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Theoretical Physics Is Pointless without Experimental Tests

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Our discipline is a dialogue with nature, not a monologue, as some theorists would prefer to believe

-- Read more on ScientificAmerican.com
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cheerfulscreech
8 days ago
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To me, science = the scientific method.
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Voting Software

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There are lots of very smart people doing fascinating work on cryptographic voting protocols. We should be funding and encouraging them, and doing all our elections with paper ballots until everyone currently working in that field has retired.
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cheerfulscreech
10 days ago
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Truth.
alt_text_bot
10 days ago
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There are lots of very smart people doing fascinating work on cryptographic voting protocols. We should be funding and encouraging them, and doing all our elections with paper ballots until everyone currently working in that field has retired.
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11 public comments
caffeinatedhominid
4 days ago
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Yep.
tante
8 days ago
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xkcd on voting software is spot-on
Oldenburg/Germany
wmorrell
8 days ago
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Hazmat suit, too. Just to be safe.
rjstegbauer
9 days ago
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Amen!! Paper... paper... paper. It's simple. It's trivial to recount. Everyone already knows how to use it. It's cheap. It's verifiable. Just... use... paper.
ianso
9 days ago
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Yes!
Brussels
ChrisDL
10 days ago
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accurate.
New York
reconbot
10 days ago
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Legitimately share this comic with anyone who represents you in government.
New York City
jth
10 days ago
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XKCD Nails Secure Electronic Voting.
Saint Paul, MN, USA
skorgu
10 days ago
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100% accurate.
jsled
10 days ago
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endorsed; co-signed; it. me. &c.

(alt text: «There are lots of very smart people doing fascinating work on cryptographic voting protocols. We should be funding and encouraging them, and doing all our elections with paper ballots until everyone currently working in that field has retired.»)
South Burlington, Vermont
alt_text_at_your_service
10 days ago
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There are lots of very smart people doing fascinating work on cryptographic voting protocols. We should be funding and encouraging them, and doing all our elections with paper ballots until everyone currently working in that field has retired.
srsly
10 days ago
Seconding this policy ^^

Keep Moving

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When Kate was in her mid-20s, she noticed that her beloved nana was starting to slow down and get more frail. Having heard that studies had shown that taking just a short walk a day could help the elderly stay healthy and avoid disability, and wanting Nana to stick around as long as possible, Kate often encouraged her to take regular strolls — advice which, to Kate’s frustration, she rarely took. “It’s so easy to take a short walk,” Kate would muse to me. “I wonder why she doesn’t do it?”

Fast forward a decade or so, and to another conversation between Kate and I. “Boy,” she said, “it sure seems to be getting harder to want to move rather than sit now that I’m in my 30s. I wonder if it just keeps getting harder to get up and go with every decade of your life, so that by the time you’re in your 80s, the inertia is super strong. That’s probably why Nana didn’t do her walks.”

I thought of this exchange recently when I heard about a recent study which showed that daily moderate to vigorous physical activity significantly cut the risk of mortality — even if accumulated in chunks of ten minutes or less. Basically, that cliché advice to park far away from the store entrance or to take the stairs instead of an elevator turns out to be dead-on, and potentially life-saving.

Movement staves off death because it’s good for the ticker, good the waistline, and good for the mind.

People often use age as an excuse for gradual (and sometimes not-so-gradual) weight gain over the years. But while metabolism does decrease about 10% each decade, that slowdown is largely not a function of age, but a result of the loss of muscle mass. People get fatter not because they get older, but because as they get older, they stop moving. They get more and more inert. They slow down, their lifestyle becomes more sedentary, their muscles deteriorate, their metabolism declines, and fat accumulates.

At the same time, physical activity wards off depression and anxiety, so that a lack of movement sickens the mind as it weakens the body.

A sedentary life thus easily turns into a cycle of greater and greater passivity. Once you stop moving, you gain weight/get frailer, and feel more depressed, which makes you less motivated to move, and when you do move, it feels harder, more uncomfortable, and less pleasurable. This only makes you less likely to move, which makes you gain more weight, become more decrepit, and get more depressed, which drives you deeper into the chair and the couch.

On the flip side, movement (especially that which involves some resistance) preserves your mood, your muscle mass, and thus your metabolism. The more you move, the easier it is to stay moving — a positive cycle is created: your body stays leaner and your joints stay limber; your mind stays more positive and motivated; you want to move more, and it feels good when you do.

The rolling stone gathers no moss; the moving man gathers less fat.

Look at this MRI scan of the quadriceps of a 40-year-old triathlete, and then compare the stark visual difference in fat/muscle composition that can be seen in scans of two 70-something men — one who is sedentary and the other who is a competitive triathlete:

40-Year-Old Triathlete

74-Year-Old Sedentary Man

70-Year-Old Triathlete

As the authors of the study for which these scans were made conclude: “It is commonly believed that with aging comes an inevitable decline from vitality to frailty . . . This study . . . show[s] that we are capable of preserving both muscle mass and strength with lifelong physical activity.”

Be the Shark

Bodies at rest, stay at rest; bodies in motion, stay in motion.

The easiest way to keep moving, is to stay moving.

Picture your body, mind, and spirit like one of those exercise bikes they have at science museums, where you have to keep pedaling to keep a light bulb lit.

Or better yet, picture yourself as a shark. Some sharks have to swim almost constantly in order to breathe. Same thing with you. You got to keep moving to “breathe” — to maintain the vitality of both your body and mind. If you don’t keep moving, you’ll die. Not right away, but slowly. And quicker than you otherwise would. 

