In 2003, British philosopher Nick Bostrom suggested that we might live in a computer simulation. From the abstract of Bostrom’s paper:
This paper argues that at least one of the following propositions is true: (1) the human species is very likely to go extinct before reaching a “posthuman” stage; (2) any posthuman civilization is extremely unlikely to run a significant number of simulations of their evolutionary history (or variations thereof); (3) we are almost certainly living in a computer simulation. It follows that the belief that there is a significant chance that we will one day become posthumans who run ancestor-simulations is false, unless we are currently living in a simulation. A number of other consequences of this result are also discussed.
The gist appears to be that if The Matrix is possible, someone has probably already invented it and we’re in it. Which, you know, whoa.
However, Savage said, there are signatures of resource constraints in present-day simulations that are likely to exist as well in simulations in the distant future, including the imprint of an underlying lattice if one is used to model the space-time continuum.
The supercomputers performing lattice quantum chromodynamics calculations essentially divide space-time into a four-dimensional grid. That allows researchers to examine what is called the strong force, one of the four fundamental forces of nature and the one that binds subatomic particles called quarks and gluons together into neutrons and protons at the core of atoms.
“If you make the simulations big enough, something like our universe should emerge,” Savage said. Then it would be a matter of looking for a “signature” in our universe that has an analog in the current small-scale simulations.
Aired as The Quest For Tannu Tuva in the UK and The Last Journey Of A Genius in the US, this hour-long program is the last extended interview that physicist Richard Feynman gave; he died a few days after the recording.
Richard Feynman was not only an iconoclastic and influential theoretical physicist and Nobel laureate but also an explorer at heart. Feynman through video recordings and comments from his friend and drumming partner Ralph Leighton tell the extraordinary story of their enchantment with Tuva, a strange and distant land in the centre of Asia.
While few Westerners knew about Tuva, Feynman discovered its existence from the unique postage stamps issued there in the early 20th century. He was intrigued by the unusual name of its capital, Kyzyl, and resolved to travel to the remote, mountainous land. However, the Soviets, who controlled access, were mistrustful, unconvinced that he was interested only in the scenery. They obstructed his plans throughout 13 years.
I could watch this guy talk all day long. Feynman is a national treasure; we should give Andrew Jackson the boot and put Feynman on the $20.
At a distance of just over 4.3 light years, the stars of Alpha Centauri are only a cosmic stone’s throw away. To reach Alpha Centauri B b, as this new world is called, would require a journey of some 25 trillion miles. For comparison, the next-nearest known exoplanet is a gas giant orbiting the orange star Epsilon Eridani, more than twice as far away. But don’t pack your bags quite yet. With a probable surface temperature well above a thousand degrees Fahrenheit, Alpha Centauri B b is no Goldilocks world. Still, its presence is promising: Planets tend to come in packs, and some theorists had believed no planets at all could form in multi-star systems like Alpha Centauri, which are more common than singleton suns throughout our galaxy. It seems increasingly likely that small planets exist around most if not all stars, near and far alike, and that Alpha Centauri B may possess additional worlds further out in clement, habitable orbits, tantalizingly within reach.
Gorilla Glass is the thin strong glass used for the screens of most smartphones. It was invented in the 1960s by Corning but was shelved in the early 1970s due to a lack of demand. The iPhone brought it out of retirement in a big way.
Chemical strengthening, the method of fortifying glass developed in the ’60s, creates a compressive layer too, through something called ion exchange. Aluminosilicate compositions like Gorilla Glass contain silicon dioxide, aluminum, magnesium, and sodium. When the glass is dipped in a hot bath of molten potassium salt, it heats up and expands. Both sodium and potassium are in the same column on the periodic table of elements, which means they behave similarly. The heat from the bath increases the migration of the sodium ions out of the glass, and the similar potassium ions easily float in and take their place. But because potassium ions are larger than sodium, they get packed into the space more tightly. (Imagine taking a garage full of Fiat 500s and replacing most of them with Chevy Suburbans.) As the glass cools, they get squeezed together in this now-cramped space, and a layer of compressive stress on the surface of the glass is formed. (Corning ensures an even ion exchange by regulating factors like heat and time.) Compared with thermally strengthened glass, the “stuffing” or “crowding” effect in chemically strengthened glass results in higher surface compression (making it up to four times as strong), and it can be done to glass of any thickness or shape.
