Years from now—maybe in a decade, maybe sooner—if all goes according to plan, the most complex machine ever built will be switched on in an Alpine forest in the South of France. The machine, called the International Thermonuclear Experimental Reactor, or ITER, will stand a hundred feet tall, and it will weigh twenty-three thousand tons—more than twice the weight of the Eiffel Tower. At its core, densely packed high-precision equipment will encase a cavernous vacuum chamber, in which a super-hot cloud of heavy hydrogen will rotate faster than the speed of sound, twisting like a strand of DNA as it circulates. The cloud will be scorched by electric current (a surge so forceful that it will make lightning seem like a tiny arc of static electricity), and bombarded by concentrated waves of radiation. Beams of uncharged particles—the energy in them so great it could vaporize a car in seconds—will pour into the chamber, adding tremendous heat. In this way, the circulating hydrogen will become ionized, and achieve temperatures exceeding two hundred million degrees Celsius—more than ten times as hot as the sun at its blazing core. 
 
 No natural phenomenon on Earth will be hotter. Like the sun, the cloud will go nuclear. The zooming hydrogen atoms, in a state of extreme kinetic excitement, will slam into one another, fusing to form a new element—helium—and with each atomic coupling explosive energy will be released: intense heat, gamma rays, X rays, a torrential flux of fast-moving neutrons propelled in every direction. There isn’t a physical substance that could contain such a thing. Metals, plastics, ceramics, concrete, even pure diamond—all would be obliterated on contact, and so the machine will hold the superheated cloud in a “magnetic bottle,” using the largest system of superconducting magnets in the world. Just feet from the reactor’s core, the magnets will be cooled to two hundred and sixty-nine degrees below zero, nearly the temperature of deep space. Caught in the grip of their titanic forces, the artificial earthbound sun will be suspended, under tremendous pressure, in the pristine nothingness of ITER’s vacuum interior. 
 
 For the machine’s creators, this process—sparking and controlling a self-sustaining synthetic star—will be the culmination of decades of preparation, billions of dollars’ worth of investment, and immeasurable ingenuity, misdirection, recalibration, infighting, heartache, and ridicule. Few engineering feats can compare, in scale, in technical complexity, in ambition or hubris. Even the ITER organization, a makeshift scientific United Nations, assembled eight years ago to construct the machine, is unprecedented. Thirty-five countries, representing more than half the world’s population, are invested in the project, which is so complex to finance that it requires its own currency: the ITER Unit of Account. 
 
 No one knows ITER’s true cost, which may be incalculable, but estimates have been rising steadily, and a conservative figure rests at twenty billion dollars—a sum that makes ITER the most expensive scientific instrument on Earth. But if it is truly possible to bottle up a star, and to do so economically, the technology could solve the world’s energy problems for the next thirty million years, and help save the planet from environmental catastrophe. Hydrogen, a primordial element, is the most abundant atom in the universe, a potential fuel that poses little risk of scarcity. Eventually, physicists hope, commercial reactors modelled on ITER will be built, too—generating terawatts of power with no carbon, virtually no pollution, and scant radioactive waste. The reactor would run on no more than seawater and lithium. It would never melt down. It would realize a yearning, as old as the story of Prometheus, to bring the light of the heavens to Earth, and bend it to humanity’s will. ITER, in Latin, means “the way.” 
 
 The main road to the ITER construction site from Aix-en-Provence, where I had booked a room, is the A51 highway. The drive is about half an hour, winding north past farmland and the sun-glittered Durance River. Just about every form of energy is in evidence nearby, from hydroelectric dams to floating solar panels. Seams of lignite, a soft brownish coal, run beneath the soil in Provence, but the deposits have become too expensive to mine. Several miles from Aix, a large coal plant, with a chimney that climbs hundreds of feet into the sky, is being converted to burn biomass—leaves, branches, and agricultural debris. ITER is being built a mile or two from the wooded campus of the Commissariat à l’Énergie Atomique et aux Énergies Alternatives, a state-funded research organization, created in 1945 to advance nuclear power, and now also renewable energy. Evergreen oak and Aleppo pine cover the foothills; beneath them, the French government maintains its largest strategic oil reserve. 
 
 ITER’s headquarters, a five-floor edifice, was erected two years ago. An undulating wave of gray concrete slats shade its floor-to-ceiling windows. Its interior is simple: whitewashed walls, polished-concrete floors. The building’s southern façade overlooks a work site, more than a hundred acres of construction on the opposite side of a berm. By the time the reactor is turned on—the formal target date for its first experiment is 2020—the site will be home to a small city. Nearly forty buildings will surround the machine, from cooling towers to a cryogenics plant, which will produce liquid helium to cool the superconducting magnets. A skywalk extends from the second floor of the headquarters to the berm, where a capacious NASA-style control room will one day be built. For now, the bridge ends in a pile of ochre dirt, and the only way to the vast expanse of construction is via a circuitous drive. ||||| Looking for news you can trust? 
 
