Motion illusions reveal new insights into perception
In the classic waterfall illusion, if you stare at the downward motion of a waterfall for some period of time, stationary objects -- such as rocks -- appear to drift upward. MIT neuroscientists have found that this phenomenon, called motion aftereffect, occurs not only in our visual perception but also in our tactile perception, and that these senses actually influence one another. Put another way, how you feel the world can actually change how you see it -- and vice versa.
In a paper published in the April 9 online issue of Current Biology, researchers found that people who were exposed to visual motion in a given direction perceived tactile motion in the opposite direction. Conversely, tactile motion in one direction gave rise to the illusion of visual motion in the opposite direction.
Science & Technology
© Sky and Telescope
By April 13th, Venus is getting to be distinctly higher than challenging little Mars deep in the dawn. The scene is drawn for latitude 40° north. The brightness of objects is exaggerated in twilight this close to sunrise or sunset.
By April 13th, Venus is getting to be distinctly higher than challenging little Mars deep in the dawn. The scene is drawn for latitude 40° north. The brightness of objects is exaggerated in twilight this close to sunrise or sunset.
The Comet Yi-SWAN challenge. It isn't much at magnitude 8.5, but this new comet is far north, crossing the bright pattern of Cassiopeia this week. It's getting quite low in the northwest just after dusk - lower than it is in the northeast just before the first light of dawn. However, the moon was full on Thursday the 9th, so the only moonless time to look for the comet this week will be right after dusk, starting about April 11th. Next week will be better, with the comet higher before dawn (but no brighter).
© Science
An Airy Beam viewed in cross section. The asymmetric beam has an intense region on the right-hand side and several less intense spots on the left.
An Airy Beam viewed in cross section. The asymmetric beam has an intense region on the right-hand side and several less intense spots on the left.
Now, US physicists have helped to break that mould by creating the first curved laser beams. The feat could one day help guide lightning to the ground.
Optics researchers led by Pavel Polynkin at the University of Arizona in Tucson generated 35-femtosecond-long laser pulses from a standard titanium-sapphire system.
The straight laser pulses differ from standard lasers in that they cover a wide range of colour frequencies rather than a single colour. Each pulse then passes through a transparent "phase pattern" mask and a lens, which together divide the laser pulse into its constituent parts, rather like breaking a musical chord into its individual notes.
© Biblioteca Marucelliana / Firenze
A new exhibit in Florence shows Galileo's contribution to humanity using astronomical artefacts, stunning artwork and impressive technology.
A new exhibit in Florence shows Galileo's contribution to humanity using astronomical artefacts, stunning artwork and impressive technology.
See some of the exhibitions' best artefacts in our gallery
"Galileo, Medici and the Age of Astronomy" opens next month at the Franklin Institute in Philadelphia, Pennsylvania featuring one of Galileo's two surviving telescopes. Meanwhile, an expansive exhibition has just opened at the Palazzo Strozzi in Florence. "Galileo: Images of the universe from antiquity to the telescope" details the development of astronomy from ancient Egypt and Mesopotamia to Galileo's new universe.
© SCIENCE SOURCE/SPL
This multi-wavelength image of Abell 520 shows the aftermath of a complicated collision of galaxy clusters, some of the most massive objects in the universe. In this image, the hot gas as detected by Chandra is coloured red.
This multi-wavelength image of Abell 520 shows the aftermath of a complicated collision of galaxy clusters, some of the most massive objects in the universe. In this image, the hot gas as detected by Chandra is coloured red.
For more than a decade, astrophysicists have grappled with evidence of a baffling force that seems to be pushing the universe apart at an ever-increasing rate. Exactly what constitutes the dark energy responsible for this cosmic speed-up is unknown, says Michael Turner at the University of Chicago. "The simplest question we can ask is 'does the dark energy change with time?'"
So far, the evidence has suggested that dark energy is constant, though its effect on the universe has become stronger as the universe has expanded and the gravitational force between objects weakens with distance.
Isfahan, Iran -- Iran Thursday declared major advances in its controversial atomic drive as President Mahmoud Ahmadinejad opened a nuclear fuel plant and announced the testing of two high capacity centrifuges.
