Skip to main content

Home/ SciByte/ Group items tagged light

Rss Feed Group items tagged

Mars Base

Twinkle, twinkle little star: New app measures sky brightness - 0 views

  • Researchers from the German "Loss of the Night" project have developed an app for Android smart phones, which counts the number of visible stars in the sky
  • The data from the app will be used by scientists to understand light pollution on a world wide scale.
  • The smartphone app will evaluate sky brightness, also known as skyglow, on a worldwide scale
  • ...7 more annotations...
  • This data can be used to map the distribution and changes in sky brightness, and will eventually allow scientists to investigate correlations with health, biodiversity, energy waste and other factors
  • The app works by interactively asking users to say whether individual stars are visible. By determining what the faintest visible star is, the researchers learn how many stars are visible at that location, and by extension how bright the sky is
  • With this app, people from around the world can collect data on skyglow without needing expensive equipment
  • some of the testers found that without intending too they learned the names of several stars and constellations
  • is based on the widely used Google Sky Map application
  • development of the app was sponsored by the German Federal Ministry of Research and Education,
  • satellites that observe Earth at night measure the light that is radiating into the sky, not the brightness that is experienced by people and other organisms on the ground
Mars Base

Confirmed: Dogs Sneak Food When People Aren't Looking - 0 views

  • The research shows that domestic dogs, when told not to snatch a piece of food, are more likely to disobey the command in a dark room than in a lit room
  • The one thing we can say is that dogs really have specialized skills in reading human communication
  • This is special in dogs
  • ...15 more annotations...
  • recruited 84 dogs, all of which were more than a year old, motivated by food, and comfortable with both strangers and dark rooms
  • The team then set up experiments in which a person commanded a dog not to take a piece of food on the floor
  • repeated the commands in a room with different lighting scenarios ranging from fully lit to fully dark
  • They found that the dogs were four times as likely to steal the food—and steal it more quickly—when the room was dark
  • the dog's behavior depended on whether the food was in the light or not, suggesting that the dog made its decision based on whether the human could see them approaching the food
  • were thinking what affected the dog was whether they saw the human, but seeing the human or not didn't affect the behavior
  • The study of dog cognition suddenly began about 15 years ago
  • Many of the new dog studies are variations on research done with chimpanzees, bonobos, and even young children
  • Selectively bred as companions for thousands of years, dogs are especially attuned to human emotions
  • are better at reading human cues than even our closest mammalian relatives
  • research reveals more and more insight into the minds
  • We still don't know just how smart they are
  • researchers are interested in whether the dog has a theory of mind
  • theory of mind is "an understanding that others have different perspective, knowledge, feelings than we do
  • Now, a new study suggests dogs might understand people even better than we thought
Mars Base

Biggest Thing in Universe Found-Defies Scientific Theory - 0 views

  • Using data from the Sloan Digital Sky Survey, an international team of researchers has discovered a record-breaking cluster of quasars—young active galaxies
  • the Milky Way, is just a hundred thousand light-years across
  • the local supercluster of galaxies in which it's located, the Virgo Cluster, is only a hundred million light-years wide
  • ...1 more annotation...
  • "It could mean that our mathematical description of the universe has been oversimplified-and that would represent a serious difficulty and a serious increase in complexity,"
Mars Base

