Friday, June 24, 2011

Vacation

See you in July. I'll backpost some stuff about my trip, but I have no internet access till the 4th.

Thursday, June 23, 2011

I am graduated.

That is all.

Graduation.

Less than 2 hours from now, I will be graduating high school.

It absolutely blows my mind. When I started this blog. I was a freshman. I was still a week away from the exams at the end of my freshman year. I wrote like a freshman and I was as socially adept as an onion. (They make everybody cry.)

So, this blog has been an experiment. A long-running and rather successful one. (I wasn't going for fame or popularity, just keeping myself sane and cataloging all the random stuff I find on the internet). And I've had a lot of fun.

I'm not sure what's going to happen now. I'm certainly going to keep blogging, and with the same pseudonym. It may be on this blog, or it may be a new one for college. I'm currently leaning towards keeping The Amateur Geek for the random geeky stuff, and having a few side blogs for occasional fiction writing, political ranting, and photography.

In any case it's been a fun ride. Regular posting (I've got a major backlog) resumes shortly.

Sunday, June 19, 2011

Three Years

Once again, I managed to miss my blogaversary. Go me.

But yeah, on the 10th it marked three years of me blogging. Which is a scary long time.

This (I think) will be post #1145. Which means I've only posted 328 times in the past year, although most of my misses were recently, due to English and other hard classes.

And, of course, I've spent the last year applying to college. And now, I've just been officially oriented as a Boston University Terrier.

Hopefully, I'll be able to blog a lot over the summer. After that, I'll be in college, and once or twice a week will be the average. (More, if I have something to procrastinate about.)

Saturday, June 18, 2011

I'm back

I apologize for the sudden drought of posts. First came exams, then Orientation. Expect regular blogging to assume shortly.

Sunday, June 12, 2011

The Resolution of Life

I've heard various claims for just how accurate the resolution of the human eye is. Wikipedia says a theoretical maximum of 1.2 arcminutes (60 arcmin = 1 degree = 1/360th circle) with practical limit around 1.7 arcmin; true 20/20 vision is the ability to recognize patterns at 1 arcmin line width.

(That said, however, there are certain situations where the human eye can detect much smaller resolutions. Stars only 0.1 arcseconds (1/600 arcminute) in width can be seen with the naked eye because of their high brightness. Lines against contrasting backgrounds are also more visible; with clear air, one can make out a 2-inch (5-cm) with power line from a distance of several miles. At 2 miles distance (3.2 km), this is equal to a resolution of about 1/20 arcmin, or 3 arcseconds.)

Assuming the resolution of the human eye is 1 arcmin for normal images, then, what resolution does a computer screen need? I personally sit 24 inches from my computer screen (laptop, on my lap); at that distance, one minute of arc is equal to 0.18 millimeters. Given that in the worst-case senario, you need two rows of RGB pixels to produce a color pixel, this means a pizel size of 0.09 mm - equal to about 280 pixels per inch.

My personal display is about 7.5" by 12" - equal to 2100 by 3360 pixels at this "lifelike" resolution. (In reality, it's 800 by 1280 - 38% of the resolution). The largest displays right now are usually 1920 x 1200 pixels, and about 24" by 15". An life-resolution image on one of these giant desktop monitors would have to be 4200 by 6720 pixels - a whopping 28 megapixels. (All image sizes given here are for jpeg format; multiply by about 4 for PNG format).

Which, in terms of cameras nowadays, isn't that much. You can find 14-megapixel cameras for under $300, and Canon offers a 10-megapixel camera for $100. (Nikon will sell you a top-of-the line DSLR with 24.5 MP if you have 4 figures to spare). But the problem lies in the filesize. A good estimate is one megabyte per three megapixels for an image with a reasonable amount of detail - so that giant 4200x6720 image will be almost 10 megabytes. (70 will fill a CD). Even the laptop-size image is 3 megabytes.

(It should be mentioned that, sitting 10 feet from a TV, 0.5mm pixels will suffice for reality. Few HDTVs offer this size pixel, but any laptop does. A life-resolution image for such a 60" non-widescreen (36" by 48") TV would be only 1800x2400 - taken by almost any digital camera on the market - and just 1.5 megabytes in size, equal to 90 Mb/s for 60fps HDTV. (1080p HDTV is just 1080 pixels wide, or only about 60% of the resolution of life).

