Science Junkie

If your brain were a computer, how much storage space would it...

Sat, 25 May 2013 14:02:00 +0200

If your brain were a computer, how much storage space would it have?

The comparison between the human brain and a computer is not a perfect one, but it does lend itself to some interesting lines of inquiry. For instance: what is the storage capacity of your brain?

The answer to the first question – how much storage space is there inside the average human head? – varies considerably, depending on who you ask. Some estimates come in as low as 1 terabyte, or approximately 1,000 gigabytes. These days, you can purchase an external hard drive with twice that capacity for under a hundred bucks.

The reasoning behind the 100-terabyte estimate has its flaws. It assumes, for example, that each synapse stores 1 byte of information. In reality, each one could conceivably store more or less than that.

Most of the computer chips that we use to model brain activity operate in this binary fashion – but the brain probably doesn’t work this way.

Consider, also, that synapses are often interdependent, and will rely on one another to convey a single piece of information. While it’s logical to assume that the brain’s extensive neural networks greatly improve its processing speed (a couple years ago, researchers writing in Science concluded that the number of nerve impulses executed by one human brain per second is “in the same ballpark [as] the 6.4*10¹⁸ instructions per second that human kind [could] carry out on its general purpose computers in 2007”), it’s also possible that they do so at the expense of storage capacity.

So, which is it? One terabyte? 100 terabytes? 2.5-thousand terabytes? Or can you fit an entire human consciousness into just 300 megabytes (approximately 60 3-minute MP3s), as suggested in an episode of Caprica? Perhaps these questions are irrelevant. As Reber himself says: “if your brain worked like a digital video recorder, 2.5 petabytes would be enough to hold three million hours of TV shows.” We’ve already established that our brains don’t work like DVRs, or the vast majority of computers, for that matter, and so down the rabbit hole we go: how much brain-space does a memory occupy? Does a more detailed memory take up more space than a foggy one? Have forgotten memories been deleted, or have they been relegated to some forgotten subfolder in the dusty corners of your consciousness? Does a deeply rooted, subconscious bias take up more space than a transient dream? Is each encoded in different file format? And while we’re exploring the brain/computer/file-size/file-type metaphor: what is the cognitive equivalent of a GIF, anyway?

Perhaps a better question is whether the size of memories and the storage capacity of the human mind are things that can be measured at all. Reason would suggest that the brain’s capacity is, in fact, limited, and therefore can be measured. Determining what it’s limited by, exactly, and how to quantify those limits, would be a significant boon to fields as diverse as neuroscience, robotics and computer science – especially where the three overlap.

Atomic weights revision changes periodic table A magnificent...

Fri, 24 May 2013 18:29:23 +0200

Atomic weights revision changes periodic table

A magnificent period piece from mid-19th-century Russia has just received a bit of a renovation. Five elements at the heart of the periodic table will never look the same again, following an update to their atomic weights.

“Your chemistry teacher probably said to you ‘atomic weights are constants of nature’, but nothing could be further from the truth,” says Tyler Coplen, director of the Reston Stable Isotope laboratory in Virginia. In fact, the atomic weight of some elements varies depending on where you are on Earth.

Most of the mass of an atom resides in its nucleus, composed of protons and neutrons (with the exception of hydrogen, whose nucleus consists of a single proton). The number of protons in the nucleus determines what atom you are dealing with: all carbon atoms have 6 protons, all oxygen atoms have 8, and so on. But the number of neutrons can vary from atom to atom of the same element. Atoms of the same element but with different numbers of neutrons are called isotopes.

Every element has a number of unstable isotopes, which break apart through radioactive decay, but some elements have more than one stable isotope too. This is where chemists run into problems when it comes to defining the atomic weight…

This has led the guardians of the periodic table – the International Union of Pure and Applied Chemistry (IUPAC) – to decide that the atomic weights of bromine and magnesium are better accommodated by intervals than by single numbers… While they were at it, the IUPAC also took the opportunity to tweak the atomic weights of three more elements: germanium, indium and mercury.

