Aqua boom?

Do you dream? I almost never dream. (And, to head you off at the pass, I know, I know, I know, I hear it every time: since ALL people dream, I actually DO dream, but just don't REMEMBER the dream. I know, I know, just humor me!) For the past decade or so, I am aware of remembering dreams, even aware of remembering having had a dream, perhaps a dozen times. A few nights ago made it a baker's dozen. I had a bizarre adventure dream. I'll spare you the details (mainly because my memory seems also to have spared me of them over the days), but I ended up under water, chasing a wicked fast, super-intelligent squid. Which led me to wonder, and then to blog.

INSCITIA:

Can you break the sound barrier underwater? Has it been done? What speed would you need to do so? And what would happen if you did it?

COGITATIO:

I think it is possible, but would require an incredibly fast speed. My ancient and rusted-out physics acumen reminds me altitude and air density are directly (or is it inversely?!) proportional to the sound barrier. (Something like 967 mph at sea level?) The higher you go, the thinner the air becomes, and the lower the sound barrier becomes. This is, I think, partially why planes make sonic booms at such high altitudes.

Despite my supersonic optimism, a major snag in the possibility of a subaquatic sonic boom, as far as I can see now, is the physical limits water resistance would put on a potentially supersonic subaquatic vessel (PSSV). It may be possible, for engineers to develop and pilots to handle a PSSV on the drawing board and in simulations, but I have a feeling the relatively enormous density of water, coupled with its friction and inertia, would top out any PSSV's velocity below the sound barrier.

A mere James Bond pipe dream?

RESPONSUM:

Fuzzy lasers?

Believe it or not, I'm a bit of a tech nerd. I like gadgets. One of my lingering day dreams is one day to build a droid or android. (Of course, the paradox is that I'm also a bit of a Luddite, insisting, for example, the Internet is one of the greatest spiritual challenges for modern humans and preferring simple, older-fashioned gizmos to overly ornate, multi-purpose thingamajigs. I don't like all this technical jargon, but I use it.) Being a gadget man, if a laser pointer comes my way, I'll take it. And who wouldn't? Who doesn't like shining red dots onto far buildings at night? Or making your little dog chase a bobbing red light on the floor? Or turning off the lights and making your fingertips and nostrils glow red in the darkness? Or imaginging shooting laser Morse code to aliens? These are the highest joys of any bored and precocious man (or, uh, so I hear...).

At any rate, a laser pointer did fall into my clutches a few weeks ago and I have had red fingertips ever since. I've also had more time to observe the little red light beam dangling from my key ring. Which made me wonder, and then blog.

INSCITIA:

What makes laser light look the way it does? I mean, when I focus on it, the light seems to shimmer and vibrate, like I can actually see clumps of photons swirling. Why does it look like red "TV snow"? All around the center of the laser beam, I note a sort of "photo fuzz", like a small patch of red "light fog" -- why?

COGITATIO:

I did a little reading about lasers today (the More How Stuff Works book) and suspect the visual "fuzziness" of laser light has to do with the "coherent" nature of laser light. Laser light is coherent, as far as I understand it, in that its photons have very similar, very close wavelengths. Mirrors within lasers help laser quanta converge, unlike incandescent light, which spreads its photons into many directions. As such, laser light's coherent quanta would appear clumpier to the naked eye. Unlike the wave fluctuations of incandescent photons, which escape our notice, coherent laser quanta tumble together in an apparent way. I think it must have to do with wavelength interference, but I'm not sure how.

It's a very wobbly lay-cogitatio, but hey, that's why I have this blog! Have at ye!

RESPONSUM: