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Mars Base

Chemistry's Biggest Loser: Official Atomic Weights Change For 19 Elements | Popular Sci... - 0 views

www.popsci.com/...mic-weights-change-19-elements

scibyte105 Chemistry

shared by Mars Base on 01 Oct 13 - No Cached
  • Improved measurements of different elements and their isotopes have changed the official atomic weights of 19 elements
  • The changes are relatively small, and they're part of a regular effort to update atomic weights
  • Every atom of an element
  • ...30 more annotations...
  • silver as an example
  • has the same number of protons
  • Silver has 47
  • not every atom of an element necessarily has the same number of neutrons
  • different versions of an element's atoms are called isotopes
  • Silver occurs as silver-109 and silver-107
  • Chemists calculate the atomic weight of an element that you see on the periodic table from the masses of its isotopes, giving more common isotopes more weight than less common isotopes
  • doesn't necessarily mean every sample of silver on Earth has an atomic weight of exactly
  • samples of elements vary from place to place
  • erences play an important role in many sciences
  • They help chemists trace the origin of different materials
  • and date archaeological findings
  • The latest atomic weights measurements differ too little from their predecessors to really change science
  • do it?"
  • If it's just small changes, why
  • should give the best numbers there are
  • some new idea will come up that needs more accurate data
  • Molybdenum, Losing 0.0122
  • Atomic weights are relative, so they don't have units
  • Thorium, Losing 0.000322
  • Yttrium and Niobium, Tied, Losing 0.00001
  • Selenium, Gaining 0.0088
  • Cadmium, Gaining 0.0026
  • Holmium, Thulium and Praseodymium, All Tied, Gaining 0.00001
  • The changes in weights mostly come from continuing improvements in atomic mass measurements
  • advances in the technology behind mass spectrometers
  • not all about measuring more accurately
  • thorium, the IUPAC decided to recognize an isotope, thorium-230, that it previously thought was too rare to include in atomic weight calculations
  • The last time international chemistry
  • really altered the periodic table was in 2009, when IUPAC decided to list the atomic weights of some elements as ranges, instead of single numbers
Mars Base

NASA rover's first soil studies help fingerprint Martian minerals - 0 views

phys.org/...-soil-fingerprint-martian.html

scibyte70 Curiosity

shared by Mars Base on 31 Oct 12 - No Cached
  • results of the first analysis of Martian soil by the Chemistry and Mineralogy (CheMin) experiment on NASA's Curiosity rover
  • presence of crystalline feldspar, pyroxenes and olivine mixed with some amorphous (non-crystalline) material
  • similar to volcanic soils in Hawaii
  • ...18 more annotations...
  • NASA's Mars rover Curiosity has completed initial experiments showing the mineralogy of Martian soil is similar to weathered basaltic soils of volcanic origin in Hawaii
  • used its Chemistry and Mineralogy instrument (CheMin)
  • quantitative results provide refined and in some cases new identifications of the minerals in this first X-ray diffraction analysis on Mars."
  • identification of minerals in rocks and soil is crucial for the mission's goal to assess past environmental conditions
  • mineral records the conditions under which it formed.
  • composition of a rock provides only ambiguous mineralogical information,
  • X-ray diffraction
  • minerals diamond and graphite, which have the same chemical composition, but strikingly different structures and properties.
  • CheMin uses X-ray diffraction,
  • reads minerals' internal structure by recording how their crystals distinctively interact with X-rays
  • provides more accurate identifications of minerals than any method previously used on Mars
  • The sample was processed through a sieve to exclude particles larger than 0.006 inch (150 micrometers), roughly the width of a human hair.
  • soil material CheMin has analyzed is more representative of modern processes on Mars
  • "We now know it is mineralogically similar to basaltic material
  • significant amounts of feldspar, pyroxene and olivine, which was not unexpected
  • Roughly half the soil is non-crystalline material, such as volcanic glass or products from weathering of the glass
  • ancient rocks, such as the conglomerates, suggest flowing water, while the minerals in the younger soil are consistent with limited interaction with water
  • "So far, the materials Curiosity has analyzed are consistent with our initial ideas of the deposits in Gale Crater recording a transition through time from a wet to dry environment
Mars Base