Smallest Exoplanet Yet Discovered by 'Listening' to a Sun-like Star - 0 views

  • Scientists have discovered a new planet orbiting a Sun-like star, and the exoplanet is the smallest yet found in data from the Kepler mission
  • Kepler-37b, is smaller than Mercury, but slightly larger than Earth’s Moon
  • discovery came from a collaboration between Kepler scientists and a consortium of international researchers who employ asteroseismology
  • ...24 more annotations...
  • measuring oscillations in the star’s brightness caused by continuous star-quakes, and turning those tiny variations in the star’s light into sounds
  • The bigger the star, the lower the frequency, or ‘pitch’ of its song
  • The measurements made by the astroseismologists allowed the Kepler research team to more accurately measure the tiny Kepler-37b
  • revealing two other planets in the same planetary system: one slightly smaller than Earth and one twice as large
  • Kepler-37b is very likely a rocky planet with no atmosphere or water, similar to Mercury
  • “The detection of such a small planet shows for the first time that stellar systems host planets much smaller as well as much larger than anything we see in our own Solar System.”
  • host star, Kepler-37, is about 210 light-years from Earth
  • All three planets orbit the star at less than the distance Mercury is to the Sun
  • Kepler-37b orbits every 13 days at less than one-third Mercury’s distance from the Sun
  • estimated surface temperature of this smoldering planet, at more than 800 degrees Fahrenheit (700 degrees Kelvin
  • hot enough to melt the zinc in a penny
  • Kepler-37c and Kepler-37d, orbit every 21 days and 40 days, respectively
  • The size of the star must be known in order to measure the planet’s size accurately
  • scientists examined sound waves generated by the boiling motion beneath the surface of the star
  • The technique for stellar seismology is analogous to how geologists use seismic waves generated by earthquakes to probe the interior structure of Earth
  • sound waves travel into the star and bring information back up to the surface
  • waves cause oscillations that Kepler observes as a rapid flickering of the star’s brightness
  • barely discernible, high-frequency oscillations in the brightness of small stars are the most difficult to measure
  • why most objects previously subjected to asteroseismic analysis are larger than the Sun
  • Kepler-37 has a radius just three-quarters of the Sun
  • the radius of the star is known to 3 percent accuracy, which translates to exceptional accuracy in the planet’s size.
  • this discovery took a long time to verify, as the signature of this very small exoplanet was hard to confirm
  • Kepler is sending astronomers photometry data that’s “probably the best we’ll see in our lifetimes
  • uncovered a planet smaller than any in our solar system orbiting one of the few stars that is both bright and quiet, where signal detection was possible
Mars Base

For the first time, astronomers have measured the radius of a black hole - 0 views

  • an international team
  • , has for the first time measured the radius of a black hole at the center of a distant galaxy—the closest distance at which matter can approach before being irretrievably pulled into the black hole.
  • scientists linked together radio dishes in Hawaii, Arizona and California to create a telescope array called the "Event Horizon Telescope" (EHT) that can see details 2,000 times finer than what's visible to the Hubble Space Telescope.
  • ...20 more annotations...
  • , the team observed the glow of matter near the edge of this black hole—a region known as the "event horizon."
  • , not everything can cross the event horizon to squeeze into a black hole
  • "cosmic traffic jam" in which gas and dust build up, creating a flat pancake of matter known as an accretion disk
  • disk of matter orbits the black hole at nearly the speed of light, feeding the black hole a steady diet of superheated material
  • Over time, this disk can cause the black hole to spin in the same direction as the orbiting material
  • Caught up in this spiraling flow are magnetic fields, which accelerate hot material along powerful beams above the accretion disk
  • resulting high-speed jet, launched by the black hole and the disk, shoots out across the galaxy, extending for hundreds of thousands of light-years
  • jets can influence many galactic processes, including how fast stars form.
  • . Because M87's jet is magnetically launched from this smallest orbit,
  • astronomers can estimate the black hole's spin through careful measurement of the jet's size as it leaves the black hole
  • Until now, no telescope has had the magnifying power required for this kind of observation
  • team used a technique called Very Long Baseline Interferometry, or VLBI, which links data from radio dishes located thousands of miles apart.
  • , taken together, create a "virtual telescope" with the resolving power of a single telescope as big as the space between the disparate dishes
  • enables scientists to view extremely precise details in faraway galaxies.
  • Using the technique
  • team measured the innermost orbit of the accretion disk to be only 5.5 times the size of the black hole event horizon
  • According to the laws of physics, this size suggests that the accretion disk is spinning in the same direction as the black hole
  • first direct observation to confirm theories of how black holes power jets from the centers of galaxies
  • The team plans to expand its telescope array, adding radio dishes in Chile, Europe, Mexico, Greenland and Antarctica, in order to obtain even more detailed pictures of black holes in the future.
  • www.eventhorizontelescope.org/
Mars Base

New look at HD 10180 shows it might have nine planets - 0 views

  • after looking at data regarding the solar system surrounding the star HD 10180, that it likely has nine planets making it the most highly populated solar system known to man
  • after studying slight wobbles by the star as it’s tugged by planetary gravitation, he found what he believes is confirmation of a seventh planet, and evidence for two more
  • HD 10180 is about 130 light years away from us
  • ...17 more annotations...
  • first noted by astronomers in 2010
  • it was thought the solar system consisted of just five planets
  • speculation that it might have as many as seven
  • other work has shown that there are likely six planets, five of which are believed to have a mass close to that of Neptune
  • other appears closer in mass to Saturn
  • to these conclusions by studying the way a star appears to wobble (a Doppler shift
  • studying these light shifts, astronomers can deduce not only the size of the planet that causes it, but its period as well
  • didn’t make any new observations
  • he went back and looked at the original data using different kinds of statistical analysis techniques
  • found evidence for three more planets, all much smaller than the original six
  • estimates to be 1.3, 1.9, and 5.1 times the size of Earth
  • much shorter periods (1.2, 10 and 68 days) than
  • they are very close to their star, closer even than Mercury is to our sun
  • far too hot to support water retention or life, at least as we know it.
  • doesn’t actually prove that any of the planets suspected of revolving around HD 10180 actually exist
  • merely offers strong evidence
  • statistical evidence offered by Tuomi suggesting that if there are truly planets there, they all appear to have stable orbits.
Chris Fisher

