Friday, December 21, 2007

Internet Loves Physics. Who Knew?

Perhaps even MIT didn’t realize, when they began posting introductory physics lectures online, that the videos would become so popular. Then again, who ever could have predicted the popularity of the Star Wars Kid? Even physics can't explain the phenomenon of internet video popularity, but if it makes more people love physics, I think they'll take it.

Here's a sampler of the type of lecture they're showing, featuring Professor Walter Lewin:


Professor Lewin is slowly but steadily gaining credibility in the internet realm as a prime source of both info and entertainment. Lewin says he spends 25 hours planning each 45 minute lecture, each of which is packed with fantastic demonstrations and constant reminders of the endless number of everyday places you see physics in action.

You can download the lectures for free on iTunes or MIT’s website http://ocw.mit.edu/OcwWeb/Physics/8-03Fall-2004/CourseHome/.

When I first heard about MIT putting their physics lectures online I was almost offended. I paid thousands of dollars for a physics education and now it turns I can just get it online?! Of course you can’t get a degree via iTunes (yet…), so it’s not quite the same thing, but I think that moment of selfishness has passed.

Having video record of my college courses would have done me loads of good, and might become an important tool for students. I am still a member of the camp that believes it doesn’t matter how you learn it or how long it takes, so long as the desire is there. And, some things are worth learning even if you don’t want to. Simply put, the videos open up the world of science to people in a new way. With the low numbers of physics and math teachers in the US, a champion of physics education is just what the country needs.

What’s also nice about this new effort is that it can’t be considered “pop physics”: that sensitive term that could mean bastardization of the field and stunted learning. Rather, it cuts away all of the brush and explains physics concepts in their natural environment; the way physics majors would learn them. Keep in mind that watching a lecture doesn't mean you understand physics, or that you've done everything needed to graduate in the field; but it might spark the start of such a journey for a few people, or just make some new fans. I say huzzah.

These videos may also serve to keep you busy with physics for the next week or so while most of us here at Physics Buzz take holiday vacations. I'll be drowning in feet of snow in Utah, so perhaps I'll squeeze in a post about the physics of sledding. Happy and safe holidays!


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Tuesday, December 18, 2007

Invasion of the Muons!

Not the interiors of the Mayan Temples, the secret chambers of the Egyptian Pyramids, nor the inside of massive Volcanoes can hide from…the Muons!

They sound like a 50’s horror movie villain, but Muons are nothing to be afraid of. If they were, we’d all be long gone. The Earth is hit with muons at a rate of about 1 per square centimeter per minute, but over time that’s lots of muons colliding with your whole body. These may sound familiar if you read my post a few weeks ago about physicist/detective Luis Alvarez who pioneered the muon method and used it on Egyptian Pyramids.

As reported by Science News this week (http://www.sciencenews.org/articles/20071208/bob8.asp), researchers are looking inside the Mayan temples and some massive volcanoes (among other things) using new muon detectors. Most notably, the new detectors don’t need to be underneath the large objects (unlike Alvarez’ original method) but can be put on the perimeter of these large objects, and detect muons coming nearly horizontally through them. Radar and seismic detection methods to see into these objects have failed for various reasons, but Mother Nature has provided a perfect solution.

Muons are remnants of cosmic rays of particles from the distant, and not so distant, reaches of space. When these rays hit the Earth’s protective atmosphere, they usually turn into pions, which interact with air and quickly decay into Muons.

When a stream of muons passes through, say, the Mayan Temple, some of them collide with layers of stone. Therefore, if you measure the number of muons that comes out on the other side, it will be significantly fewer than the number that went in. But if there is a gap in the building, like a room, the muons will pass more easily through there, and more of them will be detected on the other side. This technique can not only reveal otherwise unobtainable information (like structures in the hot depths of volcanoes) or extremely sensitive information (like the delicate interiors of rooms in a Mayan temple). A computer scan compiled over a few months will be able to see, to within a meter, the interior structure of the building or volcano like an X-ray shows your bone structure.



Image Credits: http://www.britannica.com/eb/art-15738/Mayan-Temple-of-the-Inscriptions-at-Palenque-Mexico-300-BC

http://neutron.magnet.fsu.edu/muon_relax.html


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Wednesday, December 12, 2007

The Bowl for the Tiniest Trophy in the World (It's the Size that Matters)

Don’t you think it’s about time football fans had more of an interest in physics?

Well, maybe you weren’t thinking that specific thought, but you might know that football is a smorgasbord of physics concepts in action. APS feels it’s time they did something about it, and have announced a contest to win the worlds Tiniest Trophy, and $1,000 to boot!
The trophy may be, quite literally, the tiniest trophy in the world (We'll see if a Guinness record is on the way…). The smallest aspect of the trophy, an image of a football field and helmet, is made up of lines that are only a few nanometers wide. Thats less than a thousandth of a human hair!

It’s a wafer, only a few centimeters wide, with multiple images of a football field and helmet. But inside one of those helmets are two, increasingly smaller images.

This image (above) shows the trophy. The multiple football fields you can see are each 12 millimeters wide.

The etchings are arranged Russian-doll style, with one image inside the next. Inside the helmet of the 12mm (large) engraving, is an identical image of a field and helmet that is 120 microns wide, and inside that is an even smaller one that is only 2.4 microns wide.

Above is the mid-sized, 120 micron etching (with better resolution).



The lines that make up the third, and smallest, image are only a few nanometers wide. A nanometer is only one-billionth of a meter. These lines are around 1/1000th the width of a human hair! The image is so small that it can’t be seen with even the most powerful optical telescope. You have to use an electron microscope. The engravings are created with atom and photo lithography in which (very basically) beams of atoms or light are used to create the lines.

To earn a chance to win the trophy and the prize money, all you have to do is create a YouTube video, around 2 minutes long, that demonstrates physics in football. The video can use any aspect of football, and can be real game footage or your own backyard experiment.

To submit a video, upload it to YouTube with the tag “nanobowl.” Let APS know about your video in an email to physicscentral@aps.org. The deadline is January 15, 2008, and the winner will be announced on (duh) Super Bowl Sunday, February 3, 2008.

For more info go to www.physicscentral.com/nanobowl, or check out these sites that physics central has listed as starting points for inspiration: Tim Gay's Physics of Football demonstration, hockey, NFL, body slam.


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Tuesday, December 11, 2007

The New Time Travelers

I can't change the past because the past has happened; I can’t kill my grandfather because I didn’t. But that in itself doesn't mean I can't travel to the past.

