Are sticky floor mats to blame?: Not likely.
Courtesy Ian Hampton
There's been a lot of news lately about "unintended acceleration" -- cars suddenly gaining high speed and drivers unable to stop them. Some observers question whether the problem lies with the car or with the driver. But whatever the cause, unintended acceleration is a deadly danger to the driving public.

Or is it?

Popular Mechanics crunched the numbers. They found unintended acceleration causes 3.2 deaths per year. This compares to:

• 1,550 deaths caused by drivers falling asleep at the wheel
• 6,000 deaths from distracted driving -- texting, cell phone use, etc.
• 7,400 traffic deaths attributable to bad weather
• about 11,800 deaths every year due to drunken driving

If you find your car accelerating, slam on the brakes, throw it into neutral, and steer to the side of the road. But don't waste time worrying about it. Instead, you should spend your effort avoiding bad weather, distractions, and above all not driving under the influence.

Tags : math, cars, Toyota, unintended acceleration

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Does this make you safer?: A glock 19 handgun.
Courtesy crossprocessedsoul

Tomorrow, the United States Supreme Court will hear arguments in the case McDonald v. Chicago. Chicago has some of the strictest gun laws in the country; McDonald (and others) argue that this violates their Second Amendment right to keep and bear arms.

In addition to the legal arguments, voices on both sides of the issue also talk about safety. Advocates for stricter gun control claim that reducing the number of guns on the streets will reduce the number of gun-related deaths. The Brady Campaign to Prevent Gun Violence recently released their annual survey of state gun laws, giving their highest marks to those states with the strictest regulations.

Others argue the opposite. They claim that gun-control laws only affect the law-abiding citizens who obey them. Criminals still have weapons, but the public is defenseless, leading to more deaths than if the public were armed.

Various people have tried to resolve this issue over the years, with little success. When the Brady list came out recently, blogger Jay Tea noted that some states with strict gun laws (such as California) actually had higher rates of gun death, while some states with looser laws (such as Utah) had much lower rates. (The "rates" are gun homicides per 100,000 people, and not total deaths. This allows us to compare large states and small states fairly.)

However, Mr. Tea failed to note that the reverse is also true -- that there are also states with strict laws that have low rates of gun violence, and states with loose laws that have high rates.

So, which is it: do gun controls make you safer, or put you in more danger?

To address this issue, we pulled out our old friend from math class, the coefficient of correlation. We last used this in an attempt to see if there's a connection between warm winters and warm summers (there is). This formula looks at two sets of numbers and determines how closely connected they are. Do they both move up and down together (a positive correlation)? If one moves up, does the other move down (a negative correlation)? Or, is there zero connection between them? So, we crunched the numbers, using the Brady Scorecard and the gun homicide statistics, and we found...

Nothing.

We came up with a coefficient of 0.00187. This tells us there is absolutely no connection between the Brady scores and the gun death rate: a state with strict laws is just as likely to have a high rate as a low one. The same goes for a state with loose laws.

The highest possible coefficient is 1.0. That indicates a direct one-to-one connection. In a complex system with many variables, such as human behavior, you want a score of at least 0.5 to say there is a strong connection, and a score of 0.3 to say there's even a weak connection. This score, however, was almost a perfect 0.

So, what does this all mean? Simply that neither side can use this as an argument. Gun-control advocates cannot use it to argue that regulations save lives; gun-control opponents cannot use it to argue the opposite, that regulations are dangerous.

Now, this all hinges on the Brady scoring system. It is possible that other ways of quantifying "strict" and "loose" laws could produce different results. And none of this has any bearing on the legal and Constitutional arguments being made. All we can say is, that in this case, the math is unambiguously neutral.

Tags : math, correlation, coefficient of correlation, gun, law, Supreme Court, Second Amendment, guns

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GOCE Satellite: The Gravity field and steady-state Ocean Circulation Explorer
Courtesy ESACan it be true? Yes, for a mere $5,544 dollars round-trip airfare to Greenland! In March 2009, the European Space Agency launched the Gravity field and steady-state Ocean Circulation Explorer (GOCE) into orbit around our planet, which is now transmitting detailed data about the Earth’s gravity. The GOCE satellite uses a gradiometer to map tiny variations in the Earth’s gravity caused by the planet’s rotation, mountains, ocean trenches, and interior density. New maps illustrating gravity gradients on the Earth are being produced from the information beamed back from GOCE. Preliminary data suggests that there is a negative shift in gravity in the northeastern region of Greenland where the Earth’s tug is a little less, which means you might weigh a fraction of a pound lighter there (a very small fraction, so it may not be worth the plane fare)!

