The conventional wisdom of space exploration suggests that robotic probes are both more scientifically efficient and cost effective. Not so, argues a professor of planetary science.
Astronaut Edwin E. Aldrin Jr., lunar module pilot, poses beside the deployed flag of the United States during the Apollo XI moon landing July 20, 1969. [Reuters]
When the Space Shuttle Atlantis rolled to a stop in July 2011, NASA bid farewell to the nation's symbol of manned spaceflight. The Obama administration has scrapped NASA's plan to return humans to the Moon by 2020, which was behind schedule because of technical and budgetary problems. As financial constraints threaten the possibility of future ventures into outer space, many in the astronomical community are advocating for the increased use of unmanned robotic
space, arguing that they will serve as more efficient explorers of planetary surfaces
than astronauts. The next giant leap, then, will be taken with robotic feet.
At the core of Crawford's argument is that human beings are much better at performing the type of geological fieldwork that makes planetary exploration scientifically valuable: they're faster and significantly more versatile than even the most advanced autonomous probes. "People who argue for robotic exploration argue for more artificial intelligence, the capacity for robots to make more complex decisions that somehow leads to increased efficiency," explains Crawford. "But one of the things that make them cheap is miniaturization.You can make robots more intelligent and efficient to a certain point, but they wont get smaller and therefore cheaper." With miniaturization, he explains, comes a depletion in the number of scientific instruments a probe can carry, the number of samples it can collect, and its ability to cover more ground. " [Mars rovers] Spirit and Opportunity are fantastic things on Mars, but the fact that they've traveled as far in eight years as the Apollo astronauts traveled in three days speaks volumes." At a certain point, the costs of developing 'smarter' (but not better equipped) autonomous rovers will exceed the meager gains in scientific collection and outstrip existing scientific budgets.
The advantages of human over robot explorers are recognized in the planetary sciences community: a 2005 report by the Commission on the Scientific Case for Human Space Exploration noted that "the expert evidence we have heard strongly suggests that the use of autonomous robots alone will very significantly limit what can be learned about our nearest potentially habitable planet." Steve Squyres, the Principal Investigator for the Mars Exploration Rovers Spirit and Opportunity, conceded in his book Roving Mars that "[t]he unfortunate truth is that most things our rovers can do in a perfect sol [a martian day] a human explorer could do in less than a minute." But Crawford also expresses concerns over the capacity of robots for "making serendipitous discoveries."
"We may be able to make robots smarter, but they'll never get tot he point where they can make on the spot decisions in the field, where they can recognize things for being important even if you don't expect them or anticipate them," argues Crawford. "You can't necessarily program a robot to recognize things out of the blue."
The other downside of a shift towards robotic exploration is the decline of samples, the real meat of the planetary sciences. Robotic expeditions have always been one-way trips: the probes go, land, take readings, and don't come back. But the collection and prolonged study of planetary samples are real drivers of scientific knowledge, which Crawford measures in terms of published scientific literature:
Several things are immediately apparent from Figure 2. Most obvious is the sheer
volume of Apollo's scientific legacy compared to the other missions illustrated. This
alone goes a long way to vindicate the points made above about human versus robotic
efficiency. The second point to note is that the next most productive set of missions
are the lunar sample return missions Lunas 16, 20 and 24, which highlights the
importance of sample return. Indeed, a large part of the reason why Apollo has
resulted in many more publications than the Luna missions is due to the much larger
quantity and diversity of the returned samples which, as we have seen, will always be
greater in the context of human missions. The third point to note is that, despite being
based on data obtained and samples collected over 40 years ago, and unlike the Luna,
Lunokhod, or Surveyor publications, which have clearly levelled off, the Apollo
publication rate is still rising. Indeed, it is actually rising as fast as, or faster than, the
publications rate derived from the Mars Exploration Rovers, despite the fact that data
derived from the latter are much more recent. No matter how far one extrapolates into
the future, it is clear that the volume of scientific activity generated by the MERs, or
other robotic exploration missions, will never approach that due to Apollo.
