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Mars Base

Could Blue Light Help Fight Fatigue? Study - 0 views

www.scienceworldreport.com/...t-help-fight-fatigue-study.htm

scibyte119

shared by Mars Base on 04 Feb 14 - No Cached
  • According to researchers
  • , they've found that exposure to short wavelength, or blue light, during the day can improve alertness and overall performance.
  • previous research has shown that blue light is able to improve alertness during the night, but our new data demonstrates that these effects also extend to daytime
  • ...12 more annotations...
  • "These findings demonstrate that prolonged blue light exposure during the day has an an alerting effect."
  • researchers measured wavelengths of light that were most effective in warding off fatigue via the development of specialized light equipment
  • compared the effects of blue light exposure to an equal amount of green light on alertness and performance in 16 study participants for 6.5 hours over a day.
  • participants were rated based on how they felt through reaction times that measured electrodes to assess changes going on in the brain due to light exposure.
  • Results showed that participants exposed to blue light consistently rated themselves as less sleepy with quicker reaction times and fewer attention relapses.
  • They also showed changes in brain activity patterns that indicated a more alert state.
  • open up a new range of possibilities for using light to improve human alertness, productivity and safety
  • helping to improve alertness in night workers has obvious safety benefits, day shift workers may also benefit
  • better quality lighting that would not only help them see better but also make them more alert
  • next big challenge is to determine how to deliver better lighting in many places
  • such as schools, homes and work places that could
  • provide a more productive and alert atmosphere.
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

Reseachers develop holographic technique for bionic vision - 0 views

medicalxpress.com/...c-technique-bionic-vision.html

scibyte84 BionicEye

shared by Mars Base on 27 Feb 13 - No Cached
  • Researchers
  • are testing the power of holography to artificially stimulate cells in the eye, with hopes of developing a new strategy for bionic vision restoration
  • optogenetics
  • ...16 more annotations...
  • uses gene therapy to deliver light-sensitive proteins to damaged retinal nerve cells
  • The basic idea of optogenetics is to take a light-sensitive protein from another organism, typically from algae or bacteria, and insert it into a target cell, and that photosensitizes the cell
  • Intense pulses of light can activate nerve cells newly sensitized by this gene therapy approach
  • researchers around the world are still searching for the best way to deliver the light patterns so that the retina "sees" or responds in a nearly normal way
  • The plan is to someday develop a prosthetic headset or eyepiece that a person could wear to translate visual scenes into patterns of light that stimulate the genetically altered cells.
  • The key, they say, is to use a light stimulus that is intense, precise, and can trigger activity across a variety of cells all at once.
  • The researchers turned to holography after exploring other options, including laser deflectors and digital displays
  • Digital light displays can stimulate many nerve cells at once, "but they have low light intensity and very low light efficiency
  • The genetically repaired cells are less sensitive to light than normal healthy retinal cells, so they preferably need a bright light source like a laser to be activated
  • Lasers give intensity, but they can't give the parallel projection
  • needed to see a complete picture
  • researchers have tested the potential of holographic stimulation in retinal cells in the lab
  • done some preliminary work with the technology in living mice with damaged retinal cells
  • The experiments show that holography can provide reliable and simultaneous stimulation of multiple cells at millisecond speeds.
  • implementing a holographic prosthesis in humans is far in the future
  • holography itself "also provides a very interesting path toward three-dimensional stimulation
Mars Base

Alien Super-Earth Light Seen for 1st Time | Exoplanet Search | Space.com - 0 views