Source: newscientist.com

This is kinda random, but what causes the distortion of vision when air is heated. Examples: when you look at something sitting behind a car on a hot summer day and it looks wavy, or the air above a fire distorts what you see behind it.

Fri, 24 May 2013 18:20:40 +0200

42 Refraction is the answer.

dendroica: Icebergs and rough sea, expedition to South Georgia....

Fri, 24 May 2013 13:49:00 +0200

dendroica:

Icebergs and rough sea, expedition to South Georgia. Photo by Pascal Cocco.

(via National Geographic Magazine - NGM.com)

the-science-llama: Influence of Planets on the Sun This tool...

Fri, 24 May 2013 12:06:14 +0200

the-science-llama:

Influence of Planets on the Sun

This tool shows the movement of the Sun due to the gravitational pull of the planets. You can see how little effect we have on our massive star or how much more massive Jupiter is compared to us.

If some alien astronomer was looking at our star, they would see it red/blueshift as it wobbles around dancing with the planets.

‘What if oxygen is a poison?’ The first part of...

Thu, 23 May 2013 18:35:55 +0200

‘What if oxygen is a poison?’

The first part of chocolotteyoghurt’s ask is a typical request that I overlook. Cellular respiration is a fundamental process in biology, we can easily find an answer in any biology textbook or through the huge quantity of material available on web.

The last part, however, is more interesting because it’s often ignored that oxygen is a potential poison for us.

Molecular oxygen.
If our body is subjected to prolonged exposure to high partial pressures of oxygen — for example, in underwater diving and hyperbaric medicine— our lungs and our central nervous system may be damaged depending on the pressure and the time exposure, due the excessive concentration of oxygen in the blood.

Oxidant molecular oxygen.
During the cellular respiration process, oxygen produces intermediates known as ‘reactive oxygen species’ (ROS). These intermediates are free radicals —that is, molecules having an unpaired electron in the outer orbital— so they are highly unstable. To achieve a greater state of stability through the acquisition of an electron, they have a high level of reactivity with other molecules. In turn, the molecules that react with the free radicals become unstable and seek an electron, triggering a chain mechanism.
The formation of free radicals is a physiological process and a healthy body is properly equipped to fight them through an antioxidant system.
However, if the balance between pro-oxidants and antioxidants breaks, the cells can suffer serious damage such as DNA’s deterioration and structural modification of proteins.

To respond to fuzzy-cactus, the theory on the pathophysiology of aging derives from this oxidative stress, but nothing is demonstrated and, at the moment, miraculous cures anti aging are ineffective (eg, enzymatic antioxidants added to diet are destroyed during digestion, while vitamins antioxidants added to cells reduces the production of our “natural” antioxidants, leaving unchanged the level of free radicals).

Image: [x]

thescienceofreality: Three Possible Futures for the Universe...

Thu, 23 May 2013 15:48:00 +0200

thescienceofreality:

Three Possible Futures for the Universe via Chandra X-ray Observatory (Credit: NASA/CXC/M.Weiss)

“This illustration shows three possible futures for the Universe, depending on the behavior of dark energy, by showing how the scale of the Universe may change with time. If dark energy is constant, as the new Chandra results suggest, the expansion should continue accelerating forever. If dark energy increases, the acceleration may happen so quickly that galaxies, stars, and eventually atoms will be torn apart, in the so-called Big Rip. Dark energy may also lead to a recollapse of the Universe, in the Big Crunch. The illustration also shows the early decelerating expansion of the Universe, followed by the accelerating phase that started about 6 billion years ago.”

Related Link here on dark energy.

rorschachx: In the evolutionary race, tiny plants are speedier...

Thu, 23 May 2013 15:43:30 +0200

rorschachx:

In the evolutionary race, tiny plants are speedier than their towering cousins. A new comparison of the genomes of 138 families of species with heights ranging from 5 centimeters to about 45 meters reveals that the DNA of shorter plants, such as tomato plants, mutates faster than taller plants, such as most trees. One short-in-stature herbal plant family called Tropaeolaceae (left) mutated almost 10 times as fast as a closely related family of trees called Akaniaceae (right), the team reports today in Nature Communications. The researchers suggest that shorter plants may mutate faster because they typically copy their genomes more frequently. The more a plant copies its genome, the more mistakes it makes. If correct, that could mean tall, slower-growing plants such as trees are in greater danger from the rapidly changing climate than their smaller relatives, because the greater rate of mutation gives shorter plants more opportunities to adapt. | via Science

NGC 1929: A superbubble in the Large Magellanic Cloud.