10 Amazing Things NASA's Huge Mars Rover Can Do | NASA, Mars Science Laboratory & Curio... - 0 views

www.space.com/s-rover-curiosity-science.html

scibyte22 Curiosity

shared by Mars Base on 20 Nov 11 - No Cached
  • Mast Camera (MastCam)
  • capture high-resolution color pictures and video of the Martian landscape, which scientists will study and laypeople will gawk at
  • Mars Hand Lens Imager (MAHLI)
  • ...43 more annotations...
  • will function much like a high-powered magnifying glass
  • instrument will take color pictures of features as tiny as 12.5 microns — smaller than the width of a human hair
  • MAHLI sits on the end of Curiosity's five-jointed, 7-foot (2.1-meter) robotic arm
  • Mars Descent Imager (MARDI)
  • small camera located on Curiosity's main body, will record video of the rover's descent to the Martian surface
  • will click on a mile or two above the ground, as soon as Curiosity jettisons its heat shield. The instrument will then take video at five frames per second until the rover touches down. The footage will help the MSL team plan Curiosity's Red Planet rovings, and it should also provide information about the geological context of the landing site, the 100-mile-wide
  • Sample Analysis at Mars (SAM)
  • makes up about half of the rover's science payload.
  • a suite of three separate instruments — a mass spectrometer, a gas chromatograph and a laser spectrometer
  • will search for carbon-containing compounds, the building blocks of life as we know it
  • look for other elements associated with life on Earth, such as hydrogen, oxygen and nitrogen
  • The rover's robotic arm will drop samples into SAM via an inlet on the rover's exterior
  • Chemistry and Mineralogy (CheMin)
  • CheMin will identify different types of minerals on Mars and quantify their abundance
  • will help scientists better understand past environmental conditions on the Red Planet
  • CheMin has an inlet on Curiosity's exterior to accept samples delivered by the rover's robotic arm
  • will shine a fine X-ray beam through the sample, identifying minerals' crystalline structures based on how the X-rays diffract
  • Chemistry and Camera (ChemCam)
  • This instrument will fire a laser at Martian rocks from up to 30 feet (9 meters) away and analyze the composition of the vaporized bits
  • help the mission team determine from afar whether or not they want to send the rover over to investigate a particular landform
  • The laser sits on Curiosity's mast, along with a camera and a small telescope
  • Three spectrographs sit in the rover's body, connected to the mast components by fiber optics
  • spectrographs will analyze the light emitted by excited electrons in the vaporized rock samples
  • Alpha Particle X-Ray Spectrometer (APXS)
  • sits at the end of Curiosity's arm, will measure the abundances of various chemical elements in Martian rocks and dirt
  • APXS will shoot out X-rays and helium nuclei. This barrage will knock electrons in the sample out of their orbits, causing a release of X-rays. Scientists will be able to identify elements based on the characteristic energies of these emitted X-rays
  • Dynamic Albedo of Neutrons (DAN)
  • located near the back of Curiosity's main body, will help the rover search for ice and water-logged minerals beneath the Martian surface
  • The instrument will fire beams of neutrons at the ground, then note the speed at which these particles travel when they bounce back. Hydrogen atoms tend to slow neutrons down, so an abundance of sluggish neutrons would signal underground water or ice
  • should be able to map out water concentrations as low as 0.1 percent at depths up to 6 feet (2 m).
  • Radiation Assessment Detector (RAD)
  • instrument will measure and identify high-energy radiation of all types on the Red Planet, from fast-moving protons to gamma rays
  • designed specifically to help prepare for future human exploration of Mars
  • will allow scientists to determine just how much radiation an astronaut would be exposed to on Mars
  • Rover Environmental Monitoring Station (REMS)
  • partway up Curiosity's mast, is a Martian weather station
  • measure atmospheric pressure, humidity, wind speed and direction, air temperature, ground temperature and ultraviolet radiation.
  • integrated into daily and seasonal reports
  • MSL Entry, Descent and Landing Instrumentation (MEDLI)
  • MEDLI isn't one of Curiosity's 10 instruments
  • will measure the temperatures and pressures the heat shield experiences as the MSL spacecraft streaks through the Martian sky
  • will tell engineers how well the heat shield, and their models of the spacecraft's trajectory, performed
  • data to improve designs for future Mars-bound spacecraft
Mars Base

