Sunday, July 27, 2014

Here We Go Again: Massive Dust Storms Pummel High Plains

here we go again Two huge dust storms are visible in Colorado and Texas in this mosaic of satellite images captured on Tuesday, March 18, 2014 by NASA’s Terra satellite. (Source: NASA)

Just a week ago, I posted some imagery of an intense dust storm sweeping south through the High Plains. Well, here we go again…

Today, high winds triggered two dust storms, one in Colorado stretching into Kansas and the Oklahoma Panhandle, and the other in the Texas Panhandle — the same region as last week’s storm. They were so big that they are clearly visible in a mosaic of images from NASA’s Terra satellite showing almost all of the United States. (See above.)

Here’s an animation of two close-up images of the Colorado dust storm, the first taken by Terra and the second taken later in the day by the spacecraft’s sister satellite, Aqua:

here we go again An animation of two satellite images shows the spreading Colorado dust storm. (Images: NASA. Animation: Tom Yulsman)

Here’s what it looked like on the ground today in Holly, Colorado:

As I mentioned last week, the March 11 U.S. Drought Monitor map shows this region in the grips of severe drought.

Echoes of the Dust Bowl…

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Wednesday, July 23, 2014

The Power of Conscious Intention Proven At Last?

A neuroscience paper published before Christmas draw my eye with the expansive title: “How Thoughts Give Rise to Action“

Subtitled “Conscious Motor Intention Increases the Excitability of Target-Specific Motor Circuits”, the article’s abstract was no less bold, concluding that:

These results indicate that conscious intentions govern motor function… until today, it was unclear whether conscious motor intention exists prior to movement, or whether the brain constructs such an intention after movement initiation.

The authors, Zschorlich and Köhling of the University of Rostock, Germany, are weighing into a long-standing debate in philosophy, psychology, and neuroscience, concerning the role of consciousness in controlling our actions.

To simplify, one school of thought holds that (at least some of the time), our intentions or plans control our actions. Many people would say that this is what common sense teaches us as well.

But there’s an alternative view, in which our consciously-experienced intentions are not causes of our actions but are actually products of them, being generated after the action has already begun. This view is certainly counterintuitive, and many find it disturbing as it seems to undermine ‘free will’.

That’s the background. Zschorlich and Köhling say that they’ve demonstrated that conscious intentions do exist, prior to motor actions, and that these intentions are accompanied by particular changes in brain activity. They claim to have done this using transcranial magnetic stimulation (TMS), a way of causing a localized modulation of brain electrical activity.

TMS of the motor cortex can cause muscle twitches, because this part of the brain controls our muscles. In 14 healthy volunteers, Zschorlich and Köhling aimed TMS at the area responsible for controlling movements of the left arm. Importantly, they adjusted the strength of the pulse so that it was only just strong enough to cause a tiny twitch (as measured using electrodes over the muscles of the left wrist themselves).

Remarkably, however, they found that if people were ‘consciously intending’ to flex their wrist, the same weak TMS pulse prompted a strong flexion response. Whereas if the volunteer was intending to extend their wrist, the very same pulse caused an extension movement.

Here’s an example from one representative subject, showing the differences in muscle activity in the flexing (FCR) and extending (ECR) muscles of the wrist following the TMS pulses:

intention_brainThe authors hypothesize that the brain’s ‘intention network’ prepares desired actions by increasing the excitability of the cells in the motor cortex that can produce the movement intended. On this view, a weak TMS pulse provides just enough extra activation to trigger those pre-excited cells into firing, while being too weak to activate cells that govern other movements.

intention_network

It’s an interesting model and these are striking results, from a beautifully simple experiment. My only concern is that it might be too simple. There was no control condition for the TMS: every TMS pulse was real.

It would have been better to have used a control, either a ‘sham’ pulse, or a real TMS pulse over a different part of the brain. I say that because – unless I’m missing something here – we don’t actually know that the TMS pulse was triggering the wrist movements. The volunteers got to trigger the TMS themselves:

Volunteers were asked to develop an intention [...] and to trigger the TMS with the right index finger if the urge to move was greatest before any overt motor output at the wrist.

