One Blog for the Kids!: University of California

Thursday, March 26, 2015

Chickens Agree: Counting From Left Works Best

This is the way I view numbers, along a spatial sequence. (Photo credit: Wikipedia)

Chicken, anyone?
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By ERICA GOODE

Asked to picture the numbers from one to 10, most people will imagine a straight line with one at the left end and 10 at the right.

This “mental number line,” as researchers have termed it, is so pervasive that some scientists have argued that the spatial representation of numbers is hard-wired into the brain, part of a primitive number system that underlies humans’ capacity for higher mathematics.

Now Italian researchers have found that newborn chicks, like humans, appear to map numbers spatially, in the same way.

The chicks, trained to seek out mealworms behind white plastic panels printed with varying numbers of identical red squares, repeatedly demonstrated a preference for the left when the number of squares was small and for the right when the number was larger. The research, led by Rosa Rugani, a psychologist who at the time was at the University of Padova, appeared in the journal Science.

The researchers said the findings supported the idea that the left-right orientation for numbers is innate rather than determined by culture or education – a possibility that was raised by some studies that found that in Arabic-speaking countries where letters and numbers are read right to left, the mental number scale was reversed. But the new research, Dr. Rugani and her colleagues wrote, indicates that orienting numbers in space may represent “a universal cognitive strategy available soon after birth.”

Tyler Marghetis, a doctoral candidate in psychology at the University of California, San Diego, said: “We have brains that evolved for fighting and finding food, not for doing calculus. So one of the hopes of this kind of research is that it will tell us something about the basic building blocks we have access to in building up these more human concepts.”

But Mr. Marghetis said that the studies demonstrated only that the chicks associated rough quantities that were smaller or larger with left or right, not that they represented precise numbers in a mental line. And he cautioned against leaping to the idea that chicks are capable of the same complex abilities as humans.

Judging amounts, either of how much food is available or how many predators are nearby, is an important tool for survival. And many nonhuman species – including chickens, monkeys and even some fish – have some ability to count, though these may be a capacity to distinguish rough numerical magnitude rather than precise numbers.

Human studies indicate that when presented with a task involving numbers people automatically create a mental scale, using one number as an anchor and locating smaller numbers to the left and larger ones to the right. The new research suggests that some version of this may be true for chickens. “We cannot think of any other, and simpler, explanation for the behavior of the chicks than assuming the training number is 1) remembered and 2) compared with the number seen at test,” Dr. Rugani said in an email.

Taken from TODAY Saturday Edition, The New York Times International Weekly, March 14, 2015

Tuesday, December 16, 2014

Astronomical Encounter That May Test Theory of Relativity

larger animation (Photo credit: Wikipedia)

The supermassive black holes are all that remains of galaxies once all protons decay, but even these giants are not immortal. (Photo credit: Wikipedia)

Simulated view of a black hole in front of the Large Magellanic Cloud. The ratio between the black hole Schwarzschild radius and the observer distance to it is 1:9. Of note is the gravitational lensing effect known as an Einstein ring, which produces a set of two fairly bright and large but highly distorted images of the Cloud as compared to its actual angular size. (Photo credit: Wikipedia)

BY RON COWEN

Black holes, the ultradense objects predicted by Einstein’s theory of general relativity, have extraordinary gravity: Everything is sucked in, even light, and virtually nothing leaks out.

Now, for the first time, astronomers may have a chance to watch as a gas cloud that has been hurtling toward the center of the Milky Way collides with a black hole that lies just 26,000 light-years from Earth. (While scientists expect to observe the event beginning in March or April, it occurred 26,000 years ago.) The gas cloud is as massive as three Earths – but no match for the black hole, Sagittarius A**, which has the mass of four million suns.

“This is a rare opportunity to witness spoon-feeding of a black hole,” said Avi Loeb, a theoretical astro physicist at Harvard. “Will the gas reach the black hole, and if so, how quickly? Will the black hole throw up or spit the gas out in the form of an outflow or a jet?

If the black hole devours a sizable chunk of the cloud, a digestive process that could take many months to years, fireworks could ensue. Heated to billions of degrees as it spirals inward, the doomed gas cloud may emit a last gasp of radiation, ranging from radio waves to X-rays.

“We will learn something, no matter what happens,” said Andrea Ghez, an astronomer at the University of California, Los Angeles, who has monitored the galactic center since 1995. Black holes are believed to be at the center of nearly every large galaxy.

The action is likely to unfold in two acts, said Stefan Gillessen of the Max Planck Institute for Extraterrestrial Physics in Germany.

His team discovered the gas cloud, G2, in 2011.

After the cloud, already stretched into a spaghetti-like strand by the black hole’s gravity, makes its closest approach to Sagittarius A*, its distance from the black hole will be about 200 times Earth’s distance from the sun. Nonetheless, the passage of G2 near Sagittarius A* might be near enough to plow into the outer edge of the swirling disk of matter believed to surround the black hole.

The shock wave generated by that encounter might create X-rays and radio waves that could be detected by telescopes.

If the cloud contains a star at its center, as some astronomers have proposed, it may generate more light, said Sera Markoff of the University of Amsterdam.

The encounter could have another effect: Disruptions in the cloud might alter the direction in which radio waves vibrate as they travel through. Simultaneous observations with telescopes tuned to different radio wavelengths might discern the waves’ twists, giving astronomers new details about the cloud’s properties, said Geoffrey Bower, a radio astronomer with the Taiwanese organization Asiaa, in Hilo, Hawaii.

But most of the potential fireworks are at least a year away, perhaps decades. That is how long it may take material torn from G2 to spiral inward through the black hole’s feeding disk, coming 100 times closer to the hole than it is now. At that location, gas becomes hot enough to radiate before it is swallowed.

Next year, the Event Horizon Telescope, an array of radio telescope, will gain enough acuity to discern the light that just misses being dragged into Sagittarius A*, but is bent into a halo. (That level of acuity could make out an orange on the surface of the moon, said the project’s leader, Sheperd Doeleman, of the Massachusetts Institute of Technology Haystack Observatory.) Deviations from the predicted shape of the halo would indicate Einstein’s theory of gravity needs revision.

For now, Professor Loeb said, astronomers are looking forward to the encounter. “The experience is as exciting for astronomers as it is for parents taking the first photos of their infant eating.”

Taken from TODAY Saturday Edition, March 8, 2014