The dream of time travel has been shaped and sculpted by movies, science fiction, and our own imaginations; but in those hands it’s only a dream. But to a few capable scientists, time travel is a real possibility in our universe, and one that can be examined with theories of physics. The recently published book The New Time Travelers: A Journey to the Frontiers of Physics, is "a history of the serious study of time travel" by physicists, beginning in 1988. From what the author David Toomey told me about his book, the answers to many of your time travel questions may pleasantly surprise you.

Toomey is an avid science writer, but not a scientist himself, and he brings an outsider's perspective to these sometimes mind-boggling concepts. I’m very excited about this book and made my dad buy a copy. I knew he’d be excited by the time travel aspect and it’s written for a general audience so he can understand all of it. Plus, being the only physicist in my family, my parents tell me, "We're always looking for ways to understand what it is you do.”

David Toomey also happens to be a former professor of mine (a comparable honor). He and I joined a chance to catch up with a blog entry for me. My questions are in italics, and David's responses are in regular print.


First, tell me what the book is about.

The book is a history of the serious study of time travel that began with a 1988 paper by a group of theoretical physicists at the California Institute of Technology. The authors of that paper (Mike Morris, Kip Thorne and Ulvi Yurtsever) concluded that pastward time travel might well be possible in the universe we know. Their work inspired a serious and sustained study of the question and engaged more than thirty physicists working at universities and institutes around the world.


Did you write about anything from your own experience?

I talk briefly about when I was in Jr. High School and I read H.G. Wells’ The Time Machine. I was intrigued by the conversation in the beginning when the character known as The Time Traveler and his friend discuss the theory of the 4th dimension. I was disappointed that they’d got the theory, and later the machine, but the how is glossed over. Of course, it’s glossed over because Wells didn’t have a how. When I found that physicists were exploring the “how”, that was exciting. And it answers the question left unanswered by Wells.


Ideas about time travel are viewed by some scientists as far-fetched or not worth investigating. I've also heard that some scientists believe that talking to the general public about theories for time travel are almost misleading because any actual experiments in time travel are very, very far off. What do you think?

The physicists who have done this work understand that it is unlikely to lead to any actual experiments. These are *thought* experiments, and thought experiments are valuable in that they can lead to deeper insights into the nature of our universe. Specifically, work on the possibility of pastward time travel has offered physicists a way to approach quantum gravity, the 'theory of everything.'

It is true that the general public can be misled into believing that someone is building a time machine in a university laboratory (or a garage, or a basement or an attic!); my book makes a point early on of dispelling such notions.

The public is interested in time travel, quite naturally, because its problems – the grandfather paradox, the bootstrap paradox and so forth - are 'fun' in the highest, best sense of that word. So while the book admits that no time travel is likely to be in our (near) futures, I hope it also engages in the pleasure of that thinking about it.

(The physicists are having fun, too, although a somewhat more refined sort of fun. Many physicists, even those who read science fiction, are likely to say that the real world is far more interesting than any that has been imagined by writers - and it has the added virtue of reality.)


Can you think of something really unexpected that you came across in your search?

Yes. There's an idea for something called a "clever spacecraft." Igor Novikov and a physicist named Andrei Lossev were interested in the idea that a time machine could enable us to get something from nothing. For instance, an author might go to the future, find a printed book with her name on it as author, and return with the book to the present, thereby saving herself the trouble of writing it. One question prompted by this scenario is Exactly who wrote the book? The answer is: no one. It was generated, quite literally, from nothing. Novikov and Lossev called artifacts like the book “jinn,” a word meaning a spirit that arises from nothing.

Novikov and Lossev claimed that if we presume there is a natural or pre-existing time machine somewhere in the universe (this would be a wormhole time machine of the type imagined by Kip Thorne, Mike Morris, and Ulvi Yurtsever in their 1988 paper), we might take advantage of the situation described above both to find that time machine and to use it.

First, we assemble an unmanned spacecraft and a computer that can 1) store its own design and the location of the wormhole time machine, 2) run the design and 3) give instructions for the spacecraft’s construction to an automated plant. If we do all this and simply get out of the way, so say Novikov and Lossev, immediately a very old and battered, unmanned spacecraft lands, whereupon it feeds its own design and the location of the time machine into the computer. The computer downloads this information to the plant, which then constructs a new spacecraft. The spacecraft departs Earth in the direction of the wormhole time machine. When it arrives at the time machine, it enters the "present day" mouth, emerges from the "past" mouth. The past mouth may be 100 years earlier than the “present” mouth, or 1000, or 100,000. It doesn't matter. If the spacecraft can get to Earth before it left, it departs in that direction immediately. If it needs more travel time, it returns to the “present” mouth and travels further pastward before beginning its journey homeward. By using the time machine over and over, it can buy all the travel time it needs. In any case the spacecraft that eventually returns to Earth is the “very old and battered” spacecraft we met before.

Novikov and Lossev’s idea is something of a stunner, and it may be one of the areas in this inquiry not much discussed in the other books on the serious study of time travel. Matt Visser is a physicist at Victoria University of Wellington, New Zealand. He has done quite a bit of work on time machines, and he told me that at a 1992 workshop in Aspen the idea was discussed, and the whole thing was taken kind of lightheartedly. At the same time he also said that if pastward time travel is possible, in the view of many, it has to be self-consistent. Self-consistent pastward time travel is the kind you see in a lot of Hollywood movies. To take an oft-cited example, if I travel to the past and try to kill my grandfather, something will prohibit me. It might be a slip on the wet floor, a change of mind, or a particle in the barrel of the gun; but it will be something. I can't change the past because the past has happened; I can’t kill my grandfather because I didn’t. But that in itself doesn't mean I can't travel to the past. It only means that if I travel to the past I will have always traveled to the past.



Wow. I’m kind of trying to wrap my head around that.

What questions does your book leave open or unanswered?

That would be telling, wouldn't it? Just kidding. The book leaves open the big question - that is, "Is pastward time travel possible?” It leaves the question open because, so far as most of the researchers are concerned, it *is* open, and it will remain open until we have a theory of quantum gravity.


I've also heard that there are a lot of "crazy" ideas out there about time travel physics. In a subject like time travel, how do you distinguish between a "crazy" theory and a "legitimate" one?

Well I don’t. I leave it for the physicists. What I do is look for the articles that are the most cited. The ones that are a little too crazy are the ones that are not usually cited or never cited. There were a few ideas that have been published, in fairly well-respected journals, that I was curious about. So when I interviewed a physicist I put the question to them: “What do you think about this?” And in one case, I think the physicist said to me, “It’s just wrong.”


Do you know of anyone else who has made a collection of these ideas?

Not on this subject. There are other books on science that have done things like this, and almost all of those I think were written by physicists who had done work in it.


What inspired you to write a book like this? And how did you get the idea to go about it in this way?

I think that everyone is interested in time travel. That's why it's so widely treated in fiction and film.