Wed, 22 May 2013 23:35:30 +0200

NGC 1929: A superbubble in the Large Magellanic Cloud.

climateadaptation: kqedscience: Astronauts Snag Dramatic...

Wed, 22 May 2013 20:59:00 +0200

climateadaptation:

kqedscience:

Astronauts Snag Dramatic Photographs of Alaska’s Erupting Volcano

“Astronauts living on board the International Space Station managed to get these dramatic pictures of the Pavlof Volcano as it erupted over the weekend. The volcano began acting up last Monday, the 13th, its first eruption since 2007.”

See more images at The Atlantic.

Definitely click through!

UCSB Study Shows Where Scene Context Happens in our...

Wed, 22 May 2013 18:23:12 +0200

UCSB Study Shows Where Scene Context Happens in our Brain

… Though a seemingly simple and intuitive strategy, the lookout’s visual search function –– a process that takes mere seconds for the human brain –– is still something that a computer, despite technological advances, can’t do as accurately.

“Behind what seems to be automatic is a lot of sophisticated machinery in our brain,” said Miguel Eckstein, professor in UC Santa Barbara’s Department of Psychological & Brain Sciences. “A great part of our brain is dedicated to vision.”

Over the millennia of human evolution, our brains developed a pattern of search based largely on environmental cues and scene context. It’s an ability that has not only helped us find food and avoid danger in humankind’s earliest days, but continues to aid us today, in tasks as banal as driving to work, or shopping; or as specialized as reading X-rays.

Where this –– the search for objects using scene and other objects –– occurs in the brain is little understood, and is for the first time discussed in the paper, “Neural Representations of Contextual Guidance in Visual Search of Real-World Scenes,” published recently in the Journal of Neuroscience…

The searched object’s contextual location in the scenes, according to the study, is represented in the area called the lateral occipital complex (LOC), a place that corresponds roughly to the lower back portion of the head, toward the side. This area, according to Eckstein, has the ability to account for other objects in the scene that often appear in close spatial proximity with the searched object –– something computers are only recently being taught to do.

“So, if you’re looking for a computer mouse on a cluttered desk, a machine would be looking for things shaped like a mouse. It might find it, but it might see other objects of similar shape, and classify that as a mouse,” Eckstein said…

The LOC, on the other hand, would contain the information the brain needs to direct a person’s attention and gaze first toward the most likely place that a mouse might be, such as on top of the desk, or near the keyboard. From there, other visual parts of the brain go to work, searching for particular characteristics, or determining the target’s presence.

So strong is the scene context in biasing search, said Eckstein, that if another similar-looking object was placed in the location where the mouse is likely to be, and that scene briefly flashed before your eyes, you would likely –– erroneously –– interpret that object as the mouse.

Full Article

NASA Launching Experiment to Examine the Beginnings of the...

Wed, 22 May 2013 15:03:41 +0200

NASA Launching Experiment to Examine the Beginnings of the Universe

When did the first stars and galaxies form in the universe? How brightly did they burn their nuclear fuel?

Scientists will seek to gain answers to these questions with the launch of the Cosmic Infrared Background ExpeRIment (CIBER) on a Black Brant XII suborbital sounding rocket between 11 and 11:59 p.m. EDT, June 4 from the Wallops Flight Facility in Virginia.

Jamie Bock, CIBER principal investigator from the California Institute of Technology, said, “The first massive stars to form in the universe produced copious ultraviolet light that ionized gas from neutral hydrogen. CIBER observes in the near infrared, as the expansion of the universe stretched the original short ultraviolet wavelengths to long near-infrared wavelengths today. CIBER investigates two telltale signatures of first star formation — the total brightness of the sky after subtracting all foregrounds, and a distinctive pattern of spatial variations.”

