I can't stop looking at the extraordinary photos by Tomas Shahan, an Oregon-based artist and microphotographer who creates amazing portraits of arthropods, including these awesome jumping spiders. His beautiful monsters don't make me run in fear, but make me smile (knowing they are tiny, that is.) In fact, some of their faces are hilarious.
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Alien monsters or awesome spiders, I just love these little guys
RIVERWATCH: An Autonomous Surface-Aerial Marsupial Robot Team
Every once in a while we get a tip for a project that really, really, really blows our minds. This is one of them.
It looks like a basic catamaran with a few extra bells and whistles — except it is so much more than that. You’re looking at a fully Autonomous Surface Vehicle, complete with a piggybacking 6-rotor UAV. It’s decked out in cameras, sonar sensors, laser rangefinders, high accuracy GPS-RTK tracking, an IMU, oh, and did we mention the autonomous 6-rotor UAV capable of taking off and landing on it?
It all started out as a simple experiment within ECHORD (the European Clearing House for Open Robotics Development), and since then it has become a fully funded project at UNINOVA, a Centre of Technology and Systems in Portugal.
The purpose of the mind-blowing robot team is to collect data of river environments — think of it as Google Maps 2.0 — which is almost an understatement for what it is capable of.
You seriously have to watch the video after the break.
Filed under: robots hacks
This Leech Can Survive For 24 Hours in Liquid Nitrogen
You're looking at Ozobranchus jantseanus, a little leech found in East Asia. It doesn't look much, but it has a very special skill indeed: it can survive for up to 24 hours immersed in liquid nitrogen.
Scientists Use Acid to Turn Blood Cells into Stem Cells in 30 Seconds
This is a game changer, folks. Whereas mining stem cells has been either an ethical quandary or a months-long affair, scientist can now turn any old blood cells into stem cells in just 30 seconds—by dipping them in acid.
You Can Cradle This 3-Cylinder Engine Like an 88-Pound, 400 HP Baby
This Insanely Loud Sound System Simulates the Roar of a Rocket Launch
Being shot into space puts spacecraft under extreme stress—but did you know that the sound of the rocket launch can damage a craft? Inside the Large European Acoustic Facility, engineers recreate the incredible noise of a launch to make sure satellites can survive it. According to the ESA, "no human could survive" the sound.
Scientists Turned Fruit Flies Into Glowing Cancer Detectors
One of the most exciting findings in cancer research is the ability to identify cancerous cells by the volatile odor molecules they give off. Diagnostic machines, scalpels, and even specially trained dogs have been used to identify cancer this way. We can add fruit flies to that list now: scientists have bred a strain whose antennae glow when they smell cancer.
He may not be R2-D2, but I want this remote controlled Lego astromech
It's not as big or convoluted as Lego R2-D2, but this motorized astromech by Vimal Patel is really cool. Check it out in action:
This Beautiful Map of the Internet Is Insanely Detailed
Visualizing the internet is almost as difficult as ignoring trolls, but that didn't stop Jay Jason Simons from having a damn good try. The result is this beautiful and insanely detailed map.
How to Make Electricity With Bacteria-Coated Rubber
Images: Xi Chen/Columbia University
A new electric generator has a modest and unexpected energy source: A small strip of latex rubber coated with bacterial spores.
The contraption makes use of the harmless soil bacterium Bacillus subtilis, which has a neat survival trick. When nutrients are scarce, it turns itself into a tough little spore that can withstand heat, desiccation, chemical assaults, radiation, and anything else the world can throw at it. These spores respond to changes in humidity. When the air dries they shrivel up like grapes turning into raisins; when the air is moist they plump up again. Researchers from Harvard's Wyss Institute and several other universities realized they could harness that physical movement, and could make an actuator to generate electricity.
In the experiment, published this week in Nature Nanotechnology, the researchers slathered one side of a sheet of rubber with the bacterial spores. When the sheet dried it curled up, much like a leaf does after it falls from a tree. Increasing the humidity caused the sheet to straighten out again. Researcher Ozgur Sahin then built a humidity driven generator out of Legos, in which the spore-coated rubber acts as a cantilever that flips back and forth, driving a rotating magnet to produce electricity.
