The engine burn was tense. 35 minutes is a long time for a spacecraft burn; after 20 minutes it had slowed Juno enough to be in orbit, but not the correct one. It had to continue for another 15 minutes to put the spacecraft on the correct orbit. It worked essentially perfectly. The burn time was off by just one second. That will have no real effect on the orbit.
The 35-minute burn slowed Juno down by more than 1200 mph.
How old are different parts of our bodies? Does anything stick around the entire time? The hair on our bodies lasts only a few years. Fingernails are fully replaced every six months. Your skin lasts 2-4 weeks. Even your blood and bones regenerate every so often. There’s at least one part of your body with lasts the whole time you’re alive, which I found somewhat surprising. See the ship of Theseus paradox.
The ship wherein Theseus and the youth of Athens returned from Crete had thirty oars, and was preserved by the Athenians down even to the time of Demetrius Phalereus, for they took away the old planks as they decayed, putting in new and stronger timber in their places, in so much that this ship became a standing example among the philosophers, for the logical question of things that grow; one side holding that the ship remained the same, and the other contending that it was not the same.
Analysis of growth rings from pine trees in Sweden shows that the proliferation of atomic tests in the 1950s and 1960s led to an explosion in levels of atmospheric carbon 14. Now, Jonas Frisen and colleagues at the Karolinska Institute in Stockholm have taken advantage of this spike in C14 to devise a method to date the birth of human cells. Because this test can be used retrospectively, unlike many of the current methods used to detect cell proliferation, and because it does not require the ingestion of a radioactive or chemical tracer, the method can be readily applied to both in vivo and postmortem samples of human tissues.
Launched from Earth in August 2011, the Juno probe is due to arrive at Jupiter on July 4, 2016. Once there, it will circle Jupiter 37 times, observing its atmosphere and magnetic fields, before plunging into the giant planet so as not to contaminate Europa with microbes.
Juno’s principal goal is to understand the origin and evolution of Jupiter. Underneath its dense cloud cover, Jupiter safeguards secrets to the fundamental processes and conditions that governed our solar system during its formation. As our primary example of a giant planet, Jupiter can also provide critical knowledge for understanding the planetary systems being discovered around other stars.
With its suite of science instruments, Juno will investigate the existence of a solid planetary core, map Jupiter’s intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet’s auroras.
Juno will let us take a giant step forward in our understanding of how giant planets form and the role these titans played in putting together the rest of the solar system.
After an unbelievably stressful and busy winter/spring, I am hoping to find some time to read this summer. One of the books on my short list is Sean Carroll’s The Big Picture, one of those “everything is connected” things I love. From a post by Carroll on what the book’s about:
This book is a culmination of things I’ve been thinking about for a long time. I’ve loved physics from a young age, but I’ve also been interested in all sorts of “big” questions, from philosophy to evolution and neuroscience. And what these separate fields have in common is that they all aim to capture certain aspects of the same underlying universe. Therefore, while they are indisputably separate fields of endeavor — you don’t need to understand particle physics to be a world-class biologist — they must nevertheless be compatible with each other — if your theory of biology relies on forces that are not part of the Standard Model, it’s probably a non-starter. That’s more of a constraint than you might imagine. For example, it implies that there is no such thing as life after death. Your memories and other pieces of mental information are encoded in the arrangement of atoms in your brain, and there’s no way for that information to escape your body when you die.
Telling left from right necessitates complex brain processes that include spatial perceptions, memory, language, and the integration of sensory information. The task is made increasingly complex when a person must identify laterality on someone else. Yoga teachers and other fitness instructors have it extra rough: While calling out to students to bend their left knee, the instructor has to raise their own right to mirror the class…
However, the field under the most pressure to avoid lateral confusion is medicine. In the dentist’s chair, there’s money wasted when hygienists x-ray the wrong tooth. It’s even worse when a left-right-disoriented dentist pulls one or more teeth from the incorrect side of the mouth. It’s even more serious in general surgery: A 2011 report estimates that there are 40 wrong-site surgeries done weekly in the U.S., and many of those involve mixing up a patient’s left and right. This is a devastating problem: If a doctor removes the healthy kidney and not the cancerous one, the results can be fatal. Wrong eye? Now we have a fully blind patient.
This plays a little easier when you’re playing off objects with fixed positions, like landmarks, or especially, the sun, than it does in big twisty-turny cities. But you could imagine in a world with ubiquitous handheld maps and compasses that a north/south/east/west orientation might make more sense.
What’s more, some of the old tech people used to train themselves to distinguish or remember left and right — miming handwriting, or wearing a wristwatch on one arm — aren’t as common or dominant as they once were. See also: distinguishing angular position by analogy with the face of an analog clock.