As far as I can see, volunteers could simply have been pressing the TMS button and then moving their wrist of their own accord. Ironically, they might not have consciously intended to do this; they might have really believed that their movements were being externally triggered (by the TMS) even though they themselves were generating them. This can happen: it’s called the ideomotor phenomenon, and is probably the explanation for why people believe in ‘dowsing’ amongst other things.

All we know for sure, as I understand it, is that 1. their right hand pushed a button, 2. TMS happened, and 3. their left wrist moved. We don’t know that 2 caused 3. A control TMS condition would have allowed us to know whether the TMS was really involved – and, perhaps, whether conscious intention or unconscious ideomotor acts were governing those errant wrists.

ResearchBlogging.orgZschorlich VR, & Köhling R (2013). How thoughts give rise to action – conscious motor intention increases the excitability of target-specific motor circuits. PloS ONE, 8 (12) PMID: 24386291

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Saturday, July 19, 2014

Battle of the "Cosmos," Round 3

The new Cosmos show is doing an inspirational job bringing the wonders of science to a mass audience. There was one segment of the first episode where I thought the writers went off-track, however. In an earlier post I described my concern about how that episode  depicts philosopher Giordano Bruno and his role in the discovery of the infinite universe. My column prompted a reply from Cosmos co-writer Steven Soter, along with my further thoughts.

The Spaceship of the Imagination voyages out to distant galaxies and into the mysteries of DNA in the new Cosmos. (Credit: Fox) The Spaceship of the Imagination voyages out to distant galaxies and into the mysteries of DNA in the new Cosmos. (Credit: Fox)

Now, the third and final round: Soter offers some closing commentary on the matter, which appear below.

Inevitably, this dialogue has grown increasingly detailed, focused on the thoughts and actions of men who lived more than 400 years ago. To some readers the whole discussion may seem like nitpicking (a few have said as much in the comments), but I think it is greatly important. It offers a rare opportunity to debate the evolving relationship between science and religion. It is a window into the dramatic ways our conception of the universe has changed in modern times. And I must say, it is a tribute to Soter–and the whole Cosmos project–that he is taking the time to respond and share these ideas with the whole world.

The Case for Bruno, by Steven Soter

Your suggestion that Giordano Bruno was not the first to realize that the stars are suns is mistaken. You cited his predecessor Nicolas of Cusa, who referred in one passage to “the earth, the sun, or another star.” But Cusa did not mean that the sun is another star as we understand the term. Throughout his book, he used the word “star” indifferently to refer to the earth, the moon, the sun and the planets, as was common in his time. He also distinguished them from the “fixed stars” on the surface of the eighth celestial sphere. His pre-Copernican conception of the solar system was antithetical to any notion of the stars as other suns.

You claimed that “Cosmos confusingly presents Bruno’s infinite cosmology as a physical theory of the universe”, because Bruno believed the planets and stars had souls. It is true that Bruno’s worldview was vitalistic and magical. He imagined that the Earth had a soul like the other planets. But he passionately believed in the physical reality of the planets and suns, all made of the same material elements as understood in his time. He wrote:

“. . . every one of those bodies, stars, worlds and eternal lights is composed of that which is named earth, water, air and fire . . . Those in whose composition fire predominates will be called sun, bright in itself. If water predominates, we give the name telluric body, moon or such like which shines by borrowed light . . .” Bruno was the first to recognize this fundamental distinction between stars and planets.

Bruno described a universe of  “innumerable globes like this one on which we live and grow . . . In it are an infinity of worlds similar to our own, and of the same kind.” He urged his readers to “dissolve the notion that our earth is unique . . . we may perceive the likeness of our own and of all other stars . . . the substance of the other worlds throughout the ether is even as that of our own world.” Bruno made it as clear as he could, using the rudimentary understanding of matter available in his time, that this was a physical theory of the universe.

You said that Bruno took “a big step backward by interpreting the universe more in theological than mathematical terms.” Bruno was neither a mathematician nor a scientist, and his mind was not modern by any means. But he was without doubt the first to imagine a universe resembling the one we know today.

Again, you claimed that Bruno’s cosmology “was not a correct scientific idea, nor was it even a guess as Cosmos asserts. It was a religious and philosophical statement.” However you characterize Bruno’s cosmology has no bearing on its essential correctness. Can we expect a philosopher living in a world steeped in mysticism, groping in the dark at the dawn of modern science, to see things in modern terms? Scattered among his many pages of metaphysical nonsense are nuggets of pure gold. We should be grateful for them and not expect more.