I did glass research in college so I’m a sucker for this sort of thing. (via @joeljohnson)
The drop is now falling at 90 meters per second (200 mph). The roaring wind whips up the surface of the water into spray. The leading edge of the droplet turns to foam as air is forced into the liquid. If it kept falling for long enough, these forces would gradually disperse the entire droplet into rain.
Before that can happen, about 20 seconds after formation, the edge of the droplet hits the ground. The water is now moving at over 200 m/s (450 mph). Right under the point of impact, the air is unable to rush out of the way fast enough, and the compression heats it so quickly that the grass would catch fire if it had time.
Fortunately for the grass, this heat lasts only a few milliseconds because it’s doused by the arrival of a lot of cold water. Unfortunately for the grass, the cold water is moving at over half the speed of sound.
First, this is not a conventional bulk material. The claim from Germany is that the superconductivity occurs at the interface between grains of graphite after they have dried out.
So that’s a surface effect which involves only a tiny fraction of the total mass of carbon in the powder—just 0.0001 per cent of the mass, according to Esquinazi and co.
What’s more the effect is clearly fragile. Esquinazi and co say the superconductivity disappears if the treated powder is pressed into pellets.
So whatever allows the superconductivity to occur at the grain interfaces is destroyed when the grains are pressed together.
I’m pretty sure this is the technology used by the aliens who designed The Machine in Contact.
Opening on September 15 at Edward Tufte’s gallery in Chelsea is All Possible Photons, an exhibit of sculptures by Tufte of Richard Feynman’s subatomic particle diagrams.
Made from stainless steel and air, the artworks grow out of Richard Feynman’s famous diagrams describing Nature’s subatomic behavior. Feynman diagrams depict the space-time patterns of particles and waves of quantum electrodynamics. These mathematically derived and empirically verified visualizations represent the space-time paths taken by all subatomic particles in the universe.
The resulting conceptual and cognitive art is both beautiful and true. Along with their art, the stainless steel elements of All Possible Photons actually represent something: the precise activities of Nature at her highest resolution.
Yoda’s greatest display of raw power in the original trilogy came when he lifted Luke’s X-Wing from the swamp. As far as physically moving objects around goes, this was easily the biggest expenditure of energy through the Force we saw from anyone in the trilogy.
The energy it takes to lift an object to height h is equal to the object’s mass times the force of gravity times the height it’s lifted. The X-Wing scene lets us use this to put a lower limit on Yoda’s peak power output.
First we need to know how heavy the ship was. The X-Wing’s mass has never been canonically established, but its length has-16 meters. An F-22 is 19 meters long and weighs 19,700 lbs, so scaling down from this gives an estimate for the X-Wing of about 12,000 lbs (5 metric tons).
The ideas of aerodynamics don’t apply here. Normally, air would flow around anything moving through it. But the air molecules in front of this ball don’t have time to be jostled out of the way. The ball smacks into them hard that the atoms in the air molecules actually fuse with the atoms in the ball’s surface. Each collision releases a burst of gamma rays and scattered particles.
These gamma rays and debris expand outward in a bubble centered on the pitcher’s mound. They start to tear apart the molecules in the air, ripping the electrons from the nuclei and turning the air in the stadium into an expanding bubble of incandescent plasma. The wall of this bubble approaches the batter at about the speed of light-only slightly ahead of the ball itself.