www.space.com/light-detected-55-cancrie.html

scibyte45 exoplanet Spitzer

shared by Mars Base on 09 May 12 - No Cached
  • Light from an alien "super-Earth" twice the size of our own Earth has been detected by a NASA space telescope for the first time
  • spotted light from the alien planet 55 Cancri e, which orbits a star 41 light-years from Earth
  • A year on the extrasolar planet lasts just 18 hours
  • ...27 more annotations...
  • 55 Cancri e was first discovered in 2004 and is not a habitable world
  • The world is about twice the width of Earth and is super-dense, with about eight times the mass of Earth.
  • until now, scientists have never managed to detect the infrared light from the super-Earth world.
  • pioneering the study of atmospheres of distant planets and paving the way for NASA's upcoming James Webb Space Telescope
  • Spitzer first detected infrared light from an alien planet in 2005
  • that world was "hot Jupiter," a gas giant planet much larger than 55 Cancri e that orbited extremely close to its parent star
  • other telescopes have performed similar feats
  • Spitzer's view of the 55 Cancri e is the first time the light from a rocky super-Earth type planet has been seen
  • Since the discovery of 55 Cancri e, astronomers have pinned down increasingly strange features about the planet
  • already knew it was part of an alien solar system containing five exoplanets centered on the star 55 Cancri in the constellation Cancer
  • But 55 Cancri e stood out because it is ultra-dense and orbits extremely close to its parent star
  • 26 times closer than the distance between Mercury and our own sun
  • observations revealed that the star-facing side of 55 Cancri e
  • temperatures reaching up to 3,140 degrees Fahrenheit (1,726 degrees Celsius).
  • likely a dark world that lacks the substantial atmosphere needed to warm its nighttime side
  • the planet is oozing
  • Past observations of the planet by the Spitzer Space Telescope have suggested that one-fifth of 55 Cancri e is made up of lighter elements, including water
  • the extreme temperatures and pressures on 55 Cancri e would create what scientists call a "supercritical fluid" state
  • Supercritical fluids can be imagined as a gas in a liquid state, which can occur under extreme pressures and temperatures
  • On Earth, water can become a supercritical fluid inside some steam engines.
  • This graphic illuminates the process by which astronomers using NASA's Spitzer Space Telescope have for the first time detected the light from a super-Earth planet, the alien world of 55 Cancri e 41 light-years from Earth.
  • planet is likely a rocky world covered with water in a supercritical fluid state and topped off with a steam blanket
  • could be very similar to Neptune, if you pulled Neptune in toward our sun and watched its atmosphere boil away
  • detailed in the Astrophysical Journal
  • Spitzer Space Telescope launched in 2003
  • telescope engineers modified several settings on the observatory to optimize its alien planet vision
  • conceived of Spitzer more than 40 years ago
Mars Base

Researchers identify brain cells responsible for keeping us awake - 0 views

medicalxpress.com/...1-brain-cells-responsible.html

scibyte20 brain sleep light

shared by Mars Base on 04 Nov 11 - No Cached
  • Bright light makes it easier to stay awake
  • Very bright light not only arouses us but is known to have antidepressant effects.
  • Bright light makes it easier to stay awake.
  • ...14 more annotations...
  • dark rooms can make us sleepy.
  • researchers at UCLA have identified the group of neurons that mediates whether light arouses us — or not
  • the cells necessary for a light-induced arousal response are located in the hypothalamus
  • an area at the base of the brain responsible for, among other things, control of the autonomic nervous system, body temperature, hunger, thirst, fatigue — and sleep.
  • the activity of hypocretin neurons in their WT littermates was maximized when working for positive rewards during the light phase, but the cells were not activated when performing the same tasks in the dark phase.
  • This same UCLA research group earlier determined that the loss of hypocretin was responsible for narcolepsy and the sleepiness associated with Parkinson's disease
  • This current finding explains prior work in humans that found that narcoleptics lack the arousing response to light, unlike other equally sleepy individuals
  • researchers examined the behavioral capabilities of mice that had their hypocretin genetically "knocked-out" (KO mice) and compared them with the activities of normal, wild-type mice (WT) that still had their hypocretin neurons
  • they found that the KO mice were only deficient at working for positive rewards during the light phase
  • During the dark phase, however, these mice learned at the same rate as their WT littermates and were completely unimpaired in working for the same rewards
  • These cells release a neurotransmitter called hypocretin
  • findings suggest that administering hypocretin and boosting the function of hypocretin cells will increase the light-induced arousal response
  • Conversely, blocking their function by administering hypocretin receptor blockers will reduce this response and thereby induce sleep
  • implications for treating sleep disorders as well as depression
Mars Base