Finally you claimed that Thomas Digges, “far more than Bruno, built on the tradition of Copernicus and sought to bring more of the universe into the grasp of math and geometry.” Digges made a major contribution by extending the realm of the stars into infinite space, but he then veered back from reality by describing the stars as “the palace of felicity . . . the very court of celestial angels, devoid of grief and replenished with perfect endless joy.” He is talking about the traditional theological heaven, not the material universe.

It was Bruno who used the opening made by Copernicus to give us the first glimpse of the modern astrophysical cosmos. And that was no incremental step. It was a giant leap.

Some Closing Reflections, by Corey S. Powell

It is crucial to remember that neither Bruno nor Digges was thinking about the universe in modern terms. This is, I think, one of the most meaningful upshots of this whole conversation. There is a natural tendency to project our current conceptions onto people who lived long ago. That leads to two kinds of errors.

First, we sometimes regard ourselves as inherently smarter than those in the past, simply because we start from a place of greater understanding. Such casual arrogance overlooks the incredible efforts required by people like Bruno, Digges, and thousands–no, millions–of others who have contributed to science and to the great march of human knowledge.

Second, there is a tempting inclination to view the past as a prelude toward an inevitable present. This attitude, which has been known to afflict academics as well, is known as Whig history. I still think Cosmos fell prey to this error, in trying to make Bruno’s universe look too much like our own. Seen in clear-eyed historical context, Bruno’s views still strongly resembled the spiritually ordered Church universe of the time–not to mention the philosophies of his ancient Greek influences, Lucretius and Anaxagoras.

Soter beautifully describes Bruno as “steeped in mysticism, groping in the dark.” In that context, his conception of an infinite universe full of stars and planets was an astonishing leap of insight–but it was still a theological one more than a conceptual one. Conversely, Digges made brave moves to create a cosmological model that blended the idea of a sun-centered solar system with infinite space–but he still regarded the expanse beyond our solar system as the realm of the angels.

In truth, it took both Bruno and Digges (and their many successors) to build–slowly, incrementally, with many stumbles along the way–toward our modern understanding of the universe. My biggest concern is that, in presenting Bruno as a lone hero and a lone martyr, Cosmos missed a fabulous opportunity to convey this communal and cumulative aspect of science.

In taking time to share his thoughts here, though, Soter has filled in many of those missing details. He has also shown a generous commitment to participating in the grand process of exploring the world through science. That is one of the happiest results of this whole exchange.

For more, watch the next episode of Cosmos and then join our Cosmos Rewind Google Hangout on Tuesday, March 18, at 8PM EDT. And follow me on Twitter: @coreyspowell

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Monday, July 14, 2014

Ripples in Space Are Evidence of Universe's Early Growth Spurt

Inflations' gravitational waves When the universe expanded tremendously after the Big Bang, the resulting gravity waves interacted with the cosmic microwave background to produce this characteristic “B-mode” pattern. Credit: BICEP2 Collaboration

Big news in the cosmos today! Researchers from the BICEP2 south pole telescope have found ancient proof that the universe expanded tremendously after the Big Bang, a theory known as inflation. The discovery tells us (albeit indirectly) about an even earlier stage of the universe than we’ve ever before observed, and it provides crucial evidence that inflation did indeed occur. In so doing, it extends our model of the early universe from about one second after the Big Bang right back to less than 10-37 seconds after the event — a stunning leap forward (or backward, as the case may be).

To understand this, let’s back up 13.8 billion years or so, to the Big Bang. Also known as the birth of the cosmos and the origins of time and space, this burst of everything set the universe in motion. But a few niggling issues cast some doubts on the Big Bang theory — one of which was the mystery of how the universe came to be so uniformly spread out.

Enter the idea of inflation, in 1980, which suggested that just a few instants after the big moment, the universe suddenly grew enormously. This addition to the cosmic timeline explained why the universe was relatively uniform and it fit nicely with what we already knew about the universe’s earliest moments. However, cosmologists had no direct proof of inflation.