Either we come up with new tricks and new metaphors, or it’s conceivable that what’s seemed like an intuitive, natural way to think about the relative position of bodies in space could become a whole lot less intuitive for more and more people.
This question is very important for the entertainment industry: does it matter whether you’re right, when you’re telling a story to entertain? Under some circumstances, I don’t think it matters. But with an animated movie about real, living systems, when you use the truth — their complexity and beauty — as a springboard for the story, you add a level of gravitas that is vitally important to creating a broad and deep appeal. A young audience is much more sophisticated than you think, and a story informed by a lot of facts alerts them to the presence of real concepts. I got an e-mail from an eight-year-old about Finding Nemo, explaining that characters could not emerge from a whale’s blowhole if they were in its mouth, because there is no link between the trachea and the oesophagus.
There are over 100 inaccuracies in Finding Nemo, but Summers says only one is a genuine error. (He doesn’t name it, but it might be Mr. Ray, who lists names of classes in his song about aquatic species.) Everything else, from the whale’s blowhole to ignoring clownfish’s ability to switch between male and female (although what if Marlin does become female, but just never spawns again?) is an intentional gloss or omission for storytelling purposes.
Or aesthetic ones. “The claspers — external, stick-like sexual organs on sharks — were cut off Bruce the great white shark,” says Summers, “not because of family values, but because he’s spherical, and when you add a bunch of sticks to spherical sharks, they look really stupid.” Noted.
Summers admits there’s also just a lot about the species in Pixar’s fish movies that nobody really knows.
They did ask me some questions about the biology of whale sharks (Rhincodon typus) that we just don’t know the answers to. It’s the largest fish in the sea, yet I think there’s just one record of a pregnant female, which revealed that they can have more than 300 pups at a time. That’s not much to know about the reproductive biology of such an iconic fish.
Tim Doucette is a legally blind astronomer. A pair of surgeries when he was younger to help improve his vision left him with a superpower: because his pupils were permanently dilated, he could see in the dark better than other people. He built an observatory and with the aid of his telescope, he can see details of far-off stars and nebula that no one else can, including UV and infrared light.
Siddhartha Mukherjee has a written a biography of the gene as deft, brilliant, and illuminating as his extraordinarily successful biography of cancer. Weaving science, social history, and personal narrative to tell us the story of one of the most important conceptual breakthroughs of modern times, Mukherjee animates the quest to understand human heredity and its surprising influence on our lives, personalities, identities, fates, and choices.
This book filled in a number of gaps in my knowledge, plus it is engaging to read. Overall it confirmed my impression of major advances in the science, but not matched by many medical products for general use.
This is on the must-read list this summer. Somehow. When I get a second.
Kurzgesagt and CGPGrey collaborated on a pair of videos about the self. The first video considers the human being as a collection of cells. How many of those cells can you take away before you stop being you? And does that question even make sense? The second video notes that if you sever the connection between the two halves of the human brain, they will each seemingly continue to operate as separate entities. But which of those entities is you? Are there two yous?
The B-2 stealth bomber has a length of 69 feet and a wingspan of 172 feet but possesses the radar profile of a large bird. How does the plane evade radar so effectively?
In the 90s, Bruniquel Cave was discovered to have a chamber containing an interesting human-built structure made from broken stalagmites. Carbon dating of a burnt bear bone within the chamber put the age of the activity at 47,600 years ago, smack dab in the Neanderthal era in that area. But recently, after a lull in research about these cave structures, analysis of uranium levels in the broken stalagmites resulted in a much older date for the construction: 176,500 years ago.
Nor is it clear how the Neanderthals made the structures. Verheyden says it couldn’t have been one lone artisan, toiling away in the dark. Most likely, there was a team, and a technically skilled one at that. They broke rocks deliberately, and arranged them precisely. They used fire, too. More than 120 fragments have red and black streaks that aren’t found elsewhere in the chamber or the cave beyond. They were the result of deliberately applied heat, at intensities strong enough to occasionally crack the rock. “The Neanderthal group responsible for these constructions had a level of social organization that was more complex than previously thought,” the team writes.
Jller is a machine that sorts stones from a specific river according to their geologic age.
The machine works with a computer vision system that processes the images of the stones and maps each of its location on the platform throughout the ordering process. The information extracted from each stone are dominant color, color composition, and histograms of structural features such as lines, layers, patterns, grain, and surface texture. This data is used to assign the stones into predefined categories.
