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Seen, Heard, Said

Things I’ve seen, heard, or was told by someone. Item in this category usually originate from the Internet.

9|11

Seven years since. I really don’t think I have anything to add that I haven’t said in previous years past.

I did come across the following picture, from a set of 21, posted on Boston’s The Big Picture blog (which is quite excellent, by the way).


From www.boston.com:

New York City, seen by one of the Expedition Three crew members onboard the International Space Station (ISS) on September 11, 2001. The image shows a smoke plume rising from the Manhattan area. The ISS was flying at an altitude of approximately 250 miles. The image was recorded with a digital still camera. (NASA)

Finally, An Answer

Several years ago, I posted a problem describing a plane on a massive conveyor belt:
From www.boingboing.net:

Imagine a plane is sitting on a massive conveyor belt, as wide and as long as a runway. The conveyer [sic] belt is designed to exactly match the speed of the wheels, moving in the opposite direction. Can the plane take off?

Similar, but not exact, question was busted on Mythbusters:
From mythbustersresults.com:

An airplane cannot take off from a runway which is moving backwards (like a treadmill) at a speed equal to its normal ground speed during takeoff.

Every since that episode aired, I had serious doubts about the validity of the test; although I could never fully articulate those doubts, even to myself. The biggest issues I had was the speed at which the conveyor belt (or treadmill) was moving.

And that’s the rub. The first question posits that the “belt is designed to exactly match the speed of the wheels, moving in the opposite direction,” while the second questions says “a speed equal to its normal ground speed“. These, my friends, are two entirely different questions.

I thought all hope had been lost, until Randall “xkcd” Munroe became my hero. He asks the version of question I originally posted a couple years ago. It’s actually almost the exact same wording, only he adds in a bit about it being a 747 and then provides an answer:

From blag.xkcd.com:

The practical answer is “yes”. A 747’s engines produce a quarter of a million pounds of thrust. That is, each engine is powerful enough to launch a brachiosaurus straight up (see diagram). With that kind of force, no matter what’s happening to the treadmill and wheels, the plane is going to move forward and take off.

But there’s a problem. Let’s take a look at the statement “The conveyor belt is designed to exactly match the speed of the wheels”. What does that mean?

You think you have it all wrapped up in a nice little package, and then you get to the “But there’s a problem.” And you utter to yourself, “Crap.”

I’m not going to spoil Randal’s rather excellent explanation of the problem. However, he does do a pretty good job explaining it, and you really should read it.

I will, however, add a couple of footnotes:

  • A PID controller is a Proportional, Integral, Derivative controller, which is a type of feedback controller. For example, let’s say you’re running on a treadmill and you start running faster, a PID controller can measure the speed you’re running at and automatically increase the speed of the treadmill so that you don’t run off the end.
  • I’m not sure, but I believe the “‘JetBlue’ scenario” that Randall mentions may refer to the JetBlue Flight 292 incident of a few years ago.

If you also remember the discussion from last time, I think Chris Barnhart is the winner.

P.S. Mr. Munroe claims that xkcd doesn’t stand for anything. However, if you assign each letter a number (A=1, B=2, C=3, etc), X+K+C+D => 24+11+3+4 = 42. Check that out, you can’t make up that shit. And no, I didn’t figure that out all by myself.

Image Credit: Randall Munroe

The Sarah Palin Gender Card and Republican Hypocrisy

I don’t have cable, so I don’t regularly sit down to watch The Daily Show with Jon Stewart; which is unfortunate, because then I miss things like this:

(Here’s the link if the above video doesn’t show up: http://www.comedycentral.com/videos/index.jhtml?videoId=184086)

That’s what I love about Jon Stewart and his staff. They don’t need to resort to any sort of seedy tactics, they just show clips and let people get themselves into trouble. It’s excellent!

You can catch the entirety of the The Daily Show with Jon Stewart for free at Hulu.

via BoingBoing

Your Prerogative

If you follow politics at all, you know that the DNC was just here in Denver. I managed to avoid most of the hoopla, expect when the English division of Al Jazeera decided to come to Golden. I’m really not quite sure what to say about this:

From www.rockymountainnews.com:

The city manager of Golden, Colo., [Mike Bestor] has decided to withdraw his invitation to let the Al-Jazeera news network broadcast from a barbecue in his backyard on the final night of the Democratic National Convention.
….
Bestor made his decision after a City Council meeting Thursday at which residents complained the event with the English-language service of the Middle East news network would be disrespectful to veterans and active U.S. soldiers.

While Bestor is well within his rights to rescind his offer to Al Jazeera English, I think it was incredibly foolish to do so. Especially while hiding behind the asinine idea that it would be disrespectful to veterans and current U.S. soldiers. Government officials, which Bestor is, should hold themselves to a higher standard and should lead by example, not by pressure.