One way to prove inflation occurred, physicists thought, would be to look for gravitational waves created in its wake. These are basically ripples in the “fabric” of space-time — what the universe is made out of. Gravity is a relatively weak force, though, so we could only hope to detect the largest waves out there, caused by huge interactions like black holes colliding. Even though inflation was a relatively huge thing — it literally shaped the whole universe — the gravity waves it produced are now too weak to measure directly.

So instead, researchers were looking for the effect of inflation’s gravity waves on light. And not just any light, but the cosmic microwave background, “echoes” of light leftover from the Big Bang’s energy, created when the universe was just 380,000 years old. When this light interacted with the gravity waves, the theories said, it would have produced a distinctive pattern, called the B mode, in the light’s polarization. Such a pattern would be direct evidence that the gravity waves caused by inflation were real, and thus a key proof of inflation. And today, scientists announced they’d found it.

Assuming the finding is confirmed (and that looks likely — the team apparently spent 3 years going over their own data to make sure it was sound before coming forward with it), that’s huge news for cosmology. Direct evidence for inflation has been sought after for decades. Nature quotes Alan Guth, the main “inventor” of inflation, as saying, “This is a totally new, independent piece of cosmological evidence that the inflationary picture fits together,” and adding that the findings are “definitely” Nobel prize-worthy.

But it’s also big news for a couple of other reasons. First, in addition to being the first evidence for inflation, it’s also the first direct evidence for gravitational waves. Even though some observatories have been (and will continue!) looking for these gravitational waves, they’re still incredibly hard to find. The more data we have on these weird, space-time warping ripples, the more we’ll be able to understand the universe itself, and this is a great step in that direction. 

And the other bit of significance to this has to do with understanding gravity in the first place. It’s currently the only one of the four fundamental forces not to play nice with quantum mechanics, which explains how things work on the tiniest scales. At high temperatures (like those found shortly after the Big Bang), the other three even begin to unify into a single super-force. One of the biggest issues in physics today is figuring out how (or if) gravity fits into this picture, and the findings that gravitational waves can result from inflation, a fundamentally quantum phenomenon, suggests that quantum gravity might indeed be possible.

A glimpse into the very first milliseconds of our universe, plus bigger questions ahead — all in all, it’s a pretty good day for science.

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Thursday, July 10, 2014

"What We Know" Climate Report From Leading Science Organization Seeks to Persuade Citizens. #FAIL.

AAAS What We Know global warming

The “What We Know” report about climate change issued today by the august American Association for the Advancement of Science is intended to persuade ordinary people that our climate really is changing, we’re largely responsible, and we need to do something about it. Soon.

The report features clear, straight-forward language without overly complex and opaque scientific jargon.

And as the black non-image at the top of this ImaGeo post symbolizes, there is another thing that the report lacks as well: imagery.

In fact, there is not a single image in the report — not one visualization to help us understand what’s happening to our world, not a single photograph to dramatize the impact of climate change on people, not even one little graphic to show a trend in, oh, I don’t know, temperature maybe.

Okay, I exaggerate just a little. The title page does have one ambiguous photograph of someone using a surveying instrument on some ice sheet somewhere, for what reason God only knows.

And true, the “What We Know” web site includes, in addition to the report, a number of videos. One is actually mildly entertaining and effective. It features a mountain biker racing down a trail to symbolize the perilous path ahead and the need to slow down. (Our carbon emissions, of course.)

But the rest consist of talking heads (scientists telling us what they know) intercut with what broadcast journalists call “B-roll” — time lapse video of cars, smoke pouring out of stacks, a little snippet of water pouring into the New York City subway system during Hurricane Sandy —  you get the idea.

So here’s some unsolicited advice to the creators of “What We Know” from someone who thinks visual communication is actually an incredibly powerful way to communicate complex information and also connect with the heart as well as the mind: Cliché B-roll can’t change the fact that a talking head is still a talking head. Nor will people necessarily listen, let alone understand or care, simply because those talking heads happen to be scientists.

I’ve never written a post like this here at ImaGeo. I felt compelled to do it because I’m simply dumbfounded that one of the leading scientific organizations in the world decided to launch a public persuasion campaign that lacks one of the most important ways that humans beings can be persuaded: through visual communication.