Curiosity says 'Goodbye Kimberley' after Parting Laser Blasts and Seeking New Adventure... - 0 views

www.universetoday.com/...d-seeking-new-adventures-ahead

scibyte132 Curiosity

shared by Mars Base on 22 May 14 - No Cached
  • NASA’s rover Curiosity said ‘Goodbye Kimberley’ having fulfilled her objectives of drilling into a cold red sandstone slab
  • sampling the
  • grey colored interior and pelting the fresh bore hole with a pinpoint series of parting laser blasts
  • ...16 more annotations...
  • Since then, the 1 ton robot carefully scrutinized the resulting 2.6 inches (6.5 centimeters) deep bore hole
  • the mound of dark grey colored drill tailings piled around for an up close examination of the texture and composition with the MAHLI camera and spectrometers
  • successfully delivered pulverized and sieved samples to the pair of onboard miniaturized chemistry labs
  • Chemistry and Mineralogy instrument (CheMin)
  • Sample Analysis at Mars instrument (SAM)
  • for chemical and compositional analysis.
  • rover’s
  • decided that one drill campaign into Kimberley was enough.
  • So the rover will not be drilling into any other rock targets here
  • it may be a very long time before the next drilling
  • the guiding team of scientists and engineers wants
  • arrive at the foothills of Mount Sharp as soon as possible.
  • further analysis of the ‘Windjana’ sample along the way
  • there’s plenty of leftover sample material stored in the CHIMRA sample processing mechanism to allow future delivery of samples when the rover periodically pauses during driving.
  • Windjama lies some 2.5 miles (4 kilometers) southwest of Yellowknife Bay
  • still has about another 4 kilometers to go to reach the foothills of Mount Sharp sometime later this year
Mars Base

Mars Rover Opportunity Exploring Possibly Habitable Ancient Environment | Space.com - 0 views

www.space.com/ortunity-endeavour-crater.html

scibyte74 opportunity

shared by Mars Base on 05 Dec 12 - No Cached
  • Opportunity rover,
  • is currenlty studying clay deposits on the rim of the Red Planet's Endeavour Crater.
  • clays imply that the area was exposed to relatively neutral — as opposed to harshly acidic or basic — water long ago,
  • ...10 more annotations...
  • clearly show us a chemistry that would've been suitable for life at the Opportunity site
  • Mars Reconnaissance Orbiter spacecraft spotted them from orbit, leading the rover team to point the golf-cart-size robot toward its current location, which is known as Matijevic Hill.
  • From orbit, we have seen the unambiguous infrared spectral signature of clays along the rim of Endeavour Crater
  • Opportunity has already circumnavigated Matijevic Hill
  • ikely stay at Matijevic Hill for a while, trying to understand how the clays were laid down billions of years ago
  • Opportunity is still going strong. It has some age-related issues, such as an arthritic arm, but the rover remains in good health
  • Part of the work will involve investigating mysterious tiny spherules Opportunity has discovered embedded in the clay matrix
  • initially thought the BB-size gray spheres were similar to the iron-rich "blueberries"
  • initial analyses have shown that's not the case, leading Squyres to dub them "newberries."
  • The team isn't sure exactly what the newberries are, or how they formed
Mars Base

Opportunity Rover Glimpses Conditions Suitable for Life - 0 views

www.universetoday.com/...s-conditions-suitable-for-life

scibyte74

shared by Mars Base on 05 Dec 12 - No Cached
  • first glimpse ever at conditions on ancient Mars that clearly show us a chemistry that would have been suitable for life.”
  • both the MER rovers have found evidence of past water on Mars, all indications are that it would have been very acidic
  • “battery-acid kind of numbers making it very challenging for life
  • ...3 more annotations...
  • Newly found clays that are sprinkled with two different kinds of previously unseen features point to a different type of water “that you could drink,”
  • Orbital data from the Mars Reconnaissance Orbiter
  • originally led the MER team to Endeavour Crater, the huge crater where Opportunity is now traversing around the rim.
Mars Base