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 The internet lit up this morning. The world was about to change dramatically for the better, all because of a major technological breakthrough: clean, abundant energy from nuclear fusion. “Lockheed Martin’s new fusion reactor can change humanity forever,” claims the headline in Gizmodo. A “potentially paradigm-shifting development in global energy,” says Aviation Week. Lockheed’s own promotional video for the Compact Fusion Reactor claims the company is “restarting the atomic age.” 
 
 Here are the key bits from the Reuters report Wednesday morning to bring you up to speed: 
 
 Tom McGuire, who heads the project, said he and a small team had been working on fusion energy at Lockheed’s secretive Skunk Works for about four years, but were now going public to find potential partners in industry and government for their work. Initial work demonstrated the feasibility of building a 100-megawatt reactor measuring seven feet by 10 feet, which could fit on the back of a large truck, and is about 10 times smaller than current reactors, McGuire told reporters. In a statement, the company, the Pentagon’s largest supplier, said it would build and test a compact fusion reactor in less than a year, and build a prototype in five years. 
 
 Lockheed Martin, one of the biggest military supply companies in the United States, says the technology could be deployed in as little as ten years. The company promoted the news with fanfare: 
 
 Being small is a big deal. See how compact fusion #energy will power the future: http://t.co/NCNREOYrv8 #fusionenergy pic.twitter.com/Ei9fQuG1PK — Lockheed Martin (@LockheedMartin) October 15, 2014 
 
 Rosi Reed, an assistant professor of physics at Wayne State University, and a researcher at the Large Hadron Collider, run by European Organization for Nuclear Research, said that the most impressive part of the breakthrough was the increase in energy output—ten times greater than that of previous reactors. “So this means that this reactor can be a lot smaller,” she said. 
 
 Of course, Reed said, while it’s exciting news, the promise is all theoretical at this stage. Should we believe the hype? 
 
 If there was a genuine breakthrough, said one nuclear physicist, “we’d be screaming from the treetops.” 
 
 First, let’s start with the basics. What is fusion? Stars—like our very own sun—create power in their cores using nuclear fusion. The conditions in the core of a star are very extreme—high pressures, temperatures, and densities. But “when we want to reproduce those conditions on Earth, we are at a great disadvantage,” says Dr. Swadesh M. Mahajan, a thermonuclear plasma physicist at the University of Texas. That’s because we don’t have the same immense mass as the sun. Our planet is far too small to produce the kind of gravity necessary for large scale fusion. The challenge, essentially, is putting the sun in a box. That box, in theory, is packed full of charged particles, moving at great speeds, constrained by a strong magnetic field that enhances the probability that the particles slam into each other. With enough pressure, the particles stop resisting, and finally fuse, let off an amazing amount of energy. 
 
 The problem, says Reed, is that usually it takes just as much energy to power that controlling magnetic field as the power you get from fusion, hence the current size of the reactors. Lockheed claims to be able to harness that energy at a more efficient rate, so it can then make the reactors smaller. 
 
 But there are a lot of reasons to be skeptical about Lockheed’s announcement, says Mahajan, who, with a team of scientists, designed a new way to reduce waste from nuclear reactors in 2009. First, fusion reactors right now are pretty big*. Mahajan says making them smaller is extremely hard to do—you need a very confined space, with loads of material at extremely high densities, and then you need to get that power out of the reactor to be used. “So it’s both the physics and the engineering which are extremely, extremely daunting,” he said. “We know of no materials that would be able to handle anywhere near that amount of heat.” 
 
 Mahajan called Lockheed’s announcement “poppycock.” He said, “Getting net energy from fusion is such a goddamn difficult undertaking,” he said. “We’re all aware that there’s always a finite chance of some breakthrough which is beyond the powers of imagination.” But if there was a genuine breakthrough, he said, “we’d be screaming from the treetops.” 
 
 Correction: An earlier version of this article wrongly said fusion reactors power some aircraft carriers and submarines. They are in fact “fission” reactors. ||||| Former Texas Governor Rick Perry goes before the U.S. Senate tomorrow to explain how he would run the Department of Energy (DOE), which manages the nation’s nuclear arsenal, a network of 17 national laboratories, and a vast array of basic and applied energy research programs. Scientists are eager to hear whether the two-time failed Republican presidential candidate has a vision for the $30-billion-a-year agency, which he once famously said should be eliminated, and where energy fits into the overall agenda of the man who nominated him, President-elect Donald Trump. 
 
 Members of the Senate Committee on Energy and Natural Resources have their own concerns to raise with Perry. Democrats will no doubt press him on whether he believes reducing carbon emissions is important, whereas Republicans will likely invite him to discuss how continued drilling for fossil fuels will help the country achieve energy independence. Senators may also ask him about the international agreement to limit Iran’s nuclear weapons program, which Trump has labeled one of the worst deals in history. 
 
