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10 Aug 00:16

Geologic Time

Ok, well, we'll be sure to pay you sometime soon, geologically speaking.
14 May 22:32

Moving Giant Concrete Blocks With Just Your Hands

by twistedsifter

moveable concrete blocks by matter design 4 Moving Giant Concrete Blocks With Just Your Hands

 

Design studio and research lab, Matter Design, partnered with CEMEX Global R&D to explore the idea of moveable concrete assemblages for possible use in hard to reach areas or situations where heavy machinery is not available or accessible.

In a project called Walking Assembly, Matter Design adds:

 

The mysterious knowledge surrounding the transportation and placement of megalithic structures of the past eludes contemporary building practices. Walking Assembly re-introduces the potentials of that ancient knowledge to better inform the transportation and assembly of future architectures. If a brick is designed for a single hand, and a concrete masonry unit (CMU) is designed for two, these massive masonry units (MMU) unshackle the dependency between size and the human body.
 
Intelligence of transportation and assembly is designed into the elements themselves, liberating humans to guide these colossal concrete elements into place. Structures that would otherwise rely on cranes or heavy equipment can now be intelligently assembled and disassembled with little energy. By using variable density concrete, the center of mass of the object is calibrated precisely to control the stable, but easy motion of the elements. This ensures that these massive elements successfully walk and assemble into place, creating the possibility for a crane-less tilt up construction method and turning our building sites into spectacles of play.

 

 

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moveable concrete blocks by matter design 8 Moving Giant Concrete Blocks With Just Your Hands

 

moveable concrete blocks by matter design 9 Moving Giant Concrete Blocks With Just Your Hands

 

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moveable concrete blocks by matter design 12 Moving Giant Concrete Blocks With Just Your Hands

 

moveable concrete blocks by matter design 13 Moving Giant Concrete Blocks With Just Your Hands

 

moveable concrete blocks by matter design 14 Moving Giant Concrete Blocks With Just Your Hands

 

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moveable concrete blocks by matter design 10 Moving Giant Concrete Blocks With Just Your Hands

 

moveable concrete blocks by matter design 6 Moving Giant Concrete Blocks With Just Your Hands

 

26 Mar 20:43

A superposition of possible facts causes quantum conflict

by Chris Lee
Eugene Wigner first came up with the thought experiment this real experiment is based on.

Enlarge / Eugene Wigner first came up with the thought experiment this real experiment is based on. (credit: Denver Post Inc (Photo By David Cupp/The Denver Post via Getty Images))

“More than one reality exists” screams the headline. Cue sighs of tired dread from physicists everywhere as they wonder what otherwise bland result has been spun out of control.

In this case, though, it turns out that the paper and the underlying theory are much more interesting than that takeaway. Essentially, modern physics tells us that two observers of the same event may never agree on the result, even if they have all possible knowledge. This is already accepted as part of special relativity, but now we have experimental proof that it applies to quantum mechanics as well. 

What Galileo and Einstein tell us

Let’s start with the simplest possible example of how we typically resolve conflicting measurements. I am standing on a platform and measure the speed of an approaching train to be 180km/hr. You are on the train and measure the speed of the train to be 0km/hr. We can resolve the difference by making an additional measurement on our relative speeds. Afterward, we both know that we’ve measured the speed correctly relative to our own motion. 

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25 Mar 23:35

New Robot

"Some worry that we'll soon have a surplus of search and rescue robots, compared to the number of actual people in situations requiring search and rescue. That's where our other robot project comes in..."
02 Mar 16:14

Forget growing weed—make yeast spit out CBD and THC instead

by WIRED
ROME, ITALY - FEBRUARY 15: Vendors at Canapa Mundi, an international hemp fair, on February 15, 2019 in Rome, Italy

Enlarge / ROME, ITALY - FEBRUARY 15: Vendors at Canapa Mundi, an international hemp fair, on February 15, 2019 in Rome, Italy (credit: Simona Granati - Corbis | Getty Images)

We as a species would be miserable without yeast. Baker's yeast has given us leavened bread for thousands of years. And I don’t even want to begin to imagine a world without beer and wine, which rely on yeast to convert sugar into alcohol.

Now researchers have turned to yeast to do something more improbable: manufacturing the cannabis compounds CBD and THC. By loading brewer’s yeast with genes from the cannabis plant, they’ve turned the miracle microbes into cannabinoid factories. It’s a clever scheme in a larger movement to methodically pick apart and recreate marijuana’s many compounds, to better understand the plant’s true potential.