Is the AAAS not aware that imagery can convey emotion far more powerfully than the written or spoken word, no matter how clear, concise, and free of jargon those words may be? Do they not know that visuals provide an incredible capacity to tell compelling, persuasive stories? Can it possibly be that they haven’t heard about the synergy made possible by the use of words and images together?

And did they not bother to read the literature on visual communication and persuasion?

To offer just one example: “Visual Persuasion,” which appeared in the journal Communication Research Trends in 1999. Here’s a relevant snippet:

…visual images in persuasive messages reduce the information processing burden, make a message more attention-getting, and reinforce message arguments. Also, it is believed that visual images have the superiority in memory over words.

If any of the people responsible for the “What We Know” report read this post, I have a suggestion for you: Try “Google.” It can be really helpful. With the search terms “visual communication and persuasion” you’ll find a lot of helpful tips there for your next campaign.

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Sunday, July 6, 2014

Scientists Ask Why There Are So Many Freaking Huge Ants

big old ant

An ant is not exactly the picture you see in the dictionary next to “rule-breaker.” Colonial ants work together to collect food and generally act in the best interest of the group. Yet certain enormous ants in South America break a basic rule in biology: as you move up the food chain, you should find a smaller group of organisms at each step. These ants are top predators that take up far more than their fair share of space. To find out what their secret is, scientists staked out the forest floor.

“We’re all ant nerds,” says Chad Tillberg, a biologist at Linfield College in Oregon, of himself and his coauthors. So when they started visiting a park in northeastern Argentina and noticed what seemed like a whole lot of Dinoponera australis ants, they thought it might be an illusion created by their excitement. Plus, Tillberg points out, “Dinoponera are huge.” The seven species in this genus, which can be more than an inch long, are some of the largest ants in the world.

There are many plentiful bugs in the rainforest, of course. But an abundance of this particular ant—which locals call hormiga tigre, the “tiger ant”—demands an explanation. That’s because the species is known as a top predator of the soil. Other champion carnivores—like, say, an actual tiger—are rare, compared to the things they eat.

To see why, imagine that in a given area, you could gather every individual plant or animal of one species and pile it onto a huge scale. Usually, as you moved up a food chain, each group of living things would tip the scales less. It takes a large mass of plants to feed a moderate mass of herbivores, which can satisfy a smaller mass of carnivores. If the animals are bulky, it will take fewer of them to make up their species’ allotted weight on the scale. Dinoponera australis ants are both hefty and high up on the food chain—so something about them must be out of the ordinary.

Maybe, for a start, they’re not as abundant as they seem. To find out, “we started mapping and digging up colonies,” Tillberg says. First the researchers found ant nests by spotting ants on the park trail and following them home. (He notes that this type of research would be harder if the ants weren’t “so enormous.”) Within three plots of land, they marked the location of each nest and calculated how close the ants lived to their neighbors. They also left “pitfall” traps—like buckets for bugs to stumble into—along other trails in the area.

They found that D. australis ants aren’t equally dense everywhere in the rainforest. But within the study plots, there were lots and lots of them—about 180 underground nests per hectare (a hectare is about two and a half acres), holding almost 8,000 ants. Each ant weighs about 320 milligrams. That means the “biomass” of these animals (their total on that huge imaginary scale) is more than 2,500 grams, or 5.5 pounds, per hectare. That’s at least four times the biomass of other predatory rainforest ants.

The ants were as abundant as they’d seemed. But could they be lower on the food chain than scientists thought—not truly the tigers of the soil? To find out, the researchers stole the food from the jaws of worker ants returning to their nests. Almost all of it was the bodies of other insects they’d hunted. “They weren’t secretly collecting lots of nectar or honeydew,” Tillberg says.

Another way to find out where an animal sits on a food chain is to chemically analyze its body. Heavy nitrogen isotopes start out in plants at the bottom of the food chain, then accumulate in the bodies of animals that eat them, and build up even more in animals that eat those animals, and so on. The researchers measured nitrogen isotopes in the ants’ bodies and compared them to other insects and food items around them. This confirmed the status of la hormiga tigre: not only were these ants top predators, but they probably ate other predatory insects as well.

D. australis is just what it seems—a huge, predatory ant that roams the rainforest in huge numbers. How does it break the biomass rule? Taking one more stab at solving the mystery, Tillberg and his coauthors used paint to make distinguishing marks on the backs of ants. Then they staked out the ants’ nests. “We were marking workers and watching nest entrances for hours and hours every day,” Tillberg says. Each time an ant left the nest, the researchers recorded where it went.

They saw that most ants stuck to a single hunting route. Rather than roaming freely, each ant set out on the same path whenever it looked for food.

This behavior may make the whole ant colony more efficient. “Different individuals head in different directions from each other,” Tillberg says, “so on the whole, the entire surrounding habitat of a nest gets searched.”

There may be other factors that let D. australis ants take up so much room in the forest—a lack of competition from other predators, for example, maybe because other species can’t thrive in this disturbed habitat. But Tillberg says he thinks their hunting efficiency is “at least part of the story explaining their abundance.” It seems that if you want to take over the forest floor, it pays to be efficient as well as ruthless.


Image: by Alex Wild (via Wikimedia Commons)

Tillberg, C., Edmonds, B., Freauff, A., Hanisch, P., Paris, C., Smith, C., Tsutsui, N., Wills, B., Wittman, S., & Suarez, A. (2014). Foraging Ecology of the Tropical Giant Hunting Ant (Hymenoptera Formicidae)-Evaluating Mechanisms for High Abundance. Biotropica, 46 (2), 229-237 DOI: 10.1111/btp.12097

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Thursday, July 3, 2014

Can The Doppler Effect Help You Beat The Speed Camera?

Doppler ShiftThe shortest answer is no.


Thanks to the curiosities of physics, there is this paradoxical yet plausible notion that you could beat a camera meant to photograph you speeding by going so fast that it won’t pick you up. In theory there is some speed at which the very light reflected off of your car will become undetectable to the human eye. But how fast would that be?


Don’t have time to read? Listen to the whole post below!


When you hear an ambulance headed your way, the blaring sirens increase in pitch* until the vehicle reaches you, and the pitch slides back down as it passes. This is “Doppler Effect.” Sound waves traveling in the same direction can “bunch up,” making them seem at a higher pitch. The same thing can happen with light. Edwin Hubble, the astronomer whose name christened the Hubble Telescope, discovered that galaxies moving away from us had light waves that were stretching apart. Like a fading sound, the light from the galaxies was getting redder—being “red shifted.” What happens as the galaxies gallop away from us means that if you were to go fast enough, there is some point were the light reflecting off your car would be red-shifted below human (or camera) detection.


In a paper from the Journal of Physics Special Topics, authors Worthy, Garner, and Taylor-Ashley do the Doppler number crunching. They assumed that a car would be moving away from the camera when the photo was taken, that the average license plate reflects basically yellow light, and that a license plate is undetectable when the light is red-shifted below 430 terahertz—the human limit.


Using those values and this equation, the authors concluded that the minimum velocity to beat the speed camera with the Doppler Effect is about 0.178c, or 18 percent the speed of light. Unfortunately for your outstanding tickets, even in the fastest supercar ever built, you have no hope of getting to this speed. 18 percent the speed of light is over 33,000 miles per second—if you crashed your car at this speed you would be obliterated by 10 times more energy than was released by the supervolcano Krakatoa.


So no, you can’t red-shift your way out of a ticket. But you could still speed your way out of one.


The Discovery Channel’s Mythbusters actually established that you could outrun the speed camera. So long as you passed the camera at 300 miles per hour or more, you would be far outside of the camera’s range as the photo snapped. If you want to break the law but now the laws of physics, invest in a dragster.



More Geeky Science:


What The Nerdiest Chart of Sci-Fi Ships Says About Our Dreams of Space


Excerpts From The Mad Scientist’s Handbook: So You’re Ready to Vaporize a Human


The Coroner Report: Weekend at Bernie’s


Getting the God of Thunder’s Science Straight


What Really Happens When Lightning Strikes Sand: The Science Behind a Viral Photo



Image Credit: Roads At Night: She’s Gone by Cayusa on Flickr


Paper Link: Red-Shifted Speed Cameras


Reference: Worthy, D., Garner, R., Gregory, J., & Taylor-Ashley, J. (2013, November 19). Red-shifted Speed Cameras. Journal of Physics Special Topics, 1-2.


*An earlier version of this post incorrectly linked the Doppler Effect to changes in amplitude, not pitch.

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