After The Man freaked out back in the 60s, LSD and other psychedelics were banned and criminalized. But slowly, scientists are experimenting with psychedelics to treat depression, anxiety, and other ailments.
In the 1960s, a psychologist and former Harvard teacher named Timothy Leary coined the phrase ‘Turn on. Tune in. Drop out.’ The slogan was inspired by advertising jingles, but Leary wasn’t pushing a product, he was promoting a drug: LSD.
But today, scientists are studying psychedelics once again, in the latest twist in the long, strange story of LSD.
Even outside of a therapeutic setting, many people extolled the beneficial effects of psychedelics. Former Apple CEO Steve Jobs recalled in his biography by Walter Isaacson:
Taking LSD was a profound experience, one of the most important things in my life. LSD shows you that there’s another side to the coin, and you can’t remember it when it wears off, but you know it. It reinforced my sense of what was important — creating great things instead of making money, putting things back into the stream of history and of human consciousness as much as I could.
If you’re clever, you can take normal sand or dirt and support really heavy things with it. Near the end of this video, a small block of reinforced sand holds up a car wheel with absolutely no difficulty.
In the story from classical Greece, Pandora was warned: Don’t open the box. She opens it anyway. The various pestilences are unleashed on the world but Hope remains at the very bottom of the box. Today there are microbiologists who want to continue to research smallpox. If they are given a free hand, what might they unleash?
There are those who insist that these residual stocks of smallpox should not be destroyed because some ruthless super-criminal or rogue government might be working on a new smallpox, even more virulent than existing strains of the virus. We may need existing stocks to produce new vaccines to counteract the new viruses. New viruses, new vaccines. New vaccines, new viruses. An escalating arms race with germs.
Keep this video in mind when you read about the latest advances with CRISPR.
I’m going to embed the video here, even though it seems like every time I embed a video from anywhere but YouTube or Vimeo, it either autoplays or, even worse, autoplays with the sound on. Also, while I was watching on the Times’ site, the video was glitchy and stopped twice, prompting two reloads. I get why the Times (and other media outlets) want to develop their own embeddable media, but until they get it right, they should leave it to Vimeo and YouTube, the only two sites who have actually gotten it right.↩
A new video from Kurzgesagt explores the limits of human exploration in the Universe. How far can we venture? Are there limits? Turns out the answer is very much “yes”…with the important caveat “using our current understanding of physics”, which may someday provide a loophole (or wormhole, if you will). Chances are, humans will only be able to explore 0.00000000001% of the observable Universe.
This video is particularly interesting and packed with information, even by Kurzgesagt’s standards. The explanation of the Big Bang, inflation, dark matter, and expansion is concise and informative…the idea that the Universe is slowly erasing its own memory is fascinating.
On Last Week Tonight last night, John Oliver took the media’s often shoddy coverage of science to task. Like cherry picking the results of single studies that “prove” that chocolate prevents cancer and that sort of thing.
As a somewhat reluctant member of “the media”, I’ve been guilty of this sort of behavior to varying degrees in the past. In the last few years, I’ve been working to improve on this count — by reading studies, declining to post stuff that doesn’t make the grade, reading what other trusted media sources are saying, using softer language like “could” or “may” instead of “does”, distinguishing between correlation and causation — but I still make mistakes.
At a certain point though, you have to rely on the scientific literacy of your readers. I can’t explain the scientific process to everyone every single time. At some point, I need to assume we’re all taking the results of studies with a similarly sized grain of salt.
In the end, I love science and I want you to love it too. That’s why I often write about it, about the history of how we came to know what we know, about the limits of our knowledge, and, especially, about efforts to push beyond the boundaries of the known. There’s always the temptation to gussy science up, to fit the facts to my world view. But deep down, I know that’s unnecessary — science is awesome all by itself! — and harms the goal of increasing scientific literacy and interest. I’m gonna trying reminding myself of that more in the future.
15-year-old Canadian William Gadoury has translated his interest in the Mayan civilization into two remarkable discoveries. Gadoury noticed that the locations of the biggest Mayan cities matched the locations of the stars in Mayan constellations. Furthermore, the star charts pointed to the existence of a previously unknown city, the ruins of which have since been uncovered by satellite photography.
“I did not understand why the Maya built their cities away from rivers, on marginal lands and in the mountains,” said Gadoury. “They had to have another reason, and as they worshiped the stars, the idea came to me to verify my hypothesis. I was really surprised and excited when I realized that the most brilliant stars of the constellations matched the largest Maya cities.”
Someone start a Kickstarter campaign so that he can visit those ruins! (via @delfuego)
Update: Due to a mislabeled file on Wikipedia, I used a photo of an Aztec compass instead of a Mayan image. I have replaced with an image of the Mayan zodiac.