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21 Feb 20:24

The first private mission to the Moon may launch Thursday night

by Eric Berger
An artist's concept of the Space IL lunar spacecraft on the surface of the Moon.

Enlarge / An artist's concept of the Space IL lunar spacecraft on the surface of the Moon. (credit: SpaceIL)

SpaceX is set to launch a Falcon 9 rocket on Thursday night, and while it may not be the primary payload, a small Israeli lunar lander is by far the mission's most intriguing payload.

The 180kg Beresheet spacecraft, privately developed by SpaceIL in Israel and funded largely through philanthropy, will spend more than six weeks raising its orbit and becoming captured into lunar orbit before finally making the first private attempt to land on the Moon. Until now, only the US, Russian, and Chinese space agencies have ever successfully landed on the Moon.

This means there is a lot of pressure on the small Israeli team leading the mission, both in their native country and among the commercial lunar community, which wants to prove that private ventures can do what only nations have done before. "What it means to me is that the responsibility is very high," said Yoav Landsman, a senior systems engineer for the project, in an interview.

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13 Feb 21:03

Opportunity did not answer NASA’s final call, and it’s now lost to us

by Eric Berger
The Opportunity rover leaves its landing site in Eagle Crater on Mars back in 2004.

Enlarge / The Opportunity rover leaves its landing site in Eagle Crater on Mars back in 2004. (credit: NASA)

Late Tuesday night, scientists at NASA's Jet Propulsion Laboratory sent their final data uplink to the Opportunity rover on Mars. Over this connection, via the Deep Space Network, the American jazz singer Billie Holiday crooned "I'll Be Seeing You," a song that closes with the lines:

I'll find you in the morning sun
And when the night is new
I'll be looking at the moon
But I'll be seeing you

The scientists waited to hear some response from their long-silent rover, which had been engulfed in a global dust storm last June, likely coating its solar panels in a fatal layer of dust. Since then, the team of scientists and engineers has sent more than 835 commands, hoping the rover will wake up from its long slumber—that perhaps winds on Mars might have blown off some of the dust that covered the panels.

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12 Dec 20:26

Watch How Hermit Crabs All Line Up to Exchange Their Shells

by Jason Kottke

Hermit crabs use the scavenged shells of other animals as their homes. As the crabs grow, they periodically need to upgrade their housing to bigger shells. When a new shell appears on the beach, the cramped crabs will form a orderly queue nearby and then change shells all at once, with each crab moving into the next biggest shell just abandoned by its former occupant. This is possibly the most British thing I’ve ever seen an animal do…and the David Attenborough narration is the icing on top.

Tags: David Attenborough   video
29 Nov 10:35

Plot twist: Mitochondrial DNA can come from both parents

by Cathleen O'Grady
Mitochondria (red) and cell nucleus (blue) of two connective tissue cells prepared from mouse embryo.

Enlarge / Mitochondria (red) and cell nucleus (blue) of two connective tissue cells prepared from mouse embryo. (credit: Institute of Molecular Medicine I, University of Düsseldorf)

The vast majority of our DNA—the chromosomes in the nucleus of each cell—is just what you’d expect: a mix of genetic material from both mother and father. But mitochondria are an exception. They contain a relatively tiny amount of DNA, and in nearly all mammals and even unicellular organisms, that DNA comes strictly from the mother. We've even used that fact to trace the spread of humanity around the globe.

But in 2002, researchers in Copenhagen reported a jaw-dropping finding. In an effort to work out why one of their patients had extreme fatigue during exercise despite seeming healthy in many respects, they started examining his mitochondria—the energy-generating power stations living in each cell. What they found floored them: the man had mitochondrial DNA (mtDNA) that matched both his father's and his mother's.

Since 2002, no other cases of paternally inherited mtDNA have been reported in humans, despite several research groups actively looking. But a paper in this week’s PNAS reports mtDNA inherited from both parents in 17 different people from three families. This kind of inheritance is still extremely rare and seems potentially linked to mitochondrial disease, but the robust confirmation of it in humans is huge news for biology and medicine.