Aurora Oddity: Northern Lights Flare Up Without Big Sun Eruption | Space.com - 0 views

www.space.com/e-northern-lights-display.html

scibyte34 aurora ymhs

shared by Mars Base on 18 Feb 12 - No Cached
  • Northern Lights Display Dazzles Without Big Sun Flare
  • reasons scientists can't yet explain, the northern lights blazed up in a dazzling display this week
  • despite the apparent lack of a major solar flare typically associated with these celestial light shows
  • ...13 more annotations...
  • began on Valentine's Day (Feb. 14),
  • uptick in activity in Earth's magnetic field sparked a geomagnetic storm
  • Sometimes the sky surprises us
  • with little warning, geomagnetic activity rippled around the Arctic Circle
  • producing an outbreak of auroras
  • among the best in months
  • some early speculation that a Feb. 10 sun storm, known as a coronal mass ejection (CME), may have triggered the northern lights show, but this solar outburst has not yet been confirmed.
  • occur when charged particles from the sun interact with Earth's upper atmosphere
  • creating ripples of glowing light
  • charged particles are funneled to Earth's poles by the planet's magnetic field
  • typically only visible to skywatchers in far northern or far southern latitudes
  • northern lights are called the aurora borealis
  • southern lights are dubbed the aurora australis
Mars Base

Star Trek's 'tractor' beam created in miniature by researchers - 0 views

phys.org/...ar-trek-tractor-miniature.html

scibyte79 TractorBeam

shared by Mars Base on 25 Jan 13 - No Cached
  • Although light manipulation techniques have existed since the 1970s, this is the first time a light beam has been used to draw objects towards the light source, albeit at a microscopic level.
  • Researchers
  • have found a way to generate a special optical field that efficiently reverses radiation pressure of light.
  • ...12 more annotations...
  • The new technique could lead to more efficient medical testing, such as in the examination of blood samples
  • The team
  • discovered a technique which will allow them to provide 'negative' force acting upon minuscule particles
  • Normally when matter and light interact the solid object is pushed by the light and carried away in the stream of photons
  • Such radiation force was first identified by Johanes Kepler when observing that tails of comets point away from the sun
  • Over recent years researchers have realised that while this is the case for most of the optical fields, there is a space of parameters when this force reverses.
  • scientists
  • have now demonstrated the first experimental realisation of this concept together with a number of exciting applications for bio-medical photonics and other disciplines
  • The exciting aspect is that the occurrence of negative force is very specific to the properties of the object, such as size and composition
  • allows optical sorting of micro-objects in a simple and inexpensive device
  • optical fractionation has been identified as one of the most promising bio-medical applications of optical manipulation allowing
  • scientists identified certain conditions, in which objects held by the "tractor" beam force-field, re-arranged themselves to form a structure which made the beam even stronger
Mars Base

New 'super-black' material absorbs light across multiple wavelength bands - 0 views

www.physorg.com/...sorbs-multiple-wavelength.html

light scibyte21

shared by Mars Base on 10 Nov 11 - No Cached
  • NASA engineers have produced a material that absorbs on average more than 99 percent of the ultraviolet, visible, infrared, and far-infrared light that hits it
  • The team has since reconfirmed the material's absorption capabilities in additional testing
  • Though other researchers are reporting near-perfect absorption levels mainly in the ultraviolet and visible, our material is darn near perfect across multiple wavelength bands, from the ultraviolet to the far infrared
  • ...10 more annotations...
  • "No one else has achieved this milestone yet."
  • The nanotech-based coating is a thin layer of multi-walled carbon nanotubes, tiny hollow tubes made of pure carbon about 10,000 times thinner than a strand of human hair
  • They are positioned vertically on various substrate materials much like a shag rug
  • team has grown the nanotubes on silicon, silicon nitride, titanium, and stainless steel, materials commonly used in space-based scientific instruments
  • application is stray-light suppression
  • the team found that the material absorbs 99.5 percent of the light in the ultraviolet and visible
  • 98 percent in the longer or far-infrared bands
  • We knew it was absorbent. We just didn't think it would be this absorbent from the ultraviolet to the far infrared
  • If used in detectors and other instrument components, the technology would allow scientists to gather hard-to-obtain measurements of objects so distant in the universe that astronomers no longer can see them in visible light or those in high-contrast areas, including planets in orbit around other stars
  • More than 90 percent of the light Earth-monitoring instruments gather comes from the atmosphere, overwhelming the faint signal they are trying to retrieve
Mars Base

