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Below are the 13 most recent journal entries recorded in Chris Phoenix's LiveJournal:

Wednesday, November 7th, 2007
3:23 pm
Deep Time on Mars
On Mars, things happen slowly. Because the air is so thin, wind strong enough to move the sand around happens only a few times per decade. So it takes 1000 years for the dunes to move a few meters.

There are dunes on Mars that were shaped by wind blowing from two different directions. On Earth, winds might switch direction between morning and evening, or maybe between summer and winter. But on Mars, such trivial fluctuations average out.

On Mars, the dunes are shaped by a much slower cycle. Calculations show that the dunes took their present shape as a result of a 50,000 year cycle: the cycle of the precession of Mars's axis.

Changes in the Earth's orbit have caused glaciers to come and go. On Mars, similar changes shape the sand dunes.

Hat tip to Physics News Update.

Current Mood: awed
Friday, November 2nd, 2007
11:57 pm
Everything's Possible


Yet another amazing image thanks to Dark Roasted Blend. (Scroll down to see it.) (The caption in the image says "Everything's Possible."

On another note... please ignore what I wrote in the last post, about the possibility of getting in some kind of trouble for posting about problems in the US government. That kind of thinking is easy to get into when reading about institutionalized injustice... but it is not at all helpful, and darned hard to calibrate.

On a third note... The Complex Systems conference was awesome! I'll be posting cool things from it for weeks to come.
Friday, October 26th, 2007
6:03 pm
More nasty politics
Does this sound like the Land of the Free? It starts with 9/11, but the punch line happens six years later...

Soon after 9/11, an airplane-related radio was found in some Egyptian guy's hotel room in New York City. Naturally, the guy was arrested and questioned. He claimed not to own the radio.

The FBI interrogators threatened to sic the Egyptian security forces on his family--a very serious threat, which would have meant that they'd be tortured. At which point he changed his story and admitted that he was involved in 9/11.

Some time later, an airline pilot contacted the hotel and asked if they had found his radio. So the guy was totally innocent. So he sued the FBI.

The Court of Appeals says that he may have a case and might get damages.

Now here's the really freaky part. The court's opinion, after being posted briefly, vanished from their website. When it reappeared, portions had been edited. Which portions? The parts that described what the FBI interrogator did. Why? Because someone has decided that that should be classified information.

Fortunately, the original is still available from a few bloggers. Here's a sample:

"Higazy alleges that during the polygraph, Templeton told him that he should cooperate, and explained that if Higazy did not cooperate, the FBI would make his brother “live in scrutiny” and would “make sure that Egyptian security gives [his] family hell.” Templeton later admitted that he knew how the Egyptian security forces operated: “that they had a security service, that their laws are different than ours, that they are probably allowed to do things in that country where they don’t advise people of their rights, they don’t – yeah, probably about torture, sure.” "

Full story is available at Psychsound; hat tip to Tom Tomorrow.

I'll get back to posting fun stuff, but probably not for a week or so--I'm flying back east for a fun scientific conference on complex systems. (Assuming they still let me fly...)
3:00 pm
"There will be an attack on Iran."
Not everything in the world is cool. Here are a few political stories I've been finding over the past few days...

The White House deleted half of the Congressional testimony of the Director of the Centers for Disease Control on climate change and disease. "....six pages of details about specific disease and other health problems that might flourish if the Earth warms were not delivered at the hearing."

And "Referring to the draft, one CDC official familiar with both versions, who spoke on condition of anonymity because of the sensitive nature of the review process, said that "it was eviscerated." "

One of the deleted sections stated, "
Climate change-driven ecological changes such as variations in rainfall and temperature could significantly alter the range, seasonality and human incident of many zoonotic and vector-borne diseases." So why did the White House not want this to be part of the written Congressional testimony?


According to a story in The Guardian, a CIA expert was smeared and fired because he found--and told Congress about--evidence that the US helped Pakistan develop the Bomb. "
Barlow came to the conclusion that a small group of senior officials was physically aiding the Pakistan programme. "They were issuing scores of approvals for the Pakistan embassy in Washington to export hi-tech equipment that was critical for their nuclear bomb programme and that the US Commerce Department had refused to license," he says. Dismayed, he approached his boss at the CIA, Richard Kerr, the deputy director for intelligence, who summoned senior State Department officials to a meeting at CIA headquarters in Langley. Barlow recalls: "Kerr tried to do it as nicely as he could. He said he understood the State Department had to keep Pakistan on side - the State Department guaranteed it would stop working against us.""