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21 Nov 20:04

Ion drive meets drone, as small plane flies with no moving parts

by John Timmer
Ion drive meets drone, as small plane flies with no moving parts

Enlarge (credit: Nature)

The Johnson Indoor Track at MIT probably won't go down in history in the same way as Kitty Hawk has, but it was the scene of a first in powered flight. A team of researchers has managed to build the first aircraft powered by an ionic wind, a propulsion system that requires no moving parts. While the flight took place using a small drone, the researchers' calculations suggest that the efficiency of the design would double simply by building a larger craft.

Ionic wind

In conventional aircraft, air is pushed around by moving parts, either propellers or the turbines within jet engines. But we've known for a while that it's also possible to use electrical fields to push air around.

The challenge is that air is largely made of uncharged molecules that don't respond to electric fields. But at sufficiently high voltages, it's possible to ionize the nitrogen and oxygen that make up our atmosphere, just as lightning does all the time. The electrons that are liberated speed away, collide with other molecules, and ionize some of them as well. If this takes place in an electric field, all those ions will start moving to the appropriate electrode. In the process, they'll collide with neutral molecules and push them along. The resulting bulk movement of atmospheric molecules is called an ionic wind.

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17 Sep 21:11

Study: people tend to cluster into four distinct personality “types”

by Jennifer Ouellette
Article intro image

Enlarge / Average, Reserved, Role Model, and Self-centered: not everyone falls into these four categories, but you might. (credit: Northwestern University)

People love taking online quizzes; just ask Buzzfeed and Facebook. A new study has sifted through some of the largest online data sets of personality quizzes and identified four distinct "types" therein. The new methodology used for this study—described in detail in a new paper in Nature Human Behavior—is rigorous and replicable, which could help move personality typing analysis out of the dubious self-help section in your local bookstore and into serious scientific journals.

Frankly, personality "type" is not the ideal nomenclature here; personality "clusters" might be more accurate. Paper co-author William Revelle (Northwestern University) bristles a bit at the very notion of distinct personality types, like those espoused by the hugely popular Myers-Briggs Type Indicator. Revelle is an adamant "anti-fan" of the Myers-Briggs, and he is not alone. Most scientists who study personality prefer to think of it as a set of continuous dimensions, in which people shift where they fall on the spectrum of various traits as they mature.

What's new here is the identification of four dominant clusters in the overall distribution of traits. Revelle prefers to think of them as "lumps in the batter" and suggests that a good analogy would be how people tend to concentrate in cities in the United States.

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16 Aug 01:54

MIT scientists crack the case of breaking spaghetti in two

by Jennifer Ouellette

The trick to breaking spaghetti in half is to bend and twist, new MIT study says. (credit: Tom Smith / EyeEm: Getty Images)

Pasta purists insist on plonking dry spaghetti into the boiling pot whole, but should you rebel against convention and try to break the strands in half, you'll probably end up with a mess of scattered pieces.

Now, two MIT mathematicians have figured out the trick to breaking spaghetti strands neatly in two: add a little twist as you bend. They outlined their findings in a new paper in the Proceedings of the National Academy of Sciences.

This isn't the first time scientists have been fascinated by the physics of breaking spaghetti. The ever-curious Richard Feynman famously spent hours in his kitchen one night in a failed attempt to successfully break spaghetti strands neatly in half. It should have worked, he reasoned, because the strand snaps when the curvature becomes too great, and once that happens, the energy release should reduce the curvature. The spaghetti should straighten out and not break any further. But no matter how hard he tried, the spaghetti would break in three or more pieces.

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12 Jul 19:28

Sources of banned CFCs found through their advertising

by Scott K. Johnson

Enlarge / Air pollution in China apparently includes a dash of banned ozone-depleting CFCs. (credit: NASA Earth Observatory)

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.

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30 Jun 00:16

Google researchers created an amazing scene-rendering AI

by Timothy B. Lee

Enlarge (credit: DeepMind)

New research from Google's UK-based DeepMind subsidiary demonstrates that deep neural networks have a remarkable capacity to understand a scene, represent it in a compact format, and then "imagine" what the same scene would look like from a perspective the network hasn't seen before.

Human beings are good at this. If shown a picture of a table with only the front three legs visible, most people know intuitively that the table probably has a fourth leg on the opposite side and that the wall behind the table is probably the same color as the parts they can see. With practice, we can learn to sketch the scene from another angle, taking into account perspective, shadow, and other visual effects.

A DeepMind team led by Ali Eslami and Danilo Rezende has developed software based on deep neural networks with these same capabilities—at least for simplified geometric scenes. Given a handful of "snapshots" of a virtual scene, the software—known as a generative query network (GQN)—uses a neural network to build a compact mathematical representation of that scene. It then uses that representation to render images of the room from new perspectives—perspectives the network hasn't seen before.

