driving conjunction

March 28th 2008

Normally you might consider an ambulance in the rear view mirror as something that will slow down your transit from A to B. Yesterday I found myself in an unusual driving situation where the presence of an ambulance actually saved me about 30 seconds of driving time.

cars turning right thumb

It was a rare conjunction at a T intersection, where I wanted to make a right on red, but there was a constant stream of cars turning from the opposite direction blocking me. Suddenly I looked in the rear-view mirror and saw an ambulance coming from behind. The ambulance cut off the stream of cars that were preventing me from turning, effectively setting a pick.

This allowed me to execute my right-hand turn before the stream of cars would have otherwise allowed me to do so, saving ~30 seconds. Exploiting the path cleared by an ambulance is normally illegal (ie: stay 500 feet behind), but in this odd set of circumstances, I was actually distancing myself from the emergency vehicle more by turning as I did.

Posted by dylan under humans | No Comments »

trousers

March 13th 2008

wikipedia pants

I found a factual inaccuracy in this wikipedia entry for “pants” (or “trousers” if you prefer). It has since been corrected. Looking at the history of this page reveals an extensive amount of pants-related vandalism.

pants vandalism thumb


The desecration is extended to other articles of clothing as well. A quick check at the edit history of “shirt” shows similar activity, although I do have to say that this revision is particularly concise and accurate.

Posted by dylan under humans | No Comments »

comically large block of cheese

March 10th 2008

big cheese thumb
On today’s trip to the cheese section at Andronico’s, I stumbled upon this outlandishly huge block of cheddar. I measured it as 11″x14″x6″. There was no tag on the monster to indicate its exact weight, but I took the measurements of one of its smaller neighbors. The littler block of cheese was 3.5″x3.5″x 1.5″ and weighed in at 0.73 pounds -> density(cheese) = 0.04 pounds/in^3. Extrapolating, the monster block should weigh 37 pounds (which felt about right). And at $11.99/pound, that makes it a $443.63 piece of cheese. Yikes.


expensive cheese thumb


This was not the only gargantuan piece of cheese sitting out on the showroom floor. Over next to the beemster there was a huge slab of Parrano, there for the taking at the low low price of $194.27. Andronico’s is kind of like the Maserati dealership for fine cheeses. And for that, I love it.

Posted by dylan under food | 3 Comments »

i went to a lecture and all i got was this stupid watch

February 29th 2008

autographed craig venter karyotype thumb

The Long Now Foundation hosted a seminar by Craig Venter, so of course I had to go. My impression of the man was some combination of Peter Schultz and Al Gore (that is, An Inconvenient Truth Al Gore). Beyond that I won’t even try to summarize. Here is host Steward Brand’s attempt. Hopefully the seminar audio and video will be available soon, here.

now watch thumb

What I can say is that 1) during the post-presentation book signing Dr. Venter was kind enough to autograph a printout of his own karyotype that I brought. This came from his recent PLoS publication (open access, thanks internet! You can also download a gigantic pdf of the sequence, for $0.00).

And 2) I was inspired to the point where I felt compelled to throw money at the Long Now Foundation by purchasing this very attractive watch (timepiece? bracelet?). It is the most accurate watch in the world and worth every penny. I am still trying to think of witty things to say when people ask me what time it is - suggestions welcome.

Posted by dylan under outer space & machines & humans | 1 Comment »

it wasnt me

January 5th 2008

it wasnt me

This is my first entry into the realm of lolcats. What do you think? I would be pleased as punch if this was promoted to the front page, so please click and vote 5 cheezburgers, spread the word, etc.

Posted by dylan under cats | 1 Comment »

conquering my visual cortex

December 21st 2007

Today is a landmark day where I fought a pitched battle against my very own visual cortex, and I am proud to say that I emerged triumphant. No doubt you’ve seen those pictures of a bunch of colored dots, where if you stare at them long enough a 3D picture is supposed to “pop out.”

shark stereogram thumbnail


I remember these used to be popular circa 1995 when everyone had huge Magic Eye posters plastering the walls[1]. In the 10 years that I’ve been staring at these speckled dot things (autostereogram, to be precise) I never really got it. The advice people tell you when trying to perceive these images is vague and unhelpful: “you just have to stare at it long enough!” Sometimes it worked, usually not[2]. Until today.