In America, NASA and Stanford University are also working on the gravity issue. Gravity Probe B (GP-B) is a satellite orbiting 642 km (400 miles) above the Earth and uses four gyroscopes and a telescope to measure two physical effects of Einstein’s Theory of General Relativity on the Earth: the Geodetic Effect, which is the amount the earth warps its spacetime, and the Frame-Dragging Effect, the amount of spacetime the earth drags with it as it rotates. (Spacetime is the combination of the three dimensions of space with the one dimension of time into a mathematical model.)

Quick overview time. The Theory of General Relativity is simply defined as: matter telling spacetime how to curve, and curved spacetime telling matter how to move. Imagine that the Earth (matter) is a bowling ball and spacetime is a trampoline. If you place the bowling ball in the center of the trampoline it stretches the trampoline down. Matter (the bowling ball) curves or distorts the spacetime (trampoline). Now toss a smaller ball, like a marble, onto the trampoline. Naturally, it will roll towards the bowling ball, but the bowling ball isn’t ‘attracting’ the marble, the path or movement of the marble towards the center is affected by the deformed shape of the trampoline. The spacetime (trampoline) is telling the matter (marble) how to move. This is different than Newton’s theory of gravity, which implies that the earth is attracting or pulling objects towards it in a straight line. Of course, this is just a simplified explanation; the real physics can be more complicated because of other factors like acceleration.

Albert Einstein
Courtesy noneSo what is the point of all this high-tech gravity testing? First of all, our current understanding of the structure of the universe and the motion of matter is based on Albert Einstein’s Theory of General Relativity; elaborate concepts and mathematical equations conceived by a genius long before we had the technology to directly test them for accuracy. The Theory of General Relativity is the cornerstone of modern physics, used to describe the universe and everything in it, and yet it is the least tested of Einstein’s amazing theories. Testing the Frame-Dragging Effect is particularly exciting for physicists because they can use the data about the Earth’s influence on spacetime to measure the properties of black holes and quasars.

Second, the data from the GOCE satellite will help accurately measure the real acceleration due to gravity on the earth, which can vary from 9.78 to 9.83 meters per second squared around the planet. This will help scientists analyze ocean circulation and sea level changes, which are influenced by our climate and climate change. The information that the GOCE beams back will also assist researchers studying geological processes such as earthquakes and volcanoes.

So, as I gobble down another mouthful of leftover turkey and mashed potatoes, I can feel confident that my holiday weight gain and the structure of the universe are of grave importance to the physicists of the world!

Tags : climate change, gravity, math, nasa, ocean, physics, relativity, satellite, science, space, spacetime, time

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Robots that "think for themselves"

Fly's eyes: Can the nerves, eyes, and brain function of a fly be modeled within a computer circuit?
Courtesy NeilsPhotography Engineers are trying to design machines that can "think for themselves" when on surveillance or search and rescue missions. Somehow the machines has to look at its environment and decide what to do.
Have you ever tried to catch a fly? They are pretty good at seeing your hand and knowing just how to escape your grasp.

If we can figure out how a fly can do it ...

Can we figure out how a fly is able see, and find food, and escape from our fly swatters? With today's super microscopes, I am sure that we can visualize and model every nerve connection, muscle fiber, and eye facet.

Computational biology

David O’Carroll, a computational neuroscientist who studies insect vision at Australia’s University of Adelaide has been studying the optical flight circuits of flies, measuring their cell-by-cell activity. In a paper published in Public Library of Science Computational Biology, O’Carroll and fellow University of Adelaide biologist Russell Brinkworth describe an

algorithm composed of a series of five equations through which data from cameras can be run. Each equation represents tricks used by fly circuits to handle changing levels of brightness, contrast and motion, and their parameters constantly shift in response to input.

The "fly brain" circuits are small and use only a fraction of a milliwatt

“It’s amazing work,” said Sean Humbert, who builds miniaturized, autonomous flying robots,

“For traditional navigational sensing, you need lots of payload to do the computation. But the payload on these robots is very small — a gram, a couple of Tic Tacs. You’re not going to stuff dual-core processors into a couple Tic Tacs.

Learn more - mathematical modeling of insect biology

Secret Math of Fly Eyes Could Overhaul Robot Vision Wired Science
Robust Models for Optic Flow Coding in Natural Scenes Inspired by Insect Biology Computational Biology

We have constructed a full model for motion processing in the insect visual pathway incorporating known or suspected elements in as much detail as possible. We have found that it is only once all elements are present that the system performs robustly, with reduction or removal of elements dramatically limiting performance. The implementation of this new algorithm could provide a very useful and robust velocity estimator for artificial navigation systems.

Tags : Russell Brinkworth, robotics, nanotechnology, nano, math, David O’Carroll, DARPA, computational biology, artificial intelligence, AI

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