Light From a 'SuperEarth' Detected for the First Time - 0 views

www.universetoday.com/...th-detected-for-the-first-time

scibyte46 Spitzer exoplanet

shared by Mars Base on 09 May 12 - No Cached
  • 55 Cancri
  • one of the first known stars to host an extrasolar planet
  • discovered via radial velocity measurements in 2004
  • ...13 more annotations...
  • astronomers were able to determine its mass and radius
  • Spitzer became the first telescope to detect light from a planet beyond our solar system, when it saw the infrared light of a “hot Jupiter
  • NASA’s Hubble and Kepler space telescopes
  • using the same method
  • In this method, a telescope gazes at a star as a planet circles behind it. When the planet disappears from view, the light from the star system dips ever so slightly, but enough that astronomers can determine how much light came from the planet itself
  • information reveals the temperature of a planet, and, in some cases, its atmospheric components
  • other current planet-hunting methods obtain indirect measurements of a planet by observing its effects on the star.
  • about 8.57 Earth masses
  • radius is 1.63 times that of Earth
  • density is 10.9 ± 3.1 g cm-3 (the average density of Earth is 5.515 g cm-3),
  • Cancri e is tidally locked, so one side always faces the star
  • James Webb Space Telescope, scheduled to launch in 2018, likely will be able to learn even more about the planet’s composition
  • might be able to use a similar infrared method to Spitzer to search other potentially habitable planets for signs of molecules possibly related to life.
Mars Base

Smart headlights let drivers see between the raindrops - 0 views

phys.org/...dlights-drivers-raindrops.html

scibyte53 headlight

shared by Mars Base on 05 Jul 12 - No Cached
  • During low-light conditions, drivers rely mainly on headlights to see the road but the same headlights reduce visibility when light is reflected off of precipitation back to the driver
  • Carnegie Mellon professor and his team
  • Computer science professor Srinivasa Narasimhan
  • ...22 more annotations...
  • stream light in between the drops
  • answer consists of a co-located imaging and illumination system-- camera, projector, and beamsplitter
  • integrate an imager and processing unit with a light source
  • camera images the precipitation at the top of the field of view
  • processor can tell where the drops are headed and sends a signal to the headlights
  • make their adjustments and react to dis-illuminate the particles
  • entire action, starting from capture to reaction, takes about 13 ms.
  • system runs at 120 Hz. The camera uses a 5 ms exposure time and the system has a total latency of 13 ms
  • how fast will the system need to be, to be actually effective, in a car
  • simulations show that a system operating near 1,000 Hz, with a total system latency of 1.5 ms, and exposure time of 1 ms can achieve 96.8% accuracy
  • 90% light throughput during a heavy rainstorm [25 mm/hr] on a vehicle traveling 30 km/hr
  • 400 Hz with less accuracy will be a significant [>= 70%] improvement for the driver
  • operating range is about 13 feet in front of the headlights
  • recent computer vision methods that digitally remove rain and snow streaks from captured images
  • simulation results show that it is possible to maintain light throughput well above 90 percent for various precipitation types and
  • prototype system operating at 120Hz on laboratory-generated rain, which validated their earlier simulations
  • prototype consists of a camera with gigabit ethernet interface (Point Grey, Flea3), DLP projector (Viewsonic, PJD62531), and desktop computer with Intel architecture (Intel i7 quad core processor).
  • next steps will involve making the system faster and more compact to test on a moving platform
  • research for those ends may take three to four more years and “commercializing it as a product will take additional years.”
  • the prototype was built with off-the-shelf components
  • data transfer speed is slower than if the components were more closely integrated
  • more sophisticated algorithms are needed to maximize system speed and account for factors such as vehicle motion and wind turbulence
Mars Base

Once Again, Physicists Debunk Faster-Than-Light Neutrinos - ScienceInsider - 0 views

news.sciencemag.org/...e-again-physicists-debunk.html

scibyte50 Neutrinos

shared by Mars Base on 11 Jun 12 - No Cached
  • Five different teams of physicists have now independently verified that elusive subatomic particles called neutrinos do not travel faster than light
  • instead of the nail in the coffin of faster-than-light neutrinos, the new suite of results is more like the sod planted atop their grave
  • OPERA team also discovered that a loose fiber optic cable had introduced a delay in their timing system that explained the effect
  • ...5 more annotations...
  • A month later
  • measured the speed of neutrinos fired from CERN and found that they travel at light speed, as predicted
  • Some OPERA team members thought the whole episode had besmirched the collaboration's reputation, and in March, two of the team's elected leaders lost a vote of no confidence and tendered their resignations.
  • Gran Sasso houses four particle detectors
  • All four have now found that the neutrino's speed is consistent with the speed of light
Mars Base