So, this brings us to the real question: what is the resolution of life? Well, let's assume the human field of view is 180 degrees by 180 degrees (it's actually a bit smaller, but this makes the numbers easier). From left to right, you'll need 10800 arcminutes - 10800 pixels. Thus, at best, a human can view a 10800 x 10800 image. Any image larger than that is unnecessary unless it can be zoomed; higher resolution cannot be detected by the human eye.

Now, recall that that's on a half-sphere. If half the circumference is 10800 arcminutes - or 10800 pixels - then the radius would be 3438 pixels. For a hemisphere, surface area A = 2 pi r2, or about 74.3 megapixels.

That's the magic number, then:

74.3 megapixels

. Which, among other things, means that a 25 Mb jpeg contains sufficient information to be indistinguishable from reality, even on a full-wraparound display.

Working on the L-13

My Fliskits L-13 did not have very good luck on its last outing. It was unstable under the larger motor, and a bit of flashing got ripped off.

To replace the flashing, I first tried to use similar plastic. But bent plastic has to be formed that way; trying to bent 1/64" plastic just causes it to break. So, instead, I found some old tin flashing I had squirreled away. It's thinner than the plastic, but it cuts straight, bends easily, and matches the paint perfectly. It's now fixed in place.

For stability, I decided to add nose weight, because there's no rear weight to remove, and it being a scale model I couldn't just add larger fins. I drilled two 3-centimeter deep (1.25") holes into the base of the nose cone, on opposite sides of the eyebolt. Each hole perfectly fits a 1" length of quarter-inch steel rod. Once they're fully glued in, they'll add 0.6 ounces of nose weight, which should keep it stable even on the heavier C6 and D motors.

The one remaining problem is the parachute: it never manages to come out. It's probably the parachute protector which I like to use. Perhaps a baffle may be a good choice.

Thursday, June 9, 2011

Listen.

This is music:

Google Guitar

I love having an electronic tuner. Among other things, I can figure out what the notes of the guitar currently on Google are.

It's a G major scale, from a low G up to the B an octave and a third above it.

The arrangements of the notes (B' is an octave above B, etc):

C
E
          A
G       D
B       F#
G'      A'
B

Monday, June 6, 2011

Weekend of my Senior Year

Extended weekend, that is, as it started on Thursday, with Awards Night. I won awards for having the highest math and science awards in the senior class - made even better by learning that my sister had got both three years ago. Mandachan was up on stage several times, including receiving a band award, and three of my close friends also won scholarships.

Friday night was my very last high school band concert, and it was my best. We played three neat songs in Symphonic Band, ending with von Suppe's Light Cavalry Overture. It was by far the most difficult and demanding piece I have ever played, and it was fantastic. You can listen to it here. Then, we played 4 good songs in Jazz Band, ending with "Rock with You" - an actual rock version - in which I had a solo. Finally, everyone in marching band came out into the audience to play one final song. I dropped the octave and played the trombone part on my trumpet at purely ridiculous volume. The perfect end to four great years of band.

After the concert, we hit the road. I drove to Bridgeport, and my dad (who, it should be noted, is rather awesome) drove the rest of the way to Penn State (a 7-hour drive, on I-80, overnight) for my last ARML math competition. Not a bad drive, except for the piece of semi-truck coilspring that got caught in our undercarriage for a few miles and made us think the bumper was falling off). I was on the Connecticut B1 team, and we did great. Third place in the nation in the B division, which means we'll be getting brand-new top-of-the-line TI N-spire calculators. I was one of three on the B1 team with a 7/10 on the individual round. (8/10 qualifies you to take another test for nation ranking). For the first time, there was a CT student who took that runoff - go Kei!

Here's my cell phone shot of the Delaware River Viaduct at Delaware Water Gap. Built in 1908-10, it's the largest continuous-pour-construction concrete structure in the world at 1452 feet long and 65 tall. It was built as one of the crowning jewels of the Lackawanna Cut-off for the Delaware, Lackawanna, and Western Railroad, and it's in the beginning stages of being restored for NJ Transit passenger service.



After getting back on Sunday, I went straight to the final party/banquet for tennis. My last time hanging out with my team, and my coach. Buncha wackos, all of em, but a great team, and I will miss them.

Finally, I finished and printed out my senior critique - my last high school thesis paper, and analysis of an entire novel. My final title was "Console Cowboys, Razorgirls, and Artificial Intelligences, oh my: Elements of Transhumanism in William Gibson's Neuromancer". Doing it on Gibson's seminal cyberpunk work was far more enjoyable than reading a "classic" piece of literature.

So, that was my weekend. The end of band, tennis, and math team for my high school experience, and my last major paper completed. Bittersweet, but a wonderful weekend.