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Risky Teen Behavior Is Driven by an Imbalance in Brain Development. By Jay N. Giedd. Inside NASA's New $Billion Deep-Space Rocket. Scientific American is the essential guide to the most awe-inspiring advances in science and technology, explaining how they change our. Mind. January · View Details · November Mind. November · View Details · September Mind. September · View Details · July .
For one. In the city launched its Safe Streets program. Preliminary results have ic hurdles. Gazzaniga Director. Sold Items.
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If the Florida their backyards. Panama quantity Cayman Islands East End. Nearly two thirds of the 2. In Syria. Proponents hope the levy will help reduce obesity among children. The scientists said the objects are 3. The begins this month. The three-year program will include 5.
November Sign up to hear more about new and newsworthy nonfiction at thepenguinpress. Director—Origins Project. FFRF is a c 3 educational charity white light into all the colors of a rainbow.
Adult project. Freethought Today. The codes are sorted by difficulty cies from incoming white noise or to determine from easy to hard. Dave TevisPhoto. Now a Switzerland-based team of electrical engineers Freedom From Religion Foundation has built a device that can do something similar for sound—splitting noise into its constituent FFRF.
Each code in the code book specifies could be used to separate meaningful frequen. The onstrated that a glass prism could separate Physics of Star Trek. The prism began as a thought experiment Never get bored by a cube assembly puzzle according to Esfahlani. It is evidence of lack of understanding. A Universe from Nothing. The study results were Prostigmata 2 1. Wilson Literary Science microhabitats for other forms of life. As elephants walk through the forest Nevertheless.
Such is the the study. Hemiptera Diptera which may unveil the weirdness of bly because of a buildup of 52 quantum particles. George Wittemyer. The Department of —America's Quality Tour tial at more than 2. CEO of Deep- farms. Block Island Wind Farm. For one. That project also struggled against Costa Rica. New Energy Finance.
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Travel Editor the purchase of its electricity. Nova Scotia. Analysts put the U. For the views on climate change. This year is a different story. To achieve these goals. Below are Full responses to all 20 questions—including those from Green Party candidate Jill Stein and two questions. P drunk driving laws. What are your spond to major public health crises and to develop workable solutions.
How would you improve federal research and our public health system to better protect Americans from emerging diseases and other public health threats. Apple introduced larly. Microsoft added a universal-search icon like the one on the Mac—but placed it at the lower left of the By David Pogue screen.
You can find the same cycle of mim. It certainly did to Jobs. In Windows Vista. The iPhone vation. Bigger problem: This uct types. The iPad Pro. Cortana followed in The Problem an outrageous theft of intellectual property. Phones and tablets work pretty much commands in menus. Apple was ment systems. The central premise of copyrights for creative works and patents for inventions is this: The iPod.
The iPad was the model for everyone Copying. Absolutely right. So why should a company bother to innovate? You These days. Amazon and Google basi- it. The borrowing This year Google revealed its own of tech ideas has become almost ab. But Apple lost that lawsuit. Never mind that the features Apple was proudest of—overlapping windows.
Spotify reached Pharmaceutical companies enjoy 20 years of patent protec- the U. Google Now. You could easily create a genealogy of. They are not the only ones who have appreciated the calming effect.
At first. By following their aesthetic taste. Nearly everyone in a survey conducted by the National Sleep Late one evening Lorna descended to the living room. They wrote some code to change the number and wavelength of the photons emitted by their comput- er screens as a day progressed. She and her the day. The problem is that people that Lorna could paint at night and still have an accurate sense are increasingly staring into bright screens long into the night.
Researchers have known for several decades that strong light of any kind can suppress melatonin. The tech-savvy couple engineered a crafty solution to minimize the dis- crepancy. By Ferris Jabr As it happens. Since the Herfs released the program for free in But they soon began to suspect that their new app.
Now that she had become more cell phone or similar device within an hour of going to bed at attuned to differences in lighting. But more recent studies show that Why electronic screens keep you awake blue light suppresses melatonin more effectively than any oth- at night and what you can do about it er visible wavelength.
During Lorna Herf decided to try her hand at oil painting. Similar glasses are now commercially reemit other wavelengths. But there are times. Motivated by such research. This past March. This third so-called it tantalizingly easy to stay awake and read.
By combining the new blue LEDs with older blue light emanating from electronic devices. The current state of affairs gun investigating various remedies.
Several studies have shown can be traced to the invention in Japan of the high-bright. The solu. Apple introduced a func- blue LEDs can disrupt sleep until about 15 years ago. As it turns out.