"We're still benefiting from the scientific legacy of those few soil samples brought by the Apollo mission, but we can only do this because we went to the Moon, got these samples, and came back," says Crawford. "If we sent a rover to Mars along with a return vehicle, that would enormously increase its scientific impact, but that's hasn't been implemented yet because its still incredibly expensive. If a mission goes to Mars, lands in one place, bring back half a kilogram of Mars rocks, it will be immensely valuable, but compared to Apollo, which not only visited six sites (and many hundred of sites with the help of the lunar rover) but came back with 382 kilograms of lunar material, it sort of pales in comparison."
While robotic probes find a permanent home on a planetary surface, sending manned expeditions inherently means planning for a return trip. Would a manned trip to Mars, replete with a sample-laden return vehicle, yield a similar explosion in scientific literature? Crawford thinks so. "A Martian expedition would be 5 or 10 times more expensive than Apollo in real terms, but not so much more expensive that it would negate the added benefit of being able to collect samples. They'll bring back a much larger quantity and diversity of samples than a robotic mission, and this is especially important with regards to Mars: there are reasons for wanting more lunar samples, but Mars is a much bigger and much more geologically diverse planet, with a much more complicated geology so much more inconceivably complicated history than the Moon, we won't get a full sense of its history or evolution just by scraping around on the surface with these smalls robot probes."
The scientific impact of these moon rocks is compelling: our whole
chronology of the solar system is built on the radiometric dating of the
Apollo samples. "The top scientific benefit is that it's been possible
to date areas of the lunar surface. We have this curve that plots crater density versus age, which we can use to get an estimated age of
virtually anywhere else in the Solar System," explains Crawford.
"The last major eruption of Olympus Mons [on Mars] was 400 million years
ago, and the only way we have this measurement is because of Apollo
So why, then, are scientists resigned to sending probes and rovers to the corners of the galaxy? Scientists, argues Crawford, tend to look at the enormous costs for Apollo, which nobody will ever be able to afford again, as an artificial baseline for gradual streamlining of space exploration. This is the wrong approach to take "There's lots of collective amnesia as to how efficient Apollo really was, which is really the only example of exploring the surface of another planet," explains Crawford. "An enormous amount was achieved in a very short total contact time with the lunar surface."
Planners feel the microscopic formations in Mars meteorite ALH84001, found in Antarctica, and the highly diverse samples of rocks believed to have been strewn about by ancient rivers seen at the Mars Pathfinder landing site, provide a strong motive for sending human exobiologists and geologists to the Red Planet. [Pat Rawlings/NASA]
But Crawford recognizes that, despite its benefits for scientific research, manned missions are subject to domestic forces and rarely undertaken for the sake of science alone. The United States was willing to shoulder the enormous costs of the Apollo mission because of the geopolitical and economic interests (namely, besting the Soviet Union), an argument advanced most recently by science communicator Neil DeGrasse Tyson.
"Science was the beneficiary of a human spaceflight mission that was undertaken for geopolitical purposes," explains Crawford. "The total costs is large, but the best way for scientists to look at it is not 'this is a science function.' They need to look at Apollo as the confluence of geopolitical, industrial, and social factors. You need all of these things to spend the money necessary."
Crawford's theory, then, is not necessarily targeted towards the general public: he recognizes the difficulty of justifying an expensive manned mission with no immediate economic benefit (although he notes notes that the 1987 NASA procurement of $8.6 billion generated a turnover of $17.8 billion and created 209,000 private sector jobs, according to an article in Nature), especially in the throes of an global economic downturn. His main argument, then is those scientists consigning themselves to a future of interstellar probes are shooting themselves in the foot. Ventures like the James Webb Space Telescope may hit the ceiling for government expenditures on purely scientific ventures, but researchers and scientists can -- and should -- try to make the case for manned spaceflight in other contexts, if only for the sake of maximizing the scientific gains made from planetary exploration.
