This is a repository for all cool scientific discussion and fascination. Scientific facts, theories, and overall cool scientific stuff that you'd like to share with others. Stuff that makes you smile and wonder at the amazing shit going on around us, that most people don't notice.
Post pictures, vidoes, stories, or links. Ask questions. Share science.
The universe has a huge hole in it that dwarfs anything else of its kind. The discovery caught astronomers by surprise.
The hole is nearly a billion light-years across. It is not a black hole, which is a small sphere of densely packed matter. Rather, this one is mostly devoid of stars, gas and other normal matter, and it's also strangely empty of the mysterious "dark matter" that permeates the cosmos. Other space voids have been found before, but nothing on this scale.
Astronomers don't know why the hole is there.
"Not only has no one ever found a void this big, but we never even expected to find one this size," said researcher Lawrence Rudnick of the University of Minnesota.
Rudnick's colleague Liliya R. Williams also had not anticipated this finding.
"What we've found is not normal, based on either observational studies or on computer simulations of the large-scale evolution of the universe," said Williams, also of the University of Minnesota.
The finding will be detailed in the Astrophysical Journal.
The universe is populated with visible stars, gas and dust, but most of the matter in the universe is invisible. Scientists know something is there, because they can measure the gravitational effects of the so-called dark matter. Voids exist, but they are typically relatively small.
The gargantuan hole was found by examining observations made using the Very Large Array (VLA) radio telescope, funded by the National Science Foundation.
There is a "remarkable drop in the number of galaxies" in a region of sky in the constellation Eridanus, Rudnick said.
The region had been previously been dubbed the "WMAP Cold Spot," because it stood out in a map of the Cosmic Microwave Background (CMB) radiation made by NASA's Wilkinson Microwave Anisotopy Probe (WMAP) satellite. The CMB is an imprint of radiation left from the Big Bang, the theoretical beginning of the universe.
"Although our surprising results need independent confirmation, the slightly colder temperature of the CMB in this region appears to be caused by a huge hole devoid of nearly all matter roughly 6 to 10 billion light-years from Earth," Rudnick said.
Photons of the CMB gain a small amount of energy when they pass through normal regions of space with matter, the researchers explained. But when the CMB passes through a void, the photons lose energy, making the CMB from that part of the sky appear cooler. [Reply]
May 16, 2013 — In the future, if you want to improve your ability to manipulate numbers in your head, you might just plug yourself in. So say researchers who report in the Cell Press journal Current Biology on May 16 on studies of a harmless form of brain stimulation applied to an area known to be important for math ability.
"With just five days of cognitive training and noninvasive, painless brain stimulation, we were able to bring about long-lasting improvements in cognitive and brain functions," says Roi Cohen Kadosh of the University of Oxford.
Incredibly, the improvements held for a period of six months after training. No one knows exactly how this relatively new method of stimulation, called transcranial random noise stimulation (TRNS), works. But the researchers say the evidence suggests that it allows the brain to work more efficiently by making neurons fire more synchronously.
Cohen Kadosh and his colleagues had shown previously that another form of brain stimulation could make people better at learning and processing new numbers. But, he says, TRNS is even less perceptible to those receiving it. TRNS also has the potential to help even more people. That's because it has been shown to improve mental arithmetic -- the ability to add, subtract, or multiply a string of numbers in your head, for example -- not just new number learning. Mental arithmetic is a more complex and challenging task, which more than 20 percent of people struggle with.
Ultimately, Cohen Kadosh says, with better integration of neuroscience and education, this line of study could really help humans reach our cognitive potential in math and beyond. It might also be of particular help to those suffering with neurodegenerative illness, stroke, or learning difficulties.
"Maths is a highly complex cognitive faculty that is based on a myriad of different abilities," Cohen Kadosh says. "If we can enhance mathematics, therefore, there is a good chance that we will be able to enhance simpler cognitive functions." [Reply]
The next time you're stung by a bee or wasp or hornet, remember that only females have this ability. Males don't do that shit.. Similarly, male mosquitos don't bite animals, only females do.
A stinger is actually called an ovipositor, which is part of the female's reproductive organs.
Hummingbirds are among the smallest of vertebrates and have the highest metabolism of all animals (about 30 times the human metabolic rate). This high metabolism (converting food energy to energy the body uses) is due mostly to their small size. The cells of warm-blooded animals produce heat during metabolism. A large animal, such as an elephant, has so many cells inside its body producing heat that the problem becomes getting rid of excess heat. With a small animal, however, heat is lost much more quickly to the environment and the problem becomes getting enough energy to stay warm. In fact, a warm-blooded animal smaller than a hummingbird (or shrew--they are about the same size) could not exist because it could not take in food fast enough to keep itself warm. A hummingbird deprived of food would die within a few hours!
Hummingbirds have evolved a unique method of foraging--hovering. This ability allows hummingbirds to find a food source not available to other birds. Wildflowers typically grow too high off the ground for a standing bird to reach and are too flimsy to support a perching bird. Hummingbirds get energy by feeding on the sugar-rich nectar of wildflowers, consuming three times their own weight in nectar daily. They also eat a few insects during the day to provide protein and other nutrients.
Conserving Energy.
Because they lose heat so rapidly, hummingbirds are often not able to maintain normal body temperatures during the night. To conserve energy they shut down and become "torpid." Torpidity is a sort of temporary hibernation in which the hummingbird's temperature can drop from the normal 104 F to a mere 54 F and the metabolic rate decreases significantly. Also, studies have shown that the patterns hummingbirds follow when feeding are very efficient. In fact, most hummingbird behavior can be explained in terms of increasing energy efficiency. Although I like to think that hummingbirds will sit on my daughters' fingers while drinking at the feeder because the birds are able to recognize my daughters' kind intentions, I suspect they recognize the opportunity to rest while feeding and know they could escape instantly if they felt threatened in any way.
A Hummingbird Paradox?
If hummingbirds need so much energy, why do they spend so much time perched doing nothing? This question plagued scientists for some time. If you spent a day following a hummingbird (good luck keeping up!) you would find it spent about 75% of its day perching, and only 20% of its day feeding. A group a four scientists (science is seldom an individual effort) led by Jared Diamond discovered the answer. During the perching time, hummingbirds are digesting nectar as rapidly as possible and have nothing to gain by feeding until their storage crops are at least half-empty (Do most people fill up their cars with gas when the gauge reads three-fourths full or wait until it's less than half?). It turns out that with the typical pattern of feed for one minute, perch for three minutes, hummingbirds are taking in energy as fast as their digestive system allows. [Reply]