I got the idea for the book when I learned that physicists were studying it seriously, and when I looked a little harder, I could see the shape of a story of their investigation - in fact, I could see a whole book as what in the publishing world is often called a 'scientific detective story.'


You don't have a scientific background: what challenges did you face writing the book? What advantages did it give you?

The challenges were, simply, an initial unfamiliarity with what journals count as important, with some specialized vocabulary, and so forth. I'm not sure my non-scientist status gave me any advantage at all, except that I could better anticipate places where my readers would be confused and need help.


After talking to so many of them, do you think physicists are weird?

Ha! I'm not sure I have enough of a data set to draw that conclusion. Seriously, the several I talked with at length seemed no weirder than academics in any field. But I will say that I now know that their chosen subjects – especially astrophysics and cosmology - can bring out weirdness in others. Since the book's publication, I've had my share of emails from well-meaning people who want to share their theories of ... well, everything.





David Toomey is a professor of English at the University of Massachusetts, Amherst where he teaches writing and technical writing courses. He holds a Ph.D. in English Literature from the University of Virginia (1998). He is the author of Stormchasers: the Hurricane Hunters and their Flight into Hurricane Janet; co-author of Amelia Earhart's Daughters: the Wild and Glorious Story of American Women Aviators from World War II to the Dawn of the Space Age; and second author of Scientific and Technical communication in Theory, Practice and Policy.


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Friday, December 07, 2007

Preparations for APS March Meeting Underway!

The APS March and April meetings offer every APS member the chance to give a 15 minute talk about, well, just about anything they want. Ok, it’s usually on research, but can also be essays on the history of science, science and society, science education, or a number of other sub groups. You do have to submit an abstract describing your talk, and over 6,000 abstracts have been submitted this year! Do the math...a 5 day conference, with 8 hours a day, with 6,000 abstracts...thats 1200 talks a day, and over 150 talks per hour! Assuming 15 minutes per abstract, that means about 40 separate sessions have to be going on simultaneously all day long.


To organize the jumble of electronically submitted abstracts, physicists from all over the country fly or drive into College Park, Maryland for a day of free food and physics talk. It’s fun for employees of APS because there are people running through the building all day. Here’s some pic’s from the front lines.

I asked Dr. Ted Einstein from the University of Maryland why he keeps coming back as a volunteer sorter. He answered, "We like to see the sessions well organized at the meetings. It's sort of a civic duty." It's not a great effort for Dr. Einstein to make it to the APS building (he's less than 2 miles away), but some volunteers come thousands of miles. I told Dr. Einstein, "I saw your name and thought you'd be the one to talk to. Do you get that a lot?" He replied, "No, this is the first time that's happened."



To keep the abstracts organized, volunteer sorters try to break them into smaller groups, to make up sessions on particular topics. They have to figure out where to place every single abstract (see the big board in the top picture). Plus, the sorters try to judge which abstracts might be particularly important or groundbreaking, so they can put those in popular sessions. Because of how many abstracts there are, the sessions can get VERY specific, like Neutrino Detection in the Antarctic, or Electron Structure in Reduced Dimensions.


To cushion the blow, APS divides the meetings up in to March (the larger of the two, by far) and the smaller April meeting which is for particle, nuclear and astrophysicists. The April meeting gets around 1,200 abstract submissions.

The APS March meeting will be held in New Orleans this year, and the April meeting will be in St. Louis.



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Thursday, December 06, 2007

Flying Carpets Aren't Total Fantasy


It’s pretty amazing how much Disney movies can change the way you look at the world. I am personally part of the Aladdin Generation, so when I saw a physics paper discussing the mechanics of a flying carpet, I held my breath. Since no prototypes were built, there won’t be any romantic tours of the Taj Mahal any time soon (other than in my mind), but understanding the basic mechanics might be the first step. Although highly impractical for land use or carrying people, the paper did show that a flying carpet isn’t total fantasy.

I had never noticed before, but sting rays that move along the ocean floor look a lot like how you might expect a flying carpet to move. To see what I mean, watch the video below.

The rays have the added advantage of swimming, which we'll assume a carpet would not. But in their most relaxed state, you'll notice that the rays don't move very high above the ground. The potential to have a carpet hover relies on it moving closely along a flat surface. Thus we must add the first major constraint to our flying carpet: (1) no balconies.

There’s a common example to show why they need to be close to the floor. Think about some time you dropped a very smooth piece of paper. If you’re a professional klutz like me, you might have noticed that as the paper falls initially, it just flops downward. But as it nears the floor it may suddenly slide some horizontal distance just above the floor. The presence of a rigid wall is essential to the movement.

But such smooth motion only works for thin sheets of film or foil that remain flat, not lumpy humans. So, we have major constraint number (2): a flying carpet would have to be nearly rigid to support the weight of two people.

Major constraint number (3): The size of the waves (mostly their length) made by the sides of the carpet (like the sting-ray) determine the velocity of the carpet, and the velocity is related to the size of the potential carpet. In order to get a carpet with any real speed created purely by its stingray-like wave motion, it would have to be very, very large and have a pretty impressive motor.

Oh yes, and it would need a motor. Sting-rays power their sides (fins?) by using muscle strength. Constraint number (4): noisy and/or heavy motor subject to adding weight. According to the paper, we might not even have the technology to make an engine that wouldn’t defeat it’s purpose with it’s own weight: “Making a heavy carpet fly would of course require a much more powerful engine and our computations and scaling laws suggest that still beyond current reality, even if it has existed virtually for millennia.”

The rays also bring to our attention constraint number (5): A more viscous fluid is desirable for magic carpet use. Air is very not viscous compared to water. Think about how easily you can make yourself levitate in a swimming pool, and how difficult (or impossible?) that would be in air. So, magic carpets are not so good in air, probably better in water. Ariel is more likely to get a magic carpet ride than Jasmine. Assuming those people are real (and odd assumptions are often made in theoretical physics).

So what are we left with? Considering the weight you’d be carrying, in this particularly non-dense fluid (air), in need of a HUGE piece of carpet to make HUGE waves, and an engine so big it probably wouldn’t make sense, magic carpets are very impractical, but theoretically not impossible.

I can still dream.
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Tuesday, December 04, 2007

TEA Science Advisor Fired for Having an Opinion on Intelligent Design

The news today reinforces that the battle to have intelligent design taught in science classes, rather than evolution, is going strong. Strong like a big, angry, drunk rhinoceros in a shopping mall.

The head of the Texas Education Agency's science curriculum alleges she was forced to resign because of memo about a talk on intelligent design.”