Astronomers find new planet capable of supporting life - Telegraph - 0 views

  •  
    Scientists found the planet, Gliese 667Cc, orbiting around a red dwarf star, 22 light years away from the earth.
Mars Base

A Star Is Torn - Science News - 0 views

  • In spring 2010, NASA’s orbiting Galaxy Evolution Explorer and the ground-based Pan-STARRS telescope observed a suspicious brightening around a supermassive black hole parked more than 2 billion light-years from Earth
  • Over the next few months, the flare continued increasing in brightness — then it dimmed
  • Scientists now suggest that the light show was evidence of the black hole PS1-10jh shredding a star that wandered too close
  • ...7 more annotations...
  • analysis presented online May 2 in Nature indicates that at the time of engulfment, the star was just a helium-rich core, the remainder of a former red giant
  • The black hole
  • weighing about 3 million solar masses, had probably already snacked on the star’s outer layers during a previous close encounter.
  • the black hole spat some of the stellar material into space
  • followed elongated orbits that eventually dumped them back into the black hole, producing the observed, months-long flare.
  • Such disruption events are rare, thought to occur only once every 10,000 years per galaxy
  • can help astronomers spot otherwise hidden black holes.
Mars Base

A planetary system from the early Universe - 0 views

  • A group of European astronomers has discovered an ancient planetary system that is likely to be a survivor from one of the earliest cosmic eras, 13 billion years ago. The system consists of the star HIP 11952 and two planets, which have orbital periods of 290 and 7 days, respectively. Whereas planets usually form within clouds that include heavier chemical elements, the star HIP 11952 contains very little other than hydrogen and helium. The system promises to shed light on planet formation in the early universe – under conditions quite different from those of later planetary systems, such as our own
  • widely accepted that planets are formed in disks of gas and dust that swirl around young stars
  • many open questions remain
  • ...25 more annotations...
  • what it actually takes to make a planet
  • With a sample of, by now, more than 750 confirmed planets
  • astronomers have some idea of the diversity among planetary systems
  • certain trends have emerged
  • Statistically, a star that contains more “metals” - in astronomical parlance, the term includes all chemical elements other than hydrogen and helium – is more likely to have planets.
  • suggests a key question
  • Originally, the universe contained almost no chemical elements other than hydrogen and helium
  • what about planet formation under conditions like those of the very early universe
  • ? If metal-rich stars are more likely to form planets
  • stars with a metal content so low that they cannot form planets at all
  • then when
  • should we expect the very first planets to form
  • a group of astronomers
  • has discovered a planetary system that could help provide answers to those questions
  • part of a survey targeting especially metal-poor stars
  • identified two giant planets around a star known by its catalogue number as HIP 11952
  • at a distance of about 375 light-years from Earth
  • these planets
  • are not unusual
  • What is unusual is the fact that they orbit such an extremely metal-poor and, in particular, such a very old star!
  • planets around such a star should be extremely rare
  • Compared to other exoplanetary systems
  • not only one that is extremely metal-poor
  • at an estimated age of 12.8 billion years, also one of the oldest systems known so far.
  • In 2010 we found the first example of such a metal-poor system, HIP 13044. Back then, we thought it might be a unique case; now, it seems as if there might be more planets around metal-poor stars than expected
Mars Base

Evening Star Goes Black In Rare Celestial Event - Science News - 0 views

  • Venus will take six hours to march across the star’s face, appearing as an inky black dot in silhouette against the looming solar disk
  • Because the planet’s orbit is slightly off-kilter, its solar transits come in pairs spaced eight years apart, with more than 100 years between pairs.
  • Paris Observatory, who will join Venus Express team members in Svalbard, Norway to observe the transit against the midnight sun.
  • ...4 more annotations...
  • its planetprint produces the type of dimming that occurs when exoplanets periodically block their stars’ light. Astronomers have been able to study the atmospheres of Jupiter-sized exoplanets, but similar observations of terrestrial planets are still a thing of the future.
  • Maybe one day we will be able to measure the same light that is filtered from the atmospheres of exoplanets – exo-Venuses and exo-Earths
  • such observations aren’t so simple. “Big mirrors and sensitive detectors are not good things to point at the sun
  • capture sunlight reflected off the face of the moon during the transit
Mars Base

