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For most of astronomy's history, understanding the heavens was limited to what we could see: the narrow band of the electromagnetic spectrum that constitutes visible light. Only over the last century or so have we expanded beyond that, into the infrared and microwaves and up into the higher energies of X-rays and gamma-rays. The past few years have brought an even more fundamental change: we've started detecting astronomical events without photons at all. This was done most famously by LIGO, the hardware that detected gravitational waves. But LIGO was actually late to the game, as the South Pole's IceCube detector had started listening in on cosmic neutrinos a few years earlier.
But in one critical aspect, LIGO beat IceCube to the punch: it spotted an event where the gravitational wave signal was paired with an optical signal, a burst of gamma rays. This marked the first instance of what's being termed "multimessenger" astronomy, where a single event is observed using physically distinct signals.
While IceCube has spotted some phenomenally energetic neutrinos, we've not been able to match those with a specific photon source. As of today, that has changed with the announcement that an energetic neutrino was likely to have been sent our way by a blazar, a supermassive black hole with a jet pointed in Earth's direction.
Today we present the second installment of my interview with British astronomer Stephen Webb on the subject of Fermi’s paradox. Part one ran yesterday—so if you missed it, click right here. Otherwise, you can press play on the embedded player or pull up the transcript—both of which are below.
This time, we open by talking about the second large category of possible solutions to the paradox: that intelligent aliens are out there, but we just haven’t detected them yet. Webb's book Where Is Everybody includes freestanding chapters on 25 such solutions, but of course we only tackle a subset here.
We then go on to the third major category—which is that we are quite alone in our galaxy, and perhaps in the entire universe. This idea tends to be a dismaying possibility to science-fiction authors like me (and is inimical to the entire premise of my first novel!). But it can also be seen as an optimistic—and indeed even relieving—interpretation. Stephen and I discuss why.
For around four years now, the water supply to the city of Flint, Michigan, has been contaminated with lead. Now, Tesla and SpaceX CEO Elon Musk has promised to help. Replying to a request on Twitter, Musk pledged to fund remediation work to houses with contaminated water supplies.
Please consider this a commitment that I will fund fixing the water in any house in Flint that has water contamination above FDA levels. No kidding.
— Elon Musk (@elonmusk) July 11, 2018
For some time now, people on Twitter and elsewhere have been calling on Musk to turn his attention to this domestic scandal; those calls having escalated in response to his high-profile interest in the rescue of 12 children and their soccer coach from a cave network in Thailand. As is usually the case with plans that are barely an hour old, the details are thin as of now. But Musk—tweeting from China—told people in Flint to reply to his tweet with test results showing contamination above the recommended limits, at which point he would arrange having a water filter fitted for them. (We should note that it's actually the EPA, not the FDA, that sets limits on environmental pollution exposure, and that the state of Michigan has already been supplying water filters to affected residents.)
For now, reply to my tweet with ppm & ppb test results & will send someone to install a water filter. Creating email email@example.com, but I’m in China so that won’t be working until tomorrow.
— Elon Musk (@elonmusk) July 11, 2018
In replies to other Twitter users, Musk mooted the idea of a "barnstorming weekend" installing water filters across Flint and noted that many houses in the area do actually have safe water now despite perceptions otherwise. While this isn't a flashy solution that uses offcuts from rockets, it also has the potential to make a lasting positive impact on the lives of citizens of Flint, particularly its children who can suffer from developmental delays if exposed to environmental lead.
Early hominins ventured out into the world beyond Africa even earlier than we've given them credit for, according to a new stone-tool find on the southern edge of China's Loess Plateau.
Hominins—the lineage of apes that eventually came to include humans—began making recognizable stone tools about 3 million years ago. Before that date, we know that our early relatives inhabited a place only if we find their bones or, in rarer cases, their footprints. But stone tools offer a more durable, more abundant calling card. Pick up a stone flake or scraper—or a core of flint or chert with obvious scars from flintknapping—and you know that someone made this object. Someone was here.
And that's exactly what archaeologists led by Zhaoyu Zhu of the Chinese Academy of Sciences found in a 2.1 million-year-old layer of ancient wind-blown sediment in China's southern Loess Plateau: a collection of stone cores, flakes, scrapers, borers, and points, as well as a couple of damaged hammerstones. The tools' style strongly resembles stone tools found at sites of about the same age in Africa, made by early human relatives like Homo erectus.
