Beam Reach spring 2011 begins!
Wow, just a few minutes into the first discussion on Monday morning, Kelsey saw killer whales out the window at Lime Kiln State Park. This was a very, very unlikely observation. With such a good omen, I know that we will see and learn much from orcas this spring.
On Tuesday, I ‘lectured’ on an introduction to acoustics — waves, amplitudes, frequencies, decibels and all that jazz. Take a look at the white board —
Looks colorful at least, wouldn't you agree?
After nearly finishing this fun little discussion and demo, I noticed that I had a HUGE ERROR. I had defined decibels directly in terms of signal power but that is WRONG. Decibels are defined in terms of energy or power, and energy and power are proportional to the square of the pressure (true for all linear waves). Take a look at my ugly fix —
Here,in the center, I got the correct definition. Check it out.
It looks a bit like a blue outlined blobby orca, don’t you think? In any case it is right!
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