Distant planets' atmospheres revealed | Atom & Cosmos | Science News - 0 views

www.sciencenews.org/...t_planets_atmospheres_revealed

scibyte86 exoplanet

shared by Mars Base on 15 Mar 13 - No Cached
  • Astronomers have gotten the most detailed look yet at the atmosphere of a planet outside the solar system
  • The study is among the first to directly analyze the chemical makeup of an exoplanet
  • In the past, astronomers inferred the existence of exoplanets and their gases by looking for subtle changes in the light streaming from the planet’s star
  • ...42 more annotations...
  • Now, with improved instruments, a team
  • has detected light coming directly from a planet light-years away
  • The data have high enough resolution to reveal not only the presence but the abundance of carbon monoxide and water in the planet’s atmosphere
  • Such information could shed light on how the planet formed
  • studies could also reveal the presence of life on a distant planet, but the planet’s size and orbit have already ruled it out as a habitable world
  • In 2008
  • the first image of a multiplanet system outside the solar system, showing three gas giants orbiting the star HR 8799
  • HR 8799 is about 130 light-years from Earth, in the constellation Pegasus
  • The planets are scorching hot, making them bright enough for astronomers to detect directly
  • In 2010, the researchers imaged a fourth planet around HR 8799
  • In the new study
  • focused on one of these planets, HR 8799c.
  • Five to 10 times as massive as Jupiter, HR 8799c sits about eight times farther away from its star than Jupiter does from the sun
  • Because of that great distance, the astronomers could block the star’s light and record infrared light
  • Because different gases absorb and emit light in distinct ways, the team could identify carbon monoxide and water but found no methane, which scientists had thought might be present.
  • In another new study
  • researchers simultaneously collected infrared light from the atmospheres of all four planets
  • A team led by
  • an astrophysicist at the American Museum of Natural History in New York City, found hints of ammonia, methane, carbon dioxide and acetylene in the planets’ atmospheres
  • The chemistry of each planet varies
  • different from anything in our own solar system
  • Although the teams looked at different wavelengths of light, which pick up different types of molecules, the two studies appear consistent
  • by peering at just one planet, Konopacky’s team obtained more detailed data that allowed the researchers to get a sense of how much carbon and oxygen is in HR 8799c’s atmosphere
  • Knowing the ratio of carbon to oxygen in the atmosphere may reveal how the planet formed
  • Astronomers have two competing theories of how planets arise from the disk of gas and dust encircling a young star
  • In the gravitational instability model, some of the gas and dust suddenly clumps and collapses, simultaneously creating a planet’s core and atmosphere
  • In this scenario, the chemical composition of a planet should match that of its star
  • In the other model, known as core accretion, planet building is a two-step process
  • First, material from the disk accumulates into a core.
  • Later, the core captures gases swirling in the disk to form an atmosphere.
  • In this case, the carbon-to-oxygen ratio of the planet may differ from the star because the accretion of cores may deplete the disk of certain elements
  • Compared with its star, HR 8799c appears to have slightly more carbon relative to oxygen, suggesting the planet originated via core accretion
  • surmise that when the disk around HR 8799 formed, water froze into particles of ice.
  • The bits of ice collided to form the planet’s core, leaving behind little water vapor, and therefore less oxygen, when the planet accumulated its atmosphere later on
  • Other researchers are not convinced by this conclusion
  • “We don’t really understand planetary formation enough to make a strong case either way,”
  • the data from both new studies may help astronomers refine their simulations of planetary formation
  • astronomers have directly imaged planets around three distant stars
  • researchers are poised to capture light from many more planets
  • Project 1640,
  • is looking for Jupiter-sized planets around some 200 stars
  • “Ultimately, with better instruments, people will be able to use these methods on Earthlike planets.”
Mars Base