While you wouldn’t believe it in your 20s, it does get harder to want to move as you get older. Who knows why. Less motivating dopamine in the brain? Less novelty and more boredom with routine? The cumulative effects of earth’s gravity? Whatever it is, know you’re going to have to intentionally maintain the will to move.

Remember that daily physical activity doesn’t have to be a full workout (though dedicated exercise is excellent, of course). 

Do actually take the stairs. Carry a suitcase rather than wheeling one around. Take short breaks from work to walk or perform the Daily Dozen Exercises.

Keep swimming. Keep breathing, Keep moving. Keep living.

The post Keep Moving appeared first on The Art of Manliness.

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cheerfulscreech
12 days ago
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23andMe Is Sharing Genetic Data with Drug Giant

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The genetics testing company and GlaxoSmithKline are using 5 million people’s data to develop medical treatments

-- Read more on ScientificAmerican.com
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cheerfulscreech
21 days ago
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Wise Parenting Dos and Don’ts From 1886

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Editor’s note: The following excerpt comes from Hill’s Manual of Social and Business Forms by Thomas Edie Hill, which was published in 1886.

What Parents Should Never Do

Never speak harshly to a child.

Never use disrespectful names.

Never use profane or vulgar words in the presence of a child.

Do not be so cold and austere as to drive your child from you.

Never misrepresent. If you falsify the child will learn to deceive also.

Never withhold praise when the child deserves it. Commendation is one of the sweetest pleasures of childhood.

Never waken your children before they have completed their natural slumbers in the morning. See that they retire early, and thus have the requisite time for sleep. Children require more sleep than older persons. The time will come soon enough when care and trouble will compel them to waken in the early morning. Let them sleep while they can.

Do not reproach a child for a mistake which was made with a good motive at the time. Freely forgive, wisely counsel, and the child will thus be taught that there is no danger in telling the truth.

Never give your children money indiscriminately to spend for their own use. However wealthy you may be, teach the child the value of money by requiring it to earn it in some manner. Commencing young, let the child perform simple duties requiring labor, which the parent may reward by pennies and very small sums. Let the child thus spend only money of its own earning. The boy who thus early learns by labor the value of a dollar knows how to accumulate the same in after-life, and how to save it.

Never demean yourself by getting angry and whipping a child. The very fact of your punishing in anger arouses the evil nature of the child. Some day the punishment thus inflicted will react upon yourself.

What Parents Should Do

Always speak in a pleasant voice.

Teach your children how to work; how to obtain a living by their own efforts. Teach them the nobility and the dignity of labor, that they may respect and honor the producer.

Explain the reason why. The child is a little walking interrogation point. To it all is new. Explain the reason. Your boy will some day repay this trouble by teaching some other child.

Teach your children the evil of secret vice, and the consequence of using tobacco and spirituous liquors; teach them to be temperate, orderly, punctual, prompt, truthful, neat, faithful, and honest.

Encourage your child to be careful of personal appearance; to return every tool to its place; to always pay debts promptly; to never shirk a duty; to do an equal share, and to always live up to an agreement.

Teach your children to confide in you by conference together. Tell them your plans, and sometimes ask their advice; they will thus open their hearts to you and will ask your advice.

Give your children your confidence in the affairs of your business. They will thus take interest, and become co-workers with you.

Teach your children those things which they will need when they become men and women. Think what a man and woman needs to know in order to be healthy, happy, prosperous, and successful, and teach them that.

The post Wise Parenting Dos and Don’ts From 1886 appeared first on The Art of Manliness.

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cheerfulscreech
23 days ago
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The two-time pad: midwife of information theory?

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The NSA has declassified a fascinating account by John Tiltman, one of Britain’s top cryptanalsysts during world war 2, of the work he did against Russian ciphers in the 1920s and 30s.

In it, he reveals (first para, page 8) that from the the time the Russians first introduced one-time pads in 1928, they actually allowed these pads to be used twice.

This was still a vast improvement on the weak ciphers and code books the Russians had used previously. Tiltman notes ruefully that “We were hardly able to read anything at all except in the case of one or two very stereotyped proforma messages”.

Now after Gilbert Vernam developed encryption using xor with a key tape, Joseph Mauborgne suggested using it one time only for security, and this may have seemed natural in the context of a cable company. When the Russians developed their manual system (which may have been inspired by the U.S. work or a German one-time pad developed earlier in the 1920s) they presumably reckoned that using them twice was safe enough.

They were spectacularly wrong. The USA started Operation Venona in 1943 to decrypt messages where one-time pads had been reused, and this later became one of the first applications of computers to cryptanalysis, leading to the exposure of spies such as Blunt and Cairncross. The late Bob Morris, chief scientist at the NSA, used to warn us enigmatically of “The Two-time pad”. The story up till now was that the Russians must have reused pads under pressure of war, when it became difficult to get couriers through to embassies. Now it seems to have been Russian policy all along.

Many people have wondered what classified war work might have inspired Claude Shannon to write his stunning papers at the end of WW2 in which he established the mathematical basis of cryptography, and of information more generally.

Good research usually comes from real problems. And here was a real problem, which demanded careful clarification of two questions. Exactly why was the one-time pad good and the two-time pad bad? And how can you measure the actual amount of information in an English (or Russian) plaintext telegram: is it more or less than half the amount of information you might squeeze into that many bits? These questions are very much sharper for the two-time pad than for rotor machines or the older field ciphers.

That at least was what suddenly struck me on reading Tiltman. Of course this is supposition; but perhaps there are interesting documents about Shannon’s war work to be flushed out with freedom of information requests. (Hat tip: thanks to Dave Banisar for pointing us at the Tiltman paper.)

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cheerfulscreech
32 days ago
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