"Humans bring a net benefit to space exploration that, in my opinion, outweighs the costs," says Crawford. "But people need to realize that the overall case for manned spaceflight is multifaceted, a totality woven out of these different strands, of which science is one. Industry, innovation, inspirational value -- all of these factors must be addressed before manned spaceflight can return."
People labeled “smart” at a young age don’t deal well with being wrong. Life grows stagnant.
ASPEN, Colo.—At whatever agesmart people develop the idea that they are smart, they also tend to develop vulnerability around relinquishing that label. So the difference between telling a kid “You did a great job” and “You are smart” isn’t subtle. That is, at least, according to one growing movement in education and parenting that advocates for retirement of “the S word.”
The idea is that when we praise kids for being smart, those kids think: Oh good, I'm smart. And then later, when those kids mess up, which they will, they think: Oh no, I'm not smart after all. People will think I’m not smart after all. And that’s the worst. That’s a risk to avoid, they learn.“Smart” kids stand to become especially averse to making mistakes, which are critical to learning and succeeding.
The social network learns more about its users than they might realize.
Facebook, you may have noticed, turned into a rainbow-drenched spectacle following the Supreme Court’s decision Friday that same-sex marriage is a Constitutional right.
By overlaying their profile photos with a rainbow filter, Facebook users began celebrating in a way we haven't seen since March 2013, when 3 million peoplechanged their profile images to a red equals sign—the logo of the Human Rights Campaign—as a way to support marriage equality. This time, Facebook provided a simple way to turn profile photos rainbow-colored. More than 1 million people changed their profile in the first few hours, according to the Facebook spokesperson William Nevius, and the number continues to grow.
“This is probably a Facebook experiment!” joked the MIT network scientist Cesar Hidalgo on Facebook yesterday. “This is one Facebook study I want to be included in!” wrote Stacy Blasiola, a communications Ph.D. candidate at the University of Illinois, when she changed her profile.
The Islamic State is no mere collection of psychopaths. It is a religious group with carefully considered beliefs, among them that it is a key agent of the coming apocalypse. Here’s what that means for its strategy—and for how to stop it.
What is the Islamic State?
Where did it come from, and what are its intentions? The simplicity of these questions can be deceiving, and few Western leaders seem to know the answers. In December, The New York Times published confidential comments by Major General Michael K. Nagata, the Special Operations commander for the United States in the Middle East, admitting that he had hardly begun figuring out the Islamic State’s appeal. “We have not defeated the idea,” he said. “We do not even understand the idea.” In the past year, President Obama has referred to the Islamic State, variously, as “not Islamic” and as al-Qaeda’s “jayvee team,” statements that reflected confusion about the group, and may have contributed to significant strategic errors.
The question is at the center of the Greek crisis.
In 1961, the economist Robert Mundell published a paper laying out, per the title, “A Theory of Optimum Currency Areas.” In it, he inquired about the appropriate geographic extent of a shared unit of money. Was it the world? A country? Part of a country? A border-spanning region of, say, the western parts of the United States and Canada, with a separate currency circulating in the eastern parts of the two countries?
“It might seem at first that the question is purely academic,” he wrote, “since it hardly seems within the realm of political feasibility that national currencies would ever be abandoned in favor of any other arrangement.” But it was worth considering anyway, in part because “certain parts of the world are undergoing processes of economic integration and disintegration,” and an idea of what an “optimum currency area” would look like could help “clarify the meaning of these experiments.”
For centuries, experts have predicted that machines would make workers obsolete. That moment may finally be arriving. Could that be a good thing?
1. Youngstown, U.S.A.
The end of work is still just a futuristic concept for most of the United States, but it is something like a moment in history for Youngstown, Ohio, one its residents can cite with precision: September 19, 1977.