Science Retractions: Top 5 Withdrawn Studies Of 2012 - 0 views

www.huffingtonpost.com/...ithdrawn-papers_n_2353421.html

scibyte76 Retraction

shared by Mars Base on 01 Jan 13 - No Cached
  • Hyung-In Moon is a genius, says Hyung-In Moon
  • Korean scientist Hyung-In Moon took the concept of scientific peer review to a whole new level by reviewing his own papers under various fake names
  • Moon's research — which included a study on alcoholic liver disease and another on an anticancer plant substance — can't be trusted
  • ...33 more annotations...
  • admitted to falsifying data in some of his papers
  • , 35 of his papers have been retracted in 2012.
  • Peer review is a process in which scientific peers in the same field judge the merit of a submitted journal paper
  • editors at the Journal of Enzyme Inhibition and Medicinal Chemistry grew suspicious when four of his glowing reviews came back within 24 hours. Anyone who has ever submitted a paper for peer review knows that reviewers take weeks or months to reply
  • Math paper a big, fat zero
  • "In this study, a computer application was used to solve a mathematical problem"
  • Neither the one-sentence abstract
  • nor the co-author's e-mail address, ohm@budweiser.com
  • publishing this one-page gem entitled "A computer application in mathematics"
  • published in January 2010 but not retracted until April 2012, despite silly sentences such as "Computer magnification is a Universal computer phenomenon" and "This is a problematic problem."
  • retracted the paper because it "contains no scientific content." The editors chalked it up to "an administrative error
  • Maybe his failure doesn't feel better than success
  • The Dutch social psychologist Diederik Stapel
  • has found that,
  • failure sometimes feels better than success
  • The only problem is that his research appears to be either mostly or completely fabricated
  • work has appeared in top journals
  • his good looks and clever research topics made him a media darling
  • So far, 31 papers have been retracted
  • meat eaters are absolved: One of Stapel's studies, now suspected to be fabricated, found that meat eaters are more selfish and less social than vegetarians
  • Studies proposing a link between cellphone use and cancer often rely on weak statistics. This one just used fudged data
  • in 2008, scientists published a paper
  • stating that cellphones in standby mode lowered the sperm count and caused other adverse changes in the testicles of rabbits
  • although small and published in a rather obscure journal, made the news rounds.
  • In March 2012, the authors retracted the paper
  • the lead author didn't get permission from his two co-authors and, according to the retraction notice, there was a "lack of evidence to justify the accuracy of the data presented in the article."
  • Stem-cell cure for heart disease likely faked
  • biologist Shinya Yamanaka had just won the 2012 Nobel Prize for his discovery of induced pluripotent stem cells (iPS cells), which are adult cells that can be reprogrammed to their "embryonic" stage
  • claimed at a New York Stem Cell Foundation meeting in early October to have advanced this technology to cure a person with terminal heart failure
  • Two institutions listed as collaborating on Moriguchi's related papers
  • denied that any of Moriguchi's procedures took place there
  • origuchi has admitted only to making some "procedural" mistakes
  • He is sticking to his story, however, that one patient was cured … at a Boston hospital not yet named
Mars Base

Mars Science Laboratory: Images - 0 views

mars.jpl.nasa.gov/...images

scibyte91 Curiosity

shared by Mars Base on 21 Apr 13 - No Cached
  • NASA's Curiosity Mars rover targeted the laser of the Chemistry and Camera (ChemCam) instrument with remarkable accuracy for assessing the composition of the wall of a drilled hole and tailings that resulted from the drilling
  • ChemCam fired its laser 150 times (5 bursts of 30 shots, each burst at a different target point) on the drill tailings between the two holes and 300 times (10 bursts of 30 shots) in the drill hole itself
  • The same day, ChemCam's remote micro-imager (RMI) captured images of the laser pits: small craters in the loose tailing
  • ...1 more annotation...
  • and tiny scrapes on the hard surface of the hole walls
  • Mars Base on 21 Apr 13
     
    Accurate pointing by Curiosity
Mars Base

Mars Science Laboratory: NASA Curiosity Rover Team Selects Second Drilling Target On Mars - 0 views

mars.jpl.nasa.gov/...index.cfm

scibyte94 Curiosity

shared by Mars Base on 10 May 13 - No Cached
  • The team operating NASA's Curiosity Mars rover has selected a second target rock for drilling and sampling. The rover will set course to the drilling location in coming days.
  • "Cumberland," lies about nine feet (2.75 meters) west of the rock where Curiosity's drill first touched Martian stone in February
  • Both rocks are flat, with pale veins and a bumpy surface. They are embedded in a layer of rock on the floor of a shallow depression called "Yellowknife Bay.
  • ...6 more annotations...
  • This second drilling is intended to confirm results from the first drilling, which indicated the chemistry of the first powdered sample from John Klein was much less oxidizing than that of a soil sample the rover scooped up before it began drilling.
  • Cumberland and John Klein are very similar, Cumberland appears to have more of the erosion-resistant granules that cause the surface bumps
  • concretions, or clumps of minerals, which formed when water soaked the rock long ago
  • Mission engineers
  • recently finished upgrading Curiosity's operating software following a four-week break
  • rover continued monitoring the Martian atmosphere during the break, but the team did not send any new commands
Mars Base