Star is discovered to be a close neighbor of the Sun and the coldest of its kind - 0 views

phys.org/...neighbor-sun-coldest-kind.html

scibyte128 star

shared by Mars Base on 27 Apr 14 - No Cached
  • A "brown dwarf" star that appears to be the coldest of its kind—as frosty as Earth's North Pole—has been discovered
  • Images from the space telescopes also pinpointed the object's distance at 7.2 light-years away, making it the fourth closest system to our Sun
  • Brown dwarfs start their lives like stars, as collapsing balls of gas, but they lack the mass to burn nuclear fuel and radiate starlight
  • ...13 more annotations...
  • The newfound coldest brown dwarf, named WISE J085510.83-071442.5, has a chilly temperature between minus 54 and 9 degrees Fahrenheit (minus 48 to minus 13 degrees Celsius).
  • Although it is very close to our solar system
  • is not an appealing destination for human space travel in the distant future.
  • WISE was able to spot the rare object because it surveyed the entire sky twice in infrared light
  • Cool objects like brown dwarfs can be invisible when viewed by visible-light telescopes, but their thermal glow—even if feeble—stands out in infrared light.
  • is estimated to be 3 to 10 times the mass of Jupiter.
  • With such a low mass, it could be a gas giant similar to Jupiter that was ejected from its star system. But scientists estimate it is probably a brown dwarf rather than a planet since brown dwarfs are known to be fairly common
  • If so, it is one of the least massive brown dwarfs known.
  • Combined detections
  • ken from different positions around the Sun, enabled the measurement of its distance through the parallax effect
  • In March of 2013
  • analysis of the images from WISE uncovered a pair of much warmer brown dwarfs at a distance of 6.5 light years, making that system the third closest to the Sun
  • NASA's Wide-field Infrared Survey Explorer (WISE) and Spitzer Space Telescopes.
Mars Base

Tiny Sun Activity Changes Affect Earth's Climate | Solar Sunspot Cycle | Space.com - 0 views

www.space.com/ar-activity-earth-climate.html

scibyte78 sun

shared by Mars Base on 18 Jan 13 - No Cached
  • Even small changes in solar activity can impact Earth's climate in significant and surprisingly complex ways, researchers say.
  • The sun is a constant star when compared with many others in the galaxy
  • ome stars pulsate dramatically, varying wildly in size and brightness and even exploding
  • ...24 more annotations...
  • In comparison, the sun varies in the amount of light it emits by only 0.1 percent over the course of a relatively stable 11-year-long pattern known as the solar cycle.
  • "the light reaching the top of the Earth's atmosphere provides about 2,500 times as much energy as the total of all other sources combined,"
  • even 0.1 percent of the amount of light the sun emits exceeds all other energy sources the Earth's atmosphere sees combined, such as the radioactivity naturally emitted from Earth's core,
  • Many of the ways the scientists proposed these fluctuations in solar activity could influence Earth were complicated in nature.
  • , solar energetic particles and cosmic rays could reduce ozone levels in the stratosphere
  • in turn alters the behavior of the atmosphere below it, perhaps even pushing storms on the surface off cours
  • "In the lower stratosphere, the presence of ozone causes a local warming because of the breakup of ozone molecules by ultraviolet light,
  • When the ozone is removed, "the stratosphere there becomes cooler, increasing the temperature contrast between the tropics and the polar region
  • contrast in temperatures in the stratosphere and the upper troposphere leads to instabilities in the atmospheric flow west to east.
  • feed the strength of jet streams, ultimately altering flows in the upper troposphere, the layer of atmosphere closest to Earth's surface.
  • alter the distribution of storms over the middle latitudes
  • the sun might have a role to play in this kind of process. I would have to say this would be a very difficult mechanism to prove in climate models
  • climate scientist Gerald Meehl at the National Center for Atmospheric Research and his colleagues suggest that solar variability is leaving a definite imprint on climate, especially in the Pacific Ocean.
  • When researchers look at sea surface temperature data during sunspot peak years, the tropical Pacific showed a pattern very much like that expected with La Niña,
  • cyclical cooling of the Pacific Ocean that regularly affects climate worldwide, with sunspot peak years leading to a cooling of almost 1 degree Celsius (1.8 degrees Fahrenheit) in the equatorial eastern Pacific
  • peaks in the sunspot cycle were linked with increased precipitation in a number of areas across the globe, as well as above-normal sea-level pressure in the mid-latitude North and South Pacific.
  • Scientists have also often speculated whether the Maunder Minimum, a 70-year dearth of sunspots in the late 17th to early 18th century, was linked with the coldest part of the Little Ice Age, during which Europe and North America experienced bitterly cold winter
  • This regional cooling might be linked with a drop in the sun's extreme ultraviolet radiation.
  • t, the sun could currently be on the cusp of a miniature version of the Maunder Minimum, since the current solar cycle is the weakest in more than 50 years.
  • Although the sun is the main source of heat for Earth, the researchers note that solar variability may have more of a regional effect than a global one
  • While the sun is by far the dominant energy source powering our climate system, do not assume that it is causing much of recent climate changes. It's pretty stabl
  • Ancient signals of climate such as tree rings and ice cores might also help shed light on the link between the sun and climate
  • Since variations in Earth's magnetic field and atmospheric circulation might disrupt this evidence on Earth,
  • a better long-term record of solar radiation might lie in the rocks and sediments of the moon or Mar
Mars Base

