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Yonatan Zunger
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Yonatan Zunger

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It will be made, of course, by hedge fund managers.
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But images of it will appear in young adult movies for decades in advance.
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I see articles like this on a fairly regular basis, when someone notices that there's some way to effectively make self-driving cars think there's a danger and stop, and treats this as some huge, startling vulnerability of self-driving cars.

But on the other hand, you can stop a non-self-driving car with a rock – or even worse, cause the driver to panic, lose control, and smash into something or someone. If you're firing things at cars from a distance, you have quite a few options. 

While there are certainly some novel ways to stop a self-driving car that wouldn't work against a human-piloted one, the fact that their worst consequence is "the car comes to a safe stop and won't go again," as opposed to "a high-speed collision," is actually a pretty good advantage in my book.

via +rare avis.


As IEEE Spectrum reports, security specialist Jonathan Petit will be presenting a disturbingly easy new hack this November at the Black Hat Europe conference. After recording the probe signals from an IBEO Lux lidar unit, Petit simply fired them back at the emitter using his laser. As long as they were synchronized, the lidar unit ‘saw’ an illusory object in front of it. The trick works up to 100 meters away in any direction — at the front, back or side — and doesn’t even require a tightly focused beam.
Although other hacks like spoofing the vehicle’s GPS or tire sensors have been done before, Petit’s hack could potentially bring a vehicle at speed to a full stop. Several 3D-rendered vehicles could be placed not only in front of the car, but actively moving toward it. That would present quite a gauntlet to any control now on the market.
In the self-driving car business, decisions are only as good as your sensor data. While the state-of-the-art Velodyne LIDAR that adorns benchmark research vehicles will set you back $80,000, winning the DARPA urban challenge probably requires the better part of a cool million. Unfortunately, spoofing these sophisticated sensors just got a whole lot easier.
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I think it's time we retire the word "hack" from common usage unless referring to artlessly striking something with an axe or machete. When "hack the planet" means growing a small vegetable patch, and "hack driverless vehicles" means the equivalent of just standing in front of them, we've really diluted "hack" to the point of homeopathy.

Also, you kids get of my lawn. I'm really hacked off about this.

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My wife knows my political leanings well, it seems.
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+Wojciech Burkot Whoa! That is a really well-designed campaign poster.
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If you ever have an oil fire in your kitchen, the most important thing is never to pour water on it. The physics reason is that the water will sink straight to the bottom of the burning oil, hit the bottom of the pan, evaporate nearly instantly, and now you have a rapidly expanding (not quite exploding but close) cloud of water vapor propelling burning oil in all directions.

What does that mean in practice? +The Slow Mo Guys decided to test it out, and film it at 2500fps.

Let's just say that their decision to pour the water on the fire from the end of a long pole, from behind a barricade, while wearing protective gear, was very wise indeed.

(The correct way to put out an oil fire is to starve it of oxygen: put a metal [not glass!] lid on the pot.)
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Many years ago, I briefly worked in Solar physics, doing helioseismology: using the pattern of vibrations on the Sun's surface (as measured using satellites like SOHO, and ground-based observatories like the one at the South Pole) to look at the inside of the Sun. It's one of those things that seems like it couldn't possibly work, until you do it, and it does.

The way seismic mapping works is pretty simple. If you hit a rock with a hammer, and watch how the entire surface of the rock vibrates, you can calculate the density profile of the rock, because you know how vibrations move as a function of density. Helioseismology is just that, magnified.

And now, we're doing it with Saturn – not with Saturn's surface itself, since that's roiling nonstop due to the motion of clouds and ferocious storms, but with its rings, who are also gently moved by the forces of gravity. By carefully measuring their vibrations, we can look inside the gas giant itself.

(You can, it turns out, also look at the surface of the planet; so long as you're looking at vibrations much slower than the storms, that works as well. That's something we're doing with Jupiter; see, e.g., But the resolution isn't as good.)

The field is called Kronoseismology, after Kronos, the Greek Titan whose Roman equivalent is Saturn. Unfortunately, there doesn't seem to be an equivalently wonderful name for Jovian seismology.
Kronoseismology and the Rings of Saturn

Seismology is the study of vibrations and waves through the Earth’s interior. By studying how vibrations are transmitted through the Earth we can study the structure of the Earth as a whole. Similar methods have been applied to the Sun, known as helioseismology, and through it we have an understanding of things such as the temperature and pressure of the Sun’s core. We’ve also been able to study some stars in this way (asteroseismology) from which we can determine things like a star’s age. While it’s a powerful tool, seismology methods pose a challenge for gas planets. But because Saturn has a complex ring system, its vibrations can be measured indirectly. The process is known as Kronoseismology.

If Saturn were a static mass, then the motion chunks of rock and ice that make up its rings would depend largely on the gravitational interactions between each other. But because Saturn is vibrating its gravitational field oscillates, and this induces wave patterns within Saturn’s rings. These patterns are subtle and difficult to observe, but in recent years we’ve been able to watch these changing patterns.

