Archive for the ‘entertainment’ Category
Class Clown
June 23rd, 2008
I’m a little late to the wake. Gruber and DDay’s salutes to George Carlin have included the seven words you can’t say on television—but, fortunately, can put on vinyl and type on the internets. I think their posts were both tributes and an expression of their feelings at his death.
The one Carlin line that will always stay with me is quoted in the NY Times obituary. It’s a joke that’s so simple and clear you think it must have just grown out of our cultural consciousness, like a folk song. In the voice of Al Sleet, the hippy-dippy weatherman, “Tonight’s forecast: dark.”
Hey! Bo Diddley
June 3rd, 2008
In January of last year, BBC Radio 2 broadcast a 3-part documentary (yes, they have radio documentaries in the UK) on Bo Diddley. It was narrated by Roger Daltrey and was very entertaining. I recorded it from the BBC’s internet stream using Audio Hijack Pro and still have the shows in my iTunes Library. Since the BBC would probably frown on me making them public, I’ve been nosing around their website, looking for a link that I could post.
So far, I’ve had no luck. I did learn that Radio 6 (6 Music) rebroadcast the shows in March of this year; unfortunately, the links on this page don’t work. Maybe Bo’s death yesterday will prompt another rebroadcast.
In the meantime, here’s a great performance from 1966’s The Big T.N.T. Show, a kind of followup to the better-known The T.A.M.I. Show. I Twittered a link to it yesterday—it’s my favorite Bo video on YouTube. Check out the moves by Bo and the girls and the great white guitar cords bouncing behind them.
Energy conservation prediction
June 2nd, 2008
Later this summer, newspaper editors across the country will dust off those “women will love Sex and the City, but their boyfriends/husbands will refuse to go” feature articles we’ve been seeing lately. They’ll strike out the discussion of shoes, change all the title references to Mamma Mia, and head out for a drink to congratulate themselves on a job well done.
Yes, this should have been a Tweet, but I couldn’t squeeze it down to 140 characters.
On my iPod
February 25th, 2008
I’ve just started listening to two podcasts from NPR: Krulwich on Science and Playback. They’re somewhat buried in the iTunes Store podcast directory, and I suspect they don’t have much of an audience. No doubt my mentioning them here—on a blog visited by literally tens of people a day—will launch them into the stratosphere.
Krulwich on Science is the weaker of the two; I’m still not really sure I like it. The problem is the host, Robert Krulwich, an enormously talented broadcaster who’s been kicking around public radio and ABC News for a couple of decades. He’s known for taking complex topics and simplifying them for a mass audience. And therein lies my problem with Mr. Krulwich: his simplifications often go too far, cutting out the meat of a topic and leaving only his sugar coating. There’s a tendency for cuteness that is perhaps best exemplified by the podcast’s title. Although I’ve referred to it here as Krulwich on Science, the full name is Hmmm…. Krulwich on Science. Ick. (And what’s up with the extra dot in the ellipsis?)
The shows are usually under 10 minutes, and my early review, based on 4-5 episodes currently available through iTunes, is a qualified thumbs up. Two of the episodes I listened to featured Oliver Sacks, whose presence would make any show interesting, so my opinion of the show may be inflated. I’ll stay subscribed for now, but as soon as I feel I’m being talked down to, I’m out.
Playback is a monthly podcast with an episode length of about half an hour. It’s subject matter is almost unfairly interesting to someone my age: it’s a summary, with audio clips, of the stories NPR was covering 25 years ago that month. So it’s a trip back to the early 80s, when I was in graduate school—young, vital, and with a full head of hair. And aside from this natural advantage, the show is appealing because the clips are well chosen. Yes, there’s a bit of self-congratulation (NPR had a story about global warming in 1982!), but overall the stories are well balanced.
And the balance does not always reflect well on NPR. One of the episodes I listened to covered July of 1982. Susan Stamberg and another reporter (can’t recall his name) were interviewing a record store manager and learning about these weird new musical styles called New Wave and ska. And these bands with wacky names like The Clash, The Go-Go’s, Talking Heads, and Bananarama. “How do you keep up with all this stuff?” asked Stamberg, as if she were some Victorian-era dowager. Amazingly, she was only in her mid-40s at the time—younger than I am now. I think this was the tail end of the era in which mainstream media figures often showed complete ignorance of popular youth culture without embarrassment and with no little condescension.