One of the biggest rivalries in the modern aerospace industry is between Boeing and SpaceX. Despite their radically different cultures, the aerospace giant and the smaller upstart compete for many different kinds of contracts, and perhaps nowhere has the competition been more keen than for NASA funds.
In 2014, both Boeing and SpaceX received multibillion awards (Boeing asked for, and got, 50 percent more funding for the same task) to finalize development of spacecraft to carry astronauts to the International Space Station as part of the commercial crew program. Since then, both companies have been locked in a race to the launchpad, not just to free NASA from its reliance on Russia to reach space but also for the considerable esteem that will accompany becoming the first private company in the world to fly humans into orbit.A narrow margin
Although both Boeing and SpaceX have established various launch dates—first in 2017, and now slipped to 2018 and 2019—NASA hasn't publicly tipped its hand on which company is actually ahead in the race. Now, however, a new report from the US Government Accountability Office has provided a window into NASA's internal thinking on commercial crew launch dates.
Sometimes the plucky investigator in a mystery story isn’t baffled by a “whodunnit.” Sometimes they are pretty sure about the who, but the evidence ain’t where it ought to be. Studying past climate events can be like that, with likely explanations waiting in limbo for years until good evidence turns up—or points to another explanation.
About 13,000 years ago, the warming out of the last ice age temporarily reversed course around the North Atlantic. This cold “Younger Dryas” period lasted almost 2,000 years. Like most climate events that primarily affect the North Atlantic region, ocean circulation is the prime suspect.Jamming the conveyor
Global ocean circulation is a bit like a branching conveyor belt, with currents pushing water one way at the surface and allowing it to return along the bottom. In the Atlantic, surface currents move north until they grow salty and cold, at which point they stop being less dense than the underlying deep water. In several areas around Greenland, surface and deep waters can mix while a deepwater current heads off to the south.
Between 2018 and 2020, natural gas is expected to continue to eat away steadily at coal's share of the US energy mix, barring any regulatory intervention from the federal government.
The competition between natural gas and coal is especially fierce this summer: the former could set a record in terms of its contribution to overall US energy generation.
Another interesting prediction about fossil fuels: in 2018, the average price of a gallon of gasoline has been significantly higher than the year before, but that may not be great news for the oil industry, because drivers are already responding to higher prices. The amount of gas drivers will purchase in 2018 is expected to fall year over year for the first time since 2012. The contraction amounts to 10,000 barrels of oil per day not sold—a small change for the US economy but potentially a harbinger of things to come.
Poker players are familiar with hot streaks—times where it just seems the cards consistently fall their way. But we also talk about hot streaks when it comes to athletic skill, for things like hitting in baseball and shooting in basketball. Now, a group of researchers would like to add a few more activities where hot streaks take place: science, art, and movie making.
The researchers analyzed the production of high-impact work in those fields, and they find that it tends to cluster in a single time period. And, for most people, getting hot once is all they can hope for—getting hot twice is not common, and multiple hot streaks are extremely rare.Random or streaky?
The work was an attempt to make sense of two seemingly contradictory results from past studies. Some had suggested peak productivity in creative fields tended to occur in a cluster around the middle of people's careers. Other studies had indicated that people's best work seemed to occur randomly throughout their careers.
Pfizer has agreed to roll back a round of price increases from July 1 that affected more than 100 medicines after President Donald Trump called the company’s CEO and had an “extensive discussion,” the company announced Tuesday.
Now, Pfizer says it will return the drugs to their pre-July 1 list prices “as soon as technically possible,” and it will leave them there until either the President puts in place new healthcare policy or until the end of the year—whichever comes first.
The idea is to “give the president an opportunity to work on his blueprint to strengthen the healthcare system and provide more access for patients,” Pfizer said in its announcement.
This week we’re serializing yet another episode from the After On Podcast here on Ars. The broader series is built around deep-dive interviews with world-class thinkers, founders, and scientists, and it tends to be very tech- and science-heavy. You can access the excerpts on Ars via an embedded audio player, or by reading accompanying transcripts (both of which are below).
This week, my guest is British astronomer Stephen Webb. Webb has probably spent more time than anyone on this planet—with the possible exception of Frank Drake—pondering a fascinating subject known as Fermi’s Paradox.
This is the question of why can’t we detect any signs of intelligent alien life when we look to the skies. No signs of astro-engineering projects. No signatures of relativistic space travel. No obviously artificial electromagnetic waves, and so forth. And when you think of it, this is rather surprising. Or at least it was surprising to the ingenious physicist Enrico Fermi, who first drew attention to the matter.