The patterns are measured using the Cassini spacecraft orbiting Saturn. As Cassini orbits Saturn, it’s view of background stars are often occulted by the rings of Saturn. By observing a star as the rings pass in front of it, we can gather information how thick the rings are in a particular area. This is what a team did for Saturn’s C-ring. From the data they were able to deduce 6 wave patterns that oscillated too quickly to be caused by the gravitational tug of a Saturnian moon. Instead they are caused by the oscillations of Saturn itself.

From this data, the team was able to verify that our model of Saturn’s interior is relatively accurate, though further analysis of these patterns will help us refine the model.

Paper: M. M. Hedman and P. D. Nicholson. Kronoseismology: Using density waves in Saturn’s C ring to probe the planet’s interior. The Astronomical Journal, 146:12 (16pp), 2013.
Saturn's rings can be used to study the vibrations of Saturn's interior. The process is known as Kronoseismology.
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What?  Zeuseismology would be an awesome name for that.  
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Um... because, science! Really! Not at all because this gives me a tremendous urge to try it with various mixes of gelatin!

Via +Rhys Taylor, who I'm sure was sharing this for purely scientific reasons as well.
Grating Gelatin With A Tennis Racket.
Join the Simple Science and Interesting Things Community and share interesting stuff!

Gelatin is a mixture of peptides and proteins produced by partial hydrolysis of collagen extracted from the skin, bones, and connective tissues of animals such as domesticated cattle, chicken, pigs, horses and fish. During hydrolysis, the natural molecular bonds between individual collagen strands are broken down into a form that rearranges more easily. Its chemical composition is, in many respects, closely similar to that of its parent collagen. Photographic and pharmaceutical grades of gelatin are generally sourced from beef bones and pig skin
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In case you're wondering here's the original video from the Slow Mo Guys
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Yonatan Zunger

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Pop songs don't get formed in a vacuum: there are people who write them, and to do this well and successfully is no small skill. What's rather odd is that a huge fraction of them – of the people who have written the hit songs of the past few decades, the songs that have topped the charts in countries from the UK to Korea – are Swedish.

This article dives into particular depth with Max Martin, the invisible hand behind twenty-one different #1 hits. He is, one has to say, one of the most influential composers of our time – not just from his own work, but from the long line of people he has collaborated with and mentored – and yet is nearly unknown outside his field, and only a handful of people have ever heard the recordings of him performing his own works. (Which, apparently, are quite good)

So here's a bit of how pop songs came to be. And as a side note, an explanation of why they seem to all have influences of R&B, pop, and hair metal.
Among the stranger aspects of recent pop music history is how so many of the biggest hits of the past twenty years—by the Backstreet Boys, ’NSync, and Britney Spears to Katy Perry, Taylor Swift, and the Weeknd—have been co-written by a forty-four-year-old Swede. His real name is Karl Martin Sandberg, but you would know him as Max Martin, if you know of him at all, which, if he can help it, you won’t. He is music’s magic melody man, the master hooksmith responsible for twenty-one No. 1 Billboard hits—five fewer than John Lennon, and eleven behind Paul McCartney, on the all-time list. But, while Lennon and McCartney are universally acknowledged as geniuses, few outside the music business have heard of Max Martin.
Max Martin, pictured at the 2015 Grammy Awards, has written nearly two dozen No. 1 songs, for performers including Britney Spears, Katy Perry, and Taylor Swift. Credit PHOTOGRAPH BY MICHAEL TRAN / FILMMAGIC VIA GETTY
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the porn that have topped the charts in countries from the UK to Korea – are Swedish too what acoincidence! ;P
thats why i love the swedes ;)
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You may have noticed that I'm a huge fan of +The Slow Mo Guys. What I love most about serious slow-motion photography is that it lets you see how things happen in a way that you could normally only theorize about. That can be anything from water waves, to impacts, to explosions.

You may have also noticed that I particularly like the explosions, because in my heart, I am still six.

This one is particularly fun because, as part of the Battlefield 4 release, EA paid them to set up a traditional video game scenario: a concrete building where you just happen to find a bunch of explosive barrels stacked up. And fortunately, Gav was a demolitions expert in the Royal Army, so he knows just the way to set this off properly: with an L109A1 fragmentation grenade. (He also illustrates the very important demolitions skill of running like hell and hitting the deck)

There are quite a few interesting things to watch here. When the first charge goes off (in slow-mo at 5:42), you can see the bright flash of light, followed by a spherically expanding pressure (blast) wave in a confined area. You can see how the less firmly attached parts of the building (e.g. wood) move outwards, while the concrete itself stays absolutely fixed. A second explosion exits through a side door at 5:50, and there you can see how the concrete walls redirect the blast. Explosions, just like anything else, can bounce off hard surfaces: this may be important to remember at certain times. 

Around 5:59, you can see how debris isn't spraying randomly: it's forming clear jets going upwards (radially away from the primary explosion). To the right of the screen, you can see what happens when those jets are blocked by a wall: they stop, and instead you start to see smoke rising, in billowing clouds. 