Scientific American, of all places, has a scathing article about the US government's response to climate change. "In recent years, the unilateralist foreign policy of the U.S. government has brazenly ignored or contravened countless aspects of international law, ranging from the Geneva Conventions to multilateral environmental treaties to which the U.S. is a signatory. This brazenness has infected the very core of policy discussions in our country."


"In Time magazine, former CIA officer and author Robert Baer quoted a highly placed White House official: "IEDs are a casus belli for this administration. There will be an attack on Iran."" This from a recent article about a buildup to war in Iran in Esquire. The article describes how significant diplomatic initiatives by Iran were ignored. The article also has an interesting story about Colin Powell's hands being tied at the last minute in Middle Eastern negotiations.


It's not hard to find these things... for the most part, I don't even look for them, just read science websites and random blogs. The first item came from a science website. The second came from chasing links from a cartoonist's blog--not even a political cartoonist. The third item was science, again. And the fourth came from looking up an assertion made in an email distribution sent out by an alternative-thinking guy who once included a story on molecular manufacturing (my most recent career).


At what point do average citizens have a duty to get politically active?
Wednesday, October 24th, 2007
2:28 pm
Heritage Tomatoes
Not every good thing in life is on the Internet. This is a picture of a heritage, or heirloom, tomato.



We like to laugh about how a tomato is botanically a fruit, even though everyone thinks of it as a vegetable. What's the difference? Fruits taste good, as though they were chock-full of healthy calories. Vegetables don't taste so good--they're watery, often sour, and you have to take your parents' word for it that they're actually good for you.

Vegetarians, dieters, and rabbits eat vegetables; everyone eats fruits.

A heritage tomato is a fruit.

If you've never tried one, find a local farmer's market or produce stand, and ask them how to obtain them. They will look funny; they were not bred for beauty. Instead, their type survived for hundreds of years for a much more important reason: they taste good!

In Animal, Vegetable, Miracle, Barbara Kingsolver writes that she was trained always to clean her plate--but after eating heritage tomatoes, she can't always bring herself to finish commercial tomatoes.

Heritage tomatoes come in all sizes, colors, and flavors. It's been said that if a man makes a salad for a woman and it has more than six kinds of lettuce, he's serious. But six kinds of heritage tomatoes--well, that's not just a salad, that's a meal.

So if you want to spice up your life, or just your cooking... if you're tired of eating the same old tasteless vegetables for your health's sake... go hunt down some heritage tomatoes. You're worth it.
11:39 am
Fun with "Stick Bombs"
Stick bombs are made of popsicle sticks interwoven in such a way that pulling out any stick frees up all of them. Since popsicle sticks are springy, they can jump several feet in the air when they are released. I learned about stick bombs from Lunatim's amazing work with kinetic installations. I've invented a new design of stick bomb... maybe you can invent another.

Here is a picture from Lunatim's site, showing how a stick bomb explodes...


Well, I thought this was so cool that I just had to figure out how he did it. And if you think it's cool too, you may want to build some of your own. I've invented a new design of stick bomb... maybe you can invent another.

Wear Safety Glasses!!!

Lie on your back, hold your eye open, and drop a popsicle stick end-on from three feet up onto your eyeball... what, you wouldn't do that? Then don't lean over a device that can throw popsicle sticks three feet in the air, without protecting your eyes somehow.

Lunatim's stick bombs appear to be all built with the same motif. It takes just a bit of practice to build them, and I've learned a few tricks that I will now pass on to you. You will learn to build these two stick bomb designs, the first based on Tim's techniques, the second my own invention:



First hint: work on shag carpet. It's much easier than working on a smooth surface. You'll be weaving sticks under other sticks that are pressed down onto the surface, and a spongy surface lets you push down the stick that's going under, rather than picking up the stick that's going over. Also, carpet fibers will get trapped between the sticks, anchoring the construction to the carpet, making it easier to adjust one end without displacing sticks at the other end.

Second, when two sticks overlap endwise, overlap them a lot--an inch or more. The construction will be more stable that way.