Artificial light has been enormously beneficial over hours in the evening produced less melatonin. Even dim. In that says Debra Skene. Among the studies offering evidence that screens with blue before electricity and artificial lighting. A more expen- generate full-spectrum white LED light for the first time. The most affordable countermeasures are computer pro- Researchers did not begin amassing concrete evidence that grams such as f.
Ultimately the surest solution is electronic abstinence: Cajochen and others have also shown that these throughout your home as outside of it.
When the sun begins to set. Similar- engineers and computer programmers are trying out various ly. So far no researchers have tested brain region dubbed the suprachiasmatic nucleus helps to con.
The inescapable fact is that humans evolved to nin levels. And in a two-week trial at Brigham tems for the home and office. Ger- date back to two articles written by Albert Einstein and his col.
On the surface. But having crossed it. From the outside the black holes appear to be separate at a distance. In he received a Breakthrough Prize in Fundamental Physics. Such a theory is necessary for understanding the ture compared with the exterior. The first. He is known for his contribu- tions to the study of quantum gravity and string theory.
In a paper. It also etry into two regions: The geometry that Schwarzschild came up with pected that there could be a connection between them. General relativ- Furthermore. The interior and exterior are connected in ways that are far less fantastical than we thought.
Einstein and his colleague Nathan Rosen. This equivalence could have profound consequences. The dis- gests that spacetime itself could emerge from the entanglement of tinctive feature of a black hole is that we can separate its geom- more fundamental microscopic constituents of the universe. Based on calculations involving black holes. Work done in recent years by several theorists.
It sug. T heoretical physics is full of mind-boggling ideas. Because of the presence of The Schwarzschild solution tells us that the wormhole con- matter.
If the first comes out heads. Physicists now think that these two phenomena. From the outside the two black holes would appear happen to the second. No person or signal could travel through. Meanwhile the two black hole horizons. The finding suggests that entanglement and wormholes are actually equivalent.
If two black holes were to become entangled. If two coins are two black holes. If this were the case. It elongates Most researchers view the full Schwarzschild solution. In particular. Podolsky also then at the Institute for Advanced Study. Rosen and Boris random and will not display any correlation.
Let us call these collapse of the bridge corresponds to the dough becoming infini. In the dough-stretching analogy. In this famous work. Romeo would not be able to realize. So in best-known example involves the position and velocity of a parti. The example that EPR analyzed involves two particles with lapses before we can cross it.
In other words. We can prepare them It is important to note that the wormholes we are discussing in such a way that their center of mass has a well-defined posi- are consistent with the laws of general relativity. Their families do not like each other and so put Romeo and velocities must stay the same. Sup- pose that our particles are far away from each other. But entanglement involves a different kind of correla.
The ing the actual value of the position that Juliet measured. Yet the individual particles in a pair separated by a wide distance. From the outside the wormhole looks like a pair of black ticles have been prepared.
Romeo and Juliet. If we have two different particles. Similar- ly. These love. We are here specifying a position Juliet on different galaxies. Here we get to the most amazing part and the thing black hole is too simplistic. This principle says that there are pairs of physical variables however. Unbeknownst to ment. And the same thing will happen with the veloci- sical physics. EPR wondered what would happen if Although it has been experimentally confirmed.
Once you see that you have the right-hand be the case if Juliet measured the velocity. At first glance this sit- glove. In that way they differ from sci.
Juliet can measure the position. Imagine two young lovers. It appears as if. If that Romeo and Juliet actually meet in the shared interior! Maldacena and L. It is as if entanglement can be viewed as a thread con- tum state of the second. Now imag. Podolsky and N. Santa Barbara. We still do not a large number of possible microscopic quantum states. Imagine a couple of very distant black holes. This result is surprising entanglement and wormholes might in fact be equivalent and because entanglement.
In a gas. Joseph Polchinski and James agitation of molecules. We also hole connecting the black hole to another system. December The scopic constituents that collectively are capable of adopting vari. Einstein and N. Donald Marolf. They discovered a paradox tures. When the amount of entanglement becomes for the first hole. Burning Rings of Fire. A further look at black holes points the way to the answer. Each has would not follow our usual notion of geometry.
July 1. September In such situations. We believe that the seemingly unrelated phenomena of nection between the two black holes. The fact that black holes radiate implies that they have a ing work in on the connection between entanglement and temperature—a notion with important ramifications.
Cool Horizons for Entangled Black Holes. There was also interest- plistic. May Susskind Now. In summary. In point toward it. In this picture.
But the two distant black holes in this description of quantum spacetime—and a long-awaited unifica- case are physically connected through their interior and brought tion of general relativity and quantum mechanics. Although the medical know-how for transplanting organs has expanded rapidly.
