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Scientific american september 2015 pdf

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Scientific American (ISSN ), Volume , Number 3, September , published monthly by Scientific American, a division of Nature. Years of General Relativity: Scientific American Special Issue. Does Einstein's Theory of Gravity Hold Near Black Holes? Scientific American Editorial and Einstein. Scientific American (ISSN ), Volume , Number 6, December , published monthly by Scientific American, a division of Nature.

It appears as if. Scientific American published every Thursday morning at No. It sug. Make your organization truly benefit from the power of analysis. Harvard University Professor.

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.

2015 september scientific pdf american

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.

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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.

2015 september pdf american scientific

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.

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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.

Magazine Scientific American November 2016

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.

September pdf american scientific 2015

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.

The He also co-hosts a Roswell incident was nearly 70 years ago. Many people believe the latter. The History of a Modern Myth. Global Weirdness. The majority of the evidence is composed of sightings—eyewitness accounts. They say Evidence of Alien that the government knows the aliens are here Visitations Exists but keeps the evidence under wraps at Area 51 or some other top-secret venue. Viking Adult. Why are they here now? Big Picture Science. The pyramids. Climate Central.

The killer whale findings raise ques- emergence of new species. Whatever the motivation behind it. His research focuses on the mechanisms that create. If so. The sun has burned off most of the morning mist. Exactly why the creatures engage in this scraping behavior.

Despite their name. Plumper and Kaikash gently scrape their bodies against the small. British Columbia. Observations made since the s have diversification: These cultural and physical differences.

J ust offshore from the pebble beaches of Bere Point on Malcolm Island. I watch from the boat as three killer whale brothers named Cracroft.

That is. University of London. Physical traits. In the favored scenario. Soon they will leave to hunt for salmon or look for mates. It is part of the distinctive cultural fabric of the northern resident killer whales. The brothers have already spent the better part of an hour here absorbed in this activity.

The northern resident killer whales are not the only ones Intriguingly. Mounting evidence indicates that cul. Documented examples specialize in hunting Antarctic minke whales. For the facial features and fingerprints to identify individual humans. Were the populations already living in the same whales live side by side without fraternizing. One type. There research begun in the early s inconclusive for many Northern Hemisphere killer whales. Bigg and his colleagues. Biologists can use those traits to sity in England and his collaborators hint that these ecotypes identify individual killer whales.

Burdin of the Russian Academy found only in isolated springs in California and Nevada shows of Sciences. For its part humans. Current evidence is mostly the Northeast Pacific. Andrew sary for speciation to occur. Yet scientists have now shown that in various marine the killer whales.

Resident ent environmental conditions. If this separation persists long enough. Deecke of the University of Cumbria in England. Ford and graphical barrier of some kind—perhaps a mountain range. In the parlance of The Southern Hemisphere hosts geographically overlapping biologists. B Type 1 Preferred prey: They also differ in their physical features. These separate groups. Their cultural traditions probably differ depending on their preferred prey.

The whales choose mates that share their customs rather than foreigners from other eco- types. Yet studies show that in var- ious regions distinct forms. Culture appears to keep the ecotypes apart. Whether the northern Pacific halibut ecotypes began to diverge while living and sleeper sharks in the same region or whether they started to differentiate at a time D Transient earlier in the evolutionary history Preferred prey: E Type 2 Preferred prey: Patagonian toothfish J Type C Preferred prey: Antarctic toothfish November For example.

Scientists have observed this behavior in two groups records maintained and occasionally published by SeaWorld. In May of this year. A pod of the killer whales will herd a Because these and other behaviors are found only in certain school of herring into a tight ball close to the water surface.

But the most dramatic specializations have dubbed carousel feeding—to hunt the herring that form the occurred in cultural behaviors related to food acquisition. But the ice-pack whales are diversifying by exploiting different food sources and killer whales have learned to create waves that wash the seals evolving various traits that presumably help them get those over the ice float and into the water.

Some of these distinguishing features are physical. Rather mounting evidence suggests that submerged until they are just meters away from their quarry. What is keeping them separate now? Breeding the beach. In Antarctica. G-clan and R-clan for the tions that live side by side. Do other is. These discrete sounds exhibit geographical variation like.

Although all sequently evade capture. That have diversified. The challenges the ecotypes face. Then individual so suggests that culture is keeping these ecotypes apart. Fish-eating killer have also played a role in driving speciation among those early whales do not have the same problem. January Not only do the pulsed calls and whistles differ thropologists thought that most selective pressures that shaped among killer whales from different geographical regions. Killer lations were during all phases of their diversification.

Might culture the time they swim and hunt in stealth mode. There is no evidence to suggest that killer whale ecotypes? Some preliminary studies hint that the killer whales use these signals in any way that really resembles oceans around Africa might. With the advent of and ecotype variation. April Rather the southern Asia come to mind. But they also often vary among social modern tools for studying genomes.

The drug is illegal in the U. Photographs ScientificAmerican. The windows of your bed- room disappear into blackness. This scene bleeds into a darker one of demons. You are Shea Prueger. Thunderclouds cover the bedroom ceiling. Clinic op- and other treatments. You cov- er your eyes. You cannot wake up—you cannot move your body. In the U. The year-old used to live in New York spread. Renegade Science.

Today she is recall. So for two days in erators claim that a dose can curb addictive behavior. The walls around you bend and twist. Narcotics Anonymous wide. The increase in needle what no other recovery treatment could do. She stayed clean ed remedy for an exploding problem.. An audience somewhere is clapping. Nothing worked. Sweats drips from your forehead. You want to get away. You have trouble breathing.

In diction with a psychoactive drug called ibogaine.. After all adverse events. Around that time the late Howard Lotsof. Lex Kogan. Many seek help but do so in vain. During treatment patients often suffer from car. From to a French pharmaceutical compa- works on many neural pathways at the same time.

The stimu- panies. Many of from addictions to alcohol. It is illegal to use ibogaine as medicine in damage. Because withdrawal symptoms. Prueger is now chief administrator ing one in every treatments. About 80 per. Buoyed by these ideas. Word spread. Some animal studies of ibogaine and addiction came out times death. That is why heroin addict. Published medical reports tie ibogaine to 19 in the late s. Not if it there is a toxic part. Spangler recently joined the Department of Biomedical Engineering and is interested in engineering antibody-based molecules that reshape immune cell behavior for targeted treatment of cancer, infectious diseases, and autoimmune disorders.

Coffee and snacks will be provided! RSVP 's are appreciated. Scientific American special issue: Our Story GWEN came about as we began to realize how poorly female graduate are connected and noticed the lack of support structure at the graduate level. After a few discussions, we came up with a plan: Connect, inspire, and empower women by building a network. The current mission of the Graduate Women Empowerment Network also known as GWEN is to increase the representation of women with graduate degrees at all levels of STEM professions, especially promoting those seeking leadership roles.

GWEN has been growing steadily since its foundation in November, We aim to reach out to as many individuals as possible, men and women, who like us believe that we can make a difference by helping women scientists connect, inspire and empower each other.

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