Espousing the wikipedia is passé, I know, but I feel it’s necessary because this page has allowed me to overcome a decade-long frustration and master my own personal visual perception system. The reason why it’s so hard to “see” an autostereogram is because you’re asking your brain to do something totally unnatural. Millennia of evolution have hard wired the actions of focusing and convergence into your eyeballs. Stereograms are basically just a dirty trick on the brain, and for the illusion to work you need to defeat your subconscious reflexes.

simple stereogram thumb


It’s helpful to understand how exactly the illusion works, and to practice on simple wallpaper images like this one. Then you can move on to level 2, random dots. It really is just a matter of practice and training. Once you’ve mastered the control of your visual cortex, it’s a cinch.

stereogram composite

I’m impressed at how, once locked into the illusion, you can flip between images without having to recalibrate yourself. Take a bunch of images (here’s a zip file of 50) and make them into a screensaver or slideshow. You should be able to switch pictures and stay in 3D the whole time.

Easier, download these quicktime movies I made that cycle through the whole bunch automatically:
1 second per frame or 3 seconds per frame

For best results, open in Quicktime and go to “View” -> “Present movie…” -> “Actual Size.” Stereogram animations are also cool. For the ultimate challenge try this on for size… stereogram tetris! I played for 10 minutes it left me unable to look at still objects, or walk straight.

[1] 1995 was also The Year of the Fractal. Computer-generated images used to be cool.
[2] Turns out I was doing it all wrong. I was crossing my eyes, which made the images inverted. Most stereograms are rendered to be viewed “wall eyed.”

Posted by dylan under machines & humans | 5 Comments »

comet holmes is full of deceit and lies

November 22nd 2007

comet holmes thumbnail

Normally I’m not one to get angry at celestial objects, but I’ve got some words to say about this so-called “freak comet” currently sailing above our heads. If you haven’t read the news, there’s this Comet Holmes thing, which is usually a mediocre ball of ice that’s invisible to the naked eye. For reasons unknown, a few weeks ago it got a million times brighter within the span of a few hours. Sounds pretty awesome, right? I’ve been pointing my head up every night for the past 2 weeks, expecting to see a blazing fireball, like this and this.

A big waste of time. This “comet” is hardly worthy of its namesake. Maybe it’s just because I don’t have a giant telescope, but to my naked eyeballs Comet Holmes looks pretty much like any other point of light in the sky. Perhaps ever so slightly more blurry than a star, but that’s about it. I would like to write an angry letter, but I’m not sure who to address it to.

Posted by dylan under outer space | 3 Comments »

infrared digital camera, pt. 3

November 5th 2007

point reyes hills in infrared thumb

The short story: I modified a crappy digital camera to make it capture infrared images. Step-by-step instructions available at this instructable.

The long story: A fortuitous sequence of events has led to the successful creation of a real, actual infrared digital camera, done right. The first step was to get my hands on a reasonable digital camera (ie: one that was actually compatible with my computer). For this, I marched straight into the nearest Ritz Camera store, walked directly to the counter, and stated “I would like to purchase your absolute cheapest digital camera, because I have every intention of possibly breaking it.” On that lucky day, there was a very nice woman working the register who simply reached down below the counter into some sort of lost-and-found and retrieved an orphaned VuPoint 3.1MP digicam. “You can have this one, if you want,” she said.

Not one to look a gift digital camera in the mouth, I graciously accepted the offering, said my thanks, and immediately left. Granted, this camera is just about the bottom of the barrel (fixed focus, plastic lens, dim LCD, generally cheap components), but it *does* have a removable SD card that I can simply stick in my USB card reader to make it interface nicely with iPhoto.

infrared digital camera thumb

Having procured 1/2 of the necessary components, the next step was to order a sheet of Congo Blue (Lee #181, Rosco #382) lighting filter gel from B&H. Once everything arrived in the mail, it was time to get down to business. In short, the idea here is to crack open the digital camera, remove the IR-blocking filter, replace it with lighting filters that block everything *but* infrared, and reassemble the camera, hoping nothing got broken along the way. Again, this is all describe in detail on this instructable.