That’s the word on the street today, and by street I mean the following publications, and probably many more:

http://www.earthtimes.org/articles/show/150715.html

http://news.yahoo.com/s/huffpost/20071201/cm_huffpost/074940

http://www.statesman.com/news/content/news/stories/local/11/29/1129science.html

Comer "resigned" over a memo that suggested she might have an opinion about intelligent design (particularly that it should not be taught in science curriculum). Here’s the run-down: the Texas Education Agency is claiming that it is supposed to be UNBIASED or HAVE NO OPINION EITHER WAY about the issues of intelligent-design and evolution. (Give yourself a pat on the back if this already sounds not quite right) So, when word got out that their head science advisor actually had an opinion on the matter, she was suddenly in a position to resign early. I have to wonder what the hell a Science Curriculum Advisor is doing all day if not having an opinion about what science (or non-science) is being taught in schools?

There’s plenty I could write on this topic, but it’s almost too much. More than discussing the issue of intelligent design, I choose to focus on the idea that intelligent design and evolution are two ends of the same spectrum. Lets get one thing clear: Just because you are in the middle of two extremes does not mean you are unbiased, nor does it mean you are in the middle of the road.

Take this snippet from an editorial in Caller.com:

"Christine Castillo Comer, who was until recently the state's director of science teaching, made the mistake of telling the truth. That is, she intimated that intelligent design is not on the same level as evolution as a natural science. In fact, intelligent design is not science at all, but a stalking horse for an assault on evolution by religious conservatives. Now Comer is out of a job." (http://www.caller.com/news/2007/dec/04/official-forced-out-for-telling-the-truth-on/)

Angry. Clearly angry. Can you imagine the uproar if the government insisted that there be a chemistry lesson on the likelihood of bread transforming into flesh before every Catholic sacrament? I'd be angry because I believe in freedom of religion. It's time we enforced freedom of science. You have the choice to believe it or not, but you cannot be persecuted for doing so, and science classrooms are included.

It's true that (for the most part) if you believe in Evolution, you don't believe in intelligent design. And vice versa. So for a lot of people that causes a problem. Most Christian denominations have their own methods for determining what truth is, including various ways to interpret the Bible. If something doesn’t fit with that method of determining truth, that something is not included in the doctrine of that religion. Similarly, whether or not you believe in it, science has its own method for determining what truth is. To say that one doesn’t believe in current theories of evolution may, in fact, have some scientific ground. But teaching intelligent design should not be thrown in with science because it does not fit with the method that science has for determining truth. If you don’t agree with the scientific method, don’t hire a science advisor. Just be honest, Texas: you never intended to teach science and you never will.

Just because crackpot in a cabin in Vermont thinks we can defeat global warming by throwing Skittles at it, doesn’t mean I’m middle of the road if I take his/her idea into account with fuel cells. I would never stop him/her from believing it, but I won’t teach it to my kids.


In some weird twist of fate, look what ELSE the news cat dragged in:

http://chronicle.com/news/article/3535/concern-over-scientists-support-for-intelligent-design-surfaced-before-tenure-vote">http://chronicle.com/news/article/3535/concern-over-scientists-support-for-intelligent-design-surfaced-before-tenure-vote

There is suspicion that a professor at Iowa State University was denied tenure because he has said in the past that he supports the idea of intelligent design. Reading the article, the school has a pretty good case for why their decision was based on other factors, but someone left a really good comment that I’ll include here:


“When a member of a science department declares they are both a scientist and a believer in intelligent design (AKA Creationism) that strikes us an intellectual conflict, not one of science and religious beliefs. I can be an evolutionary biologist and believe in God as creator of natural laws or the process of evolution. I cannot be an evolutionary biologist and believe in creationism.


Besides, how does a physicist teach his class that the universe in only 10,000 plus years old?”

This article does pose the question of whether or not it’s OK for scientists to believe in GOD and still believe in SCIENCE. As stated by another comment to the above article:

“As a scientist, I care whether knowledge is acquired using the objective and empirical process of science—not what someone believes might have begun the process. It would not bother me to have a physician who believes in God or creation, as long as he understands medicine. I would rather that s/he understand something of evolutionary biology and humans in their context as primates and mammals, but s/he does not have to. I do not mind if a physicist or astronomer believes in God or intelligent design or is gay or has had an abortion (or wouldn’t) if that does not get in the way of how s/he teaches science or astronomy, and if s/he is a productive scientist and scholar and teacher. But, if any of those issues do interfere, that becomes a problem.”

Very well said. Then again, how can someone not be influenced by what they believe or where they come from? The idea of being an "unbiased" human being is contradictory and nearly impossible. Which is why we need to set up distinct dividing lines (i.e. separation of church and state) and abide by them.


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Thursday, November 29, 2007

When will we see DSCOVR again?

It's sometimes terrifying, in this age of information, to realize how much we don't know. A satellite built by NASA that could answer the major questions we have about global warming, and settle disputes over the reality of man-made climate change, is gathering dust in a Maryland warehouse. The importance of the information it might have provided cannot be understated. The satellite is built and paid for, and was scheduled for launch two years ago, but for undisclosed though not unsought reasons, NASA and the federal government have kept the Deep Space Climate Observatory satellite (DSCOVR) locked away, and with it the American public's right to an answer.

It’s a slap in the face to every American citizen that the Executive Branch has denied that it should be held accountable under the Freedom of Information Act to disclose documents concerning why the DSCOVR satellite was retired before it’s first launch. NASA itself also opted to withhold all internal documents (against the FOIA), on the grounds that they wanted to protect against public confusion as to the actual reason for their actions. We’re still confused, and we should be outraged.

Prior to DSCOVR's original launch date, NASA issued no official statement, but quietly announced that the mission was canceled due to "conflicting priorities." That was after spending millions of taxpayer dollars to build it. I'm sad to say I hadn't even heard of the DSCOVR satellite until this week, thanks in part to the fact that most major news sources are playing the same quiet game as NASA and the White House (although it's not fair to take blame off myself for not being more alert). The next question was why the government would try so sloppily to cover up such a decision.

The importance of the information that could be provided by DSCOVR is emphasized by the fact that both domestic (the NOAA) and foreign (the Ukrainian government) institutions have offered to buy DSCOVR and pay for it’s launch, so that the information it can provide will be available sooner – or at all, if NASA’s plan is to keep DSCOVR under wraps for good. But to these offers NASA replied with a good kind NOTHING. There was no response, not even a polite No or explanation of why they can't bear to part with a satellite they aren’t using. Without so much as a response to the question of 'why?' it seems we can only assume the worst.

