5 ms·

A Wave-Tracking Experiment

103 points by srikar 12y ago

zafka 12y ago
Who is doing the work tracking waves today? This reminds me of the butterfly flapping his wings of fractal fame. In this case though, they are tracking the whole path.
- niels_olson 12y ago
  NOAA and a lot of secondaries using their data: surfline, magicseaweed, swell3d, etc.
ajuc 12y ago
So, what's the bandwidth and latency?
carbocation 12y ago
This is so broken on mobile that I cannot scroll down to read the article on latest Chrome on iOS.
- montibbalt 12y ago
  Works fine in mobile IE
omegant 12y ago
Flying you can see when strong winds blow from land. The sea is flat at the beach. But just 3 or 5 miles inland waves can be 1 meter high or more. It's amazing how fast they go from milimeters to meters. It's also possible to see how the wind blows differently, when guided by hills and valleys. Just like pointing a huge hair dryer to a bathtub. Edit: typos
- rcthompson 12y ago
  I'm having trouble visualizing what you're talking about here. What do you mean by inland waves?
  - satori99 12y ago
    I think he mean't offshore waves
rcthompson 12y ago
Anyone familiar with standard wave mechanics will expect that crossing waves will pass right through each other. The part that confuses me is why the waves don't spread out laterally. For instance, take the waves in the article that went from the Indian ocean to the Mexican coast. Wouldn't they fan out across the entirety of the Pacific ocean after passing between Australia and Antarctica? Or maybe they do, but they're so big to begin with that even after they do so, they're still big enough to crash on the entire west coast of the Americas? Would the same storm have caused gigantic waves to crash on the much closer southern Australian shore?
- dj-wonk 12y ago
  It may not answer your question directly, but the following is a nice write-up: http://www.acs.psu.edu/drussell/Demos/waves/wavemotion.html http://www.acs.psu.edu/drussell/Demos/waves/wavemotion.html "Water waves are an example of waves that involve a combination of both longitudinal and transverse motions. As a wave travels through the waver, the particles travel in clockwise circles. The radius of the circles decreases as the depth into the water increases." The animation is mesmerizing.
  - ovis 12y ago
    Here's another visualization, which let's you play with the wave parameters. http://web.mit.edu/~njwilson/www/waves.html http://web.mit.edu/~njwilson/www/waves.html
  - t0ss3r 12y ago
    Good visualization of what any aware surfer/bodyboarder/bodysurfer/etc. has likely noticed.
  - rcthompson 12y ago
    That's a cool animation, and I've seen it before, but I'm talking about the waves spreading out in the 3rd dimension, horizontally along the length of the wave (i.e. perpendicular to the screen in that animation).
scotchmi_st 12y ago
> "The astonishing thing is, you'd think it would bump into a million other waves that are coming at it from every direction; that it would pass through other storms, spreading, bumping, traveling, that all this travel would sap its momentum. But, as Walter Munk would discover, that's not what happens." Kinda weird that the article spends so long explaining high-school physics, and in such astonished terms. Zomg! Waves pass through each other! The Superposition principle! If they think that's cool, they should see some of the stuff you can do with light and sound.
- javert 12y ago
  Many Americans don't take physics in high school. I didn't and I'm a computer science phd student (so it's not that I wasn't intelligent enough to take it). I was surprised to learn that waves coming from different directions just pass through each other. I did take physics in college, from a guy who could barely speak English.
  - scoot 12y ago
    If this is true (and I have no evidence one way or the other), then surely this is the bigger surprise (coming from an environment where science is mandatory to middle-school equivalent, and at least one science subject almost un avoidable before university level.
    - learc83 12y ago
      >coming from an environment where science is mandatory to middle-school equivalent, and at least one science subject almost un avoidable before university level. School districts are ran locally and the curriculum is usually set at the state level, so there are differences, but 3 years of science is mandatory in middle school in every state I've ever heard of. In addition, almost all American high schools require 3 or 4 years of science for university bound students (maybe a bit less for non college bound students but usually not less than 3 years). At my high school, in a not very big town in Georgia, everyone took physical science, chemistry, and biology. However, you had choices for senior year--physics, AP physics, AP chemistry, ecology or anatomy (you could take more than one if you wanted).