 But many issues will probably not be broached. Here are 10 questions that scientists might want to ask Perry if they were sitting in the hearing room, along with a brief explanation of each topic. 
 
 What is the role of science at DOE? 
 
 Recent presidents from both parties have used science as a way to connect DOE's myriad activities, both administratively and by appointing Cabinet secretaries with advanced science and engineering degrees. Perry doesn’t have that kind of training. But if confirmed he will play a role in picking the people who run DOE’s research programs. One key decision: finding a successor to Franklin Orr, the outgoing undersecretary for science and energy. 
 
 What areas do you plan to emphasize within DOE’s Office of Science? 
 
 The agency's $5.1 billion Office of Science is the single largest funder of basic research in the physical sciences in the federal government. It is also the nation's leading builder of large scientific facilities; the 10 labs funded by the office host x-ray synchrotrons, neutron sources, atom smashers, and other user facilities. These machines serve thousands of scientists from universities, industry, and other federal research agencies in fields ranging from particle physics to structural biology. 
 
 An early indication of priorities may be Perry’s choice of a successor to physicist Cherry Murray to manage the office’s six research programs. The Obama administration emphasized advanced computing and materials for energy in the basic energy sciences’ program, and biofuels in the environmental research program; House of Representatives Republicans have tried repeatedly to cut climate research within that program. For many researchers, Trump’s first budget request, for the 2018 fiscal year beginning next fall, will be a key indicator of which way the wind is blowing. 
 
 How will you decide whether the United States should remain in the ITER fusion energy project? 
 
 ITER is a multinational project to prove that generating energy by fusing hydrogen isotopes together at temperatures exceeding those in the center of the sun is scientifically feasible. But the project, currently under construction in southern France, is at least a decade behind schedule and could cost three times original estimates. 
 
 If a U.S. domestic project were similarly so far out of control, Congress or the White House likely would have killed it long ago. But the United States has only a 9% stake in ITER—matched by China, India, Japan, Russia, and South Korea—whereas the European Union, as host, is footing 45% of the bill and is determined to see it through. 
 
 Attitudes in Congress range from enthusiastic flag waving to vocal opposition. The Senate has repeatedly put forward budgets that zero out ITER, while the House continues the back it. The annual compromise has been to provide only just enough money to remain a partner; but that has squeezed domestic fusion programs to the point of near-extinction. What path will Perry take? 
 
 Does the United States need to resume testing of nuclear weapons, and what reforms are needed to ensure the safety and reliability of the nuclear stockpile? 
 
 The last U.S. nuclear test occurred in 1992. Since then, DOE’s three weapons labs have used supercomputer simulations to ensure the safety and reliability of the stockpile, along with replacing components—such as heavy water in thermonuclear bombs—that decay or degrade. The Obama administration has lowered the number of nuclear warhead types to 12, from 23 in 1990, and there are plans to take another 50% cut over the next decade. A Trump tweet that the United States “must greatly strengthen and expand its nuclear capability until such time as the world comes to its senses regarding nukes” was later clarified to be a reference to modernization, which has been a pillar of Obama’s nuclear strategy. But it is unclear whether that modernization will require a resumption of testing. The United States signed the Comprehensive Nuclear-Test Ban Treaty 20 years ago but has not ratified it. 
 
 What is DOE’s role in fostering exascale computing? 
 
 The United States has dominated the field of high-performance computing for decades, which has helped the nation maintain its leadership in science and technology. But China now has the world’s two fastest supercomputers, and three countries (China, Japan, France) have promised by 2020 to unveil an exascale machine—one that can perform a billion billion operations per second, more than 10 times more powerful than today’s leader. Those announcements forced DOE to shorten its timeline from 2022 to 2021, but the agency has struggled to obtain the desired funding from Congress. Supercomputing advances push the boundaries of technology development. That allows the companies and countries setting the pace to reap the commercial rewards of their sizeable investments in chips and software. 
 
 Is ARPA-E working, and should its funding be increased? 
 
 The Advanced Research Projects Agency-Energy (ARPA-E) was created in 2007 and funded its first projects in 2009. Modeled after the Department of Defense's ARPA, ARPA-E aims to turn basic research into budding energy technologies that private industry will then develop. Republicans once saw that role as unnecessary government intervention in the free market, so one concern from scientists is whether Perry may rekindle that debate. As with so much in Washington, D.C., money may provide the answer; specifically, whether the Trump administration requests more or less than ARPA-E’s current $291 million budget. 
 
 Will you rebuild nuclear cooperation with China and resuscitate agreements with Russia? 
 