(Let me put this in perspective for you youngsters out there. By 1982, New Wave had peaked and ska was about 20 years old [admittedly, ska had never been big in the States, but still: 20 years old]. The Clash were known as “the only band that really matters,” and the London Calling and Sandinista albums had been out for a couple of years; the Go-Go’s were all over the radio and the year-old MTV; Talking Heads had put out four of their five best albums [Speaking in Tongues was 1983]; and Bananarama—OK, Bananarama hadn’t really done anything in the US by 1982. But anyway, what Stamberg did was like a reporter today asking what hip-hop is.)
So yes, Playback is fun to listen to and fun to think about after listening to it. Maybe not so fun if you’re too young to remember the 80s; you can wait until Playback gets to the 00s.
Python appscript and random ten
February 24th, 2008
Last summer, I wrote a post about the Python appscript module. I liked it, but got away from using it because Apple didn’t include it with Leopard, going with the Scripting Bridge framework instead. I’ve done some reading on the Scripting Bridge, but it just hasn’t clicked with me; appscript seems so much easier to use.
As I learned with my shortened URL scripts, AppleScript itself is sometimes the best language to use when plucking information out of a Macintosh application. But AppleScript’s text handling pales in comparison with Python and Ruby’s, so when most of the script involves manipulation of text, appscript seems like the best way to go.
To get myself back in appscript shape, I rewrote my random ten script. The AppleScript version looks like this:
1: tell application "iTunes"
2: set p to playlist "****"
3: set songlist to (get name of every track of p)
4: set artistList to (get artist of every track of p)
5: set albumList to (get album of every track of p)
6: set textlist to ""
7: repeat with i from 1 to 10
8: set textlist to textlist & i & ". \"" & ¬
9: item i of songlist & ¬
10: "\" by " & item i of artistList & "
11: from *" & item i of albumList & "*
12: "
13: end repeat
14: set the clipboard to textlist
15: end tell
The repeat loop from line 7 through 13 is not the most clumsy example of text handling in AppleScript, but there are better ways to grab a bunch of strings and put them together. Here it is in Python:
1: #!/usr/bin/env python
2:
3: import appscript
4: import os
5:
6: # Get the first 10 tracks from the **** playlist.
7: tracks = appscript.app('iTunes').playlists['****'].tracks.get()[0:10]
8:
9: # Get the name, artist, and album from the tracks and format them for
10: Markdown.
11: info = [ (n, x.name.get(), x.artist.get(), x.album.get())
12: for n,x in zip(range(1,11), tracks) ]
13: infoString = '\n'.join([ '%d. "%s" by %s \nfrom *%s*' % x for x in info ])
14:
15: # Put the information onto the clipboard, ready for pasting.
16: os.popen('pbcopy', 'w').write(infoString)
Overall, I like this one better. may have gotten carried away with stacking methods on top of one another, but it’s so easy to write and doesn’t really seem hard to understand. On the other hand, os.popen('pbcopy', 'w').write(infoString) does seem a bit more opaque than set the clipboard to textlist.
And the output:
- “Bulldog” by The Fireballs
from Rock Instrumental Classics Vol. 2: The Sixties - “Heart Association” by The Emotions
from Stax-Volt Soul Singles Vol. 2 - “Further On Up The Road” by Eric Clapton
from The Blues [Disc 2] - “Jump Up” by Elvis Costello
from My Aim Is True - “Almost Grown” by Chuck Berry
from The Great Twenty-Eight - “Because They’re Young” by Duane Eddy & The Rebels
from Rock Instrumental Classics Vol. 2: The Sixties - “The Long Black Veil” by Johnny Cash
from The Essential Johnny Cash 1955-1983 - “Hey Joe” by Wilson Pickett
from A Man And A Half: The Best of Wilson Pickett - “She Don’t Love Nobody” by Nick Lowe
from Basher -The Best of Nick Lowe - “Tupelo (Part 1)” by Pop Staples, Albert King, Steve Cropper
from Stax-Volt Soul Singles Vol. 2
Moptops
February 7th, 2008
The British invasion started 44 years ago today.
Airplane on a conveyor
January 31st, 2008
I wasn’t able to watch the end of last night’s Mythbusters, but I take it that they got the airplane to take off from an opposite-moving conveyor belt. Not surprising. Also not surprising is that people are still arguing about it. Part of the arguing seems to be based on different interpretations of the problem. Let’s walk through the problem step by step and look at the consequences of the different interpretations.
