PhET Waves on a String
April 15, 2008 8:31 PM Subscribe
Oscillating beads... now with damping, tension, and loose or fixed ends!
There are, actually, one or two things you can do on this that are hard to see with a Slinky.
OTOH, I've never seen a Shockwave file walk down stairs.
posted by eritain at 8:44 PM on April 15, 2008
OTOH, I've never seen a Shockwave file walk down stairs.
posted by eritain at 8:44 PM on April 15, 2008
It vibrates?
posted by TheOnlyCoolTim at 8:50 PM on April 15, 2008
posted by TheOnlyCoolTim at 8:50 PM on April 15, 2008
It's interesting to change the settings and watch the change propagate through the string. Very nice!
posted by SPrintF at 8:50 PM on April 15, 2008
posted by SPrintF at 8:50 PM on April 15, 2008
Burhanistan:
1. WTF IS THAT THING?
2. How is that related to this again?
posted by CitrusFreak12 at 8:50 PM on April 15, 2008
1. WTF IS THAT THING?
2. How is that related to this again?
posted by CitrusFreak12 at 8:50 PM on April 15, 2008
I can't get past the first level.
posted by brain_drain at 8:56 PM on April 15, 2008 [2 favorites]
posted by brain_drain at 8:56 PM on April 15, 2008 [2 favorites]
Burhanistan's link seems to be a mantis shrimp fighting a blue-ringed octopus.
Both are clearly enemies of humanity and I hope they never join forces.
posted by TheOnlyCoolTim at 9:08 PM on April 15, 2008
Both are clearly enemies of humanity and I hope they never join forces.
posted by TheOnlyCoolTim at 9:08 PM on April 15, 2008
I very much liked the string of beads that wiggled. I was able to put one end out the window, where it got to taste precious freedom.
I did not care for Burhanistan's link where the horrible monster in the tube ate the spotted blue octopus.
posted by Lord_Pall at 9:40 PM on April 15, 2008 [5 favorites]
I did not care for Burhanistan's link where the horrible monster in the tube ate the spotted blue octopus.
posted by Lord_Pall at 9:40 PM on April 15, 2008 [5 favorites]
There is this flash exploit which appeared today on reddit. I have no reason to think any of the flash here is infected, but personally I will wait until a security update to flash is released, before I click on any of those. Then again, perhaps some pages have some small flash component hidden among the other things.
posted by nervousfritz at 9:56 PM on April 15, 2008
posted by nervousfritz at 9:56 PM on April 15, 2008
Well, if I were going to infect a flash file, I think I'd skulk around someplace like youtube, and not an edu science lab experiment, but then, you're the nervous one, so thanks for the warning.
posted by Dave Faris at 10:11 PM on April 15, 2008
posted by Dave Faris at 10:11 PM on April 15, 2008
The other thing is that the actual bad guys tend to just send out e-mails pretending to be a subpoena and telling you to download and run this executable rather than figuring out ridiculously complicated vulnerabilities.
posted by TheOnlyCoolTim at 10:25 PM on April 15, 2008
posted by TheOnlyCoolTim at 10:25 PM on April 15, 2008
Lord_Pall, mantis shrimp are not horrible monsters, they are incredible creatures with more mind-bogglingly badass adaptations condensed into one organism (hyperspectral/trinocular vision; attacking strikes that can break double-layer glass and create cavitation bubbles; wheel like locomotion). Plus they're the only monogamous invertebrate.
The one in the video is probably an Odontodactylus scyllarus, similar to the one which an acquaintance of mine kept as a pet (named Stagger Lee) for a while before his tragic early death when fumes from a flea bombing in another apartment leaked into her fishroom. There's also one at the Toledo Zoo. Someday when I have the funds to get into saltwater tanks, I'm going to get into one of my own.
That said, as a great admirer of both mantis shrimp and blue-ring octopi, I am really quite annoyed by that video, because while it would normally be great to see such lovely shots of a fairly reclusive animal in motion, the only reason I could think of to put these two animals - both aggressive hunters - together would be for some kind of idiotic, chest-thumping cage-match. Yes, how lovely, you're going to make one dangerous animal kill another one to reveal your masculine* insecurities! Ugh.
...