Read more

odditiesoflife: Newton’s Cradle Newton’s cradle, named after...

Wed, 22 May 2013 14:21:03 +0200

odditiesoflife:

Newton’s Cradle

Newton’s cradle, named after Sir Isaac Newton, is a device that demonstrates conservation of momentum and energy via a series of swinging spheres. When one on the end is lifted and released, the resulting force travels through the line and pushes the last one upward.

seafarers: Giant’s Causeway by Horia Bogdan Name and legend...

Tue, 21 May 2013 21:20:58 +0200

seafarers:

Giant’s Causeway by Horia Bogdan

Name and legend fit because this expanse of stone columns, viewed from above, can easily be mistaken for a road paved by a giant. But geologists know a thing or two about natural structure of volcanic origin and they tell us a different story. They let us know that, about 50 million years ago, a large part of Northern Ireland and the West of Scotland were subjected to prolonged volcanic activity of the crust.

Spilling from long cracks in the crust, lava covered these areas with thicknesses of hundreds of meters. Cooling slowly and uniformly, the lava generated regular polygons of basalt in the more superficial layers, through a process of contraction — like the mud when it dries in the sun.
The surface cracks gradually deepened, dividing the entire thickness of basaltic rock in the stone columns. Then, when the wall rock surrounding these basalt formations were eroded by the activity of the sea, the entire columns came to light.

Anyway, they take the breath away.

distant-traveller: Cottonwood trees and the Milky Way Image...

Tue, 21 May 2013 20:54:00 +0200

distant-traveller:

Cottonwood trees and the Milky Way

Image credit: Randy Halverson/Dakotalapse

Hello, I was curious. Bi polar disorder, what is going in in the brain? I have it, personally. I seem a bit off. I tend to go through serious highs, and super bad lows. And well, recently I've picked up binge drinking. Probably not a good idea, but I want to know what's going on in my head that my psychiatrist can't tell me. Thank you!

Tue, 21 May 2013 18:10:31 +0200

Your psychiatrist is not a cruel sadist. He/She can’t give you an explanation because we don’t know what happens in the brain to trigger bipolar disorder.
Researchers think that it’s a multifactorial disorder, that is, many factors (genetic, neurochemical, environmental) act together to trigger the disease, but nothing definite has been established.
So I advise you to trust your physician (or find a physician that you can trust If the current one is downright reluctant to any explanation) and with him/her focus yourself on the how (to get better) not the why. And don’t get me started on how wrong alcohol intoxication is in this situation… Do you know a John Francis Anthony Pastorius III?

More information about bipolar disorder here.

“Whodunnit” of Irish potato famine solved It is the first time...

Tue, 21 May 2013 15:10:53 +0200

“Whodunnit” of Irish potato famine solved

It is the first time scientists have decoded the genome of a plant pathogen and its plant host from dried herbarium samples. This opens up a new area of research to understand how pathogens evolve and how human activity impacts the spread of plant disease.

Phytophthora infestans changed the course of history. Even today, the Irish population has still not recovered to pre-famine levels. “We have finally discovered the identity of the exact strain that caused all this havoc”, says Hernán Burbano from the Max Planck Institute for Developmental Biology.

For research to be published in eLife, a team of molecular biologists from Europe and the US reconstructed the spread of the potato blight pathogen from dried plants. Although these were 170 to 120 years old, they were found to have many intact pieces of DNA.

“Herbaria represent a rich and untapped source from which we can learn a tremendous amount about the historical distribution of plants and their pests - and also about the history of the people who grew these plants,” according to Kentaro Yoshida from The Sainsbury Laboratory in Norwich.

Images: [x][x][x]

Bacteria use hydrogen, carbon dioxide to produce...

Mon, 20 May 2013 21:35:28 +0200

Bacteria use hydrogen, carbon dioxide to produce electricity

Researchers have engineered a strain of electricity-producing bacteria that can grow using hydrogen gas as its sole electron donor and carbon dioxide as its sole source of carbon. Researchers at the University of Massachusetts, Amherst report their findings at the 113th General Meeting of the American Society for Microbiology.