Is the government keeping DSCOVR hidden because it’s afraid of the information it will inevitably retrieve? Is there really such a huge need to keep global warming in the politically golden realm of “still being investigated”? By giving no reason as to why it wasn't launched, denying the release of supposedly free documents, the lack of response to counter offers, and NASA's total lack of comment on the situation, I feel there is little else that we can assume. Furthermore, it’s unclear if we can hope that the next administration will change this decision. It is important that people know about this. I'm begging someone to prove this wrong, particularly with news that DSCOVR is being launched.

I’ve compiled a list of articles and blogs that are writing about DSCOVR. In particular I should point out the efforts of Mitchell Anderson, who has been hounding the DSCOVR issue for more than a year and is the person who initially went after the DSCOVR documents that were denied. Here is a link to one of his articles on the topic, that summarizes the situation with DSCOVR quite well: http://www.desmogblog.com/nasa-stonewalls-
another-us-agency-that-wants-to-launch-dscovr.

Physics Buzz will be writing more on this story next month, so keep you eyes peeled, and please post any other links you find important.


DSCOVR Articles and Blog Entries:

The official NASA website of DSCOVR, not updated since 2001.
http://enso.larc.nasa.gov/triana.html

DSCOVR website through the Scripp's Institution of Oceanography (Not updated since DSCOVR's non-launch):
http://cloud.ucsd.edu/dscovr.html

White House Denies Inquiries over DSCOVR cancellation (Oct.2007)
http://www.goodcleantech.com/2007/10/white_house_denies_inquiries_a.php


Washington Post Article (August 2007)
http://www.washingtonpost.com/wp-dyn/content/article/2007/08/22/AR2007082202441.html


Important Comment on the Debate (October 2007)
http://mitchellanderson.blogspot.com/2007/10/dscovr-debacle-part-3.html


The Bush Administration and Al Gore: Where DSCOVR might fit in (October 2007)
http://gristmill.grist.org/story/2007/10/16/101926/97


Blog by a climate modeler from Argonne Ntnl Lab (September 2007)
http://climatespin.blogspot.com/search/label/DSCOVR


BBC Covers DSCOVR’s initial grounding (July 2006):
http://news.bbc.co.uk/2/hi/science/nature/5134022.stm


Scientific Paper about the uses and benefits of DSCOVR:
http://adsabs.harvard.edu/abs/2006cosp...36.1653V


Early DSCOVR blog (September 2006):
http://seedmagazine.com/news/2006/09/free_dscovr.php


One of the early DSCOVR blogs (2006):
http://www.desmogblog.com/anyone-for-a-dscovr-bake-sale



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Something to get you through the day...


I decided to do a search of all the books titled "The Physics of _______". Everything is physics, but many books give it to ya straight in specific cases. With over 300 hits, here is a list of my favorites:

The Physics of
Superheroes, Consciousness, Christianity, Everyday Life, Everyday Phenomena, Christmas, Insultingly Stupid Movies, Medical Imaging, Golf, Basketball, Baseball, Hockey, Sailing, Dancing, Skiing, Sports, Radiology, The Body, Electric Propulsion, Angels, Music, Irrigated and Nonirrigated soils, Musical Instruments, Shock Waves and High-Temperature Hydrodynamic Phenomena, Foams, Immortality, Interstellar Dust, William of Ockham, Quasicrystals, Liquid Crystals, Coronary Blood Flow, Cerebrovascular diseases, Diamond, Galactic Halos, Laser Plasma Interactions, Three-Dimensional Radiation Therapy, The Non Physical, Agriculture, Time Asymmetry, Time Reversal, Laser Fusion, The Earth’s Core, Blown Sand and Desert Dunes, Glaciers, Ice, Monsoons, Heaven and Earth, Explosive Volcanic Eruptions, Clouds, Rain clouds, Mesospheric (Noctilucent) Clouds, Atmospheres, Traffic, The Ear, Balls in Motion, Birdsong, Welding, Pocket Billiards, Sound, Flight, Viruses, Paranormal Phenomena, Eternity, and Television.


New titles I might suggest:
Babies, Wrestling, and MySpace.

Additions/Suggestions welcome.
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Tuesday, November 27, 2007

It’s Physics, My Dear Watson. -- OR -- Pyramids, JFK, and Dinosaurs


Physics can be like a universal tool kit for solving mysteries. It doesn’t come with instructions, but if you figure out how to use it you’ll find that it comes equipped with everything you need to discover whether or not an ancient pyramid has hidden chambers, how to explain discrepancies in the JFK assassination footage, or find substantial evidence that a meteor impact killed the dinosaurs. And for those who don’t know how to use the tool kit, be sure you get a detective like Luis W. Alvarez.

As reported by Phil Schewe in this week’s Physics News Update (http://www.aip.org/pnu/2007/split/847-2.html), a paper by Charles G. Wohl, published in the November issue of the American Journal of Physics reflects admiringly on the career of a true physicist. Luis W. Alvarez won a Nobel prize in 1968 for his work in elementary particle physics, but his other work stands out for it’s application to classic mysteries.


The Pyramid Burial Chambers:
The two largest pyramids ever built are in Cairo, in honor of Cheops and his son Chephren. With over 13 acres of floor space hardly being used, it boggled archeologists why there weren’t more rooms in Chephren’s pyramid. It was highly hypothesized that there were hidden chambers in the pyramid, but no clear way to find them. Luis Alvarez knew that if you pass waves or particles through a dense substance (like X-rays through your body) you can gather information about the interior structure of that substance (the X-rays bounce off your bones but penetrate flesh). If there were chambers in the pyramids, sending particles or waves through them might reveal where. Alvarez realized that X-rays would be no good through the very dense rock. So instead of blasting particles up through the pyramid, he had the idea of letting the particles come from above.

Cosmic rays in our galaxy are responsible for a shower of relatively large particles called muons raining down on us constantly. Our bodies have adapted to the barrage so as to keep us from sprouting holes. Muons are strong, but they can be partially stopped by rock. In other words, fewer muons will make it through a wall of rock than started in. Alvarez’s team put a muon detector in the main room, in the center of the lowest part of the pyramid. If there was a hidden chamber in the pyramid, more muons would show up on the detector because they met less resistance: a gap in the rock, or chamber, would allow more of them to pass through. Somewhat sadly, Alvarez’s team found no sign of hidden chambers. From Wohl’s paper:

It was a disappointment to find no burial chambers and no mmarvelous treasures. But the use of “rays” provided by nature together with the new tool of spark chambers was ingenious. And the mystery was solved. People would say to Luie, “So you didn’t find any chambers.” “No,” Luie would reply, “We found that there are no chambers.”

The JFK Assassination Video Tapes:
The immediate wave of conspiracy theories in the murder of John F. Kennedy in 1963 were often based on one seemingly disturbing fact: video footage of Kennedy being shot showed his head bucking forward, in the direction of the bullet, and then back toward the shooter. Intuition told people that his head should only move in the direction of the bullet, and that it’s motion backward suggested a second shooter somewhere on the scene that day.