 In recent years, scientists in U.S. nuclear labs have had very little interaction with their peers in those two countries. A 1999 report by a House committee detailed allegations that China had stolen design information on advanced U.S. thermonuclear weapons, and that Chinese agents had penetrated U.S. labs for decades. Although China denied the allegations, the charges poisoned the well of collaboration. Joint projects with Russian nuclear scientists began to ebb soon after President Vladimir Putin came to power in 2000, and reached a nadir last October when Russia suspended an agreement with the United States on nuclear R&D cooperation and terminated another on retooling Russian research reactors to no longer run on weapons-grade uranium fuel. 
 
 U.S. nuclear scientists are working with their Chinese and Russian counterparts to implement the Iranian nuclear deal, which faces an uncertain future. The political predilections of Trump and his Cabinet augur continued improvement of scientific ties with Russia. And science could also become a counterweight to diplomatic battles with China over trade if the new administration wants to find common ground with the Asian power. 
 
 What role should DOE play in fostering a greener U.S. transportation system? 
 
 Car magazines are filled with articles about driverless cars, battery-powered vehicles, and climate-friendly fuels made from corn or algae. But the reality is that nearly all of the more than 250 million cars and trucks on the road today guzzle gasoline refined from oil, and don’t do it very efficiently. 
 
 The Obama administration made a concerted effort to transform the U.S. transportation system with battery startups, regulations that ramp up the use of cellulosic ethanol and other biofuels, and a near doubling of fuel efficiency requirements for light-duty cars and trucks. The impact of those policies is just beginning to be felt, although the more than half a million all-electric and gas-electric hybrids on U.S. roads is a good start. However, the continued greening of U.S. transportation will likely require scientific advancements in engine technology, lighter cars, and rules requiring their use. Trump has yet to signal whether his administration plans to continue driving in this direction. 
 
 Should the government reopen Yucca Mountain, or do you favor the current consent-based approach to finding a long-term storage site for high-level nuclear waste? 
 
 Congress decided in 1987 that the nation’s high-level nuclear waste from commercial reactors and other sources should be buried deep beneath Yucca Mountain in Nevada. But efforts to build and open the repository have run afoul of political opposition and technical obstacles. A presidential commission formed by the Obama administration concluded that Yucca was doomed, and that the nation needed a new siting process—involving a wide range of stakeholders, including state governments and advocacy and industry groups—to forge a workable deal. That process has yet to get off the ground. But supporters are hoping the retirement of one of the project’s most powerful adversaries—Senator Harry Reid (D–NV)—and Republican control of the White House will breathe new life into the project. 
 
 Should DOE spend more to help companies improve existing technology to extract and burn fossil fuels? 
 
 Environmental groups, climate activists, and some Democrats in Congress have long complained that federal agencies, and DOE in particular, have spent too much money supporting the fossil fuel industry, even as it racked up decades of impressive profits. But fossil fuel advocates note that DOE support has been critical to industry advances, including developing the technology behind fracking, offshore drilling, and cleaner-burning coal and natural gas power plants. The Obama administration, as part of its all-of-the-above energy strategy, increased DOE’s support for nonfossil fuels, but Congress made sure the agency also stayed in the fossil fuel game. Will Perry and the Trump administration shift the balance back again, or argue that the fossil fuel industry is mature enough to pay its own way? 
 
 Adrian Cho, Daniel Clery, Warren Cornwall, David Malakoff, Jeffrey Mervis, Robert Service, and Richard Stone contributed to this story, which was edited by Jeffrey Mervis.
– Hoping scientists will find a brilliant alternative to oil and coal? How about a thermonuclear reactor that will hit temperatures ten times hotter than the sun and "could solve the world's energy problems for the next thirty million years," writes Raffi Khatchadourian in the New Yorker. The project—called the International Thermonuclear Experimental Reactor, in France—only needs to overcome rock-bottom morale, constant delays, tensions between engineers around the world, grumbling politicians, and a multi-billion-dollar budget that's never quite high enough. "There is a lot of anxiety here that it is all going to implode," says a physicist. Scientists have long dreamed of such a reactor to harness power by nuclear fusion, a cleaner process than fission that produces almost no radioactive waste. First proposed in 1985, ITER relies on an oft-squabbling, international cadre of experts who vie for the spotlight and struggle to convince politicians that it's still viable. The US has yanked and recommitted funding over the years, and a family-owned company in San Diego is building the all-important solenoid—in this case, a 20-mile-long cable wrapped around a metal column—to harness the plant's plasma in a "magnetic bottle" (because no physical material can contain it). But engineering challenges remain, and parts made around the world may or may not all fit together. If they do, Earth could have a new energy source in about 10 years. "I think ITER is an absolute necessity for the world—otherwise I wouldn't put up with the frustrations," says a top ITER official. Click for the full article, or see a Science Insider report on a damning assessment of ITER's management.