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28 May 19:30

Selection Effect

fMRI testing showed that subjects who don't agree to participate are much more likely to escape from the machine mid-scan.
23 May 20:35

How you end up sleep-deprived matters

by John Timmer

Enlarge (credit: Aaron Jacobs)

Anyone who has tried to pull a late-night study session and wound up rereading the same pages of their textbook because they couldn't focus has experienced it. And countless studies confirm it: if you're sleep deprived, your brain starts functioning poorly. Your reaction times slip, you are more prone to careless actions, and you generally just get bad at things. But how is it your body registers "too little sleep"? It could be after you spend too much time awake. Or it could be the amount of sleep you get in a 24-hour period. Or it could be tracked in relationship to your body's internal 24-hour circadian clock.

A new study out this week suggests it's not just one of these things, and different aspects of our mental capacities are either more sensitive or less sensitive depending on how we end up short on sleep.

Deprived

The challenge with separating out different aspects of sleep deprivation in the real world is that anything you do will involve multiple aspects of sleep. Get too little sleep during a 24-hour cycle, which means more awake time—and awake at times your circadian clock says you shouldn't be. So, the researchers behind the new work messed with people's clocks. They got a small group of people (because it would be hard to recruit a large one) to live at a sleep center for 32 days, cut off from any indication of outside time.

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17 May 09:19

It seems someone is producing a banned ozone-depleting chemical again

by Scott K. Johnson

Enlarge / The latest satellite measurements of ozone from May 14 show the "hole" that still exists over the South Pole. (credit: NASA Ozone Watch)

The Montreal Protocol—a 1987 international agreement to end production of ozone-destroying chemicals like freon—seems miraculous compared to the long struggle to achieve meaningful action on climate change. Even more astonishing is that the agreement has worked. Those chemicals (known as CFCs) take a long time to flush out of the atmosphere, but monitoring has shown that the flushing is proceeding largely according to plan.

That keeps the hole in the ozone layer on track to shrink over the coming decades. However, a new study shows that someone has been cheating in the last few years.

A group of researchers led by Stephen Montzka of the US National Oceanic and Atmospheric Administration had been tracking the progress of CFCs and noticed something off with CFC-11. This chemical has been used as a refrigerant, solvent, and propellant for aerosol spray cans, as well as in the production of styrofoam. As with the other CFCs, nations agreed to end production of CFC-11 entirely. While there may still be some older machines leaking CFC-11, these sources should gradually disappear over time, allowing the decline of its atmospheric concentration to accelerate.

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07 May 19:45

Driving Cars

It's probably just me. If driving were as dangerous as it seems, hundreds of people would be dying every day!
25 Apr 21:02

Meteorologist

Hi, I'm your new meteorologist and a former software developer. Hey, when we say 12pm, does that mean the hour from 12pm to 1pm, or the hour centered on 12pm? Or is it a snapshot at 12:00 exactly? Because our 24-hour forecast has midnight at both ends, and I'm worried we have an off-by-one error.
11 Apr 20:35

History

HISTORIANS: We've decided to trim the past down to make things more manageable. Using BCE/CE, would you rather we lose the odd-numbered or even-numbered years?
07 Mar 22:48

Scientists find odd and amazing cyclones at Jupiter’s poles

by Eric Berger

NASA/JPL-Caltech/SwRI/ASI/INAF/JIRAM

Scientists studying data from NASA's Juno spacecraft have published a trove of papers in Nature this week, making a number of intriguing and surprising findings about the atmosphere of the largest planet in our Solar System. The papers are summarized and linked in this NASA news release.

Some of the most striking discoveries come from visible and infrared observations made by Juno during its first five science passes in its elongated orbit around Jupiter. (The spacecraft entered Jupiter's orbit on July 4, 2016. It will make its 11th pass on April 1.) In these initial passes, scientists found clusters of strange and long-lasting cyclones orbiting the north and south poles of Jupiter.

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05 Feb 21:25

Linguistic bots explain why big groups produce simple grammar

by Cathleen O'Grady

Enlarge / But nobody can explain Welsh. (credit: flickr user: Groundhopping Merseburg)

A funny thing happens to languages that have huge numbers of speakers: over time, they seem to simplify. They lose all the fiddly bits that make languages like Hungarian so incredibly hard to learn, and instead become more regular and grammatically simple.