All science writing should (and probably could!) be this entertaining. (via @delfuego)
“We observe in our data clear signs of a new particle, at the level of 5 sigma, in the mass region around 126 GeV. The outstanding performance of the LHC and ATLAS and the huge efforts of many people have brought us to this exciting stage,” said ATLAS experiment spokesperson Fabiola Gianotti, “but a little more time is needed to prepare these results for publication.”
“The results are preliminary but the 5 sigma signal at around 125 GeV we’re seeing is dramatic. This is indeed a new particle. We know it must be a boson and it’s the heaviest boson ever found,” said CMS experiment spokesperson Joe Incandela. “The implications are very significant and it is precisely for this reason that we must be extremely diligent in all of our studies and cross-checks.”
How sure are they that they’ve found the Higgs? Brian Cox notes on Twitter:
5 sigma is the usual particle physics threshold for discovery. It roughly means that you’re 99.9999% sure
In this series of slow motion clips, you can see that if you hold a Slinky by one end and drop it, the bottom end doesn’t actually move until the top end catches up with it.
I’ve watched this like six times and it drops my jaw every time…the bottom of the Slinky JUST. DOES. NOT. MOVE. Here’s the scientific explanation:
The explanation that “it takes time for the bottom of the slinky to feel the change” might work ok, but it isn’t the best.
Then why doesn’t the bottom of the slinky fall as the top is let go? I think the best thing is to think of the slinky as a system. When it is let get, the center of mass certainly accelerates downward (like any falling object). However, at the same time, the slinky (spring) is compressing to its relaxed length. This means that top and bottom are accelerating towards the center of mass of the slinky at the same time the center of mass is accelerating downward.
After opening, the new bridge shortly came to be known as “Galloping Gertie,” so named by white-knuckled motorists who braved the writhing bridge on windy days. Even in a light breeze, Gertie’s undulations were known to produce waves up to ten feet tall. Sometimes these occurrences were brief, and other times they lasted for hours at a time. Numerous travelers shunned the route altogether to avoid becoming seasick, whereas many thrill-seeking souls paid the 75-cent toll to traverse Gertie during her more spirited episodes.
I missed this last July when the news came out, but since I’ve been following the Pioneer Anomaly for the past eight years, I wanted to mention it here for closure purposes. First, what the hell is the Pioneer Anomaly?
The Pioneer anomaly or Pioneer effect is the observed deviation from predicted accelerations of the Pioneer 10 and Pioneer 11 spacecraft after they passed about 20 astronomical units (3×10^9 km; 2×10^9 mi) on their trajectories out of the Solar System. Both Pioneer spacecraft are escaping the Solar System, but are slowing under the influence of the Sun’s gravity. Upon very close examination of navigational data, the spacecraft were found to be slowing slightly more than expected. The effect is an extremely small but unexplained acceleration towards the Sun, of 8.74±1.33x10^-10 m/s^2.
For their new analysis, Turyshev et. al. compiled a lot more data than had ever been analyzed before, spanning a much longer period of the Pioneers’ flight times. They studied 23 years of data from Pioneer 10 instead of just 11, and 11 years of data from Pioneer 11 instead of 3. As explained in their new paper, the more complete data sets reveal that the spacecraft’s anomalous acceleration did indeed seem to decrease with time. In short, the undying force had been dying after all, just like the decaying plutonium.
A more recent paper by the same researchers offers even more support for their theory. Case closed, I say.
Mustafa invented a way of tapping this quantum effect via what’s known as the dynamic Casimir effect. This uses a “moving mirror” cavity, where two very reflective very flat plates are held close together, and then moved slightly to interact with the quantum particle sea. It’s horribly technical, but the end result is that Mustafa’s use of shaped silicon plates similar to those used in solar power cells results in a net force being delivered. A force, of course, means a push or a pull and in space this equates to a drive or engine.