Right then, I'm going to go play with the pretty beads from the FPP now to make myself feel better. My apologies, folks, I have this thing about aquatic animal cruelty.
(*Yes, yes, it could be a woman. We all know it's unlikely.)
posted by bettafish at 11:16 PM on April 15, 2008 [1 favorite]
The one in the video is probably an Odontodactylus scyllarus, similar to the one which an acquaintance of mine kept as a pet (named Stagger Lee) for a while before his tragic early death when fumes from a flea bombing in another apartment leaked into her fishroom. There's also one at the Toledo Zoo. Someday when I have the funds to get into saltwater tanks, I'm going to get into one of my own.
That said, as a great admirer of both mantis shrimp and blue-ring octopi, I am really quite annoyed by that video, because while it would normally be great to see such lovely shots of a fairly reclusive animal in motion, the only reason I could think of to put these two animals - both aggressive hunters - together would be for some kind of idiotic, chest-thumping cage-match. Yes, how lovely, you're going to make one dangerous animal kill another one to reveal your masculine* insecurities! Ugh.
...
Right then, I'm going to go play with the pretty beads from the FPP now to make myself feel better. My apologies, folks, I have this thing about aquatic animal cruelty.
(*Yes, yes, it could be a woman. We all know it's unlikely.)
posted by bettafish at 11:16 PM on April 15, 2008 [1 favorite]
Er: "more mind-bogglingly badass adaptations condensed into one organism than almost any other on earth," is what I left out.
posted by bettafish at 11:17 PM on April 15, 2008
posted by bettafish at 11:17 PM on April 15, 2008
Just to continue the Mantis Shrimp derail:
In Cantonese cuisine, the mantis shrimp is a popular dish known as "pissing shrimp" (攋尿蝦, Mandarin pinyin: lài niào xiā, modern Cantonese: laaih niuh hā) due to its tendency to urinate when cooked [citation needed]. Because of this, mantis shrimp are speared to induce them to evacuate their bowels prior to being introduced into the cookpot
Tasty!
Also: Either that Mantis Shrimp is exacting vengeance for a zillion raped anime virgins -- or I'm watching too much Asian cinema.
Also also: I was expecting some kind of oscillating anal beads, so the FPP was something of a disappointment. Hence all the Mantis Shrimping.
posted by PeterMcDermott at 1:28 AM on April 16, 2008
In Cantonese cuisine, the mantis shrimp is a popular dish known as "pissing shrimp" (攋尿蝦, Mandarin pinyin: lài niào xiā, modern Cantonese: laaih niuh hā) due to its tendency to urinate when cooked [citation needed]. Because of this, mantis shrimp are speared to induce them to evacuate their bowels prior to being introduced into the cookpot
Tasty!
Also: Either that Mantis Shrimp is exacting vengeance for a zillion raped anime virgins -- or I'm watching too much Asian cinema.
Also also: I was expecting some kind of oscillating anal beads, so the FPP was something of a disappointment. Hence all the Mantis Shrimping.
posted by PeterMcDermott at 1:28 AM on April 16, 2008
This is great. I like setting up a wave (dampening off) then a second one, and see how they interact. Suddenly analogue radio makes sense! Brilliant, thanks Dave Faris.
posted by alasdair at 4:55 AM on April 16, 2008
posted by alasdair at 4:55 AM on April 16, 2008
My favorite physics applet is on the same site.
posted by MrMoonPie at 5:47 AM on April 16, 2008 [1 favorite]
posted by MrMoonPie at 5:47 AM on April 16, 2008 [1 favorite]
OTOH, I've never seen a Shockwave file walk down stairs.
OTOOH, I've never seen a slinky do it either.
posted by smackfu at 6:08 AM on April 16, 2008
OTOOH, I've never seen a slinky do it either.
posted by smackfu at 6:08 AM on April 16, 2008
Amplitude 10
Frequency 67
damping 0
tension high
oscilate on
fixed end
Result is as close as I could get to a standing wave, but you can see it oscilating in power as the waves constructively and then destructively sum.
posted by garlic at 6:40 AM on April 16, 2008
Frequency 67
damping 0
tension high
oscilate on
fixed end
Result is as close as I could get to a standing wave, but you can see it oscilating in power as the waves constructively and then destructively sum.
posted by garlic at 6:40 AM on April 16, 2008
Lots more. I like the one with the curling rock because - well. Curling!!!
posted by clavicle at 6:54 AM on April 16, 2008
posted by clavicle at 6:54 AM on April 16, 2008
I can't get past the first level.