Odd Alien Planets So Close Together They See 'Planetrise' | Kepler Mission | Space.com - 0 views

  • Astronomers have discovered two alien planets around the same star whose orbits come so close together that each rises in the night sky of its sister world
  • ,200 light-years from Earth
  • differ greatly in size and composition but come within just 1.2 million miles (1.9 million kilometers) of each other, closer than any other pair of planets known,
  • ...15 more annotations...
  • Kepler-36b, appears to be a rocky "super-Earth" 4.5 times as massive as our planet
  • Kepler-36c, is a gaseous, Neptune-size world about eight times as massive as Earth
  • planets meet up every 97 days in a conjunction that would make each dramatically visible in the other's sky.
  • At their closest approach, the two planets are separated by five times the distance between the Earth and the moon
  • as different in density as Earth and Saturn
  • Kepler-36b and c are actually more like 20 times closer together than any two planets in our neck of the woods
  • Kepler-36c, which is about 3.7 times wider than Earth, likely has a rocky core surrounded by a substantial atmosphere filled with lots of hydrogen and helium
  • Kepler-36b, on the other hand, is a super-Earth just 1.5 times wider than our planet. Iron likely constitutes about 30 percent of its mass, water around 15 percent and atmospheric hydrogen and helium less than 1 percent
  • Kepler-36c orbits once every 16 days, at an average distance of 12 million miles (19 million km). Kepler-36b orbits each 14 days and sits about 11 million miles (18 million km) from the star.
  • Kepler-36b probably formed relatively close to the star
  • Kepler-36c likely took shape farther out
  • large-scale migrations that can bring initially far-flung planets much closer together
  • Kepler-36b probably sporting lava flows on its surface
  • orbit roughly three times closer to their host star, known as Kepler-36a, than the hellishly hot planet Mercury does to our sun
  • Kepler-36a is likely a bit hotter than our star
Mars Base

Weird World! 'Oozing' Alien Planet Is a Super-Earth Wonder | Exoplanets & 55 Cancri e |... - 0 views

  • A new look at an alien planet that orbits extremely close to its parent star suggests that the rocky world might not be a scorching hot wasteland, as was thought
  • The exotic planet 55 Cancri e is a relatively close alien planet, just 40 light-years away from Earth
  • long thought to harbor surface temperatures as high as 4,800 degrees Fahrenheit (about 2,700 degrees Celsius
  • ...8 more annotations...
  • 55 Cancri e could be a wetter and weirder place than   though
  • 55 Cancri e has a mass 7.8 times that of Earth, and a width just over twice that of our planet
  • observations suggest that about a fifth of the planet's mass must be made up of light elements and compounds, including water
  • experiences such extreme temperatures and high pressure, these elements and compounds likely exist in what is known as a "supercritical" fluid state,
  • Supercritical fluids can best be imagined as liquid-like gases in high pressure and temperature conditions
  • water becomes supercritical in some steam turbines
  • supercritical carbon dioxide is used to scrub caffeine from coffee beans
  • supercritical fluids could be seeping out from the planet's rocks. And, while conditions on the strange world are not suitable to host life, 55 Cancri e does give exoplanet hunters an interesting example to study
Mars Base

News | SDSU | Discovery Creates New Class of Planetary Systems - 0 views

  • Using data from NASA’s Kepler Mission
  • astronomers announced the discovery of two new transiting “circumbinary” planet systems — planets that orbit two stars.
  • two new planets, named Kepler-34 b and Kepler-35 b, are both gaseous Saturn-size planets
  • ...6 more annotations...
  • Kepler-34 b orbits its two sun-like stars every 289 days, and the stars themselves orbit and eclipse each other every 28 days.
  • eclipses allow a very precise determination of the stars
  • Kepler-35 b revolves about a pair of smaller stars (80 and 89 percent of the sun’s mass) every 131 days, and the stars orbit and eclipse one another every 21 days
  • Kepler-34 at 4,900 light-years from Earth
  • Kepler-35 at 5,400 light-years
  • among the most distant planets discovered.
Mars Base