Such a device, properly scaled up, could use the natural evaporation of water to generate useful amounts of clean electricity, the researchers say.
Images and video: Xi Chen/Columbia University
WIRED Space Photo of the Day: Spots on Mars
Rexster and Scala
Graph databases have generate more interest in the last few years. After blogging a bit about Neo4j, I’ve now started kicking the tires with Titan. Specifically, given the Scala work I’ve been doing recently, I thought it appropriate to factor in some of the data into Titan, since it fit nicely. Additionally, it makes a change from Neo4j. Further, Titan has some interesting performance data available as food for thought.
Praise Kids' Efforts Instead of Abilities and Make it Specific
From the Northern to the Southern Cross (astronomy photo by Nicholas Buer)
There is a road that connects the Northern to the Southern Cross but you have to be at the right place and time to see it. The road, as pictured above, is actually the central band of our Milky Way Galaxy; the right place, in this case, is dark Laguna Cejar in Salar de Atacama of Northern Chile; and the right time was in early October, just after sunset.
You can follow APOD on Twitter, too.
Glow-in-the-dark astronomical underwear
Etsy seller Makeitgoodpdx has a sweet line of glowing textiles, including several pieces of glow-in-the-dark astronomical underwear, like the panties shown above. There's also a men's version.
Glow in the Dark Solar System Underwear Womens (via Seanan McGuire)
A Watch That Puts an Entire Planetarium on Your Wrist
If you're planning on sticking around for longer—a lot longer—than a standard human lifespan, you'll need a watch that keeps time on the galactic level. Van Cleef & Arpels' new Complication Poétique Midnight Planétarium will certainly fit the bill. Instead of hands denoting the hours and minutes, it incorporates six of our solar system's planets rotating a tiny version of the sun in real time.
A Spice Rack Full of Cylindrical Shakers That Let You Grab a Pinch
Cooking is rarely about using perfectly precise portions—so Umbra designed this clever spice rack with a set of six cylindrical containers, each with its own adjustable ring that lets you shake out as much seasoning as you need. Or, you can simply remove the cap to grab a tried-and-true pinch of whatever spice the recipe calls for.
Gridded "Superlens" Brings Wireless Power Transmission A Step Closer
CyberpowerPC stuffs full-size graphics into a tiny gaming desktop
This building is designed for everyone to climb all over it
This is one of the coolest buildings I've seen in a long time: a structure designed to turn everyone into Spider-man by allowing people to climb all over its interior and exterior. It kind of feels like a glitch in the Matrix: a computer-generated mountain that needs more polygons and some textures.
Google reportedly buying artificial intelligence startup for $400 million
A U.S. Company Now Owns This (Probably Fake) Cold Fusion Reactor
Cold fusion is a theoretical (and highly doubtful) reaction that makes huge amounts of energy. Last year, the inventor claimed his Energy Catalyzer fusion device could produce electricity at 1% the cost of coal. This week, a North Carolina company bought the rights to the tech. Did they get bamboozled?
The Best Time and Time of Day to Book Airline Tickets
Tiny power plant can charge a pacemaker through heartbeats
Does 1+2+3+4+ . . . =-1/12?
(Spoiler alert: Yes it does . . . probably . . . um, maybe . . .I mean, it has to.)
An interwebs firestorm has been raging recently about a Numberphile video that makes the astounding claim that if you add up all the positive whole numbers from one to infinity, the result will be -1/12. To write it out more concisely
1+2+3+4+ . . . = -1/12 , (where the three dots indicate all the rest of the positive numbers up to infinity)
If you haven't seen the video, take a look - it's short.
Fascinating, isn't it?
Renowned science writer and astronomer Phil Plait (Bad Astronomy) blogged about the video recently, calling it "simply the most astonishing math you'll ever see." The post led to a Twitter and comment storm, fueled both by people bowled over by the calculation and a much larger number of people convinced it was nothing short of mathematical fraud.The passionate response he got to his post led Plait to write a follow up piece, partly in self defense, and partly as penance for his various mathematical sins as pointed out by his readers.
Clearly, only a fool would consider defending this absurd calculation after the reception Plait got.
So here I go . . .