But at the same time that the grammatical challenge of these languages shrinks, their vocabulary explodes. This leaves a mystery for researchers who study how language structures emerge in humans: why does population size seem to drive increased complexity in vocabulary but reduced complexity in grammar? There are some intuitive answers to this question, but we need to confirm whether those intuitions are backed up by data.

Evolutionary linguists Florencia Reali, Nick Chater, and Morten Christiansen have used a computational simulation to suggest an answer: the two different kinds of complexity are very different in how easy they are to learn, and they're passed on to others through conversation. Their results imply that “language, and possibly other aspects of culture, may become simpler at the structural level as our world becomes increasingly interconnected,” they write.

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30 Jan 22:01

Pocket-sized DNA reader used to scan entire human genome sequence

by John Timmer

Enlarge / Sequence on a stick. (credit: Oxford Nanopore)

A few years back, a company called Oxford Nanopore announced it was developing a radically different way of sequencing DNA. Its approach involved taking single strands of the double helix and stuffing them through a protein pore. With a small bit of current flowing across the pore, the four bases of DNA each created a distinct (if tiny) change in the voltage as it passed through. These could be used to read the DNA one base at a time as it wiggled through the pore.

After several years of slow progress, Oxford Nanopore announced that its sequencing hardware would be as distinctive as its wetware: a USB device that could fit comfortably in a person's hand. As the first devices went out to users, it became clear that the device had some pros and cons. On the plus side, the device was quick and could be used without requiring a large facility to support it. It could also read very long stretches of DNA at once. But the downside was significant: it made lots of mistakes.

With a few years of experience, people are now starting to learn to make the most of the devices, as demonstrated by a new paper in which researchers use it to help sequence a human genome. By using the machine's long reads—in one case, nearly 900,000 bases from one DNA molecule—the authors were able to get data out of areas of the human genome that resisted characterization before. And they were able to distinguish between the two sets of chromosomes (one from mom, one from dad) and locate areas of epigenetic control in many areas of the genome.

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28 Jan 18:23

3D, volume-filled imagery created with hovering dots

by John Timmer

Enlarge (credit: Brigham Young University)

All sorts of 3D-imaging technologies tend to get lumped under the label "hologram." But there's actually a variety of distinct technologies that can create the appearance of depth. Now, we can add another to the list: the photophoretic-trap volumetric display. The device uses one set of optical hardware to control the motion of a tiny sphere and a second set to illuminate the sphere as it travels. Provided the sphere can be kept moving fast enough, the result is a true-color image that has real depth since it's built from light reflected from different locations.

The downside is that a single sphere can't cover all that much ground in the amount of time our brain needs to construct an image. As a result, photophoretic-trap volumetric display is currently limited to either small images or showing only part of an image at a time.

The recent work, from a team at Brigham Young University, is a variation on volumetric displays. These involve projecting a changing image onto a moving reflective surface. If the change in the image is properly matched to the changing location of where it's projected, the result will be the appearance of depth, since the light you see will actually be reflected at different locations. On the plus side, this doesn't require the viewer to wear any hardware, and multiple people can view the image at the same time, each seeing it from the appropriate perspective.

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16 Jan 21:13

Beware a bottled booger blast—they can blow up your throat, doctors warn

by Beth Mole

Enlarge / Picture shows a woman about to sneeze holding a handkerchief in her hand. (credit: Getty | Bettmann)

Ah… AHHH… Choose wisely when it comes to handling that impending sneeze. Holding one in can lead to some serious damage, British doctors report Monday in BMJ Case Reports.

In their rare-disease case report, they relay the tale of an otherwise healthy 34-year-old male who managed to tear a hole in the back of his throat trying to extinguish a snot explosion.

The man showed up in an emergency room with an alarming popping sensation and swelling in his throat. He was also in terrible pain and could barely talk. Subsequent X-rays and CT scans revealed that he had bubbles of air throughout his neck, including along his spine. The doctors also noted a crackling, grating sound coming from both sides of his throat down to his chest, which is a sign of gas trapped inside tissue.

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11 Dec 23:57

12/11/17 PHD comic: 'Nuclear War Explained'

Piled Higher & Deeper by Jorge Cham
www.phdcomics.com
Click on the title below to read the comic
title: "Nuclear War Explained" - originally published 12/11/2017

For the latest news in PHD Comics, CLICK HERE!