Hubble directly observes the disc around a black hole - 0 views

  • Scientists have used the NASA/ESA Hubble Space Telescope to observe a quasar accretion disc -- a glowing disc of matter that is slowly being sucked into its galaxy's central black hole
  • Scientists have used the NASA/ESA Hubble Space Telescope to observe a quasar accretion disc -- a glowing disc of matter that is slowly being sucked into its galaxy's central black hole.
  • the team measured the disc's size and studied the colours (and hence the temperatures) of different parts of the disc
  • ...11 more annotations...
  • Using the NASA/ESA Hubble Space Telescope, combined with the gravitational lensing effect of stars in a distant galaxy, the team measured the disc's size and studied the colours (and hence the temperatures) of different parts of the disc.
  • These observations show a level of precision equivalent to spotting individual grains of sand on the surface of the Moon.
  • show a level of precision equivalent to spotting individual grains of sand on the surface of the Moon
  • Quasars — short for quasi-stellar objects — are glowing discs of matter that orbit supermassive black holes, heating up and emitting extremely bright radiation as they do so.
  • Until now, the minute apparent size of quasars has meant that most of our knowledge of their inner structure has been based on theoretical extrapolations, rather than direct observations.
  • using the stars in an intervening galaxy as a scanning microscope to probe features in the quasar's disc that would otherwise be far too small to see
  • As these stars move across the light from the quasar, gravitational effects amplify the light from different parts of the quasar, giving detailed colour information for a line that crosses through the accretion disc.
  • the team were able to reconstruct the colour profile across the accretion disc
  • allowed the team to measure the diameter of the disc of hot matter, and plot how hot it is at different distances from the centre
  • Quasars' physical properties are not yet well understood
  • This new ability to obtain observational measurements is therefore opening a new window to help understand the nature of these objects."
Mars Base

Speed-bump device converts traffic energy to electricity - 0 views

  • A Maryland company
  • has devised that kind of speed-bump device
  • has devised that kind of speed-bump device
  • ...17 more annotations...
  • A Maryland company
  • that harvests kinetic energy from vehicles and converts the energy into electricity
  • for installation where vehicles are traveling faster than 15 mph and are slowing-down before stopping, including parking lots, border crossings, exit ramps, neighborhoods with traffic calming zones, rest areas, toll booths, and travel plazas
  • devices become a part of the toll booths, rest areas, parking lots, airport arrival and departure areas, city lighting systems, zones in other places where traffic should be slowing down—scenarios that can benefit from a greener approach to energy and electricity cost savings.
  • devices become a part of the toll booths, rest areas, parking lots, airport arrival and departure areas, city lighting systems, zones in other places where traffic should be slowing down—scenarios that can benefit from a greener approach to energy and electricity cost savings
  • recently got a boost in publicity by partnering with the city of Roanoke in Virginia to put its MotionPower Express system to the test
  • recently got a boost in publicity by partnering with the city of Roanoke in Virginia to put its MotionPower Express system to the test
  • that harvests kinetic energy from vehicles and converts the energy into electricity
  • for installation where vehicles are traveling faster than 15 mph and are slowing-down before stopping, including parking lots, border crossings, exit ramps, neighborhoods with traffic calming zones, rest areas, toll booths, and travel plazas.
  • during a busy time when the center was hosting a gun show and circus. A total of 580 cars passed over the rumble strip in six hours.
  • was during a busy time when the center was hosting a gun show and circus. A total of 580 cars passed over the rumble strip in six hours.
  • Reports claim this traffic over this amount of time generated enough electricity to power an average U.S. home for a day
  • Reports claim this traffic over this amount of time generated enough electricity to power an average U.S. home for a day.
  • traffic over a six hour period was claimed to produce enough electricity for a 150 square-foot electronic billboard or marquee for a day.
  • traffic over a six hour period was claimed to produce enough electricity for a 150 square-foot electronic billboard or marquee for a day
  • estimated that each MotionPower speed bump would cost $1,500 to $2,000 and earn back its cost in two to three years
  • estimated that each MotionPower speed bump would cost $1,500 to $2,000 and earn back its cost in two to three years.
Chris Fisher

Faster-than-light neutrino result reportedly a mistake caused by loose cable - 0 views

  • a loose fiber optic cable was causing one of the atomic clocks used to time the neutrinos' flight to produce spurious results.
  • If the report is confirmed (right now, there's only one source), then it provides a simple explanation for the fascinating-yet-difficult-to-accept results.
« First ‹ Previous 61 - 80 of 220 Next › Last »
Showing 20 items per page