Sources:
Encyclopedia Britannica--School edition
NASA: Mission Science
NASA: Goddard Space Flight Center
NASA: EMS For Kids
Encyclopedia Britannica--School edition
NASA: Mission Science
NASA: Goddard Space Flight Center
NASA: EMS For Kids
BECAUSE OF SLOW LOAD TIMES AT THIS SITE, FUTURE CONTENT WILL BE ON WORDPRESS:
http://akibascienceref.wordpress.com/
http://akibascienceref.wordpress.com/
light experiments and colors
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electromagnetic spectrum
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the sun
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science fair--pictures and video
standing waves, review
Recall that standing waves are the combined effect of multiple waves running into each other to produce a single wave form, with nodes (zero points) and anti-nodes (high-low points). When the waves combine (through constructive and destructive interference) in the right way, they sometimes produce regular patterns, which we call a standing wave. To reiterate, a bunch of moving waves combine to make the shape of a wave that doesn't move: this is a "standing wave." It's just a pattern, or form, or effect of multiple waves combining, not an actual wave (actual waves move through the medium). In class, we made standing waves with plastic tubing by shaking it. Each shake of our hand made a wave in the tube, and when we got the frequency and amplitude just right, the waves combined just right, and we produced standing wave patterns.
the fabulous mantis shrimp
Radiolab:
How the Mantis Shrimp sees the rainbow. Start at 9:35 or at 14:40: |
On Mantis Shrimp eyeballs:
Like insects and other crustaceans, mantis shrimps possess compound eyes composed of thousands of rows of light-detecting units called ommatidia. These are especially refined in mantis shrimps, containing a mix of photoreceptors and filters that let them see 100,000 different colors -- 10 times more than can be detected by humans. On Mantis Shrimp punches:
Patek managed to capture footage of a smasher’s strike, slowed down over 800 times. What she found was staggering. With each punch, the club’s edge travels at about 50 mph, over twice as fast as scientists had previously estimated. “The strike is one of the fastest limb movements in the animal kingdom”, says Patek. “It’s especially impressive considering the substantial drag imposed by water.” ...mantis shrimps use an ingeniously simple energy storage system. Once the arm is cocked, a ratchet locks it firmly in place. The large muscles in the upper arm then contract and build up energy. When the latch is released, all this energy is released at once and the lower arm is launched forwards. But Patek found that even this system couldn’t account for the mantis shrimp’s speed. Instead, the key to the punch is a small, structure in the arm that looks like a saddle or a Pringle chip. When the arm is cocked, this structure is compressed and acts like a spring, storing up even more energy. When the latch is released, the spring expands and provides extra push for the club, helping to accelerate it at up to 10,000 times the force of gravity. ...each of the smasher’s strikes produced small flashes of light upon impact. They are emitted because the club moves so quickly that it lowers the pressure of the water in front of it, causing it to boil. This releases small bubbles which collapse when the water pressure normalises, unleashing tremendous amounts of energy. This process, called cavitation, is so destructive that it can pit the stainless steel of boat propellers. Combined with the force of the strike itself, no animal in the seas stands a chance. |
human echolocation:
Summary clip:
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Full documentary:
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If a tree falls in a forest...
From the science of sound to philosophy. A class discussion.
From the science of sound to philosophy. A class discussion.
Doppler effect: some explanations
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Explaining sonic booms before class:
Example of a sonic boom.
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Another sonic boom. The sound waves produced by the plane accumulate on top of each other, producing a large, cumulative compression wave (instead of the little tiny compression waves you would hear if the plan were going slower).
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Listen to the siren in the first seconds of this video. Note the pitch change due to Doppler effect.
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vocal cords: a demo
Vocal cords seem strange up close if you haven't seen them before, but remember that this one of the most mundane things in our lives: talking.
See following up through 2:00:
the ear: a class demonstration
class videos
For the following, watch from 13:00 and from 31:00-33:30.
For the following, change the resolution to 1080 (use the gear icon at bottom right) in order to hear all the tones properly. Also use earphones or high-quality speakers.
Science in action: What were the first humans like?
Early human evolution: 1.8 million years ago, were there many species or just one?
Science words: homo erectus; archeology; human evolution
Science words: homo erectus; archeology; human evolution
Standing wave patterns from sound
Standing waves form any time multiple wave impulses combine into stable patterns. Here, sound waves combine together to form standing waves. You can see the resulting patterns in the sand formations on the vibration plate.
Just as we saw waves combine in water during class, here we can see them combine in the air.
Science words: standing waves, constructive and destructive interference.
Sound: Tuning forks and compression waves (2 min.)
Ship on the sea: fun with wave frequency and amplitude
To have fun with amplitude and frequency, click here:
http://www.classzone.com/books/ml_science_share/vis_sim/wslm05_pg18_graph/wslm05_pg18_graph.html |