I’ll start by saying that I have a Ph.D. in engineering and that I used to teach mechanical engineering at a major US university. Further, I taught statics and dynamics courses, the very courses that deal with the issues at hand. This will, of course, mean nothing to the great self-appointed experts of the internet, but I think it’s worth a mention. Onward.
There are three things about the problem setup that everyone seems to agree on. First, there is a speed, call it v0, that the airplane needs to achieve to take off from a normal, stationary runway. Second, the top surface of the conveyor is set to move at this same constant speed, v0. Third, the airplane is placed on the conveyor with its nose pointing in the direction opposite the motion of the conveyor. (I.e., if the top surface of the conveyor is traveling south, the plane is pointed north.)
At this point there’s a fork in the way people interpret the problem. You can assume:
- The engine speed of the plane on the conveyor is set to the same speed as it would be when taking of from a normal runway, which means that the propellor is producing the same thrust. This will lead to an airplane body speed (or wing speed) of v0 relative to the ground and the surrounding air. Since it is the wing speed relative to the air that produces lift, the plane will take off. This is what the Mythbusters assumed and is how they set up their tests.
Or you can assume:
- The body speed of the plane relative to the conveyor is set to the normal takeoff speed, v0. This will lead to a wing speed of zero relative to the ground. There will be no lift and the airplane will not take off. It turns out, though, that the engine speed needed to achieve this body or wing speed is much, much less than the engine speed needed for a normal takeoff.
I suspect that a lot of people think you can have it both ways: an engine speed equal to that of normal takeoff and a body speed of v0 relative to the conveyor. That, in fact, is the trick of the problem. But you can’t have it both ways.
Here’s a side view of an old biplane that I lifted from this site. I’ve added the arrows that represent the forces that act on the plane as it’s trying to take off. This sort of drawing is called a free body diagram and is one of the fundamental tools for solving mechanics problems.
If we assume the first scenario, with the engine speed equal to that of a normal takeoff, the thrust will be much higher than the sum of the drag and friction forces, and the plane will accelerate to the left. (The friction force won’t increase much as the speed increases and won’t be significantly different from the friction in a normal takeoff.) Eventually, the plane will reach a speed relative to the ground and air where the lift forces at the wings will be greater than the weight. At this point, the contact force will drop to zero and the plane will take off.
If we assume the second scenario, with the body speed of the plane relative to the ground and the air of zero, the drag force will be zero (because the wings won’t be moving relative to the air). Since the plane is stationary relative to the ground, its horizontal acceleration is zero and its horizontal forces must be balanced. Therefore, the engine will only have to provide enough thrust to balance the relatively small friction at the wheels. This is much less thrust than is required for the first scenario, so the engine speed will also have to be much less than in the first scenario.
The upshot is you can’t have a stationary plane with its engine running like it would for a normal takeoff. You have to pick one or the other.
[Those of you familiar with free body diagrams may take issue with where I’ve placed some of the forces. Me too. I know the moments aren’t in balance, but I wanted to keep force arrows separated enough to be easy to distinguish. If moment equilibrium were important to the problem I’d be more careful where I drew the arrows.]
If you’re wondering why the thrust is forward rather than backward, the explanation is that while the propellor is pushing back on the air, the air is pushing forward on the propellor. Newton’s third law. It’s the same reason you’re able to walk forward: your feet push back on the ground and the ground pushes forward on your feet.
Ugliest campuses
December 12th, 2007
You’ve probably seen this article about the country’s 20 ugliest campuses. Number 9 is the Illinois Institute of Technology, which is in a less-than-picturesque location and whose buildings were not aging well the last time I was there. Still, ninth ugliest in the country? It’s not even the ugliest in Chicago. UIC—a forest of textured concrete that resembles the circular expressway interchange it used to be named after—holds that title.
But then I saw this line in the description of IIT:
They need to get better architects at these schools.
As David St. Hubbins said, there’s a fine line between stupid and clever. With so much idiocy on the internet, I’m finding it difficult to tell when someone is being clever by feigning stupidity. The old “he must be kidding, no one could be that dumb” rule has failed me so many times, but I’m going to invoke it here anyway. The IIT entry was the only one to make a specific remark about the school’s architect, so the writer must have known who he was insulting.