Having also explored the physics of photography (what hasn’t he studied?) but really only needing basic mechanics, Alvarez thought he could explain the puzzle in the video. If a bullet strikes an object and sticks to it perfectly, the motion of the combined object-bullet will only be in the initial direction of the bulle. The bullet's momentum has to be conserved. But the energy of the bullet is changed into heat and damage to the object: so in the case of a human head, the bullet causes jets of blood and brain matter (pardon the gore) to also move in the direction of the bullet (away from the shooter). These jets also have momentum that must be conserved. So, the jets push the head back toward the shooter, causing a seemingly counterintuitive motion. It may seem hard to believe, but both mathematics and demonstrations (they used melons wrapped in filament tape) illustrated Alvarez’s point.

Alvarez did additional analysis of the film, but nothing to settle the conspiracy theories or bring us any closer to really understanding what happened that day. The paper emphasizes that even if a bullet from one direction were responsible for the motion of JFK’s head, it can't actually tell us the number of shooters at the scene. Such mysteries may remain unsolved.


The Extinction of the Dinosaurs
This may truly have been Alvarez’s biggest achievement and one that set off a chain reaction of discoveries. Alvarez's son, Walter, is a geologist. In the 1970’s Walter showed his father a slice of clay, a centimeter thick, in he middle of a tall wall of limestone in Italy. The clay was known as the KT boundary, marking the end of the Cretaceous period. The limestone below this line of clay is full of fossils, but the limestone above it is scarce. Geologists knew that whatever happened to put that layer of clay there, also caused a mass extinction and wiped out nearly half the species on earth, including the dinosaurs. What they didn’t know was why.

At this point, the paper notes that there were many, many wrong turns, dead ends, and unsuccessful attempts at solving this mystery. You’d expect as much for such a huge puzzle.

Alvarez knew that during Earth’s formation, heavy particles like iron, platinum, and iridium (to name a few) sunk through the molten layers of the newly forming planet and came to rest in its core. Thus there is very little of any of these elements in the Earth’s crust. But rocks in space haven’t gone through this process of separation, and carry with them a mixture of elements including these heavy metals. Meteorites burning up in our atmosphere leave a light but constant sprinkling of these heavy elements on the surface of the Earth. An increased level of one of these elements would imply that a larger than usual amount of rock from space had come to rest on the Earth’s surface. Alvarez focused on iridium. The amount of iridium in the soil is less than parts per billion, which means it is only detectable using techniques of nuclear chemistry. This would explain why geologists didn't noticed what Alvarez and his son found.

The levels of iridium in the KT boundary clay were through the roof compared to the rock around it. In a very short period of time, a large amount of an element known to be present in meteorites was deposited on the Earth’s surface and a significant amount of clay was deposited before limestone could form. Most importantly, these deposits coincided with a mass extinction. The father and son raced to get samples from other parts of the world. If their theory was correct, the deposits should be everywhere on Earth, since the proposed impact would have to have spread around the world to do the kind of damage they were suggesting. And indeed, over a hundred sites showed the same results. Further analysis of the clay showed that other materials were present that supported the meteorite theory including soot (suggesting much of the vegetation burned) and microscopic diamonds (created from intense heat and pressure), among others.

The work done by Alvarez and his son of course led to further investigation into the theory that the mass extinction was caused by a meteorite impact, and after Alvarez’s death scientists found what they think is the crater left over from the impact.

For a more in-depth portrait of Luis Alvarez's discoveries, see the paper by Charles G. Wohl, cited below.

Adventures in physics never fail to amaze me. Answers literally falling from the sky! Physicists like Luis Alvarez are truly geniuses for their combined discipline, ingenuity, and creativity, using the fantastic tools given to us by the natural world.

1. Wohl, Charles G. “Scientist as detective: Luis Alvarez and the pyramid burial chambers, the JFK assassination, and the end of the dinosaurs.” American Journal of Physics. 75 (11), November 2007.


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Wednesday, November 21, 2007

That Sweet, Sweet Voltage: The Electric Addiction

Futurama has a fantastic episode titled “Hell is Other Robots,” in which the show’s main robot, Bender, turns to the seedier side of robot life and develops a heroin-like addiction to electricity. Bender has to get his fix from an outlet or battery; otherwise he gets shaky, nervous, and irritable. The episode pitches the idea that if robots were like humans, electricity would take the place of hard drugs. But an article in the Daily India suggests that electricity might be the vice of robots and humans alike.

In the Indian district of Uttar Pradesh' Lalitpur, a village priest needs to have a small electrical stimulus before he can fall asleep each night. The priest gets his electricity from home appliances or live wires plugged into the wall. He sometimes leaves the wires in his mouth, under his arms, or behind his ears for the entire night. The article doesn’t say exactly how strong the stimuli is, or if the priest prefers a short jolt to a long tingle, but doctors in the village believe he’s built up a tolerance to it after using it for four years.

The article seemed like a fluke, until I read that the priest used to be addicted to drugs like opium and marijuana. While some villagers think the priest is divine for his ability to handle the impulses, he believes they’re what have kept him clean. Instead of doping up on traditional drugs, he satisfies his cravings with the electrical stimulus.

It turns out that electrical stimulus has been used as a treatment for alcohol addiction for a few years now. Cranial Electrical Stimulation (CES) units have drastically improved the success rates of some alcoholism treatment centers in the US. The patients attach the ends of the device to their earlobes and receive a small current “similar to the electrical pulses in the body.” Patients who were constantly re-entering rehabilitation have found long-term success with the devices, and one treatment adviser thinks it’s the miracle they’ve been looking for. Somehow, the electrical stimulus has satisfied or taken the place of the chemical stimulus they used to seek in alcohol and other drugs.

I was thinking about electrical stimulus on the brain, when I recalled that not all electrical treatments are similar to the ‘mild pulses of the body’. Electroshock therapy (EST) uses enough electricity to cause nerve damage in a few seconds, and can kill a person in a few minutes. It was discovered in the 1930’s and is used to treat severe cases of manic-depression and schizophrenia. In the film A Beautiful Mind, mathematician John Nash undergoes EST, only to be left slightly handicapped and still suffering from schizophrenia. In fact it has been said that considering its damaging side effects, the treatment may have been used too frequently in its early days, when doctors understood it even less. But use of the treatment continued because in some cases, EST yielded amazingly positive results. Cases of manic depression and schizophrenia practically disappeared in patients who showed no response to drug treatment. Somehow, the electrical stimulus drastically altered a malfunctioning process of the brain.