To what degree would nuclear research become shackled by the requirements of national security? Would the open circulation of new scientific knowledge cease if that knowledge was relevant to nuclear fission? Those questions were hardly idle speculation: From the fall of 1945 through the summer of 1946, the US Congress was crafting new, unprecedented legislation that would legally define the bounds of open scientific research and even free speech. The idea of restricting open scientific communication “may seem drastic and far-reaching,” President Harry S. Truman argued in an October 1945 statement exhorting Congress to rapid action. But, he said, the atomic bomb “involves forces of nature too dangerous to fit into any of our usual concepts.”
The former Manhattan Project scientists who founded what would eventually become the Federation of American Scientists were adamantly opposed to keeping nuclear technology a closed field. From early on they argued that there was, as they put it, “no secret to be kept.” Attempting to control the spread of nuclear weapons by controlling scientific information would be fruitless: Soviet scientists were just as capable as US scientists when it came to discovering the truths of the physical world. The best that secrecy could hope to do would be to slightly impede the work of another nuclear power. Whatever time was bought by such impediment, they argued, would come at a steep price in US scientific productivity, because science required open lines of communication to flourish.
At the University of Pennsylvania were nine scientists sympathetic to that message. All had been involved with wartime work, but in the area of radar, not the bomb. Because they had not been part of the Manhattan Project in any way, they were under no legal obligation to maintain secrecy; they were simply informed private citizens. In the fall of 1945, they tried to figure out the technical details behind the bomb.
As a naturalist, da Vinci probed, prodded, and tested his way to a deeper understanding of how organisms work and why, often dissecting his object of study with this aim. “I thought, why not present the idea of data analysis to the world within the naturalist world of Leonardo?” Cittolin says. In the drawing below, the CMS detector is the organism to be opened; the particles passing through it and the tracks they leave behind are organs exposed for further investigation.
Cittolin brings a sense of humor to his work. For example, after betting CMS colleague Ariella Cattai that he could produce a quality drawing for the cover of the CMS tracker technical proposal by a given deadline, he included in the drawing a secret message in mirror-image writing-which was also a favorite of da Vinci’s. The message jokingly demanded a particular reward for his hard work. The completed picture was delivered on time and within a few hours Cattai cleverly spotted and deciphered the message. She promptly presented him with the requested bottle of wine.
The Democrat and Chronicle learned of the facility when an employee happened to mention it to a reporter a few months ago.
The recent silence was by design. Detailed information about nuclear power plants and other entities with radioactive material has been restricted since the 2001 terrorist attacks.
Nuclear non-proliferation experts express surprise that an industrial manufacturer like Eastman Kodak had had weapons-grade uranium, especially in a post-9/11 world.
“I’ve never heard of it at Kodak,” said Miles Pomper, senior research associate at the Center for Nonproliferation Studies in Washington. “It’s such an odd situation because private companies just don’t have this material.”
In a review of the Color Uncovered iPad app, Carl Zimmer highlights something I hadn’t heard before: Claude Monet could see in ultraviolet.
Late in his life, Claude Monet developed cataracts. As his lenses degraded, they blocked parts of the visible spectrum, and the colors he perceived grew muddy. Monet’s cataracts left him struggling to paint; he complained to friends that he felt as if he saw everything in a fog. After years of failed treatments, he agreed at age 82 to have the lens of his left eye completely removed. Light could now stream through the opening unimpeded. Monet could now see familiar colors again. And he could also see colors he had never seen before. Monet began to see — and to paint — in ultraviolet.
The Dyson sphere, also referred to as a Dyson shell, is the brainchild of the physicist and astronomer Freeman Dyson. In 1959 he put out a two page paper titled, “Search for Artificial Stellar Sources of Infrared Radiation” in which he described a way for an advanced civilization to utilize all of the energy radiated by their sun. This hypothetical megastructure, as envisaged by Dyson, would be the size of a planetary orbit and consist of a shell of solar collectors (or habitats) around the star. With this model, all (or at least a significant amount) of the energy would hit a receiving surface where it can be used. He speculated that such structures would be the logical consequence of the long-term survival and escalating energy needs of a technological civilization.