“This represents the first result of current production solely on hydrogen,” says Amit Kumar, a researcher on the study who, along with his co-authors are part of the Lovley Lab Group at the university.

Under the leadership of Derek Lovley the lab group has been studying Geobacter bacteria since Lovley first isolated Geobacter metallireducens in sand sediment from the Potomac River in 1987. Geobacter species are of interest because of their bioremediation, bioenergy potential, novel electron transfer capabilities, the ability to transfer electrons outside the cell and transport these electrons over long distances via conductive filaments known as microbial nanowires.

Kumar and his colleagues studied a relative of G. metallireducens called Geobacter sulfurreducens, which has the ability to produce electricity by reducing organic carbon compounds with a graphite electrode like iron oxide or gold to serve as the sole electron acceptor. They genetically engineered a strain of the bacteria that did not need organic carbon to grow in a microbial fuel cell.

“The adapted strain readily produced electrical current in microbial fuel cells with hydrogen gas as the sole electron donor and no organic carbon source,” says Kumar, who notes that when the hydrogen supply to the microbial fuel cell was intermittently stopped electrical current dropped significantly and cells attached to the electrodes did not generate any significant current.

Source: eurekalert.org

Image: [x]

Bloodthirsty ‘factual’ TV shows demonise...

Mon, 20 May 2013 18:08:30 +0200

Bloodthirsty ‘factual’ TV shows demonise wildlife

“Major US TV channels are promoting hysterical and outdated ideas about wildlife in popular, blood-soaked shows”

My 2¢ and a plea.

When it comes to animals and especially wildlife, we always have to deal with two big groups and the political/economic forces that support them.
Farmers/Hunters seek to protect their livestock and their game clinging, tooth and nail, to the story of the bad wolf (and the like).
Animal “Lovers” choose the beasts to defend (generally, cute, majestic or colorful ones) and, undeterred, they go on and on with their cause, often without the slightest awareness of these animals’ biological cycles and the possible problems that they could cause without a minimum of contrast.
Then, in a world largely disconnected and ignored, there are the scientists, who are trying to produce impartial and legitimate studies — like this one — to be used to develop management plans, where everything is taken into consideration (wildlife, species at risk of extinction, habitat conservation, hunting sustainability) to ensure the precarious balance of an ecosystem of which we are part.

Where are the networks in all this?

The link on top of the post gives us the answer for some of these networks (Discovery, Animal Planet, History Channel). They are widely recognized for their ‘factual’ shows, but essentially they sensationalize facts and notions to capture more audience possible.
I understand this necessity, but the shows mentioned in Adam Welz’s article offer an alarming disinformation service. They excuse the killing of carnivore wildlife (being cruel and vengeful beasts thirsty for human blood) shielded by ambiguous facts, viewpoints of convenience, one-sided argument, and often, as in the case of wolves, taking advantage of old fears: historically terrifying, but now inconsistent for more than 200 years .

Now, I am not here to claim that these networks should broadcast lessons of biology and ecology in place of these shows. However, I wonder if they can attract the same number of viewers by stopping this nonsense and offering an useful service to people. A service that provides a real insight into nature, into mankind, and therefore into man-nature connection and coexistence.
If the answer is “NO”, they turn on and off the switch of science at will and the difference between these networks’ documentaries and, in Welz’s words, the “‘trashy’ material that dominates free-to-air network TV” will be non-existent.

Image credit: Kaya.

Discovery, Animal Planet, and History Channel exposed for killing animals for profit

Mon, 20 May 2013 17:42:22 +0200

Discovery, Animal Planet, and History Channel exposed for killing animals for profit:

climateadaptation:

These channels are failing the spirit of conservationism and education. They are failing inspiring awe in young people. Failing much needed inspiration in a very confused and conflicted world.

These shows are failing their core values, their main purpose, which is leadership in environmentalism and cultural education. Far worse, they are failing millions of young people - millions - who look up to them.

Please join me in asking Discovery, Animal Planet, and the History Channels to stop, apologize, and correct.