Mars Science Laboratory: NASA Curiosity Rover Collects First Martian Bedrock Sample - 0 views

mars.jpl.nasa.gov/...index.cfm

scibyte81 Curiosity

shared by Mars Base on 11 Feb 13 - No Cached
  • Rock powder generated during drilling travels up flutes on the bit
  • The bit assembly has chambers to hold the powder until it can be transferred to the sample-handling mechanisms of the rover's Collection and Handling for In-Situ Martian Rock Analysis (CHIMRA) device
  • Before the rock powder is analyzed, some will be used to scour traces of material that may have been deposited onto the hardware while the rover was still on Earth, despite thorough cleaning before launch
  • ...7 more annotations...
  • take the powder we acquired and swish it around to scrub the internal surfaces of the drill bit assembly
  • use the arm to transfer the powder out of the drill into the scoop, which will be our first chance to see the acquired sample
  • To get to the point of making this hole in a rock on Mars, we made eight drills and bored more than 1,200 holes in 20 types of rock on Earth
  • Inside the sample-handling device, the powder will be vibrated once or twice over a sieve that screens out any particles larger than six-thousandths of an inch (150 microns) across
  • portions of the sieved sample will fall through ports on the rover deck into the Chemistry and Mineralogy (CheMin) instrument and the Sample Analysis at Mars (SAM) instrument
  • "John Klein" in memory of a Mars Science Laboratory deputy project manager who died in 2011
  • The fresh hole, about 0.63 inch (1.6 centimeters) wide and 2.5 inches (6.4 centimeters) deep in a patch of fine-grained sedimentary bedrock, can be seen in images and other data Curiosity beamed to Earth Saturday.
Mars Base

Japanese Team Claims Discovery Of Elusive Element 113, And May Get To Name It | Popular... - 0 views

www.popsci.com/...lement-113-and-may-get-name-it

scibyte65 elements

shared by Mars Base on 30 Sep 12 - No Cached
  • Japanese researchers claim they’ve seen conclusive evidence of the long-sought element 113, a super-heavy, super-unstable element near the bottom of the periodic table
  • not yet verified by the International Union of Pure and Applied Chemistry
  • if the IUPAC grants its blessing, the researchers could be the first team from Asia to name one of nature’s fundamental atoms.
  • ...5 more annotations...
  • Super-heavy elements do not occur in nature and have to be discovered in the lab, using particle accelerators, nuclear reactors, ion separators and other complex equipment
  • Science have been hunting for 113 for nine years, and have claimed to see it a few times already — but the evidence has never been this clear,
  • the team used a customized gas-filled recoil ion separator paired with a semiconductor detector that can pick out atomic reaction products
  • created element 113 by speeding zinc ions through a linear accelerator until they reached 10 percent of the speed of light.
  • ions then smashed into a piece of bismuth. When the zinc and bismuth atoms fused, they produced an atom with 113 protons
Mars Base