Third, it may help to dip the sticks in warm water, especially when you're first learning. This will make them a bit less springy and slippery, so your constructions won't fall apart while you're working on them.

Fourth, build with a decent amount of precision; if the sticks are placed unevenly, the construction will warp out of plane, perhaps badly enough to explode prematurely. You don't have to use measuring instruments; you'll learn how neat you need to be, but it's quite easy to do it by hand.

Now, to construct a basic stick bomb:



Notice that the sticks are woven under and over each other. I've drawn arrows to show where a stick dips under another stick. Notice also that I'm holding down one of the sticks; otherwise, it would tend to pop up a bit, since it's levered over the right-hand vertical stick.

Here's how stick bombs are held together: If a stick wants to pop up, put another stick on top of it. If a stick is pressing into the floor, put another stick under it. So, first you extend the horizontal sticks, edges and center, on this principle. Add vertical sticks following the same principle: under the bottom-most edge sticks, over the top-most edge sticks. When the vertical sticks cross the center horizontal sticks, put the stick that's being held down on the ends (whether that's the horizontal or the vertical stick) over the stick that's held up on the ends. That will spring-load them so they pop apart when they are released.

Pulling any single stick out of a stick bomb will release all the others; but with all the sticks in place, the stick bomb is stable. A stick bomb under construction is not stable, which is why you'll see me holding down one or two sticks in each picture. You will need to hold down the sticks with one hand while placing the new sticks single-handed. This may be awkward at first, but the carpet makes it much easier to get sticks under other sticks as needed.

So let's see what happens as I add sticks:


As you can see, the sticks are arranged in alternating segments, one where the middle stick wants to pop up and has to be held down, the next where the middle stick wants to press down and the outer sticks want to pop up.

So I can keep adding segments until I have a line as long as I want it. When I'm done, I just add one last stick at the end to keep the middle stick up or down, hooking it under/over the outer sticks which want to be down/up.




So how about those cool right-angle and T joints? To build a T joint, you just start a new row, hooking it under a stick that you will eventually remove to leave the joint open.


If you didn't remove that horizontal stick, then you could detonate the lower part without affecting the upper part--not what you want! It takes some care to slide the stick out sideways without disrupting the rest of the bomb, but work slowly, watch for sticks moving that you don't intend, slide it out a bit at a time, practice a bit, and you'll be fine.

OK, what about right-angle turns? They're basically like going straight, except that you don't put in one of the horizontal sticks, and instead you cap the end; then you start building the next row just like you'd expect. I capped it right away in this sequence, but you don't have to. Note that the viewpoint rotates 90 degrees between the first and second pictures.



So that's how you build Tim's rectilinear stick bombs. You can extend this to building quite large patterns, as seen in Tim's video of almost 2000 sticks being detonated. You can make the tracks cross each other; as long as the upper track detonates first, it won't disturb the lower track. (That's how Tim built the spiral that opened this article.)

But what if you're bored with rectangles? Well, you can try building 3D structures by sticking two tracks back-to-back. I did that, but it wasn't extremely satisfying... I'd still like to figure out a better way to take stick bombs into the 3rd dimension. In this design, the middle vertical sticks are pressing on each other, while the outer vertical sticks are pulling past each other, held in place by the "roof" sticks. It' still the case that pulling any stick will make the others disassemble violently, but it's a pretty flimsy construction, and only gets out-of-plane with a pretty shallow angle.



So how about... triangles? A bit of history first: while fooling around, I built a couple of rings and decided to stick them together corner-to-corner. So I pulled the corners apart and hooked the downward-pressing stick of one ring over the upward-pressing stick of the other, and vice versa.



But this is not a real stick bomb, since it's held together by its own weight: if gravity went away, the two rings would twist each other around until the sticks could slip, and the thing would detonate. In other words, each ring is trying to stand the other ring on edge; they are not really locked in place. (It does detonate quite satisfactorily, though.)

So I tried to think of a design that would have twisted corners, but would be stable. I finally came up with one, probably the simplest possible one... and it's triangles! See, instead of having the sticks that go into the corner pushed up or down by a large construction, just have them pushed up or down by each other. Use one additional stick to hold them in place. Let's take a look again at that cool triangular shape I promised to teach you how to build, and then a detail of its construction...