Taken that way, it’s a pretty funny line, even though it’s been done better.
Hocus Pocus
December 5th, 2007
I heard this song on Steve Harley’s Sounds of the 70s show on BBC Radio 2. A listener in Australia dedicated it to his wife, further evidence of how clueless men can be. The song stuck in my head, and I had to go to YouTube to see if there were any videos of it. There were several. This is my favorite because of the intro by Gladys Knight and the Japanese (I think) subtitles. Jan Akkerman looked a lot like Pete Townsend back then. Best not to talk about Thijs van Leer’s look.
Fibonacci numbers on In Our Time
November 30th, 2007
The most recent episode of BBC Radio 4’s In Our Time was about Fibonacci numbers. The host, Melvyn Bragg, usually doesn’t do well with the math and science shows, and this show was not a particularly good one, especially compared with last weeks wonderful show on Wordsworth. (There’s too much of a Two Cultures gap and Bragg tends to spend too much time talking about how hard the topic is—something he never does with any topic in the humanities. Still, I give him credit for including subjects he’s not comfortable with.) There were, however, a couple of things I learned.
First, I learned that Fibonacci numbers have cousins called the Lucas numbers, which have the same recurrence relation—each number in the sequence is the sum of the two previous numbers—but start with a different pair of seeds. As with the Fibonacci numbers, the ratio of successive Lucas numbers converges to the golden ratio.
Second, I learned that one of the simpler cool properties of Fibonacci numbers is that the square of a Fibonacci is always one less or one more that the product of the two Fibonaccis on either side of it. As you go through the sequence, the square alternates between being one less and one more than the product. I had to check this out, so I whipped up a quick Python program.
1: n = 25
2: f = [0, 1];
3: for i in range(2, n):
4: f.append(f[i-2] + f[i-1])
5:
6: for i in range(1, n-1):
7: sign = (-1)**(i+1);
8: symbol = '+' if sign>0 else '-'
9: print "%d*%d %s 1 == %d^2 :" % (f[i-1], f[i+1], symbol, f[i]),
10: print (f[i-1]*f[i+1] + sign == f[i]**2)
Lines 1-4 create a list with the first 25 Fibonaccis: 0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377, 610, 987, 1597, 2584, 4181, 6765, 10946, 17711, 28657, and 46368. Lines 6-10 test the square/product property and print out the results. Here’s the output:
0*1 + 1 == 1^2 : True
1*2 - 1 == 1^2 : True
1*3 + 1 == 2^2 : True
2*5 - 1 == 3^2 : True
3*8 + 1 == 5^2 : True
5*13 - 1 == 8^2 : True
8*21 + 1 == 13^2 : True
13*34 - 1 == 21^2 : True
21*55 + 1 == 34^2 : True
34*89 - 1 == 55^2 : True
55*144 + 1 == 89^2 : True
89*233 - 1 == 144^2 : True
144*377 + 1 == 233^2 : True
233*610 - 1 == 377^2 : True
377*987 + 1 == 610^2 : True
610*1597 - 1 == 987^2 : True
987*2584 + 1 == 1597^2 : True
1597*4181 - 1 == 2584^2 : True
2584*6765 + 1 == 4181^2 : True
4181*10946 - 1 == 6765^2 : True
6765*17711 + 1 == 10946^2 : True
10946*28657 - 1 == 17711^2 : True
17711*46368 + 1 == 28657^2 : True
Line 7 alternates the addition and subtraction of one. Line 8 uses Python’s new conditional expression to set the plus or minus symbols in the printed equations. That line won’t work in Pythons before version 2.5; you’ll have to use a traditional if/else block.
Python can deal with very large integers—integers beyond 32 bits—with no fuss. Changing Line 1 to n = 100, for example, yields a list of tests where the last few are
31940434634990099905*83621143489848422977 - 1 == 51680708854858323072^2 : True
51680708854858323072*135301852344706746049 + 1 == 83621143489848422977^2 : True
83621143489848422977*218922995834555169026 - 1 == 135301852344706746049^2 : True
These 20-21 digit numbers are well beyond the limits of what will fit in 32 bits.
I think my older boy has done some simple things with Fibonacci numbers. Tonight I’ll see if he knows about this square/product thing.