atmosphere – Tech Today w/ Ken May

Planets of TRAPPIST-1: Complex atmospheres, probably lots of water

Enlarge (credit: ESO/M. Kornmesser ) We’ve now developed a healthy-sized catalog of planets orbiting in the habitable zone of distant stars. But we don’t have the slightest idea whether any of them are actually habitable. That’s largely because, at these distances, it’s extremely difficult to get any sense of what the planets are made of and what their atmospheres are like. And the greenhouse potential of the atmosphere can make the difference between a frozen world like Mars and an out-of-control hothouse like Venus. But at least in the case of one nearby star, scientists are slowly narrowing down the options. TRAPPIST-1 has at least seven planets , all small enough to be Earth-like, with several inside the star’s habitable zone. In two papers released this week, teams of scientists have narrowed down what their atmospheres might look like and provided a greater sense of their composition. The results suggest that at least one planet has the potential to be a watery world. In the air The first study, which appears in Nature Astronomy , looks at the atmospheres of several of the planets, but not directly. Instead, it relies on the Hubble to observe the star’s light as a planet passes in front of it. A tiny fraction of the photons will have passed through the planet’s atmosphere on their way to Earth. Any colors of light that are absorbed or scattered by the gases in the atmosphere will be missing from that fraction, making it possible to infer the atmosphere’s composition. Read 11 remaining paragraphs | Comments

New measurement confirms: The ozone is coming back

Enlarge / Each year’s ozone hole is a little bit different. (credit: NASA ) The Montreal Protocol, which went into effect in 1989, is a rare instance of a global agreement to solve a global problem: the release of vast quantities of ozone-destroying chemicals into the atmosphere. In the decades since, however, changes in ozone have been small and variable, making it hard to tell whether the protocol is making any difference. But evidence has been building that the ozone layer is recovering, and a new paper claims to have directly measured the ozone hole gradually filling back in. CFCs and ozone During the 1970s and ’80s, evidence had been building that a class of industrial chemicals, the chloro-flurocarbons (CFCs), were damaging the ozone layer, a region of the stratosphere rich in this reactive form of oxygen. Ozone is able to absorb UV light that would otherwise reach the Earth’s surface, where it’s capable of damaging DNA. But the levels of ozone had been dropping, and this ultimately resulted in a nearly ozone-free “hole” above the Antarctic. Read 14 remaining paragraphs | Comments