Have you tried burning the rope?
posted by The Bellman at 8:25 AM on April 16, 2008
Have you tried burning the rope?
posted by The Bellman at 8:25 AM on April 16, 2008
To show the total geek that I am:
I calculated that the frequency setting to be 0.03 Hz per setting (So a setting of 10 is equivalent to 0.3 Hz). The length of the bead chain (l) is 1 meter long, and with the tension on high the wave propagates at a velocity (v) about 0.5 meters per second. Thus standing waves should form at v/l=0.5 Hz. Converting into the settings, 0.5Hz/0.03Hz = 16.67. So standing waves should form at settings around 17, 33, 50, 67, 84, and 100.
So other settings than 67 should result in standing waves (and show the effects of harmonics!).
Off to try my calculations now! Science is so cool :-)
posted by forforf at 1:02 PM on April 16, 2008 [1 favorite]
I calculated that the frequency setting to be 0.03 Hz per setting (So a setting of 10 is equivalent to 0.3 Hz). The length of the bead chain (l) is 1 meter long, and with the tension on high the wave propagates at a velocity (v) about 0.5 meters per second. Thus standing waves should form at v/l=0.5 Hz. Converting into the settings, 0.5Hz/0.03Hz = 16.67. So standing waves should form at settings around 17, 33, 50, 67, 84, and 100.
So other settings than 67 should result in standing waves (and show the effects of harmonics!).
Off to try my calculations now! Science is so cool :-)
posted by forforf at 1:02 PM on April 16, 2008 [1 favorite]
I have to say the setting at 100 was a resounding success ... made me dizzy just watching it.
A frequency setting of 95 was also extra cool, as the wave eventually cancels itself out and then starts again. Now I'm gonna have to try and remember half-forgotten equations to try and derive when to expect wave cancellations like that ... bye bye work productivity!
posted by forforf at 1:11 PM on April 16, 2008
A frequency setting of 95 was also extra cool, as the wave eventually cancels itself out and then starts again. Now I'm gonna have to try and remember half-forgotten equations to try and derive when to expect wave cancellations like that ... bye bye work productivity!
posted by forforf at 1:11 PM on April 16, 2008
You know, you say this:
mantis shrimp are not horrible monsters,
and then you completely and utterly contradict yourself with this:
they are incredible creatures with more mind-bogglingly badass adaptations condensed into one organism (hyperspectral/trinocular vision; attacking strikes that can break double-layer glass and create cavitation bubbles; wheel like locomotion)
posted by Faint of Butt at 1:19 PM on April 16, 2008
mantis shrimp are not horrible monsters,
and then you completely and utterly contradict yourself with this:
they are incredible creatures with more mind-bogglingly badass adaptations condensed into one organism (hyperspectral/trinocular vision; attacking strikes that can break double-layer glass and create cavitation bubbles; wheel like locomotion)
posted by Faint of Butt at 1:19 PM on April 16, 2008
Okay, point granted, Faint of Butt, but "horrible" and "awesome" are not the same thing, right? Then again, you're talking to the girl who played chicken with this barracuda, that one time...
I won.
posted by bettafish at 1:22 PM on April 16, 2008
I won.
posted by bettafish at 1:22 PM on April 16, 2008
Burhanistan, that video is awesome. I actually wrote a song about that conflict two years ago, having only read about it those fights. I meant to make a video for it, but never got around to it. Now, I guess I don't need to!
posted by ignignokt at 8:12 PM on April 16, 2008
posted by ignignokt at 8:12 PM on April 16, 2008
If you set the tension all the way down and the damping to zero with a loose end, you can get colliding waves that go through each other, back and forth endlessly. Then you can add a wave to it and it will just run through the others.
posted by krinklyfig at 8:40 PM on April 16, 2008
posted by krinklyfig at 8:40 PM on April 16, 2008
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posted by Blazecock Pileon at 8:37 PM on April 15, 2008