The surgery was a complete success, and I now have in my possession a 100% certified infrared digital camera. For something that cost slightly more than $0, I am completely in love with this camera. Here is a smattering of pictures that I took at Point Reyes National Seashore and more recently at the Russian Ridge Open Space Preserve. Yes!

Posted by dylan under machines | 1 Comment »

infrared digital camera part 2.

October 7th 2007

Prior to dismantling and potentially destroying a perfectly good digital camera for the sake of an infrared modification, I have embarked on an simpler way to achieve the same effect. What it boils down to is this: the CCD on your average ordinary digicam absorbs infrared light quite effectively, so much that camera manufacturers try their hardest to block IR from ever reaching the detector. They install an IR-blocking filter behind the lens that mops up most but importantly not all infrared from getting through. So it’s actually possible to take an infrared picture using an unmodified digital camera, if you trick it. By placing a filter in front of the lens that blocks out every thing *but* infrared, you can in fact produce an IR image.

I went to a photo store and picked up a sheet of Roscolux #27 “Medium Red” filter gel. If you look at the transmission curve for this filter you will see that it blocks out pretty much all of the visible spectrum except for red and beyond. Then I took a few test shots out on the street, using 8 pieces of the filter gel to make my IR images. The downside to this method is that you need to take very long exposures (ie: use a tripod), and the images are a little blurry from the thickness of plastic in front of the lens. But it definitely works. The green of the trees turns snow white after a little post processing.

street shot unfiltered thumb

street shot unfiltered desaturated thumb

street shot 8 layers red thumb

street shot 8 layers red desaturated thumb

infrared composite
N.B. The color channels of the images with the filter still contain some useful information, and if you fiddle around with them in photoshop you can get some bizarre effects. Here I have done autolevels and then swapped the red and blue channels (you do this with the “channel mixer” tool in PS).
infrared shot rb swap thumb

Posted by dylan under machines | 3 Comments »

infrared digital camera part 1

September 28th 2007

Dark Tree by Zach Stern
Infrared photography a fun way to create some interesting and unusual images, like these. Photographs of outdoor scenery are the most impressive, where trees and grass look bright white instead of green (chlorophyll is transparent to infrared light). Once upon a time, the only way to take pictures in infrared was to use a 35mm camera loaded with special film, but nowadays you can modify any digital camera to capture infrared relatively easily.

I found this set of instructions for how to modify a digital camera and I thought I’d give it a shot. In principal all you have to do is remove the IR blocking filter from behind the lens, and put in some red plastic gel lighting filters in its place. But in reality, taking apart a digital camera involves working with a lot of miniscule screws and very fragile components, and there’s a high probability you will ruin your camera forever if you mess up even slightly. Options to consider are 1) paying a professional hundreds of dollars to modify your camera for you, like this place, or 2) practicing on a really cheap camera so that you won’t cry when you turn it into a brick.
25 dollar camera
I chose option 2. I went to Fry’s and picked up the cheapest digital camera I could find. This item here set me back a cool $24.99. Don’t be fooled by its stylish appearance. It’s 100% plastic and would probably disintegrate into a million pieces if you sneezed on it. It came in a big piece of plastic packaging along with a “digital photography for dummies” book and a CD full of dubious-looking software. The software was only for PC and it was unclear whether the camera would work with my shiny macintosh without it. But it was USB, so I figured there was a good chance it would just mount when I plugged it in, and I could pull off the images.
digital camera with book
I got it home and took two pictures of my feet, then plugged it into my computer. Alas, it didn’t mount. I’ve since returned it (my apologies to the next person who may buy the camera and find it loaded with pictures of my feet, there was nothing I could do). The quest to find a disposable digital camera goes on. While I was in the camera department of Fry’s a feeling overtook me, which I can only describe as megapixel-related-depression. My current “nice” digital camera is a Canon PowerShot S30 that was state of the art when I got it back in 2002. Now its 3.2 megapixels are easily outshined by even the cheapest digicam (of the ones that don’t come in plastic packaging).

Posted by dylan under machines | 3 Comments »

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