Why scientists are redefining the kilogram

Physics is a funny thing. Despite dictating the behaviors and states of everything from atoms to stars, our interpretation of its effects are rooted in very human constructs. Meters, amperes and seconds were all defined using arbitrary terms and methods. For years, the kilogram and meter weren’t just terms, they were physical objects held in a Paris vault that some Victorian era committee just decided would be the standard. But now, for the first time since the international system of units (SI) was launched in 1960, the International Bureau of Weights and Measures (BIPM) is redefining four basic units of measurement , not by any human metric but by the immutable forces of the universe. “This is the most important decision that the BIPM has made in maybe 100 years, which may be a slight exaggeration, but at least since 1960 when they adopted the international system of units, ” Dr. Terry Quinn, Emeritus Director of the BIPM said. A committee from the BIPM met in Paris this week and voted on Friday to recommend redefining the kilogram, mole, ampere, and Kelvin. The motion will be put up for a vote at the General Conference on Weights and Measures (CGPM) next November. “For the scale that’s in your grocery store or bathroom, nothing’s going to change, ” Dr. David Newell of the National Institute of Standards and Technology (NIST) said. Instead, as Dr. Quinn explains, “it will give you the ability to make accurate measurements on scales far different from the current scale.” “This redefinition is a major overhaul, ” Newell continued, but certainly not the first. For example, we currently define the second by a specific number of cycles of radiation in a cesium-133 atom (9, 192, 631, 770 periods). It was originally considered to be the fraction 1/86400 of the mean solar day. The meter used to be a real thing that you could hold (like the kilogram still is) rather than the distance light travels in 1 / 299, 792, 458 seconds. “The SI is slowly evolving to the use of the invariance of nature, ” Newell said, rather than basing our observations on specific, physical artifacts. “What is going to change is that with this redefinition, the uncertainties of fundamental constants is either going to go to zero, ” he said. “Or the uncertainties of the related fundamental constants is going to be drastically reduced.” This means researchers will have far more accurate tools with which to make measurements. That higher fidelity will empower them to go back and reexamine the laws of physics that we believe to be correct and see if they’re as accurate as we think they are. “We may actually find that we don’t know everything, ” Newell said. Eventually, we may even take those insights and once again redefine the scientific measurement system when our technology has sufficiently advanced. Another advantage is these fundamental constants appear throughout nature, Newell explained. Researchers would no longer be tied to the kilogram and would be able to easily scale their units between the macroscopic and microscopic worlds. “Moreover the present system is explicit unit based — the second, the kilogram, the meter, the ampere — and there’s definitions for all of them, ” Newell continued. “The new system is explicitly constants-based — the transition frequency of a cesium atom is an exact number of hertz, the speed of light is an exact number of meters per second.” Take amperes for example. An ampere (or amp) is the basic unit of electrical current and is defined by the SI as the equivalent to one coulomb (the base unit of electrical charge) per second. Originally it was defined using a thought experiment . This is problematic for a couple reasons, PhysicsWorld points out. First, it relies on other units of measure — specifically kilograms, meters and seconds — for its definition. This methodology is exactly what the BIPM is trying to get away from. Second, the aforementioned “thought experiment” can never be tested in reality, since it imagines a situation with wire infinitely long, so at some point you’re going to have to approximate. Instead, the BIPM wants to define amps by the number of electrons that flow through a wire by the exact number of electrons that actually flow through a wire. Recently, a team of researchers from German National Metrology Institute (PTB) in Braunschweig developed a Single Electron Pump . Electrons are generated on one side of a circuit, become trapped as they pass through a series of gates and then are released one at a time on the other side where they can be easily counted. Using this, we can define the ampere as the specific number of single electrons passing through a wire for a given length of time. Kilograms are equally quirky. The International Prototype Kilogram (IPK) is a cylinder of platinum-iridium sitting in a Paris Vault and is what all other kilograms are measured against. Problem is, materials have a habit of gaining and losing atoms due to chemical interactions with the atmosphere. Of the six official copies of the IPK, one has lost approximately 5 micrograms while two others have gained more than 50 micrograms of mass. You’d be hard-pressed to notice if someone dropped a 50 microgram weight on your toe but for the scientific community, those fluctuations make a big difference. The IPK isn’t just susceptible to atmospheric reactions. Being a physical object, it can be stolen or damaged. However, “you can’t steal Planck’s Constant, ” Quinn quipped. “If I were to drop [the IPK] on the floor and chip a piece off, the definition of mass would have to be changed because it is defined as this hunk of metal, ” Dr. Willie May, former Director of NIST and current VP of the BIPM, said. “But, by definition, it can’t change, ” Quinn interjected. “And so what would happen, had Dr. May dropped it on the floor and knocked a piece off, it would have remained the IPK and the mass of the rest of the universe would have changed.” That’s where the Kibble Balance comes in. Now on normal balancing scales, you determine the mass of an object by adding mass to the opposite side until they are in equilibrium. In the Kibble balance, the gravitational force generated by the weight on one side is countered with electromagnetic force on the other. With this method, and a bit of math, researchers can measure something called the Planck Constant . Thus we can define kilograms in terms of the Planck Constant rather than a lump of metal. Kelvin, thankfully, is a bit more straightforward. It’s the measure of temperature, terminating at absolute zero when all molecular motion stops. That absolute nature is important, since, unlike mass, relative temperatures don’t stack. For example, smash two, 10-pound blobs of clay, each heated to 100 degrees Fahrenheit together, the result will weigh 20 pounds but it won’t be any hotter. As such, measuring temperatures in Kelvin is more accurate than Fahrenheit or Celsius though it’s still being framed in an outdated model. Should the CGPM approve the redefinition of Kelvin next year, the unit will be defined using an acoustic thermometer . These devices measure the speed of sound waves travelling through a low-gravity gas sphere. Since the speed of those waves is fixed for a set temperature, you can calculate that by measuring the frequency of the resonating sound waves and the volume of the sphere. Even the mole is getting a makeover. This fundamental unit measures the amount of substance known as the Avogadro constant. Moles are used to bridge the gap between the micro and macroscopic worlds. It provides a useable frame of reference when dealing with miniscule items. Or, as XKCD once pointed out, a mole of moles would be 602, 214, 129, 000, 000, 000, 000, 000 animals (602 trillion trillion moles). That’s also the number of sand grains needed to bury the entire UK to a depth of about 40 centimetres, according to the NPL , or the number of human cells on Earth. The Mole is currently defined using an experiment known as the “primary method” which involves weighing a material of known composition. However, because this system bases the value of the mole on the mass of the prototype kilogram, the CGPM is considering redefining the unit. Instead, the group wants to drop carbon (the reference substance for moles) altogether and replace it with a 1Kg, 94-mmm wide, nearly spherical mass of 99.9995-percent pure silicon-28. Since the physical characteristics of the sphere — weight, diameter, size of the individual crystal lattices — are known, as well as how much a single silicon atom weighs, these measurements can be used to calculate the total number of atoms in the sphere and, in turn, a revised Avogadro’s constant . This isn’t the end of the BIPM’s efforts. The group is eyeing the atomic second ahead of the unit’s 50th anniversary of being tied to the radiation cycles of Cesium-133. “At the time we used the best atomic clock we could possibly have, ” Quinn explained. “But a lot of science has taken place and there are now ways of making atomic clocks 100 times better. And in the next ten years, I would say, there will be a new definition of the atomic second that is 100 times better.” Such an advancement will have implications in everything from space exploration and cutting edge physics research to more accurate GPS navigation in your car. “If we allow the art of the possible, ” May said, “you open up the future to things you’ve never even thought of.”

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Why scientists are redefining the kilogram

Massive 70-Mile-Wide Butterfly Swarm Shows Up On Denver Radar System

dryriver shares a report from BBC: A colorful, shimmering spectacle detected by weather radar over the U.S. state of Colorado has been identified as swarms of migrating butterflies. Scientists at the National Weather Service (NWS) first mistook the orange radar blob for birds and had asked the public to help identifying the species. They later established that the 70-mile wide (110km) mass was a kaleidoscope of Painted Lady butterflies. Forecasters say it is uncommon for flying insects to be detected by radar. “We hadn’t seen a signature like that in a while, ” said NWS meteorologist Paul Schlatter, who first spotted the radar blip. “We detect migrating birds all the time, but they were flying north to south, ” he told CBS News, explaining that this direction of travel would be unusual for migratory birds for the time of year. So he put the question to Twitter, asking for help determining the bird species. Almost every response he received was the same: “Butterflies.” Namely the three-inch long Painted Lady butterfly, which has descended in clouds on the Denver area in recent weeks. The species, commonly mistaken for monarch butterflies, are found across the continental United States, and travel to northern Mexico and the U.S. southwest during colder months. They are known to follow wind patterns, and can glide hundreds of miles each day. Read more of this story at Slashdot.

A nearby Sun-like star hosts four Earth-sized planets

Exoplanet discoveries are getting pretty common , so it takes something special to catch our attention. A star called Tau Ceti fits the bill, as it’s just 12 light years away and unlike the Trappist-1 red dwarf, is very similar to our own yellow dwarf (G-type) sun. Researchers have determined that it probably hosts planets like Earth that sit in its habitable zone. The only hitch is that the star is known to have a massive debris disk that probably bombards its worlds with asteroids, so living there would be a pretty big challenge. Four rocky worlds were found, with two in the habitable zone, about 0.5 and 1.25 times as far from their star as the Earth is from the Sun. That works out well, as Tau Ceti is a bit smaller (78 percent) than the Sun, and is correspondingly less intense. The smallest of the worlds is about 1.7 times the size of Earth, but the habitable zone planets are much larger “super Earths” that could potentially support life. However, Tau Ceti is known to have a big debris disk that probably produces far more impact events via comets and asteroids than we have on Earth. While that makes life improbable, the discovery is still important because of the techniques used. On smaller stars, planets can be detected by the “transit method, ” observing the dimming of light as planets pass in front. That doesn’t work as well for bigger stars like Tau Ceti though, as the light levels drown out any dimming. The W.M. Keck HIRES-MAGIQ detector Instead, the team observed wobbles in the star’s movement as small as 30 centimeters (one foot) per second. That has only become possible recently by combining multiple observations from different instruments and sophisticated modeling. In this case, the team obtained observations from the HARPS spectrograph on the European Southern Observatory in Chile, and Keck HIRES (above) on the W.M. Keck Observatory in Mauna Kea, Hawaii. “We can [now] disentangle the noise due to stellar surface activity from the very tiny signals generated by the gravitational tugs from Earth-sized orbiting planets, ” said UC Santa Cruz Professor and co-author Steven Vogt. “Our detection of such weak wobbles is a milestone in the search for Earth analogs.” Using the new techniques, the same team actually ruled out two planets they previously identified in 2013 as planets. “But no matter how we look at the star, there seem to be at least four rocky planets orbiting it, ” said coauthor Mikko Tuomi. We can disentangle the noise due to stellar surface activity from the very tiny signals generated by the gravitational tugs from Earth-sized orbiting planets. Our detection of such weak wobbles is a milestone in the search for Earth analogs. The team hopes to refine the techniques to find wobbles as small as 10 cm (4 inches) per second, small enough to detect Earth-sized planets. That could be crucial, because while its easier to spot exoplanets around dim red dwarf stars like Trappist-1 using the transit method, astronomers are beginning to wonder if such stars can actually support life. Planets tend to get tidally locked to red dwarf stars early in their life because their years are so short — often a week or less. As a result, much like our moon is to the Earth, one side is constantly exposed to radiation and the other is in the dark. “Because of the onslaught by the star’s radiation, our results suggest the atmosphere on planets in the Trappist-1 system would largely be destroyed, ” said researcher Avi Loeb . That makes the likelihood of life just one percent compared to Earth. Since life has enough challenges already, it’s probably got a much better shot on a planet around a type-G, main sequence star. We know for a fact that those can support life, as here we are. Via: CNET Source: UC Santa Cruz