103 points by srikar 12y ago

zafka 12y ago

Who is doing the work tracking waves today? This reminds me of the butterfly flapping his wings of fractal fame. In this case though, they are tracking the whole path.

niels_olson 12y ago
NOAA and a lot of secondaries using their data: surfline, magicseaweed, swell3d, etc.

ajuc 12y ago

So, what's the bandwidth and latency?

carbocation 12y ago

This is so broken on mobile that I cannot scroll down to read the article on latest Chrome on iOS.

montibbalt 12y ago
Works fine in mobile IE

omegant 12y ago

Flying you can see when strong winds blow from land. The sea is flat at the beach. But just 3 or 5 miles inland waves can be 1 meter high or more. It's amazing how fast they go from milimeters to meters. It's also possible to see how the wind blows differently, when guided by hills and valleys. Just like pointing a huge hair dryer to a bathtub. Edit: typos

rcthompson 12y ago
I'm having trouble visualizing what you're talking about here. What do you mean by inland waves?
- satori99 12y ago
  I think he mean't offshore waves

rcthompson 12y ago

Anyone familiar with standard wave mechanics will expect that crossing waves will pass right through each other. The part that confuses me is why the waves don't spread out laterally. For instance, take the waves in the article that went from the Indian ocean to the Mexican coast. Wouldn't they fan out across the entirety of the Pacific ocean after passing between Australia and Antarctica? Or maybe they do, but they're so big to begin with that even after they do so, they're still big enough to crash on the entire west coast of the Americas? Would the same storm have caused gigantic waves to crash on the much closer southern Australian shore?

dj-wonk 12y ago
It may not answer your question directly, but the following is a nice write-up: http://www.acs.psu.edu/drussell/Demos/waves/wavemotion.html http://www.acs.psu.edu/drussell/Demos/waves/wavemotion.html "Water waves are an example of waves that involve a combination of both longitudinal and transverse motions. As a wave travels through the waver, the particles travel in clockwise circles. The radius of the circles decreases as the depth into the water increases." The animation is mesmerizing.
- ovis 12y ago
  Here's another visualization, which let's you play with the wave parameters. http://web.mit.edu/~njwilson/www/waves.html http://web.mit.edu/~njwilson/www/waves.html
- t0ss3r 12y ago
  Good visualization of what any aware surfer/bodyboarder/bodysurfer/etc. has likely noticed.
- rcthompson 12y ago
  That's a cool animation, and I've seen it before, but I'm talking about the waves spreading out in the 3rd dimension, horizontally along the length of the wave (i.e. perpendicular to the screen in that animation).

scotchmi_st 12y ago

> "The astonishing thing is, you'd think it would bump into a million other waves that are coming at it from every direction; that it would pass through other storms, spreading, bumping, traveling, that all this travel would sap its momentum. But, as Walter Munk would discover, that's not what happens." Kinda weird that the article spends so long explaining high-school physics, and in such astonished terms. Zomg! Waves pass through each other! The Superposition principle! If they think that's cool, they should see some of the stuff you can do with light and sound.

javert 12y ago
Many Americans don't take physics in high school. I didn't and I'm a computer science phd student (so it's not that I wasn't intelligent enough to take it). I was surprised to learn that waves coming from different directions just pass through each other. I did take physics in college, from a guy who could barely speak English.
- scoot 12y ago
  If this is true (and I have no evidence one way or the other), then surely this is the bigger surprise (coming from an environment where science is mandatory to middle-school equivalent, and at least one science subject almost un avoidable before university level.
  - learc83 12y ago
    >coming from an environment where science is mandatory to middle-school equivalent, and at least one science subject almost un avoidable before university level. School districts are ran locally and the curriculum is usually set at the state level, so there are differences, but 3 years of science is mandatory in middle school in every state I've ever heard of. In addition, almost all American high schools require 3 or 4 years of science for university bound students (maybe a bit less for non college bound students but usually not less than 3 years). At my high school, in a not very big town in Georgia, everyone took physical science, chemistry, and biology. However, you had choices for senior year--physics, AP physics, AP chemistry, ecology or anatomy (you could take more than one if you wanted).