Investigators have struggled. A few years ago scientists thought that they could do that by using stem cells. Re- replacement search continues on this approach. Global fig- ures are hard to come by. Such an achieve. That virtuoso performance sports the head and wings of an eagle and the body of a lion.
We believe After sacrificing the animal. My colleagues and I believe that it may be possible to cluded. Evolution has already created an exquisite process man cells—in an animal such as a pig or cow. A normal pig heart would. A small but increasing number of investigators.
Our occurs in the weeks and months after a fertilized egg gives rise dream is to create a chimera by injecting human stem cells into to an embryo that grows and—without having to rely on an arti. The idea might sound far-fetched. Sev- would overwhelmingly reject a direct cross-species implant. These so-called chimeric embryos would then gestate in surrogate animals until the organs Pdx1 can be harvested. After a few weeks of gestation. The resulting ani- for turning a handful of identical cells into all the specialized or.
For starters. Pig eral different teams injected custom-designed mouse embryos heart valves are suitable substitutes for human tissue only after with rat stem cells and then allowed the resulting chimeras to de- they have been chemically treated to prevent this immune reac. Relying on human origin. We still have much to learn about how taken from animals and human stem cells grown in cell cul- best to prepare human stem cells and animal embryos so that tures.
This around the world. Gestation in pigs normally lasts about four months. We fertilize a pig egg with pig sperm. Waiting lists could become a thing of the once identical cells soon start to move and behave differently as past as we develop a bountiful supply of replacement parts they divide. Each of these cells organs. The cells make and release special- to four weeks.
We are nowhere near ready to take that final step of produc. Liver Gallbladder iPSCs begin to develop Dorsal into pancreas cells Ventral pancreatic pancreatic bud bud mice—except that they had the pancreas of a rat. A lot later the combined cell. Within a few days several hundred cells have from farm animals for tens of thousands of suffering people formed a kind of ball within a ball. After completing several more intermediate exper. But even if we are unable to create fully formed two and then four seemingly identical cells.
If success. Thanks to the complex interplay of genes and proteins. Provided these experiments are successful—and this still incomplete understanding and a lot of trial and error. Then we transferred the chimeric embryos into ed by the precise location of different cells at various times with- surrogate sows.
The raw materials we use include porcine eggs and sperm ing chimeric piglets. We also recognize how much this growth is guid- mature normally. Experimenting on human ent potential problems. To date. Pigs also have Closer study of the human iPSCs created to date. They are already so far along to becom- velop fully. If the added cells develop appropriately.
Previous work has demonstrated.
Using iPSCs would offer the added ad- concentrated our efforts on creating pig embryos. As the embryo grows. The fact that a single gene. By deleting the was transplanted in Because mice are too small to generate or. If we wait any longer. Recent- gan unless we inject enough human stem cells that contain the ly researchers led by George Church of Harvard University have missing gene.
Because normal human embryos require nine months to de. More recently. A few cells located in the middle layer. Because these iPSCs do not human cells to the somewhat longer pig timeline should require respond correctly. Other organs. Adapting tell them to grow into something else. My colleagues and I stopped the experimental em- means that emptying the niche for these organs will require de.
Hiromitsu Nakauchi. Biologists refer to this physiological state as be- sity of Tokyo. The result would ic of Barcelona. August September 3. There are additional concerns. Truly naive stem cells. I believe the knowledge and techniques we dis- Moxie Foundation for supporting this early work when no one cover along the way will prove enormously valuable.
The best way to prevent such a troubling outcome is to make our lab would not be able to accomplish such a task by our. Together with embryologists. One of the thought our approach was even feasible. The tantly related species such as pigs. We have also begun tracing the way the hu.
But we must pay special attention to three types— velop a little longer—until they are six weeks old. Imagine the ethical nightmare. But the preliminary re- best number of human iPSCs that need to be implanted for the sults I have described in this article make me cautiously opti- embryo to develop successfully and the time at which we need mistic that we may generate human organs from chimeric ani- to implant them. I knew mal. Studies To date. At that point.
We began injecting pig All bets are off. I vividly remember his advice: If we cannot figure out a bio. Scientists are people. And we can be overly ments have helped us to gain some basic knowledge about the optimistic about what our discoveries may imply—not just for development of chimeric embryos. We are starting to learn the our own fields but also for humankind.
So far we have allowed the chimeric embryo to grow into a fetus. Although it is a long shot. The guidelines that we and tell them when to stop growing—the better they may be able have worked out with regulatory authorities require us to sacri. We get excited about Overall. November 5. We can forestall that problem by delet- mans and pigs are not as closely related. I am especially grateful to surmountable.
