Science & Technology
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Fireball

The biggest threat to humanity, far bigger than global warming/climate change, is about to get bigger, much bigger

© Unknown
The chelyabinsk asteroid fireball, a “near-Earth object” (NEO), an asteroid (likely made of rock) between 15 and 20 meters across (about the length of a school bus), which just happened to arrive in the same place as planet Earth that morning. The mass of the object was about 10 thousand tons. It struck the atmosphere moving at about 40,000 MPH (more than double the speed of the Space Shuttle).
A press release from some former NASA astronauts on the current asteroid impact threat to earth, based on data on in-atmosphere detonations since 2001, gleaned from a nuclear weapon detonation detection system has yielded some startling numbers.

The threat is 3 to 10 times higher than previously predicted. The data will be presented at the Seattle Flight Museum, Tuesday April 22, at 6:00pm PDT.

Just last night, another fireball was seen over Russia, caught on a dashcamera. See video.
Document

Turning science on its head: Harvard researchers offer new views of body's insulating material

© Daniel Berger and Giulio Tomassy
The higher you look in the cerebral cortex, the less myelin you'll find, according to Professor Paola Arlotta. Not only that, but “neurons in this part of the brain display a brand-new way of positioning myelin along their axons that has not been previously seen," Arlotta added. Pictured is an image of three neurons.
Harvard neuroscientists have made a discovery that turns 160 years of neuroanatomy on its head.

Myelin, the electrical insulating material in the body long known to be essential for the fast transmission of impulses along the axons of nerve cells, is not as ubiquitous as thought, according to new work led by Professor Paola Arlotta of the Harvard Stem Cell Institute (HSCI) and the University's Department of Stem Cell and Regenerative Biology, in collaboration with Professor Jeff Lichtman of Harvard's Department of Molecular and Cellular Biology.

"Myelin is a relatively recent invention during evolution," says Arlotta. "It's thought that myelin allowed the brain to communicate really fast to the far reaches of the body, and that it has endowed the brain with the capacity to compute higher-level functions."

In fact, loss of myelin is a feature in a number of devastating diseases, including multiple sclerosis and schizophrenia.

But the new research shows that despite myelin's essential roles in the brain, "some of the most evolved, most complex neurons of the nervous system have less myelin than older, more ancestral ones," said Arlotta, co-director of the HSCI neuroscience program.
Bulb

Michael R. Eades, M.D.: Beware the confirmation bias

Recently, while alone and unsupervised, I allowed myself to be goaded into an ill-advised Twitter debate. With someone who calls himself Ducks Dodger, no less. (For those of you who didn't see it, you can go to my Twitter account, scroll back to April 8-9 and check out this tar baby I got caught up in.)

I soon realized the entire affair was an exercise in futility, so extracted myself from it. It was an exercise in futility because it was a blatant case of the confirmation bias writ large. But my aggravation hasn't gone to waste because I've been waiting for an excuse to write a little essay on the confirmation bias that plagues us all. Who knew fate, in the guise of Ducks Dodger, would give me the prod I needed.

Taktu cleaning fat from seal skin with an ulu
Cape Dorset (Kinngait), Nunavut, Canada, August, 1960
In a bit, I'll describe the details of this Twitter fiasco and how the confirmation bias reared its head. But first, let's look at provoker-in-chief of the confirmation bias: cognitive dissonance.

Comment: More food for thought: The Truth Wears Off.

Robot

Why there will be a robot uprising

Terminator
© Mike Heywood/Shutterstock
In the movie Transcendence, which opens in theaters on Friday, a sentient computer program embarks on a relentless quest for power, nearly destroying humanity in the process.

The film is science fiction but a computer scientist and entrepreneur Steven Omohundro says that "anti-social" artificial intelligence in the future is not only possible, but probable, unless we start designing AI systems very differently today.

Omohundro's most recent paper, published in the Journal of Experimental & Theoretical Artificial Intelligence, lays out the case.

We think of artificial intelligence programs as somewhat humanlike. In fact, computer systems perceive the world through a narrow lens, the job they were designed to perform.

Microsoft Excel understands the world in terms of numbers entered into cells and rows; autonomous drone pilot systems perceive reality as a bunch calculations and actions that must be performed for the machine to stay in the air and to keep on target. Computer programs think of every decision in terms of how the outcome will help them do more of whatever they are supposed to do. It's a cost vs. benefit calculation that happens all the time. Economists call it a utility function, but Omohundro says it's not that different from the sort of math problem going in the human brain whenever we think about how to get more of what we want at the least amount of cost and risk.

For the most part, we want machines to operate exactly this way. The problem, by Omohundro's logic, is that we can't appreciate the obsessive devotion of a computer program to the thing it's programed to do.

Put simply, robots are utility function junkies.
Comet 2

Possible spectacular meteor shower from Comet 209/LINEAR in May

209P/LINEAR is a periodic comet discovered by the Lincoln Laboratory Near-Earth Asteroid Research (LINEAR) survey on five images taken on 2004, February 3.40 (discovery magnitude ~18.1). Reported by LINEAR as an apparent asteroidal object, it has been found to show a narrow 1'.1 tail in p.a. 274 deg (slightly expanding toward the end) on CCD images obtained by R. H. McNaught with the 1.0-m f/8 reflector at Siding Spring on Mar. 30.8 UT. This comet has been assigned the permanent designation 209P on 2008, December 12 (previous designation were P/2008 X2 (LINEAR) = P/2004 CB).