Unprecedented Maya Mural Found, Contradicts 2012 "Doomsday" Myth - 0 views

news.nationalgeographic.com/...-calendar-end-of-world-science

scibyte46 MayanCalender

shared by Mars Base on 11 May 12 - No Cached
  • last known largely unexcavated Maya megacity, archaeologists have uncovered the only known mural adorning an ancient Maya house
  • still vibrant scene of a king and his retinue
  • walls are rife with calculations that helped ancient scribes track vast amounts of time
  • ...21 more annotations...
  • markings suggest dates thousands of years in the future
  • Perhaps most important, the otherwise humble chamber offers a rare glimpse into the inner workings of Maya society
  • in today's Xultún
  • just 6 square miles (16 square kilometers) of jungle floor—it's a wonder Saturno's team found the artwork at all
  • At the Guatemalan site in 2010 the Boston University archaeologist and Ph.D. student Franco Rossi were inspecting a looters' tunnel, where an undergraduate student had noticed the faintest traces of paint on a thin stucco wall.
  • began cleaning off 1,200-year-old mud and suddenly a little more red paint appeared.
  • What the team found, after a full excavation in 2011, is likely the ancient workroom of a Maya scribe, a record-keeper of Xultún.
  • this was a workspace. People were seated on this bench" painting books that have long since disintegrated
  • The books would have been filled with elaborate calculations intended to predict the city's fortunes. The numbers on the wall were "fixed tabulations that they can then refer to—tables more or less like those in the back of your chemistry book," he added.
  • Undoubtedly this type of room exists at every Maya site in the Late Classic [period] and probably earlier, but it's our only example thus far."
  • Maya civilization spanned much of what are now Guatemala, Belize, and Mexico's Yucatán region. Around A.D. 900 the Classic Maya centers, including Xultún, collapsed after a series of droughts and perhaps political conflicts
  • The apparent desperation of those final years may have played out on the walls of the newly revealed room—the only major excavation so far in Xultún.
  • Despite past looting, the interior of the newfound room is nearly perfectly preserved.
  • Among the artworks on the three intact walls is a detailed orange painting of a man wearing white disks on his head and chest—likely the scribe himself
  • the researchers noticed several barely visible hieroglyphic texts, painted and etched along the east and north walls of the room
  • One is a lunar table, and the other is a "ring number"—something previously known only from much later Maya books, where it was used as part of a backward calculation in establishing a base date for planetary cycles
  • Nearby is a sequence of numbered intervals corresponding to key calendrical and planetary cycles.
  • The calculations include dates some 7,000 years in the future
  • The Maya at Xultún were likely less concerned with the end of the world than the end of their world
  • Sadly, we may never understand the full context of the workroom. Many of the glyphs are badly faded. Worse, the entire city of Xultún was looted clean during the 70s, leaving very little other writing or antiquities.
  • Because of this, and despite Xultún's obvious prominence in the Maya world, many archaeologists had written off the
Mars Base

Nanotechnology breakthrough could dramatically improve medical tests - 0 views

phys.org/...logy-breakthrough-medical.html

scibyte49 NanoDevice MedicalTreatment

shared by Mars Base on 01 Jun 12 - No Cached
  • The material consists of a series of glass pillars in a layer of gold. Each pillar is speckled on its sides with gold dots and capped with a gold disk. Each pillar is just 60 nanometers in diameter, 1/1,000th the width of a human hair
  • laboratory test used to detect disease and perform biological research could be made more than 3 million times more sensitive
  • increased performance could greatly improve the early detection of cancer, Alzheimer's disease and other disorders by allowing doctors to detect far lower concentrations of telltale markers than was previously practical.
  • ...20 more annotations...
  • The greater the glow, the more of the biomarker is present.
  • if the amount of biomarker is too small, the fluorescent light is too faint to be detected, setting the limit of detection
  • major goal in immunoassay research is to improve the detection limit.
  • involves a common biological test called an immunoassay, which mimics the action of the immune system to detect the presence of biomarkers
  • When biomarkers are present
  • the immunoassay test produces a fluorescent glow (light) that can be measured in a laboratory
  • tackled this limitation by using nanotechnology to greatly amplify the faint fluorescence from a sample
  • fashioning glass and gold structures so small they could only be seen with a powerful electron microscope
  • able to drastically increase the fluorescence signal compared to conventional immunoassays, leading to a 3-million-fold improvement in the limit of detection
  • key to the breakthrough lies in a new artificial nanomaterial called D2PA
  • a thin layer of gold nanostructures surrounded glass pillars just 60 nanometers in diameter.
  • A nanometer is one billionth of a meter; that means about 1,000 of the pillars laid side by side would be as wide as a human hair.
  • e pillars are spaced 200 nanometers apart and capped with a disk of gold on each pillar
  • sides of each pillar are speckled with even tinier gold dots about 10 to 15 nanometers in diameter
  • a sample such as blood, saliva or urine is taken from a patient and added to small glass vials containing antibodies that are designed to "capture" or bind to biomarkers of interest in the sample
  • Another set of antibodies that have been labeled with a fluorescent molecule are then added to the mix
  • biomarkers are not present in the vials
  • fluorescent detection antibodies do not attach to anything and are washed away
  • immunoassays are commonly used in drug discovery and other biological research.
  • plays a significant role in other areas of chemistry and engineering, from light-emitting displays to solar energy harvesting
Mars Base