Allowing these animals to then breed only way to determine whether human iPSCs can cross species could lead to the ethically disastrous case in which a fully human barriers and contribute to the formation of a human organ in a fetus the result of a humanized sperm from one pig fertilizing a pig is to role up your sleeves and do the experiment. Yet even if we fail to create functional organs for the San Antonio Catholic University of Murcia in Spain and the transplantation.
Wayt Gibbs Photographs by Chris Mueller. The shiny. Even if it succeeds. Warning lights start flashing. For decades academic On the video feed overhead. Preliminary results have ic hurdles. The second discouraging example is ITER. The temperature inside that chamber will rise.
There they collide and form a hot. In April. The warning lights switch off. The current energizes the ring magnets and nearly inexhaustible and have no carbon.
Such fusion power plants would run on morning using power from the local grid. This reactor is an early prototype for a power plant balize its parts for a more advanced reactor—dubbed C-2W—to be completed in mid I click it. The system stant. It will rely on giant superconducting magnets to control a team all the data it needed to move on. When you fire as many as pulled the plug on designing a prototype power plant.
Two years ago Livermore Just another shot at fusion. They also would zap to come. One example is the million kilometers an hour. Clouds of hydrogen ions form at the opposing ends of the that have clarified some fusion science but are not on track to vacuum cylinder and are propelled toward the center at nearly a pump electricity into the grid by midcentury.
Sitting in the control room W. A power plant room had dropped a wrench onto the concrete floor. I see workers out on the floor of scientists have designed gargantuan machines intended to solve this nondescript warehouse near Irvine. The plants would charges up banks of beefy capacitors. ITER will make no electricity. All the new pioneers need to do is solve some of the hardest over loudspeakers. The backers are placing high-risk. That typically disruptive electric currents and magnetic fields.
The tremes: Equally important. In this design. Frustrated senators voted 90—8 to cut off U. ITER aims for a low plasma density.
Congress was. Most of the newcomers are searching for sweeter spots that lie in the less explored middle ground. NIF and ITER are at opposite ends of a spectrum of plausible designs that spans a huge range of plasma densities and energy- confinement times a measure of how long heat stays inside the plasma. Forewarned by the glacial progress of the giants. Tri Alpha claims to have raised hundreds of millions of greater than about seconds per cubic centimeter.
That pleases their investors. Fission reactors. A big opportunity. But after a subsequent though guarded vote of confidence by the U. A get the candle lit.
Another fast-moving group is ITER. Two atomic nuclei. Department of Energy. As of May. As a rule of thumb. To deliver. Any show-stopping flaws in these schemes most likely will plenty of space to have a bad surprise—or a good one. Full operation will not come until at the earliest.
In a power reactor. But the tests plasma. The fusion converts the missing mass into energy. Just three scale reactor that powers itself as well as the grid. The blobs remained stable and hot for five milliseconds. The designs shown here are for commercial-style reactors.
Neutral beam injector 8 total Beams run along tube. Laberge describes the stability problem. They have essentially solved tall. With each beat. The entire neutral atoms into the edges of the tube process would repeat once every second. The liquid chamber degrees Celsius for fusion reactions to metal captures the neutrons and heat take off. A brief. Eight injectors shoot beams of released by the fusion.
If all goes well. But the Sandia system is. The team is trying to improve the sides. The machine imposes a covers the open end of the fuel target may be scattering the separate magnetic field to keep the resulting plasma from light.
Laberge argues. It has in experiments thus far. The thin window that ionizes the fuel as it starts to implode. Sandia researchers calculate that it might be. That is more than 20 times for late Daniel Sinars. But if But competition could change that sentiment. Half a continent away in New Mexico. According to Slutz. Is that enough to achieve General Fusion must struggle with unproved physics. A brief trillion-watt laser blast nearly as much as their models predict.
For a squirting out the ends of the cylinder. But a laser may simply be the wrong tool for the job. It is an elegant solution on a whiteboard, but no one has ever built such a system. And Laberge worries that as shock waves from the pistons pass through the lead-lithium mixture, some of the metal could spray into the plasma, squelching the fusion.
The start-ups Currently that race in the U. Federal money for alternative paths to fusion has been face numerous practical challenges. Scientists Maybe, maybe not. Tri Alpha is pursuing proton-boron fusion precisely to avoid Is it worth taking a few more shots? Plasma Physics: The Fusion Upstarts. But that technology does not yet exist. We once believed that the continents were fixed on the surface of Earth; now we know they move.
We thought margarine was healthier than butter and that hormone-replacement therapy was the right treatment for vast numbers of postmenopausal women; now we know better.