Planck's most detailed map ever reveals an almost perfect Universe - 0 views

phys.org/...3-planck-reveals-universe.html

scibyte87 PlanckConstant

shared by Mars Base on 22 Mar 13 - No Cached
  • the most detailed map ever created of the cosmic microwave background
  • the relic radiation from the Big Bang
  • was released
  • ...31 more annotations...
  • revealing the existence of features that challenge the foundations of our current understanding of the Universe
  • The image is based on the initial 15.5 months of data from Planck and is the mission's first all-sky picture of the oldest light in our Universe, imprinted on the sky when it was just 380 000 years old.
  • At that time, the young Universe was filled with a hot dense soup of interacting protons, electrons and photons at about 2700ºC
  • protons and electrons joined to form hydrogen atoms, the light was set free
  • As the Universe has expanded, this light today has been stretched out to microwave wavelengths, equivalent to a temperature of just 2.7 degrees above absolute zero.
  • that correspond to regions of slightly different densities at very early times, representing the seeds of all future structure: the stars and galaxies of today
  • According to the standard model of cosmology, the fluctuations arose immediately after the Big Bang and were stretched to cosmologically large scales during a brief period of accelerated expansion known as inflation.
  • Planck was designed to map these fluctuations across the whole sky with greater resolution and sensitivity than ever before
  • By analysing the nature and distribution of the seeds in Planck's CMB image, we can determine the composition and evolution of the Universe from its birth to the present day
  • because precision of Planck's map is so high, it also made it possible to reveal some peculiar unexplained features that may well require new physics to be understood
  • Since the release of Planck's first all-sky image in 2010, we have been carefully extracting and analysing all of the foreground emissions that lie between us and the Universe's first light
  • revealing the cosmic microwave background in the greatest detail yet
  • One of the most surprising findings is that the fluctuations in the CMB temperatures at large angular scales do not match those predicted by the standard model
  • their signals are not as strong as expected from the smaller scale structure
  • Another is an asymmetry in the average temperatures on opposite hemispheres of the sky
  • This runs counter to the prediction made by the standard model that the Universe should be broadly similar in any direction we look
  • a cold spot extends over a patch of sky that is much larger than expected.
  • The asymmetry and the cold spot had already been hinted at with Planck's predecessor
  • NASA's WMAP mission, but were largely ignored because of lingering doubts about their cosmic origin
  • One way to explain the anomalies is to propose that the Universe is in fact not the same in all directions on a larger scale than we can observe
  • In this scenario, the light rays from the CMB may have taken a more complicated route through the Universe than previously understood, resulting in some of the unusual patterns observed today.
  • ultimate goal would be to construct a new model that predicts the anomalies and links them together
  • we don't know whether this is possible and what type of new physics might be needed
  • the Planck data conform spectacularly well to the expectations of a rather simple model of the Universe, allowing scientists to extract the most refined values yet for its ingredients
  • dark energy, a mysterious force thought to be responsible for accelerating the expansion of the Universe, accounts for less than previously thought.
  • Normal matter that makes up stars and galaxies contributes just 4.9% of the mass/energy density of the Universe
  • Dark matter, which has thus far only been detected indirectly by its gravitational influence, makes up 26.8%, nearly a fifth more than the previous estimate.
  • Planck data also set a new value for the rate at which the Universe is expanding today, known as the Hubble constant
  • At 67.15 kilometres per second per megaparsec, this is significantly less than the current standard value in astronomy
  • The data imply that the age of the Universe is 13.82 billion years.
  • We see an almost perfect fit to the standard model of cosmology, but with intriguing features that force us to rethink some of our basic assumptions
Mars Base