At 6:02, you can start to see the secondary explosion's core, presumably the blast of the barrels of explosives going off. And by 6:26, that burst has dimmed enough that you can see things again, and you can see a mushroom cloud forming.

(Mushroom clouds are normally associated with nuclear explosions, but they actually happen with any big enough blast. What happens is that the explosion creates a sphere of very hot gases. The center of the sphere is hotter than the outside, so it rises faster, and that gradual deformation forms the characteristic "mushroom" shape)

So hopefully, I've given enough technical discussion here to justify posting this under "Today I Learned:". Because I obviously would never have posted this just because watching things blow up is fun.

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I just wish they didn't use Bank Gothic as their font.
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I don't know if there's anything profound I can add to this; it's just one of those things that reminds you that sometimes, the world doesn't suck.
Sometimes it's the sudden serendipitous connections that make us remember what is so wonderful about life. 
I met you in the rain on the last day of 1972, the same day I resolved to kill myself. One week prior, at the behest of Richard Nixon and Henry Kissinger, I'd flown four B-52 sorties over Hanoi. I...
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ALL THE ALLERGY ONIONS, whether it's real or not...
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These codes get so detailed because they aren't just used in insurance; they were originally developed as a way of managing statistics about medical events, and they really needed codes for everything possible. But that doesn't stop them from being morbidly fascinating and amusing. It's sort of like how Borges would imagine a catalogue managed by the Angel of Death.

Via +Rachel Blum​.
The disaster of ICD 10 starts today in full earnest. 

I mean...what could possibly go wrong?
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Humans have a tremendous garbage problem. In stable ecosystems, one creature's waste products are food for others, and so nutrients and resources and so on keep flowing through the entire system; the problem is when resources start piling up somewhere and not being consumable, so in effect they're taken out of action.

Because of this, I've always been very interested in the ways we can find organisms which eat our waste products, from organic waste to heavy metals. And here we have a very interesting example indeed: it appears that there's a species of mealworm which finds styrofoam tasty.
It's probably not yet time to start putting your plastics into the compost pile but we're getting closer to that point.
Consider the plastic foam cup. Every year, Americans throw away 2.5 billion of them. And yet, that waste is just a fraction of the 33 million tons of plastic Americans discard every year. Less than 10 percent of that total gets recycled, and the remainder presents challenges ranging from water contamination to animal poisoning. Enter …
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+Todd Underwood Scope?

How about the not-so Great Pacific Garbage Patch? A pile of garbage floating in the ocean that's estimated to be the size of Texas at the lower bounds?

I think that qualifies as a "tremendous garbage problem" - relative risk notwithstanding.
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Today, I would like to present to you the answer to one of the pressing problems of our time: a classification of the fauna of our world between 300 and 50 million years ago according to their kosher status. 

And yes, the title of the underlying research paper begins "Jurassic Pork."
So, now we know...};-) "The answer to what kosher observing Jew would eat 310 million year ago is finally answered thanks to three paleobiologist.  The short answer?  Dinner will be short.
A tremendous amount of thought and review of rules of Kosher and how that pertains to different forms of animal life is included.  A lot of work also went into reviewing the fossil record in light of these rules.

Roy E. Plotnick*, Jessica M. Theodor and Thomas R. Holtz (2015) Jurassic Pork: What Could a Jewish Time Traveler Eat? Evolution: Education and Outreach 2015, 8:17 doi:10.1186/s12052-015-0047-2"
The answer to what kosher observing Jew would eat 310 million year ago is finally answered thanks to three paleobiologist. The short answer? Dinner will be
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  • Stanford University
    Ph. D., Physics, 2003
  • University of Colorado, Boulder
    B. A., Mathematics, Physics, 1997
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Chief Architect, Google+
Lots of people ask me what my job title means. I'm the senior engineer on the Google+ team, and my primary responsibility is to oversee and guide the technical design of Google+ and all of the things related to it. In practice, I'm also involved in lots of non-technical issues as well: my job is to make Google as fun, exciting, social, and pleasant a place to be as it can possibly be.

(I've been at Google since 2003, but you probably haven't seen me before this, because I worked deep in the back end: planet-scale storage, very large-scale search, ranking, and so on. Lots of teams whose unofficial motto is "if we told you, we'd have to kill you" -- as opposed to Google+, where we get to go out and talk and interact with our users.)

For those who just came here, welcome to the Google+ Project. It's something that we're all very passionate about, and which (as its name indicates) is going to continue to develop and improve at what we hope is an amazing rate. I'm avidly interested in hearing user feedback, and while I can't guarantee that I'll have time to respond to all of it, it will most certainly be listened to.

And the obligatory (very important!) disclaimer: I'm not on this system as an official representative. While I'm listening to user feedback and interacting about the system, I'm also here for perfectly ordinary social networking purposes. If I am saying something official on behalf of Google, I will make that explicitly clear; anything else that I say here is not the position of Google, or of anyone other than myself.

In fact, most of what I post about has nothing to do with CS at all. If you want a taste of it, take a look at my blog.
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