toy key sizes. https://nautil.us/issue/64/the-unseen/the-most-dangerous-muse-rp > Shaish is part of a subset of people with Parkinson’s disease who experience an urgent flowering of creativity even as their brain cells die and their bodies decline due to the neurodegenerative disease. Patients with no prior history of artistic proclivities begin to draw, paint, sculpt, and write poetry. In recent years case studies have shown the brains of the Parkinson’s patients are being reshaped by their disease and medications. > Parkinson’s experts are finding that newly artistic patients like Shaish are tapping a well of creativity that had previously been sealed off. Their bursts of inspiration, the scientists say, offer insights into the neural mechanisms of creativity that lie within us all, and underscore the dictum that creativity flows when our filters are down and the world rushes in. > The underlying cause of Parkinson’s disease is not yet known. Its symptoms are the result of a signaling problem: Brain cells begin to die that produce a certain neurotransmitter, a chemical that triggers the action of other neurons. This particular neurotransmitter, dopamine, is critical in regulating movement, which explains why Parkinson’s patients often have shaking hands, stiff limbs, and overall difficulty in initiating and executing motor tasks. But dopamine doesn’t only work in the motor-control system. It plays a role in reward-seeking behavior, risk-seeking tendencies, and addiction. > He believes the two phenomena are linked. “There may be something in this constellation of symptoms where people have a certain amount of impulsiveness and risk taking behavior that gets expressed through art,” Chatterjee says. He says his artistic patient would get up at four in the morning to paint. “Our patient would pick themes and keep working them and working them,” he says. “There was a ritualistic component.” > Inzelberg thinks that dopaminergic drugs alone can’t explain the creative outbursts. She notes that other studies have shown brain damage from a stroke, or frontotemporal dementia—damage to lobes associated with planning, judgment, and speech—have inspired creativity. “Damage to the brain in certain areas might trigger the sudden appearance of skills that did not exist before,” she says. Interestingly, Inzelberg adds, “dopaminergic drugs will probably not generate creative skills in neurologically normal individuals.” Indeed, the neural degeneration caused by Parkinson’s helps stir the artistic flowering. https://undark.org/article/book-review-bonnett-beyond-the-map/ https://www.thecalculatorsite.com/articles/units/calculating-chance.php > And what about the chances of a particular number, say five, coming up on at least one of the two dice? Well, if the probability of throwing a five on one dice is 16.6 per cent, you might assume that it's twice as likely (33.3 per cent) to happen when doubling the number of dice. But that wouldn't be exactly correct. There are six possible events in which Dice A shows a five and six more where the five shows on Dice B. That's 12 events out of 36 but one of those is shared between both dice (the double five) so the actual number of events is 11, and so the probability is slightly reduced to 11/36, or around 30 per cent. > > Another way to work out the probabilities is the Rule of One. Plainly there is total certainty (1/1 or 100 per cent) that the dice will either end up showing a five or not. Therefore the chances of no five showing on two dice are 36/36 minus 11/36, which is 25/36. Subtracting the probabilities of any given event from one always tells you the chances of the opposite occurring. Breakfast: cafe latte, egg bites Lunch: chicken wrap, coffee Dinner: ice cream

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