Speed Of Light In Vacuum Is Not Actually Constant, Study Finds | Popular Science - 0 views

www.popsci.com/...um-varies-slightly-study-finds

scibyte88 Speed-of-Light

shared by Mars Base on 28 Mar 13 - No Cached
  • Mars Base on 28 Mar 13
     
    Speed Of Light In Vacuum
Chris Fisher

Trillion FPS Camera Captures Advancing Light Waves - 0 views

www.wired.com/...captures-advancing-light-waves

scibyte light wired waves camera fps

shared by Chris Fisher on 13 Dec 11 - No Cached
  • MIT’s new camera will shoot one trillion frames per second.
  • One trillion seconds is over 31,688 years
  • played it back at 30fps, it’d still take you over 1,000 years to watch it.
  • ...3 more annotations...
  • use “femtosecond laser illumination, picosecond-accurate detectors and mathematical reconstruction techniques” to illuminate a scene and then capture the pulses of laser light.
  • The movies are 480 frames long, and show a slice in time of just 1.71 picoseconds.
  • The result is a movie of an advancing wave of light.
Mars Base

Solar Flare May Spark Weekend Northern Lights Show | Solar Flares & Northern Lights | S... - 0 views

www.space.com/kend-northern-lights-show.html

scibyte30 sun solar flare CME

shared by Mars Base on 21 Jan 12 - No Cached
  • A powerful flare erupted from the sun Thursday (Jan. 19
  • solar flare occurred at about 11:30 am EST (1600 GMT
  • coronal mass ejection
  • ...2 more annotations...
  • aimed at Earth
  • sun explosion should reach Earth by Saturday night (Jan. 21), and could amp up northern lights
Mars Base

Bionic retina runs on laser power - 0 views

optics.org/1

Scibyte55 RestoringVision

shared by Mars Base on 18 Jul 12 - No Cached
  • tiny implant that is inserted into the eye and attached to the retina in a minimally invasive procedure no more complicated than conventional cataract surgery
  • consists of photodetectors, microelectrodes and electronic circuitry that act together to replace the eye’s natural photoreceptors that have been damaged by AMD and feed visual information to the brain
  • photoreceptors in a healthy retina convert light into a series of electrical signals which are transmitted to the brain via complex neural pathways
  • ...14 more annotations...
  • AMD, the photoreceptors do not function, which prevents the brain from receiving these signals from the eyes
  • bio-retina implant is essentially a combined imaging circuit and neural interface which is glued rather than sutured to a patient’s macula
  • area of the retina responsible for high-resolution central vision
  • Measuring 3 x 4 mm and 1 mm thick, the implant is designed to capture light through the normal optical track of the eyeball and stimulate neurons to transmit information to the brain, essentially restoring the function of the damaged photoreceptors
  • Light incident on the implant is collected by an array of CMOS pixels
  • first-generation bio-retina will use an array of 600 pixels, although the aim is to increase this to 5000 pixels in future generations
  • Nano Retina has dedicated a substantial amount of time developing a proprietary algorithm that translates the received visual information and image into the neuron language
  • translating circuitry that discriminates 100 gray-scale levels and responds to varying light levels. It is a sophisticated process
  • implant uses an array of micro-electrodes that first penetrate into the retina, then connect closely to the neurons and thereafter transmit the information. The goal is that every pixel will connect to a neuron, so that every pixel in the array would use a micro-electrode
  • neurons must be stimulated electrically
  • the bio-retina implant also requires a source of electrical power
  • Patients who undergo surgery to implant a bio-retina will need to wear a special set of glasses
  • glasses feature a built-in battery and an infrared diode laser. “The infrared laser light is transmitted into the eye and captured by a miniature photovoltaic cell on the bio-retina
  • harvests the energy, which in turn powers the electronic circuitry. Our goal is for the imager and the electronics to consume no more than 1mW
Mars Base