Needless to say, the amount of energy that could be extracted in this way is mind-boggling. According to Anders Sandberg, an expert on exploratory engineering, a Dyson sphere in our solar system with a radius of one AU would have a surface area of at least 2.72x1017 km2, which is around 600 million times the surface area of the Earth. The sun has an energy output of around 4x1026 W, of which most would be available to do useful work.
The downside: we’d have to part with Mercury to do it.
And yes, you read that right: we’re going to have to mine materials from Mercury. Actually, we’ll likely have to take the whole planet apart. The Dyson sphere will require a horrendous amount of material-so much so, in fact, that, should we want to completely envelope the sun, we are going to have to disassemble not just Mercury, but Venus, some of the outer planets, and any nearby asteroids as well.
At Forbes, Alex Knapp explains why Dvorsky’s scheme and timeline might not work.
I emailed Astronomer Phil Plait about this project, who told me in no uncertain terms that the project doesn’t make sense.
“Dismantling Mercury, just to start, will take 2 x 10^30 Joules, or an amount of energy 100 billion times the US annual energy consumption,” he said. “[Dvorsky] kinda glosses over that point. And how long until his solar collectors gather that much energy back, and we’re in the black?”
Now available in its entirety on YouTube, a 95-minute documentary on physicist Richard Feynman called No Ordinary Genius.
The excellent film on Andrew Wiles’ search for the solution to Fermat’s Last Theorem is available as well (watch the first two minutes and you’ll be hooked).
With their ability to move seamlessly through walls, rocks, lead shielding, and entire planets, neutrinos would seem like a great choice for a new method of wireless communication. Scientists at Fermilab have demonstrated sending messages via neutrino but the downside is that the slippery particles can also move seamlessly through detectors.
In the Fermilab experiment, the physicists fired a proton beam into a carbon target to produce a shower of particles called pions and kaons that quickly decay into neutrinos. For every pulse of 22.5 trillion protons, the physicists registered an average of 0.81 neutrino with the 170-ton MINERvA detector.
That translates into a data rate of 0.1 bits/second, or just slightly faster than America Online’s dialup service circa 1992. (Hey, hey, if you liked that one, perhaps you’ll also enjoy my impression of Dana Carvey doing George H.W. Bush.)
I’ve spent years studying all this, and it still sometimes gets to me: just how flipping BIG the Universe is! And this picture is still just a tiny piece of it: it’s 1.2 x 1.5 degrees in size, which means it’s only 0.004% of the sky! And it’s not even complete: more observations of this region are planned, allowing astronomers to see even deeper yet.
Here’s a full view of the image that looks sorta unimpressive:
The NY Times is reporting that a data bump “smells like the Higgs boson”. The odor is emanating not from CERN in Europe but from Fermilab near Chicago, where their Tevatron still flings some pretty fast particles.
“Based on the current Tevatron data and results compiled through December 2011 by other experiments, this is the strongest hint of the existence of a Higgs boson,” said the report, which will be presented on Wednesday by Wade Fisher of Michigan State University to a physics conference in La Thuile, Italy.
None of these results, either singly or collectively, are strong enough for scientists to claim victory. But the recent run of reports has encouraged them to think that the elusive particle, which is the key to mass and diversity in the universe, is within sight, perhaps as soon as this summer.
Update: The Tevatron is no longer flinging, having been shut down in 2011 due to budget cuts. Which makes the Higgs discovery a little bittersweet, to say the least. (thx, miles)
According to sources familiar with the experiment, the 60 nanoseconds discrepancy appears to come from a bad connection between a fiber optic cable that connects to the GPS receiver used to correct the timing of the neutrinos’ flight and an electronic card in a computer. After tightening the connection and then measuring the time it takes data to travel the length of the fiber, researchers found that the data arrive 60 nanoseconds earlier than assumed.
Neutrinos? More like Nintendo…they forgot to blow in the cartridge. (via @tcarmody)
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