We have a good idea of what makes individual cells old. Things like DNA damage, shortened chromosome ends, and a lack of proliferative ability can all cause cells to basically shut down—they don't die, but they stop dividing and become quiescent. But we don't have a strong sense of what makes an organism old. It could be the cumulative effect of lots of their cells getting old, or there may be additional means of registering an organism's age.
Now, a new study suggests at least part of the answer may be a mix of the two. The study, done using mice, indicates that having a small population of cells that have hit the wall due to aging can induce symptoms of age-related decline in otherwise young mice. And a drug combination that targets these cells can block these problems from taking root. The same drugs, when given to elderly mice, also reduce mortality and limit some of the symptoms of age.Senescent
Cells pick up damage all the time, either through environmental exposures or simply as a byproduct of their normal metabolism. If the damage is sufficiently critical, the cell will respond by committing an orderly sort of suicide called apoptosis, which keeps it from causing any further problems. For lesser damage, there's a less drastic alternative called senescence, in which the cell remains active and contributes its normal functions to the organism's health, but it commits to no longer dividing. Over time, as animals age, more and more cells enter senescence, a process that's thought to contribute to aging.
The most recent slippage of the James Webb Space Telescope, which now will launch no earlier than March, 2021, has raised some questions about how it will get into space. This is because NASA's chosen rocket for the mission, the proven Ariane 5 launcher, is likely to fly for only a few more years before it is phased out in favor of a newer, less expensive booster.
Back in 2015, when NASA formally reached an agreement with Arianespace to launch on the Ariane 5 rocket, the projected launch date was 2018. NASA partnered with the European Space Agency and its affiliated rocket company for the launch to keep costs down. Essentially, Europe provided a rocket in exchange for some of the observing time. The telescope's massive heat shield was then designed to fold 12 times to fit within the Ariane 5's payload fairing.
Last year, when the telescope's launch date was delayed into 2019, this was still no problem. But the telescope's launch has since been delayed twice more: first into 2020 and then into 2021. The Ariane 5 can still launch during these years. Further delays, however, may prove problematic.
On Tuesday, divers in Thailand completed the rescue of all 12 boys and their coach trapped in a flooded cave. And they did it without the aid of a tiny "submarine" that Elon Musk developed for possible use in the rescue mission.
Musk had a team of SpaceX engineers working feverishly over the weekend to construct the device. Thai officials began the rescue operation before Musk's team had completed his work. But Musk decided to complete the device anyway and personally flew to Thailand to deliver it to the rescue site.
According to The Guardian, when Musk arrived with his device, Thai officials made it clear that it wasn't needed. "Although his technology is good and sophisticated it’s not practical for this mission," said Narongsak Osatanakorn, the head of the joint command center coordinating the rescue effort. At that point, Thai officials had already finished rescuing at least eight of the 12 boys, and were already planning the third and final rescue mission.
A couple months ago, an atmospheric study revealed that someone had started producing an ozone-depleting pollutant that had been banned under an international agreement to protect the ozone layer. The new source was preventing the chemical from dissipating on schedule. Although the researchers were careful about what they could conclude from regional measurements, they found that eastern Asia was likely the source.
Now, a UK-based NGO called the Environmental Investigation Agency (EIA) says that it has uncovered a number of Chinese companies that are responsible. If you’re expecting an elaborate infiltration and undercover sting... adjust your expectations. The investigation seems to have been shockingly easy, with the culprits’ representatives strangely amenable to detailing their illegal operations.Mystery solved through Google
The EIA started with a simple Internet search, which turned up a few companies that were apparently advertising sales of the banned chemical, known as CFC-11. Like other CFCs, 11 can be used as a refrigerant or a propellant in aerosol spray cans. But it was also widely use to “inflate” foam insulation, and that seems to be the market where at least some of its illicit use has continued.
A Chinese battery company called Contemporary Amperex Technology Ltd (CATL) has chosen a site in eastern Germany to build a battery-cell factory that will help supply the country's major automakers as they shift to building more and more electric vehicles.
Volkswagen Group, BMW, and Daimler have all set targets to make and sell more electric vehicles in the coming years, but making the economics work out on battery supply has often proven elusive.
According to Agence France Presse (AFP), German Chancellor Angela Merkel will meet with Chinese Prime Minister Li Keqiang today in Berlin. Reuters notes that the Chinese prime minister will participate in a signing ceremony related to the decision to build a CATL factory in Erfurt, a city in the German province of Thuringia.