Also, per my post about media coverage of science yesterday, I’ll point out quickly that there’s much to be skeptical about re: this story (see this post from a Mesoamerican archaeologist). More likely than not, there’s a Mayan scholar mailing list going bananas right now…I’ll let you know if I hear anything specific.
The rectangular feature seen on satellite is likely an old corn field (it’s not the right shape to be a pyramid). There are indeed ancient Maya sites all over the place, and satellite imagery and LiDAR are being used to discover them, but this doesn’t seem to be one of those cases…
On the bright side, the “if it sounds too good to be true, it probably is” study has been successfully replicated again. Science rolls on…
Jimmy Kimmel had some scientists on his show recently to tell the American public that anthropogenic climate change is real, that’s it’s not a prank, and that the scientific community is “not fucking with you” about this. Trigger warning: the first minute of this video features Sarah Palin speaking.
The latest video from Kurzgesagt is on space elevators. How would you build one? Why not just keep launching rockets into space instead? Would be easier to build one on the Moon first?
In the past two weeks, the results of three surveys and studies about the Earth’s climate have been released: a paper on a possible dramatic climate shift, a survey of coral bleaching at the Great Barrier Reef, and a study on the West Antarctic ice sheet. All three investigations tell the story of climate change happening quicker than was previously anticipated.
Virtually all climate scientists agree with Dr. Hansen and his co-authors that society is not moving fast enough to reduce emissions of greenhouse gases, posing grave risks. The basic claim of the paper is that by burning fossil fuels at a prodigious pace and pouring heat-trapping gases into the atmosphere, humanity is about to provoke an abrupt climate shift.
Scientists who have dedicated their careers to studying the reef and its ecosystem say the current bleaching is unprecedented, and perhaps unrecoverable. The emotion in their responses so far have been palpable.
“I witnessed a sight underwater that no marine biologist, and no person with a love and appreciation for the natural world for that matter, wants to see,” said Australian coral scientist Jodie Rummer in a statement, after spending more than a month at a monitoring station in the Great Barrier Reef.
Though corals comprise only about 0.2 percent of the global oceans, they support perhaps a quarter of all marine species.
The great ice sheet, larger than Mexico, is thought to be potentially vulnerable to disintegration from a relatively small amount of global warming, and capable of raising the sea level by 12 feet or more should it break up. But researchers long assumed the worst effects would take hundreds — if not thousands — of years to occur.
Now, new research suggests the disaster scenario could play out much sooner.
Continued high emissions of heat-trapping gases could launch a disintegration of the ice sheet within decades, according to a study published Wednesday, heaving enough water into the ocean to raise the sea level as much as three feet by the end of this century.
You can think of the Earth as a massive machine, with many interconnected, resilient, and redundant systems. For a long time, humans thought it was too big for our actions to affect this machine in a meaningful way. But the Industrial Revolution’s release of hundreds of millions of years of stored greenhouse gases in less than 300 years put a strain on that entire machine. We didn’t notice that strain for a long time, but we’re starting to now in the form of higher temperatures, weird weather, bleaching coral reefs, rapidly melting ice sheets in Greenland & Antarctica, and dozens of other ways. I hope there’s still time to do something meaningful about it before the slower moving parts of the machine fail permanently.
In 1989, a Rockwell engineer named Ron Jones published his Integrated Space Plan, a detailed outline of the next 100 years of human space travel, from continuing shuttle missions in the 1990s to the large scale habitation of Mars. The plan includes all sorts of futuristic and day-dreamy phrases like:
Create new moons for Mars if required
Humanity begins the transition from a terrestrial to a solar species
Humanity commands unlimited resources from the Moon and asteroids
Space drives global economy
Independent spacefaring human communities
The graphic is divided into nine columns that show, in chronological order, the path toward human exploration of deep space. The center row of boxes, the “critical path,” outlines the major milestones Jones decided were attainable within the next century of space travel; the boxes to the left and right of the critical path are support elements that must be realized before anything on the critical path can happen. The Integrated Space Plan can be read top to bottom and left to right. The big circles intersecting the boxes are the the plan’s overarching long-range goals, which include things like Humanity begins the transition from a terrestrial to a solar species and Human expansion into the cosmos. In many ways, it’s a graphical to-do list.
The keen observer will note that we are waaaaay behind in the plan. A lunar outpost was supposed to be up and running before 2008 and a self-supporting lunar base is due to happen in the next year or two. Can Musk and Bezos get us back on track? (via @ftrain)
Stewart Brand wrote a summary of a seminar given by Jane Langdale about how the efficiency of photosynthesis might be improved for some of the world’s plants, particularly rice.