For much of the 20th century, Youngstown’s steel mills delivered such great prosperity that the city was a model of the American dream, boasting a median income and a homeownership rate that were among the nation’s highest. But as manufacturing shifted abroad after World War II, Youngstown steel suffered, and on that gray September afternoon in 1977, Youngstown Sheet and Tube announced the shuttering of its Campbell Works mill. Within five years, the city lost 50,000 jobs and $1.3 billion in manufacturing wages. The effect was so severe that a term was coined to describe the fallout: regional depression.
As sunny and smiley as gyms’ front-desk employees can be, they’re covering up a secret that keeps the industry going: Once you’ve signed up for a membership, they don’t want you to come in very often.
In fact, gyms are set up to entice the type of customer who will prepay for months or years and then rarely show up. In order to make money, private clubs need to bring in about 10 times as many members as their weight and cardio rooms can accommodate at any given time. This fact ends up shaping the way gyms are designed as physical spaces. In order to attract the type of people who will buy a membership but probably never work out with any regularity, designers give gyms sleek, hotel-like lobbies where membership paperwork is handled. Meanwhile, the intimidating equipment is kept in the back, out of sight—along with the sometimes intimidating brutes who grunt while using them.
The country's inability to pay its debt or reach a deal makes it the largest nation in history to be in arrears to the IMF.
What happens now?
Greece’s missed payment to the IMF is a milestone—it’s both the first time a developed country has missed such a payment, and the first time a Eurozone country has defaulted on its debt. (Or it’s “in arrears”—as Bouree Lam explains below, the IMF isn’t using consistent terminology.)
But that doesn’t mean automatic expulsion from the Eurozone. Yanis Varoufakis, the country’s finance minister, made the case on his blog three years ago that “a defaulted Greece can easily remain in the Eurozone,” and that in fact “Europe’s optimal strategy is to let Greece default.” The Lisbon Treaty, which forms the legal basis of the European Union, actually makes no provision for a member’s expulsion. A 2009 legal analysis by the ECB found that, “while perhaps feasible through indirect means, a Member State’s expulsion from the EU or EMU [the European Monetary Union], would be legally next to impossible.”
The second episode of the new season was a slow burner with a dramatic twist.
Let’s start at the beginning, with Frank in bed with his wife, Jordan, discussing water stains on the ceiling and childhood entombments. I don’t know about you guys, but I found this whole bit slack and familiar. Maybe there was a two-minute scene in there, but five? Maybe a more charismatic actor could have pulled off that lengthy monologue. But Vince Vaughn is no Robert Shaw, and his childhood basement is no U.S.S. Indianapolis.
The star has been accused of having a “large blind spot” on issues of race—but testing the boundaries of jokes is part of the process of stand-up.
There’s a fine line in comedy between subversive and offensive, and with every meteoric rise from stand-up to film and television stardom these days, there tends to be controversy over whether or not that line has ever been crossed. Amy Schumer, whose Comedy Central sketch show Inside Amy Schumer has been dominating the Internet on a weekly basis since its third season debuted in April, and who stars in the upcoming Judd Apatow comedy Trainwreck, is the latest figure to experience the pitfalls of being under such sharp scrutiny. A recent profile of Schumer in The Guardian by Monica Heisey, although largely positive, criticizes the comedian for having a “shockingly large blind spot” on race—and cites some clunky jokes she’s made about Latinos as examples.
The power in the president’s eulogy for Clementa Pinckney came not from his singing, but from the silence that preceded it.
Coverage of the memorial service held for Reverend Clementa Pinckney in Charleston last week focused largely on the surprising moment when the leader of the free world broke into song. That song, of course, was “Amazing Grace” and the president sang it distinctly in the style of the black church.
For all the attention Obama’s unexpected performance received, though, it’s worth taking another look at the “Amazing Grace” clip, this time watching for the silence. His singing seems to be a release of the collective tension that had been building for a week after the Emanuel A.M.E. shooting. But the preceding pause seems to hold its hearers captive. Though he is frequently interrupted with cheers and amens throughout his eulogy for Reverend Pinckney, the pause he takes 35 minutes into the speech is easily the longest break from the text before him.