First, About the Math
I'm not going to follow Plait's example of trying to explain the math that goes into the calculation. But I will point out that many of the problems that commenters and Twitterers latched onto are irrelevant if you look at the more elaborate discussion in the Numberphile's extra footage. In the much longer second video, they come to the same reviled result as in the first video, except that they use an approach first written down by Leonhard Euler.
If you dislike the initial video, you really should watch this one to see if it sways you at all.
That's much better, isn't it? I'm sure it's not perfect, but the flaws are beyond my mathematical abilities to recognize.
In any case I'm willing to believe 1+2+3+4+ . . . = -1/12 is a mathematically legitimate thing to write down for the following three reasons.
1. Euler, who was one of the greatest mathematicians of all time, proved the equation for real numbers.
2. Another great mathematician, Bernhard Riemann, generalized Euler's approach to include complex numbers, and came up with the same equation.
3. My favorite mathematician, the self-taught genius Srinivasa Ramanujan, rediscovered the equation and stood by it, even though he realized that he might be thought be mad for making the claim, writing in a letter to mathematician G.H. Hardy, "I told him that the sum of an infinite number of terms of the series: 1 + 2 + 3 + 4 + · · · = −1/12 under my theory. If I tell you this you will at once point out to me the lunatic asylum as my goal."
So, counting the Numberphiles' somewhat dubious derivation, there are at least four ways to prove that the sum of all the positive integers equals -1/12. And as far as I know, there's no way to prove that it doesn't equal -1/12.*
If you don't believe any of these people, then there's nothing I can do, mathematically speaking, to change your mind. I mean these guys are among the greatest. What could I add that would improve on their proofs?
But, Obviously 1+2+3+4+ . . . = -1/12 Doesn't Really Mean Anything - Right?
Of the mathematicians and physicists I've talked to about it, several of them are willing to accept that it's possible to derive the equation, but insist that it's meaningless. They tell me, if I understand them correctly, that it's some sort of numeric fluke that can't possibly have any consequences in the real world. There's just no way to add positive numbers together get a negative result in reality, especially when the numbers you're adding are getting larger and larger. In effect, it's nothing more than an artifact that results from a method that makes sense when applied to complex variables or other series, but not for the sum of positive integers. To think otherwise would be nuts, right?
The problem is, they're wrong (or so a number of physicists have told me). The equation 1+2+3+4+ . . . = -1/12 is vital for describing the real world.
As the Numberphile people point out, the dreaded equation pops up in many places in physics. They specifically note it's appearance in a string theory textbook (see page 22 in this Google book). But that's only one example and, depending on how you feel about string theory, among the least convincing ones. What's much more compelling is the fact that this sort of equation is integral to Quantum Electrodynamics (QED).
QED is the theory that explains the interaction between charged particles like electrons and protons. Along with neutrons, electrons and protons make up atoms, which in turn make up molecules and everything built of them. In other words, QED essentially describes much of the physical world we live in. And it does it extremely well. QED calculations for the spin of the electron have been confirmed to better than one part in ten trillion - making QED just about the most precise and successful theory of all time.
If QED is correct (and it appears to be the most correct theory yet developed, if experimental confirmation is a reasonable way to judge correctness), then I would argue that the things that go into QED calculations must be just as correct. Doing QED calculations requires using 1+2+3+4+ . . . = -1/12, so the equation is at least as correct as QED theory itself.
In fact, the Wikipedia page on a QED phenomenon known as the Casimir Effect shows a derivation of the effect that includes an even more audacious equation involving the sum of the cubes of the natural numbers up to infinity. Specifically, calculating the effect involves using the equation
1^3+2^3+3^3 +4^3+ . . . = 1/120, (where the notation 2^3 means 2x2x2)
(In the Wikipedia article, they have an equation that looks like this , but the stuff on the left hand side is just another way of writing 1^3+2^3+3^3 +4^3+ . . .)
The number on the right is positive this time, but it's ten times smaller than 1/12, even though each of the terms in the sum is much bigger than the corresponding terms in the equation 1 + 2 + 3 + 4 + . . . = −1/12 (except for the first term, of course, since 1^3 = 1). Both equations come from the same sort of derivation, so it's not surprising that they are both seemingly incredible and ridiculous. But if you believe in QED and the Casimir Effect, how can you not believe the pieces that go into them?