03 Dec 21:33

After 37 years, Voyager 1 has fired up its trajectory thrusters

by Eric Berger

Enlarge / The Voyager team is able to use a set of four backup thrusters, dormant since 1980. They are located on the back side of the spacecraft in this orientation. (credit: NASA/JPL-Caltech)

At present, the Voyager 1 spacecraft is 21 billion kilometers from Earth, or about 141 times the distance between the Earth and Sun. It has, in fact, moved beyond our Solar System into interstellar space. However, we can still communicate with Voyager across that distance.

This week, the scientists and engineers on the Voyager team did something very special. They commanded the spacecraft to fire a set of four trajectory thrusters for the first time in 37 years to determine their ability to orient the spacecraft using 10-millisecond pulses.

After sending the commands on Tuesday, it took 19 hours and 35 minutes for the signal to reach Voyager. Then, the Earth-bound spacecraft team had to wait another 19 hours and 35 minutes to see if the spacecraft responded. It did. After nearly four decades of dormancy, the Aerojet Rocketdyne manufactured thrusters fired perfectly.

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03 Dec 21:30

Life, but not as we know it

by John Timmer

Enlarge (credit: Adapted from an image created by Dennis Sun, Mezarque Design)

To the best of our ability to tell, everything on Earth shares a few common features. It encodes information in DNA using four bases, A, T, C, and G. Sets of three consecutive bases are used to code for a single amino acid, and most organisms use a set of 20 amino acids to build proteins. These features appear everywhere, from plants and animals to bacteria and viruses, suggesting that they appeared in the last common ancestor of life on Earth.

This raises a question that comes up a lot in evolutionary studies: are these features used because they're in some way efficient, or did we end up stuck with them as a result of some historic accident?

A team of California-based researchers has been building an argument that it's an accident. And it's doing so by expanding life beyond the limitations inherited from its common ancestor. After having expanded the genetic alphabet to six letters, the team has now engineered a bacterial strain that uses the extra letters to put an unnatural amino acid into proteins.

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25 Nov 15:59

Lightning strikes leave behind a radioactive cloud

by John Timmer

Enlarge / Don't mind us, just performing some alchemy here. (credit: NOAA)

Thunderstorms have a lot of overt indications of power, from the thunder and lightning to torrential rains and hail. But the full extent of their power wasn't obvious until recent years, when we discovered they generate antimatter. Now, researchers in Japan have looked at this phenomenon more closely and determined that a lightning bolt generates a zone that contains unstable isotopes of oxygen and nitrogen, leading to series of radioactive decays over the next minute.

Transformative

All of these phenomena are powered by the fact that the electric fields within thunderstorms are able to accelerate electrons to extremely high energies. Whenever these electrons move along a curved path, they emit radiation that's proportional to their energy. As a result, a storm can be associated with bursts of gamma rays, extremely high-energy photons.

Gamma rays rays are primarily noted for their interaction with the electrons of any atoms they run into—it's why they're lumped in the category of ionizing radiation. But they can also interact with the nucleus of the atom. With sufficient energy, they can kick out a neutron from some atoms, transforming them into a different isotope. Some of the atoms this occurs with include the most abundant elements in our atmosphere, like nitrogen and oxygen. And, in fact, elevated neutron detections had been associated with thunderstorms in the past.

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22 Nov 20:15

New paper makes the case that Mars is dry

by John Timmer

Enlarge / Those dark streaks come and go with the seasons. We still don't know what causes them. (credit: NASA/JPL-Caltech/Univ. of Arizona)

Mars clearly had extensive water in the past, and there's still plenty of it locked up as ice in glaciers and the polar ice caps. But the atmosphere is too thin and cold to allow liquid water to exist on the surface, which makes prospects for life on the Red Planet far less likely.

Back in 2011, however, researchers suggested that, contrary to our expectations, there might still be some water seeping out onto Mars' surface. Darkened features were identified on a variety of slopes, and they seemed to appear during warmer seasons and vanish as temperatures plunged again. The Mars Reconnaissance Orbiter appeared to detect water at the site. But other researchers proposed a physical mechanism that didn't involve water that could account for the seasonal changes.

Now, a review of the evidence in Nature Geoscience argues that there are problems with almost all of the potential causes for these seasonal features. And, in the absence of a compelling case for water, it's best to assume that the harsh conditions mean what we typically thought they did: Mars is a dry planet.

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