But while scientists do not know everything, there is plenty they. And especially during this political season, it is dispiriting to see how many people—including political candidates—bizarrely reject some of the most basic, evidence-based truths that underlie modern science. Psychological research has shown that being confronted with that mounting evidence can actually harden the positions of the truth deniers, so we do not pretend that the essays that follow will fix the problem.
Nevertheless, we feel it is our duty to point out that some things actually are true, even in the constantly growing and evolving world of science. Because of a convergence of evidence from many lines of inquiry. Darwin came to this conclusion: Not only are the dates consistent. It is not as if one scientist finds that a fossil hominin is 1. If new species are created naturally—not supernatu- rally—what place.
No wonder that more than a cen- tury and a half later people of some religious faiths still find the theo- But in those intervening years scientists ry so terribly threatening. Nobody knows where this have never been shown to be dangerous.
For example: The ages are given in estimates.
And of course. Dobzhansky famously noted. The consistency of dating techniques also gives us confidence that the theory is true.
Explanation for vinced quite contrary to opinion I started with that species are not it is like confessing a mur- the Diversity der immutable. Trilobites and mammals are separated by many millions of years. A product called Oscillococcinum is sold based on the unscientific thinking of a single mis. They consult two books.
That means Muscovy duck the heart and liver. The el Hahnemann. What are you afraid of? You do have to replace fluids lost to urine and perspira no access to healthy food or a balanced diet. If any of that makes sense to you. It is active ingredient. They ask way to explain homeopathic theory is with this example: If coffee a laundry list of irrelevant questions What color are your eyes?
What keeps you awake. Any chemis- and Its Kindred Delusions. It is inconsistent with our basic knowledge of physics. All that remains is the quack. We have learned plenty since then. The cabal would also have to fake all the data from past climates that tells us there is no magic mechanism clouds or otherwise that will save us from the well-established warming effects of carbon dioxide acting in concert with water vapor. Our understanding of the connection between greenhouse gases and global warming rests on the same principles that underlie heat-seeking missiles.
Some of my favorites: Berlin wall. Likewise the carbon isotope and car- bon budget data that prove that the carbon dioxide accumulating in the atmosphere really does come from deforestation and burning fossil fuels.
If it is a conspiracy. Global warming is a problem. Homeopathy was bunk in Earth is not flat. It would have to fake the observed conjunction of strato- 0 spheric cooling with tropospheric warming. Irish-born physicist John Tyndall have used homeopathy instead of effective drugs. Science rewards those who overturn previous dogma think quantum theory versus classical mechanics. People have died. I wish they radiation emitted back into space. As Edzard Ernst. It adds up to an awful lot of stuff to fake and makes faking the moon landing look like a piece of cake.
It would take quite a conspiracy to fake all that. Energy is conserved. And so on and so forth. People temporary Gustav Kirchhoff. You know it. By now There were many later developments in the 20th century. The Conspiracy Theories ed that it works no better than placebos. Austrian Ludwig Boltzmann in the mids and his German con- strates the inability of the general public to think critically. At the time. As a consequence. Animal tests But despite a handful of suspicious-looking studies.
If the disorder is genetic. For the most part. Frederick Banting and Charles Best discovered insulin. It is nice to be able to point a finger at an evil force causing autism. Another possibility is that the notion that vaccines cause autism is comforting—certainly far more comforting than studies that have shown a genetic basis. Until a clear cause and cure for autism emerge. The most encouraging aspect of the vaccine-autism controversy has been the emergence of academics.
If autism is caused by events occurring out- side the womb. Criminal activity does not increase during the full moon. There are several plausible rea- sons why they feel this way.
Conspiracy theorists argue that the only reason studies have shown that vaccines do not cause autism is that a vast international con- spiracy is hiding the truth. Although only a small group of parents hold this belief. And everyone loves a bogeyman.
Since then. That should tell you something: Assuming an aliens- without-borders effort. Even aside from the formi- dable technical challenges of interstellar travel. If aliens have been here weekly radio program. Aurum Press. Seth Mnookin. The Panic Virus: If despite nonprofit organization the lack of good evidence.
I think the United Nations would notice. Most of these can be explained as aircraft. Unless the extraterrestrials come from a very close star system. Unless extraterrestrials prefer Americans and exceptionalism aside.
There remains no scientifically validated evidence that extraterrestrials have been here. Used, overall good condition, good binding, no apparent defects or missing pages. The Absolut ad is on the back cover and is in very good condition.
September 19, April 10, April 17, and April 24 of issues of Scientific American. All three are in good to very good vintage condition. Clean, unfaded, and no odors. Magazines have fascinating articles, photos, and illustrations on a variety of s scientific and technological subjects.
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