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A nearby Sun-like star hosts four Earth-sized planets

Cheap catalyst takes sunlight and carbon dioxide, makes methane

Enlarge / The catalyst in question. (credit: John Timmer) The carbon dioxide we’re currently dumping into the atmosphere started out as atmospheric carbon dioxide hundreds of millions of years ago. It took lots of plants and millions of years of geological activity to convert it to fossil fuels. One obvious way of dealing with our atmospheric carbon is to shorten that cycle, finding a way to quickly convert carbon dioxide into a usable fuel. Unfortunately, carbon dioxide is a very stable molecule, so it takes a lot of energy to split it. Most reactions that do so end up producing carbon monoxide, which is more reactive and a useful starting material, but it’s far from a fuel. Now, though, researchers have discovered a catalyst that, with a little help from light, can take CO 2 and make methane, the primary fuel in natural gas. While the reaction is slow and inefficient, there are a number of ways it could be optimized. Unexpected methane The work started out with a catalyst that converts carbon dioxide to carbon monoxide when supplied with a source of electrons. The catalyst is a complex ring of carbon-based molecules that latch on to an iron atom at the center. The iron interacts with carbon dioxide, allowing hydrogen atoms from water to break one of the carbon-oxygen bonds, liberating water. The iron loses some electrons in the process, and these have to be re-supplied for the cycle to start again. Typically, that supply comes in the form of a separate chemical that readily gives up some electrons. Read 10 remaining paragraphs | Comments

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Cheap catalyst takes sunlight and carbon dioxide, makes methane

NASA Will Create Fake Red And Green Clouds Near Virginia

An anonymous reader quotes CNET: The early morning hours on the U.S. East Coast might be unusually colorful as NASA plans to produce artificial blue-green and red clouds that may be visible from New York to North Carolina… It’s a test of a new system that helps scientists study the auroras and ionosphere. A NASA sounding rocket (a small, sub-orbital rocket often used in research) will launch from Wallops Flight Facility off the coast of Virginia and release several soda-sized canisters of vapor tracers in the upper atmosphere that may appear as colorful clouds. The tracers use vapors made up of lithium, barium and tri-methyl aluminum that react with other elements in the atmosphere to glow, letting researchers visually track the flows of ionized and neutral particles. It’s a bit like being able to dye the wind or ocean currents to be able to get a visual picture. CNN adds that “If you’re near the eastern U.S. coast, look toward the eastern horizon beginning about 4:30 a.m. The farther you are from the launch location, the lower the clouds will appear on the horizon.” Basically, try to adjust your gaze towards Virginia’s eastern shore — and if you’re not on the east coast, NASA is livestreaming the launch and posting updates on Facebook and Twitter. Read more of this story at Slashdot.

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NASA Will Create Fake Red And Green Clouds Near Virginia

These Are the Wildly Advanced Space Exploration Concepts Being Considered by NASA

Earlier today, NASA announced funding for 22 projects as part of its Innovative Advanced Concepts (NIAC) program. From a planet hopping laser-driven sail and a solar powered Venusian weather balloon to an autonomous rover on Pluto, the future of space exploration looks incredibly bright. Read more…

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These Are the Wildly Advanced Space Exploration Concepts Being Considered by NASA

This Tricorder-Like Device Can Tell if Your Brain Is Bleeding

Following a head injury, patients typically undergo a CT scan to rule out brain bleeding. A new head worn device that scans the brain’s electrical patterns has shown tremendous promise in clinical trials, presenting an inexpensive way for physicians to make a potentially life-saving diagnosis. Read more…

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This Tricorder-Like Device Can Tell if Your Brain Is Bleeding

The US Army Finally Gets The World’s Largest Laser Weapon System

It’s been successfully tested on trucks, as well as UAVs and small rockets, according to a video from Lockheed Martin, which is now shipping the first 60kW-class “beam combined” fiber laser for use by the U.S. Army. An anonymous reader quotes the Puget Sound Business Journal: Lockheed successfully developed and tested the 58 kW laser beam earlier this year, setting a world record for this type of laser. The company is now preparing to ship the laser system to the U.S. Army Space and Missile Defense Command/Army Forces Strategic Command in Huntsville, Alabama [according to Robert Afzal, senior fellow for Lockheed’s Laser and Sensor Systems in Bothell]. “We have shown that a powerful directed energy laser is now sufficiently light-weight, low volume and reliable enough to be deployed on tactical vehicles for defensive applications on land, at sea and in the air…” Laser weapons, which complement traditional kinetic weapons in the battlefield, will one day protect against threats such as “swarms of drones” or a flurry of rockets and mortars, Lockheed said. Read more of this story at Slashdot.