Your nose is an airborne molecule detector. And higher concentrations of molecules will give you a more intense smell. There are olfactory receptor neurons in the top of the nose. These have cilia that extend down into the mucosa lining.
The actual “receptor” parts are on the cilia. There are as many as 1000 different kinds of receptors, and each one “binds” (sticks) to a different kind of volatile chemical. This makes the neuron fire, telling the brain that that neuron’s special kind of volatile is present. The combinations of different kinds of neurons firing is perceived as a smell.
Humans have 10 square cm of olfactory epithelium; dogs have 170 sq cm. Dogs are way better at smelling than we are. Insects have these things on their antennae.
How exactly the “binding” works: still up for debate. Reason to become a scientist!
Japanese Researchers Develop Artificial Synapse
Japanese researchers developed a tiny device that has a gap bridged by a copper filament under a voltage pulse stimulation. This results in a change in conductance which is time-dependant — a change in strength that’s nearly identical to the one found in biological synaptic systems. The inorganic synapses could thus be controlled by changes in interval, amplitude, and width of an input voltage pulse stimulation.
Why this is exciting is that the device is essentially mimicking the major features of human cognition, what the researchers refer to as the “emulation of synaptic plasticity”, including what goes on in short-term and long-term memory. Not only that, it responds to the presence of air and temperature changes, which indicates that it has the potential to perceive the environment much like the human brain.
The researchers are hoping that their newfound insight could help in the development of artificial neural networks, but it’s clear that their system, which operates at a microscopic level, could also be used to treat the human brain. The day may be coming when failing synaptic systems could be patched with a device similar to this one, in which biological function is offloaded to a synthetic one.
Spectrometers in progress.
The DIY Spectrometry Kit turns a smartphone into a mobile material analysis lab.
After successfully funding the kits just two months ago, creator Jeffrey Yoo Warren has already launched a full-scale assembly operation, which kicked off with the delivery of 800+ pounds of aluminum conduit boxes earlier this week.
The finished spectrometers look beautiful and seem to work like a charm — and rewards should be out the door on time.
AND WHAT DOES THIS BUTTON DO? Pictured above is the flight deck of Space Shuttle Endeavour, the youngest shuttle and the second to last ever launched. The retired orbiters are now being sent to museums, with Endeavour being sent to California Space Center in Los Angeles, California, Atlantis to the Kennedy Space Center Visitor Complex on Merritt Island, Florida, and Discovery to the Udvar-Hazy Annex of the National Air and Space Museum in Chantilly, Virginia. (Photo: Ben Cooper / Spaceflight Now via NASA APOD)
How Does Our Brain Know What Is a Face and What’s Not?
Objects that resemble faces are everywhere. Whether it’s New Hampshire’s erstwhile granite “Old Man of the Mountain,” or Jesus’ face on a tortilla, our brains are adept at locating images that look like faces. However, the normal human brain is almost never fooled into thinking such objects actually are human faces.
Full Story: Science Daily
It followed from the special theory of relativity that mass and energy are both but different manifestations of the same thing — a somewhat unfamiliar conception for the average mind. Furthermore, the equation E is equal to m c-squared, in which energy is put equal to mass, multiplied by the square of the velocity of light, showed that very small amounts of mass may be converted into a very large amount of energy and vice versa. The mass and energy were in fact equivalent, according to the formula mentioned above. This was demonstrated by Cockcroft and Walton in 1932, experimentally.
- Albert Einstein
“Classic” Lesson: Lesson #5 - Fame
This was one of the first STW comics I ever made, and it’s still one of my favorites - not because of the punch-line, but because it was the first original idea I first had for the comic (as opposed to adapting it from something else I had come up with).
I also love this one because it angers so many people who misread it as me saying that ‘there is more skill in profession X than profession Y’. That’s not what it says, but people never read it that way. It’s the skill required to reach a certain level of fame. So the long, long arguments about it in the comments of wherever it gets posted are delightful to read. Mainly because it initiates interesting debates, and because it proves some people need to learn how to read a graph.
And yes, the x- and y- axes are switched, but that had to be done for the sake of building up to the punchline.
The brain is in default mode when we stare into space, sleep, succumb to anesthesia, make our mind a blank while sitting motionless—in short, when the brain’s only task seems to be keeping us alive and breathing. This default activity, to everyone’s surprise, is no mere murmur in the background of a loud symphony. It is the symphony, consuming 20 times as much energy as the conscious life of the mind, including thinking, feeling, and using our senses—the mental acts captured by the brain imaging that so entrances the public. “The brain at rest is not at rest,” says neuroscientist Alvaro Pascual-Leone of Harvard. “Even more important, this resting activity is not random, but is well organized and constitutes the bulk of the brain’s activity.
(image via upload.wikimedia.org)
The nucleus of every atomic isotope contains two different types of sub-atomic particles: protons and neutrons. The interesting thing about this is that the nucleus has a net-positive charge. Classical physics would tell us that the nucleus shouldn’t exist because of this net-positive charge. The coulombic repulsion caused by having a bunch of positive charges in close proximity to one another should cause the nucleus to fly apart in all directions.
The reason that the nucleus doesn’t fly apart is due to the weak and strong nuclear forces, which act as a sort of “glue” that holds the nucleus together. These forces work in such a way that only some combinations of neutrons and protons result in stable nuclei, forming what is called the “continent of stability”. Neutrons that don’t have this magic combination tend to be instable and fly apart over short time periods.
This “continent” dwindles as nuclei become very large, as is the case in heavy isotopes. This instability is responsible for nuclear fission, atomic power and all of the associated wonders and terrors our civilization experienced in the last century. The continent doesn’t dwindle altogether as atomic mass increases, however. Scientists predict that as fermionic energy levels are filled, an “island of stability” could, theoretically, result.
It may take us another thirty years of research and improvements in atom smashing techniques to find this island. However, if current theories are correct and it does actually exist, the door could be open to an entirely new class of stable super-heavy elements with their own chemical and physical characteristics. These atoms would be fascinating to study in the heart of a supercollider, but there is a possibility that they could be stable for use outside of the lab, possibly as fissile materials for energy or some other as-yet unforeseen application.