Today, EST is used less frequently, and only on patients with severe symptoms who don’t respond to drug treatment. And sometimes it shows remarkable, positive results; saving people from otherwise untreatable mental illness. What makes these results all the more incredible is that neurologists still don’t really know what happens to the brain during EST. Questions remain such as why the treatment works for some people and not for others; why it can cure manic-depression and schizophrenia, but not other ailments; and especially why it can have such dramatically different effects than chemical treatment. And in the cases presented here, we have to wonder why it is that electrical stimuli can do the equivalent of chemical stimuli for the Indian priest, and then do what chemicals can’t do for those cured by EST. But it works for some people, and that’s enough reason to move forward with both treatment and investigation. The Indian priest’s self medication is an example of neuroscience having data but no solid theory.

The idea of an "electricity addiction" might sound funny, but when I Googled the phrase, I got a lot more hits than I expected. I soon realized that most of them were referring to the fact that even though we don’t all stick our tongues in the toaster every the morning, America’s energy usage suggests that we’re all fairly hooked on that sweet, sweet voltage.


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Tuesday, November 20, 2007

Fire from Salt Water: Lets Focus, People.

A man in Erie can make salt water burn!

In a manner of speaking, yes. He’s freeing the hydrogen and it makes a flame but really it's just re-bonding with oxygen so it...


You
can run an engine with it!

Well, yes, it's fire, which can do that, but you have to run the radio wave generator and...


We have tons of salt water! We can use this instead of coal and oil!
No.

No no no no no no.

No.

Stop. No. Ow. Can I get an aspirin?

“New Source of Energy in Salt Water” sounds so good you just want to believe it. Bless your little heart for having so much faith in these times of despair and no snow, but unfortunately a gallon of free gas isn’t worth anything if you use up two gallons getting to the station.

Always ask questions. It’s where answers come from. Questions like, if radio waves + salt water = fire, why don't the oceans ignite from radar? Or, if our bodies are 70% water and some salt, why doesn't the radio wave generator cause internal bleeding in the guy running it? Here are the most common questions I’ve seen on blog discussions on this topic:


So…can salt water burn or not?

The video isn’t a fake; he’s actually started a fire. But do you think water can burn? Really, does that make sense? Usually water puts fires out. Knowing that, you might suspect that something isn't being fully explained here. And in fact, this is where most news stories on this are getting things backward: water doesn't burn. Water is produced when hydrogen "burns".

It's really no mystery what's going on in the video. The hydrogen can’t burn if it’s bound to oxygen (like it is in water). But, if you mix the water with sodium chloride you loosen those bonds. Then, if you do something like hit it with a very strong radio wave, then you separate the hydrogen and oxygen. Now add heat and the hydrogen will make a flame. This is the flame you see in the video. The experimenter has separated the oxygen and hydrogen and is burning the hydrogen, not the water.

But wait. Remember what I said about questions! What does it mean to burn hydrogen? Where does the oxygen go? Here's where the confusion arises: hydrogen burning = bonding with oxygen to form water. The hydrogen, in order to "burn" must re-bond with the oxygen you just separated it from. You're just ending up with exactly what you started with but spending energy to get it.

All that the radio man has done is spent energy breaking apart the water bond, given heat to the hydrogen/oxygen mixture, and released a little bit of energy putting them back together. The bottom line is all you are doing is taking apart the water molecules, and by making a flame you put them back together but that does not release any more energy than you've already spent. This is not a matter of how efficient the radio wave generator is. This is not a matter of how much salt is in the water. This is simply a matter of understanding what chemical reaction is actually taking place.


What if we get a more efficient radio wave generator?
The inefficiency of this system has nothing to do with the radio wave generator, although it is a bit like pulling apart a piñata with a team of horses (excessive). This has to do with the simple fact that it is impossible to break the bonds between hydrogen and oxygen in water and put them back together (=burn the hydrogen) without losing energy.


But it's still revolutionary that he's managed to make flame by splitting water molecules...right?

I sense you're starting to doubt CNN.

We already know how to separate water molecules into hydrogen and oxygen. You can do it at home with a battery. There are lots of very easy ways to do it. This might be the first time someone has done it with a radio wave. But really, there was no need. Check out this website on how you can do it at home:

http://www.theodoregray.com/PeriodicTable/Stories/001.1/index.html


Fire is energy. We need energy. Can we use this as an energy source?

No.

A guy in a lab shoots a radio wave (using energy) at a beaker of salt water and fire starts atop it (creating energy). Unfortunately, the radio wave (or whatever method you use to break the bonds) consumes more energy than the fire releases. You spend two gallons of gas getting one for free. Therefore, it can’t be used as an energy source, because you haven’t actually found a source of energy. You’ve found a terrible exchange rate.

It costs energy to split the hydrogen and oxygen. Putting them back together does release energy but not as much as you spent breaking them apart. That is just a fact of nature.


If you can’t create energy or destroy it, how can a reaction end up with more or less energy than it started with?
The salt-water-on-fire reaction is a negative energy equation. Negative because you lose some energy to the system around you, or for processes that don’t pay off in the energy release, or just because you took three lefts to make a right. Breaking those bonds might cost more energy than they give back, depending on how you break them. Even if the reaction were perfect, though, you could only get as much energy out as you put in because you're simply reversing the action.

There are such things as positive energy equations. These exist when energy has been stored in something prior to the start of the reaction, and often involve a catalyst (something to lower the energy needed to make the reaction happen). The best example: gasoline.

Lighting gasoline on fire gives off more energy than the person who ignited it put in. The energy comes from the breaking of chemical bonds. They key is that nature put those bonds together, not us. We’re taking advantage of someone else’s work. It’s what we do when we eat food: the plant got energy from the sun, stored it in a little energy piñata, and we came along, broke it open and took all the candy. So to speak. The earth and millions of years under pressure put energy into oil and coal. The sun could heat things for us. The wind could move things for us. There are ways to get energy out without putting it in, but breaking apart salt water and putting it back together is not one of them.


Is getting energy from water hopeless?

Hard to say. Keep your eye on scientists studying electrolysis, or ways of getting hydrogen out of water with electricity, for new innovations. But the trouble is finding innovative ways to get more energy out, not finding new ways to separate hydrogen and oxygen.

Buzz Skyline pointed out to me that we should look to nature when questioning this phenomenon. Nature is far more resourceful than we are. If there were a way to get energy out of salt water, without spending more energy than you get, there would probably be creatures utilizing it already.


We use energy to turn oil into gasoline, to process it and ship it. It’s getting very expensive and cars aren’t 100% efficient when they burn it; isn’t that putting in more energy than it’s getting out?
Possibly. This is partly why oil prices fluctuate so much. Some people might argue that we put more energy (and money) into getting oil than we can actually use it for, especially with the environmental costs. For that reason, people might think that we should at least investigate this salt water thing to see if it turns up something useful and less harmful. But remember that burning hydrogen is really what you’d be talking about. For that, there is no reason to use the radio waves or to break apart water; we have un-bonded hydrogen in the air.