In May, a US delegation to the World Health Organization issued stunning trade and military threats in its opposition to a well-established and otherwise uncontroversial resolution encouraging breastfeeding, according to new reporting by The New York Times.
The hundreds of delegates in attendance expected an effortless approval of the resolution by the World Health Assembly, which is the decision-making body of WHO. The resolution simply put forth that mother’s milk is the healthiest option for infants and that countries should work to limit any misleading or inaccurate advertising by makers of breast-milk substitutes. It affirms a long-held position by the WHO and is backed by decades of research.
But more than a dozen participants from several countries—most requesting anonymity out of fear of US retaliation—told the Times that the American officials surprised health experts and fellow delegates alike by fiercely opposing the resolution. At first, the US delegates attempted to simply dilute the pro-breastmilk message, voiding language that called for governments to “protect, promote, and support breastfeeding” and limit promotion of competing baby food products that experts warn can be harmful. But when that failed, the US reportedly put the squeeze on countries backing the resolution by making aggressive trade and military threats—a move that further stunned the assembly.
If Lowell Observatory’s Gerard van Belle gets his way, someday soon you’ll be watching an exoplanet cross the face of its star, hundreds of light-years from the Earth. He can’t show you that right now, but he should be able to when the new mirrors are installed at the Navy Precision Optical Interferometer in northern Arizona. They're arriving now, and should soon start collecting starlight—and making it the highest-resolution optical telescope in the world.
Van Belle recently showed Ars around the gigantic instrument, which bears almost no resemblance to what a non-astronomer pictures when they hear the word “telescope." There are a couple of more traditional telescopes in dome-topped silos on site, including one built in 1920s in Ohio, where it spent the first few decades of its life.Going big
The best way to improve imagery on these traditional scopes is to increase the diameter of the mirror catching light. But this has its limits—perfect mirrors can only be built so large.
These are not the best of times for the Russian space industry. Due to budgetary reasons, Roscosmos has reduced the number of cosmonauts on the International Space Station from three to two. Because of technical problems with its rockets and cost pressure from SpaceX, the country's once-lucrative commercial launch industry is fading. And soon, conditions may worsen.
As soon as next year, the United States plans to stop paying hundreds of millions of dollars a year to Russia for Soyuz seats, because it is developing its own transport to the space station. And the European Space Agency has signaled that it will stop launching Russian Soyuz rockets from its French Guiana-based spaceport in the early 2020s.
Russian space editor Andrei Borisov has captured the fading zeitgeist of the Russian space program in a lengthy article on the new leader of Roscosmos, Dmitry Rogozin, and the changes he has proposed. "The 'Russian Space' Rogozin is trying to create reminds one of the Dark Ages in Europe," Borisov writes on Lenta.Ru, where he serves as editor of science and technology. "In it, there is no place for modernization, there is only the mission of survival."
Scuba divers in Thailand have already rescued four of the 12 boys who have been stranded, along with their coach, in a flooded cave. And they are hoping to rescue the rest in the next couple of days. But in the meantime, Elon Musk has continued working on alternative strategies divers could use if conventional diving proves too difficult the remaining boys.
On Saturday, Musk settled on the idea of building "a tiny, kid-size submarine using the liquid oxygen transfer tube of Falcon rocket as hull." He ordered SpaceX engineers to begin building the device, saying that it could be ready by the end of the day on Saturday.
Elon Musk tweeted on Saturday that a team of SpaceX engineers is hours away from completing work on a "tiny kid-sized submarine" that could be used to extract 12 teenagers and preteens who are stranded with their soccer coach in a flooded cave in Thailand. Musk has had a team of engineers working on the problem for the last couple of days and has been keeping the world updated on the work via Twitter.
On Thursday night, Musk tweeted about an idea to use an inflatable nylon tube to help the kids escape. By Friday afternoon, Musk's thinking had evolved. He tweeted that his team was working on building "double-layer Kevlar pressure pods with Teflon coating to slip by rocks." A mid-day tweet on Saturday provided another update:
Got more great feedback from Thailand. Primary path is basically a tiny, kid-size submarine using the liquid oxygen transfer tube of Falcon rocket as hull. Light enough to be carried by 2 divers, small enough to get through narrow gaps. Extremely robust.
— Elon Musk (@elonmusk) July 7, 2018
And this isn't just a theory: Musk says that his team is building the contraption now. "Construction complete in about 8 hours, then 17 hour flight to Thailand," Musk tweeted just before noon, California time.