Super-sensitive Camera Captures a Direct Image of an Exoplanet - 0 views

www.universetoday.com/...a-direct-image-of-an-exoplanet

scibyte115 exoplanet

shared by Mars Base on 08 Jan 14 - No Cached
  • The world’s newest and most powerful exoplanet imaging instrument
  • has captured its first-light infrared image of an exoplanet
  • which orbits
  • ...15 more annotations...
  • the second-brightest star in the southern constellation Pictor
  • a distant planet 63 light-years away and several times more massive — as well as 60% larger — than Jupiter
  • many exoplanets have been discovered and confirmed over the past couple of decades using various techniques, very few have actually been directly imaged
  • Most planets that we know about to date are only known because of indirect methods that tell us a planet is there
  • With GPI we directly image planets around stars
  • doesn’t just image distant Jupiter-sized exoplanets; it images them quickly
  • early first-light images are almost a factor of ten better than the previous generation of instruments
  • In one minute, we were seeing planets that used to take us an hour to detect
  • Beta Pictoris b is a very young planet — estimated to be less than 10 million years old (the star itself is only about 12 million
  • presence is a testament to the ability of large planets to form rapidly and soon around newly-formed stars
  • saw this on only the first week after the instrument was put on the telescope
  • what it will be able to do once we tweak and completely tune its performance
  • Another
  • images captured light scattered by a ring of dust that surrounds the young star HR4796A , about 237 light-years away
  • “Some day, there will be an instrument that will look a lot like GPI, on a telescope in space. And the images and spectra that will come out of that instrument will show a little blue dot that is another Earth.” – Bruce Macintosh, GPI team leader
Mars Base

NASA Space Telescopes Find Patchy Clouds on Exotic World - NASA Jet Propulsion Laboratory - 0 views

www.jpl.nasa.gov/...news.php

scibyte105 exoplanet

shared by Mars Base on 05 Oct 13 - No Cached
  • Astronomers using data from NASA's Kepler and Spitzer space telescopes have created the first cloud map of a planet
  • known as Kepler-7b
  • Previous studies from Spitzer have resulted in temperature maps of planets orbiting other stars
  • ...21 more annotations...
  • this is the first look at cloud structures on a distant world.
  • observing this planet with Spitzer and Kepler for more than three years, we were able to produce a very low-resolution 'map' of this giant, gaseous planet
  • wouldn't expect to see oceans or continents on this type of world, but we detected a clear, reflective signature that we interpreted as clouds
  • Kepler-7b was one of the first
  • Kepler's visible-light observations of Kepler-7b's moon-like phases led to a rough map of the planet that showed a bright spot on its western hemisphere
  • data were not enough on their own to decipher whether the bright spot was coming from clouds or heat
  • Spitzer Space Telescope played a crucial role in answering this question
  • Spitzer can fix its gaze at a star system as a planet orbits around the star, gathering clues about the planet's atmosphere
  • Spitzer's ability to detect infrared light means it was able to measure Kepler-7b's temperature, estimating it to be between 1,500 and 1,800 degrees Fahrenheit (1,100 and 1,300 Kelvin).
  • relatively cool for a planet that orbits so close to its star -- within 0.06 astronomical units (one astronomical unit is the distance from Earth and the sun)
  • , too cool to be the source of light Kepler observed.
  • Instead, they determined, light from the planet's star is bouncing off cloud tops located on the west side of the planet.
  • Kepler-7b reflects much more light than most giant planets we've found, which we attribute to clouds in the upper atmosphere
  • the cloud patterns on this planet do not seem to change much over time -- it has a remarkably stable climate
  • With Spitzer and Kepler together, we have a multi-wavelength tool for getting a good look at planets that are trillions of miles away
  • exoplanet science
  • moving beyond just detecting exoplanets, and into the exciting science of understanding them
  • observations of Kepler-7b previously revealed that it is one of the puffiest planets known: if it could somehow be placed in a tub of water, it would float
  • found to whip around its star in just less than five days
  • a fully rendered 3D visualization tool, available for download at http://eyes.nasa.gov/exoplanets
  • program is updated daily with the latest findings from NASA's Kepler mission and ground-based observatories around the world as they search for planets
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