Most plants use what’s called C3 photosynthesis to produce sugars and starch, but the process is not very efficient. Some plants, like corn and sugarcane, have evolved the capability to produce sugars and starch using the much more efficient C4 photosynthesis process. So if you could modify rice to use C4 instead of C3, yields would increase dramatically.
Rice is a C3 plant — which happens to be the staple food for half the world. If it can be converted to C4 photosynthesis, its yield would increase by 50% while using half the water. It would also be drought-resistant and need far less fertilizer.
You can read more about the efforts in developing C4 photosynthesis in Technology Review.
Randall Munroe’s best-selling Thing Explainer, in which he explains scientific concepts using only the 1000 most common words, will be incorporated into the upcoming editions of some of Houghton Mifflin Harcourt’s high school science textbooks.
Mr. Munroe, 31, said the project appealed to him. He recalled as a child a foldout diagram showing different animals at the starting line of a race and then sprinting/flying/crawling to show the different speeds of different species. “For some reason, I fixated on that illustration,” he said. “It stuck with me my entire life.”
Mr. Munroe said he hoped his drawings would break up the monotony and pace of a typical textbook. “I’m hoping it will be, ‘Oh, here’s a kind of fun and unexpected component,’” he said.
Virtually all climate scientists agree with Dr. Hansen and his co-authors that society is not moving fast enough to reduce emissions of greenhouse gases, posing grave risks. The basic claim of the paper is that by burning fossil fuels at a prodigious pace and pouring heat-trapping gases into the atmosphere, humanity is about to provoke an abrupt climate shift.
Non-linear systems, man. Gradually, then all at once.
In addition to the risk of “several meters” of sea level rise this century, which Hansen calls the most important finding, the final version of Hansen’s paper gives new emphasis to the possibility that the ocean’s heat circulation system may be in the process of shutting down. The circulation shutdown would precede the rapid increase in global sea levels. If the shutdown happens, simultaneous cooling of the waters near Greenland and Antarctica and warming in the tropics and midlatitudes could spawn frequent strong storms on the order of Hurricane Sandy or worse.
Mathematicians have calculated pi out to more than 13 trillion decimal places, a calculation that took 208 days. NASA’s Marc Rayman explains that in order to send out probes and slingshot them accurately throughout the solar system, NASA needs to use only 15 decimal places, or 3.141592653589793. How precise are calculations with that number? This precise:
The most distant spacecraft from Earth is Voyager 1. It is about 12.5 billion miles away. Let’s say we have a circle with a radius of exactly that size (or 25 billion miles in diameter) and we want to calculate the circumference, which is pi times the radius times 2. Using pi rounded to the 15th decimal, as I gave above, that comes out to a little more than 78 billion miles. We don’t need to be concerned here with exactly what the value is (you can multiply it out if you like) but rather what the error in the value is by not using more digits of pi. In other words, by cutting pi off at the 15th decimal point, we would calculate a circumference for that circle that is very slightly off. It turns out that our calculated circumference of the 25 billion mile diameter circle would be wrong by 1.5 inches. Think about that. We have a circle more than 78 billion miles around, and our calculation of that distance would be off by perhaps less than the length of your little finger.
When was humanity’s calculation of pi accurate enough for NASA? In 1424, Persian astronomer and mathematician Jamshid al-Kashi calculated pi to 17 digits.
There are some things that humans don’t need to survive anymore still hanging around on our bodies, including unnecessary arm muscles and vestigial tail bones.
The latest video from Kurzgesagt is an explainer on antibiotics and superbugs (drug resistant bacteria).
What would you say if we told you that humanity is currently making a collaborative effort to engineer the perfect superbug, a bug that could kill hundreds of millions of people?
Agaricus bisporus has increased in popularity in North America with the introduction of two brown strains, Portabella (sometimes also spelled portobello, portabello, or portobella) and Crimini. The three mushrooms you see to the right are all actually the same species. Portabella is a marketing name the mushroom industry came up with for more flavorful brown strains of Agaricus bisporus that are allowed to open to expose the mature gills with brown spores; crimini is actually the same brown strain that is not allowed to open before it is harvested.
See also the magical Brassica oleracea plant (cabbage, kale, broccoli, brussels sprouts, kohlrabi, collard greens, and cauliflower are all the same species of plant). (via @dunstan)
First contact with an alien civilization will be a momentous event in the history of Earth. Unless the other civilization is kind of a dick. Tim Urban didn’t quite cover this scenario in his post about the Fermi Paradox.
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