The shadow behind the full construction is there because I actually picked it up, stood it on end, and propped it there, without it falling apart. Stick bombs can be surprisingly durable. On the right-hand photo, you can't see it, but the two sets of sticks are torquing each other around; the top left and bottom right sticks are lifted into the air. When all six triangles are in place and interlocked, the twist is forced into a plane, spring-loading the entire structure.

To construct this, precision is required. Otherwise, it will twist out of plane unevenly and fall apart. It helps to make sure that every stick you place is exactly parallel to another stick in the previous triangle. When you get to the end, you have to join the last triangle to the first--and here you will be very glad you were precise, because you're not going to be able to rearrange the structure much to make the ends match up.

Also, I found it necessary to dip the sticks in water. (This caused them to bend and make the structure not very springy.) Perhaps a different brand of stick would work better. Finally, in order to keep the structure from twisting up and falling apart while you build it, you have to kneel on the first triangle while building all the others (or clamp it down, or put an encyclopedia on it, etc). When you get to the end, hook the triangles together.

So, I hope you've enjoyed this... perhaps it will even inspire you to play with sticks. It only takes an hour or two to get to where you can build 100-stick constructions in a few minutes, and amaze, or at least amuse, your friends, relatives, and loved ones.

Which reminds me: This is one I learned in college many years ago, and I always like to leave this in restaurants (assuming I'm eating with people nerdy enough to let me do it). It's quite strong--you can stack several pounds of glasses, plates, water pitchers, or whatever on top. Beware: if the foundation glasses are wider at the top  than at the bottom, they may be tipped over if you put too much weight on the knives, so you may have to empty and invert them if you want to put more than one or two things on top.

Tuesday, October 23rd, 2007
9:21 am
Hypnotic moving picture
Don't stare at this one too long....



This is, of course, the work of LunaTim.
Sunday, October 21st, 2007
6:09 pm
More Kinetic Art
The last kinetic art video led me to this one... If you're not laughing out loud at some point from the sheer coolness of the gizmos, then your brain is not like mine.

There's a lot more at the artist's website.
5:59 pm
Kinetic Art
You have got to see this video. It will knock your socks off. If you're not wearing socks, it will manicure your toenails.



Hat tip to SummerJackel, who also has a lot of cool cephalopod videos and some nifty artwork (some of it humorous) scattered through her LJ. This video led to another cool one, which led to some other good links, some of which I'll be posting here over the next few days.
11:17 am
Architecture art: Real-life Hobbit Home
Go to this website to see an awesome home... built out of trees, hay, dirt, and about £3000 worth of purchased stuff. The guy who built it says he's not an architect or carpenter... in that case, he must be a genius.





Hat tip to Dark Roasted Blend, which is one of my favorite websites. You'll be seeing more of their stuff on here...
11:11 am
Science art: catalysis spirals

These patterns are what happens when oxygen and carbon monoxide land on the surface of a platinum crystal. Not only intricate, but beautiful. These pictures are from a story in Physical Review Focus that explains how they were taken and why the scientist who did it won a Nobel for it.
10:38 am
Welcome!

Do you ever find something online that's so cool you want to share it with your friends, but you don't have time to write the email and find all the addresses, and you know you'll forget someone, and you know someone else will be too busy that day and your email will be buried unread and add to their guilt karma, and it's just too much hassle, so you leave it up in a Firefox window for weeks because you know if you bookmark it you'll never get around to it, and then you never get around to it anyway, and you have 20 windows open and you hate to reboot your machine so it gets slower and slower (sadly, I'm running Windows) because one time Firefox didn't reopen all the web pages like it's supposed to, and your computer is getting almost as cluttered as your actual desk?

Am I the only one that happens to? Anyway, I'm starting this journal to have a place to put all the cool things I want to share with my friends. Science, art, neat videos, occasional personal news...

If you use Google Reader, you can easily see when new entries appear, without having to check back every few days. Google makes it really easy; you should be able to just put the URL of this page into Google's "subscribe" box, and Google will figure out how to check for new content.

Enjoy!
Wednesday, February 21st, 2001
6:30 pm
Hi, world...
Joined to see how well this will work for collaboration... my main interest is nanotech, and I have several ideas going in that area. Go to nanodot.org and search for ChrisPhoenix if you want to see what I've written.
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