Water Boils Sans Bubbles - Science News - 0 views

www.sciencenews.org/...Water_boils_sans_bubbles

scibyte63 BoilingWater

shared by Mars Base on 13 Sep 12 - No Cached
  • researchers covered a steel ball with Glaco Mirror Coat, a water-hating material, along with some other water-repelling chemical
  • turned the sphere’s exterior into a nanoscale mountain range peppered with deep valleys
  • Heating the sphere to 400º Celsius and dropping it in room-temperature water spurred boiling, but no furious bubbles
  • ...3 more annotations...
  • water near the sphere became vapor that got trapped in the valleys on the sphere’s surface. Eventually this sheet of vapor slipped off and a new one formed
  • Treating the surface of another sphere to make it water-loving had the opposite effect, locking the water in the violent bubbling phase
  • Manipulating this phase-chemistry could lead to tricks for reducing drag on ships or preventing forceful bubbling explosions in labs or kitchens
Mars Base

Telescope spies water plumes on dwarf planet Ceres - 0 views

phys.org/...spies-plumes-dwarf-planet.html

scibyte117 Asteroid Ceres

shared by Mars Base on 23 Jan 14 - No Cached
  • Scientists
  • have made the first definitive detection of water vapor on the largest and roundest object in the asteroid belt, Ceres.
  • Plumes of water vapor are thought to shoot up periodically from Ceres when portions of its icy surface warm slightly
  • ...26 more annotations...
  • Ceres is classified as a dwarf planet, a solar system body bigger than an asteroid and smaller than a planet.
  • "This is the first time water vapor has been unequivocally detected on Ceres or any other object in the asteroid belt and provides proof that Ceres has an icy surface and an atmosphere,"
  • Michael Küppers of ESA in Spain
  • NASA's Dawn mission, which is on its way to Ceres now after spending more than a year orbiting the large asteroid Vesta
  • Dawn is scheduled to arrive at Ceres in the spring of 2015, where it will take the closest look ever at its surface.
  • will map the geology and chemistry of the surface in high resolution
  • International Astronomical Union, the governing organization responsible for naming planetary objects
  • Ceres was known as the largest asteroid in our solar system
  • reclassified Ceres as a dwarf planet because of its large size. It is roughly 590 miles (950 kilometers) in diameter
  • When it first was spotted in 1801, astronomers thought it was a planet orbiting between Mars and Jupiter
  • Scientists believe Ceres contains rock in its interior with a thick mantle of ice that, if melted, would amount to more fresh water than is present on all of Earth
  • The materials making up Ceres likely date from the first few million years of our solar system's existence and accumulated before the planets formed.
  • Until now, ice had been theorized to exist on Ceres but had not been detected conclusively
  • far-infrared vision to see, finally, a clear spectral signature of the water vapor. But
  • did not see water vapor every time it looked
  • spied water vapor four different times, on one occasion there was no signature.
  • what scientists think is happening
  • when Ceres swings through the part of its orbit that is closer to the sun, a portion of its icy surface becomes warm enough to cause water vapor to escape in plumes
  • a rate of about 6 kilograms (13 pounds) per second
  • When Ceres is in the colder part of its orbit, no water escapes
  • The strength of the signal also varied over hours, weeks and months
  • water vapor plumes rotating in and out of Herschel's views as the object spun on its axis
  • This enabled the scientists to localize the source of water to two darker spots on the surface of Ceres
  • previously seen by NASA's Hubble Space Telescope and ground-based telescopes. The dark spots might be more likely to outgas because dark material warms faster than light material.
  • "The lines are becoming more and more blurred between comets and asteroids," said Seungwon Lee of JPL
  • Paul von Allmen, also of JPL. "We knew before about main belt asteroids that show comet-like activity, but this is the first detection of water vapor in an asteroid-like object."
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