Maybe It's Just a Trick
One response I've gotten after querying my more mathematically savvy friends is that the equations are nifty tricks, and nothing more, to get rid of infinities in QED and produce the correct finite answers. I guess that's possible, but you would have to be one heck of a mathamagician to come up with a trick resulting in accuracy of a part in ten trillion.
It's even more impressive when you consider that the QED predictions came before the experiments that measured things like the electron spin to fourteen decimal places. It's one thing to design a trick to rationalize a number you already know. It's a whole other matter to come up with a trick that gives you the answers in advance of the experiment. In that case, it's not a trick, it's simply a very good theory.
Maybe It's Not Necessary, Just Handy
One final possibility that I can think of is that the equations are not really necessary for doing QED calculations, and that instead there is a correct and intelligible approach that gives answers without using nonsense like 1 + 2 + 3 + 4 + . . . = −1/12 or 1^3+2^3+3^3 +4^3+ . . . = 1/120.
I can't imagine why physicists would rather rely on trickery than doing things correctly, so I tend to dismiss the idea that some sort of mathematical conspiracy is behind it all. If it turns out that it's possible to have physical theories that describe the real world as well as QED does without relying these equations, then we might as well use those theories and forget the whole controversy.
So What's Really Wrong?
If you accept that Euler, Riemann, and Ramanujan did things properly when they found 1 + 2 + 3 + 4 + . . . = −1/12, and if you accept that it and related equations are necessary to describe the real world, then how can you not accept that the equation is true? And yet, many people still claim that there's something wrong. It doesn't make sense. It's so counter intuitive that the phrase "counter intuitive" seems far too weak a description. It's an alien, freakish, mind f----.
But that's OK. Some things are true without being conceivable. This is just the most recent example I can think of. Pythagoras and and his followers apparently committed human sacrifice because they couldn't handle the idea of irrational numbers. For centuries, ancient mathematicians struggled with unsolvable problems because they didn't know that pi is a transcendental number. And today, there are still things about quantum mechanics that defy intuitive understanding - the whole point of Schrodinger's Cat is to illustrate the absurdity of quantum superposition. But just because people didn't intuitively grasp those things, it didn't change the fact the the square root of 2 is irrational, that pi's transcendental nature means it's impossible to square the circle, and that particles can become quantum mechanically entangled just like Schrodinger's Cat.
Yes, there's a problem with 1 + 2 + 3 + 4 + . . . = −1/12. But I suspect the problem is with us and our failure to understand infinity. Why shouldn't an infinite sum of numbers going to infinity add up to a finite (and negative!) number? I don't really know what infinity means anyway, so I can't think of any way to object to a statement that includes not one but TWO infinities in it.
You might as well ask me why a bandersnatch of numbers going to bandersnatch add up to -1/12. But if you're able to mathematically sum a bandersnatch of bandersnatches, and then use that sum to describe the real world and predict the outcomes of real world experiments
So, Does 1 + 2 + 3 + 4 + . . . = −1/12 or not?
You bet your bandersnatch it does! (I think, anyway)
Aggregating Messages using Akka – Trait and actorSelection
Whilst on the plane back from NY recently I began to ponder about the aggregation pattern and akka. Luckily, it would appear that Jamie Allen, followed by a few other bloggers have a solution that is well documented – the aggregator trait.
So, if I use the actorSelection to fire off messages to a group of identical actors e.g. algo’s or some such thing;
context.actorSelection("../<Parent>/*") ! <message>
I need to use the expect rather than the expectOnce to process the replies
context.actorSelection("../<Parent>/*") ! <message> expect { case <response> => ... collectAllResponse() }
In the Akka aggregator pattern documentation, there is a results.size check to known when you have all the response messages (or timeout), since you originally knew how many you had sent. How do I know how many messages the actorSelection sent?
Lasers Create Ultra-Lightweight Mirrors From Styrofoam Beads
It's much easier for a telescope to see deep into the universe when it doesn't have to peer through the Earth's atmosphere, but getting them into space is expensive. There is a much cheaper solution, though, as researchers have actually found a way to make incredibly light mirrors using lasers and polystyrene—aka styrofoam—beads.