Why Telling Stories is Important for Engineers

Over the last few years, I’ve made a concerted effort, both on my blog and in meatspace, to become a better story teller. I’m still not a great story teller, but I do think I’m improving.

Robert Krulwich is the co-host of Radiolab on WNYC, which is “what you’d get if you put Freakonomics, Malcolm Gladwell, and This American Life in a blender.”1 This past spring, Krulwich gave the commencement speech at CalTech. He called it “Tell Me a Story” and he makes a case for the importance of telling stories.

From www.radiolab.org:

[In] the next hour or two, there you’ll be in your cap and gown surrounded by your family and by friends, and by friends of friends, and somebody, you know, maybe an uncle or a buddy, somebody, is gonna turn to you and say, “So, like, what were you doing at Caltech? I mean what were you working on?” Not that they really wanna know, you know. But after all you’ve been here for four years, so you know, or a different number if you’re a grad student, you must have been doing something here. So it’s only polite to ask.

And I know that a lot of you have scientifically illiterate dads and moms, some brothers and some sisters, not all of them, of course, but some. And let’s assume that one of these people…he’s not a scientist, he’s not an engineer, and the last time he had…a complex thought about biology or math was back in eleventh grade, when he got a C- in both subjects and vowed ever never to think about biology or math ever again. But because this is your day, and because this person loves you, or because he can’t really think of anything to say after ‘Hey!’, he asks you about your work.

And to make it still more interesting, let’s assume that if you explain to this person, what you’ve been working on, you might have to use certain words like protein or quark, or differential or maybe hypotenuse, and if you do, they’re gonna listen to you very, very politely, but upstairs those words are gonna mean not a whole lot to them, you know. Cause science is not their thing. They can lip-sync every words to ‘N Sync’s “Bye, Bye, Bye,” but you know hypotenuse is hard.

So here’s my question. When you are asked, ‘What are you working on?’, should you think, ‘There’s no way I can talk about my science with this guy, cause I don’t have the talent, I don’t have the words, I don’t have the patience to do it. It’s too hard. And anyway what’s the point?’, which is, by the way, not an unusual position. No less than Isaac Newton, and I mean Sir Isaac Newton, that one, when asked, ‘Why did you make your Principia Mathematica, your earthshaking book about gravity and laws of motion so impossibly hard to read?’, he said, ‘Well, I considered writing a popular version that people might understand, but’, and I am quoting Newton here, ‘To avoid being baited by little smatterers in mathematics,’ that was his phrase “little smatterers,” he intentionally wrote a book in dense scholarly Latin with lots of maths so that only scholars could follow. In other words, Isaac Newton didn’t care to be understood by average folks. But here is the argument I wanna make to you guys this morning. And you’re not gonna hear this advice often, I suggest you may never hear it again. When asked about your work, do not do what Isaac Newton did. No, no, no.

When a cousin or an uncle or a buddy comes up and asks you, “So what are you working on?”, even if it’s hard to explain, even if you know they don’t really wanna hear it, not really, I urge you to give it a try. Because talking about science, telling stories to regular folks is not a trivial thing. Scientists need to tell stories to non-scientists, because science stories, you know this, have to compete with other stories about how the universe works and how the universe came to be. And some of those other stories, bible stories, movie stories, myths can be very beautiful and very compelling. But to protect science and scientists, this is not a gentle competition. So you’ve got to get in there and tell yours, your version of how things are and why things came to be.

…

You know, you know that when you receive your degree today, you are part of and you’re celebrating something very rare, and very precious, and very fragile in our world. This place celebrates freedom and because you are now free men and women, you have to protect what you’ve been given by helping others who haven’t been here, who are never coming here to understand the value of what you do and what your teachers do, and what their predecessors have done, which is why an hour or so from now when your brother, or your aunt or your mom asks you ‘So what have you been up to while you’ve been here?’, take a chance, find the words, find the metaphor, share the beauty, and tell them what’s on your mind. Tell them a story.

Every engineer, scientists, mathematician, or anyone else with a Bachelors (or Masters, or Doctorate) of Science degree should listen to his speech, which I’ve included below. However, I’d also encourage you listen to it even if you’re not in the above category.

  1. http://www.37signals.com/svn/posts/553-if-the-freakonomics-guys-and-malcolm-gladwell-hosted-this-american-life ↩

Laser Kitten

On Friday night, while working on the rover, Ryan was killing some time and watching videos on Today’s BIG Thing. I got a kick out of this one:
From www.todaysbigthing.com:

There are so many cat videos on the Internet today, that a cat needs to something really ridiculous to get noticed. This kitten goes absolutely bonkers over a laser pointer. He wants nothing to more than to destroy the tiny red dot.

Also worth noticing is the enormous oaf of a cat in the beginning. He sees the laser, then wanders off to find a lasagna.