Ahmadinejad's announcements at a function in central Isfahan province marking national nuclear day are likely to trigger fresh concerns among world powers, who fear Iran's nuclear programme is aimed at making atomic weapons.
Tehran insists its programme is for peaceful purposes only.
Ahmadinejad's announcements at a function in central Isfahan province marking national nuclear day are likely to trigger fresh concerns among world powers, who fear Iran's nuclear programme is aimed at making atomic weapons.
Tehran insists its programme is for peaceful purposes only.
For millennia, people have watched the birds and bees and wondered: "How do they do that?" Thanks to high-speed film and some persistent scientists, at least one of the secrets of flight is now revealed. When birds, bats or bugs make a turn, all they have to do is start flapping their wings normally again and they straighten right out.
That came as a surprise to researchers who thought turning and stopping took more steps.
Lead researcher Tyson L. Hedrick of the University of North Carolina compared it to sitting at a desk chair and turning left. It's a three-step process, launch the turn by pushing with one foot, turn, then stop by pushing with the other.
It's a simpler, one-step process for flying animals, he explained in a telephone interview, launch a turn and then simply flap normally to end it and fly away.
That came as a surprise to researchers who thought turning and stopping took more steps.
Lead researcher Tyson L. Hedrick of the University of North Carolina compared it to sitting at a desk chair and turning left. It's a three-step process, launch the turn by pushing with one foot, turn, then stop by pushing with the other.
It's a simpler, one-step process for flying animals, he explained in a telephone interview, launch a turn and then simply flap normally to end it and fly away.
© Jen Rowland
In a world first, researchers believe that a robot scientists has independently discovered new scientific knowledge.
The robot, Adam, which is a computer system that fully automates the scientific process, hypothesized that certain genes in baker's yeast code for specific enzymes that catalyse biochemical reactions in yeast. Adam then devised experiments to test these predictions, ran the experiments using laboratory robotics, interpreted the results and repeated the cycle. Separate manual experiments have been used to confirm that the hypotheses were both novel and correct.
"Because biological organisms are so complex it is important that the details of biological experiments are recorded in great detail. This is difficult and irksome for human scientists, but easy for robot scientists," says Ross King, who led the research at Aberystwyth University.
Oslo - A $6 cardboard box that uses solar power to cook food, sterilize water and could help 3 billion poor people cut greenhouse gases, has won a $75,000 prize for ideas to fight global warming.
The "Kyoto Box," named after the United Nations' Kyoto Protocol that seeks to cut emissions of greenhouse gases, is aimed at billions of people who use firewood to cook.
Costing 5 euros ($6.60) to make, it can also make it easier to boil polluted water.
"We're saving lives and saving trees," the Kyoto Box's developer Jon Boehmer, a Norwegian based in Kenya, said in a statement.
The "Kyoto Box," named after the United Nations' Kyoto Protocol that seeks to cut emissions of greenhouse gases, is aimed at billions of people who use firewood to cook.
Costing 5 euros ($6.60) to make, it can also make it easier to boil polluted water.
"We're saving lives and saving trees," the Kyoto Box's developer Jon Boehmer, a Norwegian based in Kenya, said in a statement.
© Wired
The largest of the four top recording companies and YouTube's parent company announced on Thursday that they are working together on Vevo, a new music and video entertainment service set to launch later this year. YouTube will handle the technology while Universal Music supplies the content. The two companies will share ad revenue.
The companies said and at this point it appears that Universal's content and artists will be the only label represented on the site. However, Doug Morris, Universal Music's chief executive, said in a conference call with the media that he is in negotiations with other top record labels and is confident they will join.
Google CEO Eric Schmidt said on the same conference call that YouTube and Universal Music have renewed their existing licensing agreement. YouTube will continue to be licensed to allow visitors to use songs from Universal Music. Professionally made videos from the label will only appear on Vevo, the companies said.
This is the first time that YouTube has launched a satellite Web site, Schmidt said but he added that he hopes there will be more.