And remember that neither hydrogen in the air nor in seawater is a renewable resource. We could still run into ecological problems if we tried to use either of those.

Plus, if we just offer ourselves another energy source that doesn’t make us change anything, doesn't make us more aware of our energy spending, and which potentially hurts our ecosystem in another way, then what good have we done? Ideally, hydrogen cars would replace gas cars without disrupting the driving schedule of most Americans. But what does that teach us about solving the problems we create? Even hybrid cars give a false pat on the back to consumers because we think a handful is making a difference. We need to stop looking for a magical solution to the energy crisis and admit that there are solutions available, but accepting them would just mean being aware of the problem we've created.


You’re being awfully nice about this whole thing. Doesn’t it make you just a little bit ANGRY that the news is manipulating this story to make people think we’ve found a new energy source, and that people aren’t taking the time to question why this hasn’t been used already, or why a retired radio technician is being treated like a revolutionary physicist?

Good question.


And remember kids, the inventor of fire breathing salt water says:

“This is the most abundant element on Earth. Water. Salt water.”

I’ll just let the chem geeks stew on that one.


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Friday, November 16, 2007

Stonehenge: Just add physics

Wally Wallington can move 2-ton cement blocks or barns over large distances by himself. No heavy machinery. No help. Just physics! He thinks he may have figured out how Stonehenge was built, and that it could have been done with very few people. This video shows not only some very basic physics principles in action, but illustrates that physics needs creativity and ingenuity to be put to work.

This video is about 6 minutes long, but it’s worth a look. Full of lots of physics and really awesome feats!

Read on to learn a little more about why Wally can move a barn with a 2x4. Getting it up on the pivot is something you’ll have to figure out from the video. The physics involved: center of mass and inertia; an object in motion tends to stay in motion; basic lever. This might be old hat if you’ve had basic physics classes, but I had to check my book to make sure I got the mechanics right.

Balancing a Barn- Put a pivot under and object's center of gravity, and the object will balance. No matter how big or oddly shaped the object is, that little point means equilibrium and that means it will sit tight. If you threw a tractor in the back left corner, gravity would pull more on that side, and the center of gravity would change. In terms of the barn, that point is relatively close to the center.

Rotating it- Wally uses a lever to push the barn around. Try opening a door by pushing on a spot right next to the hinges. It takes way more effort than to push it out by the handle, but you move your hand further using the handle. If you tried to rotate the barn by pushing directly on it, it’d be much harder than pushing a long 2 by 4 extending off the side of the barn. It works like a crowbar; you can move lots of mass but you have to move yourself a greater distance. Wally has to go all the way around the barn just to move it a few inches. So crowbars, see-saws, and barn movers still move a lot of mass, but they have to move over a larger distance to do it.

Getting it going - Once the barn is balanced on the pivot, gravity only plays a part in the frictional forces between the pivot and the ground. The motion of the barn in the horizontal direction is in the hands of its rotational inertia. Heavier objects are harder to push because of their mass, not their weight: Mass=stuff it’s made of; weight=stuff it’s made of + gravity; gravity only pushes down

The inertia is Newton’s second law. The barn doesn’t want to move while it’s at rest, but once it gets going it doesn’t want to stop! You have to overcome the initial energy needed to get it going, but then as you can see in the video, the barn moves much easier. Frictional forces eventually slow it down again

Moving the Barn Forward -Think of the center of mass as being in the center of a cement block. Now picture two pivot points on either side of the center of mass. If you put a mass on one side of the block you can change the center of mass to one of those pivot points. You can change the point where the block will balance. If you rotated that mass 180 degrees on one of those side pivots, the longer end would be pointing in the other direction. The block has moved in that direction. Change the center of mass to the other side of the block, and the long end is now the short end. Swing it around and the block has moved again.

Ok, think about it like walking with your knees and hips locked in place so your legs are totally straight. You step on one foot and pivot forward, step on another foot and pivot forward. Kind a like that.

In addition, Wally’s lever has its load on the pivot. This anchors the pivot and maximizes the work the lever can do.

Side Note on COM:

Center of mass is easy to imagine in an evenly weighted square block: it’s in the center. But if you really want to see how center of gravity works take a piece of paper cut like a pear or a kidney, and try to pin it to a wall. Keep the paper so it’s not touching the wall, or friction will play a part. Try pivoting it on the pin and it will usually slip back to a place of equilibrium where the heavier end is pulled down. But pin that piece of paper at its center of gravity, and you can pivot it all you want, and it will never slip down. The larger end can point up, down, or sideways. That’s equilibrium! It’s being pulled on equally from all sides.

Check out Wally Wallington's Website:

http://www.theforgottentechnology.com/



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Thursday, November 15, 2007

The Musical Tesla Coils

Will Tesla Coils make their way to Best Buy shelves this year? It's unlikely that they'll trump an iPod on sound quality, but you can’t beat the visuals.

That singing highway was awesome (see the Nov. 13 entry), but I think it’s strongly challenged by today’s feature: The Musical Tesla Coils. Manipulation of Tesla coils to make noise has been done before, but this takes the cake. What you’re hearing is the theme from Super Mario Brothers, created by an output of plasma pushing on the air as it's frequency is changed.

Also check out "The Dance of the Sugar Plum Fairy" and others:
http://www.youtube.com/watch?v=Opf5jIukSBM&feature=related

Sound waves are vibrations of the air around us, which you can make just by clapping your hands or talking. Pitch is just the number of times the air vibrates per second. Higher frequency, higher pitch. Tesla coils are a combination of circuits that output thousands to millions of volts. That high electric field arcs up and out of the coil, filling the air with sparks and making it possible to light up fluorescent lights wirelessly. Certain types of Tesla coils, like the one used here, are putting out hundreds of sparks per second, with a rest between each spark. That's already a lot like a sound wave. Each spark is pushing on the air and can create a sound. Change the frequency of the sparks and you get an equal frequency wave, hitting your ears like a note of music. The creators had to find a way to move seamlessly between frequencies to make the notes sound distinct, instead of just playing the whole scale.

The creators and musicians Jeff Larson and Steve Ward have a website explaining how to make your own musical tesla coil, if you have the means.
http://www.stevehv.4hv.org/MusicalSSTCs.htm

Another example of the creativity that comes with such heavy machinery: the Tesladownunders Car Theft Protection (this is not an altered photo).

From http://tesladownunder.com/tesla_coil_sparks.htm.


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