We performed follow-up measurements of this object on 2014, April 14.95 with the 2.0-m f/10.0 Ritchey-Chretien + CCD telescope of La Palma-Liverpool (J13 MPC code). You can see our image below with the comet a about magnitude ~17.
Comet 209P/Linear
© Remanzacco Observatory
According to a prediction by E. Lyytinen and P. Jenniskens, comet 209P/LINEAR will possibly cause a big meteor shower on May 24, 2014.
Better Earth

Innovative axe chops through wood like it's butter

Axe
© Vipukirves
A traditional axe uses a wedge-shaped head to split the wood. The wedge, as you know, is a simple machine that gives a person a physical advantage over wood. (Other simple machines include the wheel and axle, pulley, inclined plane, screw and the lever.) For eons, humans have used the wedge combined with strength and some help from gravity, to splinter wood.

Even though the tool is simple, using it can be dangerous in unskilled hands. One uses a lot of power to drive the sharp tip into wood and once the head of an axe gets going, it's not easy to stop. The chopper can miss the wood and impale a body part or hit the log at the wrong angle, causing the axe to bounce and do little chopping at all.

But check out this ax from Finnish company Vipukirves. It's called the Leveraxe and instead of a wedge, this ax works more like a lever. The head is attached to the handle from the side instead of the center, which also moves the center of gravity off to the side. The specialized shape of the head also capitalizes on the natural kinetic energy of a person's swing. The tip is not strictly a wedge. A couple of inches from the tip, the blades widens. That causes the head to slow when it penetrates the wood, but the momentum from the swing is still there and because the head is off center, gravity forces the tip to rotate downward, which turns the blade into a lever.
Mars

Mars used to be a lot wetter than it is now

© NASA/JPL-Caltech/University of Arizona
A high resolution digital terrain model (DTM) of an ancient river and tributaries on Mars as observed by the HiRISE camera on NASA's Mars Reconnaissance Orbiter (MRO).
Trying to understand the ancient climate of our own planet is hard enough, but to understand Mars' climatic history, planetary scientists have had to turn to a rather inventive method of climate forensics.

In case you didn't get the memo, Mars used to be a lot wetter than it is now; water flowed across its surface and vast lakes - or even seas - used to cover huge swathes of land. But as the red planet's atmosphere was stripped away by the solar wind, global air pressure plummeted, leaving Mars to freeze-dry. The liquid water froze into the crust and sublimated while any atmospheric moisture was lost to space.

However, the biggest puzzle for scientists isn't necessarily why Mars is now so dry now, but how it was able to sustain liquid water on its surface at all.
Blue Planet

Earth 2.0? Scientists discover Earth's "twin"

earth
© Credit NASA Ames/SETI Institute/JPL-CalTech
An artist's concept of Kepler-186f, the first Earth-size planet found in the habitable zone, a range of distances from a star where liquid water could pool on an orbiting planet's surface
It is a bit bigger and somewhat colder, but a planet circling a star 500 light-years away is otherwise the closest match of our home world discovered so far, astronomers announced on Thursday.

The planet, known as Kepler 186f, named after NASA's Kepler planet-finding mission, which detected it, has a diameter of 8,700 miles, 10 percent wider than Earth, and its orbit lies within the "Goldilocks zone" of its star, Kepler 186 - not too hot, not too cold, where temperatures could allow for liquid water to flow at the surface, making it potentially hospitable for life.

"Kepler 186f is the first validated, Earth-size planet in the habitable zone of another star," Elisa V. Quintana of the SETI Institute and NASA's Ames Research Center in Mountain View, Calif., said at a news conference on Thursday. "It has the right size and is at the right distance to have properties similar to our home planet."
Blue Planet

What happens during a magnetic field reversal?

magnetic field
© unknown
The Earth's magnetic field protects life on Earth, shielding it from damaging radiation and moderating our climate. So the idea that it could completely flip around, or collapse altogether, should cause us to worry, right? Well, yes and no.

Magnetosphere Basics

The result of electrical currents generated deep within the Earth through dynamic action, the magnetosphere is a fluid force that is constantly changing in strength and orientation.

The Center of the Earth

The very heart of our planet is a solid inner core of mostly iron that is about the size of the moon. It is so hot (9000°F to 13000°F or about 5000°C to 7200°C) that its temperature equals that of the "surface" of the sun, but it remains solid because of the combined pressure of everything above it being pulled toward it by gravity.

Surrounding this solid inner core is a second layer made primarily of an iron-nickel alloy. Nearly as hot (7200°F to 9000°F or about 4000°C to 5000°C) but under a bit less pressure, this outer core is liquid.
Laptop

The entire internet should be encrypted

lock
© Getty Images
The Heartbleed bug crushed our faith in the secure web, but a world without the encryption software that Heartbleed exploited would be even worse. In fact, it's time for the web to take a good hard look at a new idea: encryption everywhere.

Most major websites use either the SSL or TLS protocol to protect your password or credit card information as it travels between your browser and their servers. Whenever you see that a site is using HTTPS, as opposed to HTTP, you know that SSL/TLS is being used. But only a few sites - like Facebook and Gmail - actually use HTTPS to protect all of their traffic as opposed to just passwords and payment details.

Many security experts - including Google's in-house search guru, Matt Cutts - think it's time to bring this style of encryption to the entire web. That means secure connections to everything from your bank site to Wired.com to the online menu at your local pizza parlor.

Cutts runs Google's web spam team. He helps the company tweak its search engine algorithms to prioritize certain sites over others. For example, the search engine prioritizes sites that load quickly, and penalizes sites that copy - or "scrape" - text from others.
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