dan’s blog

Dear Dan, Are you an internet oracle?

August 29, 2006 on 6:17 am | In Uncategorized | No Comments

Why yes, glorious reader. I have recently been a contributing author to the short-lived pseudonymous persona of Ask Cassandra, Instructables Oracle. Cassandra answers questions about “electronics, relationships, and stuff”, from a point of view only Cassandra can give. Here are some of my Oracularies:

Q: Dear Cassandra, why do hot dogs come in packages of 12 while hot dog buns come in packages of 8?

A: Marketing

Q: Dear Cassandra, I recently purchased an old military ram air parachute to build a paramotor rig with. I need to know what type of horsepower would be required to drive the propellor to provide enough forward thrust to lift me off the ground.

A: Dear Reader, Let us come to terms with this problem starting with a simple thought experiment: consider the case where you use a prop with infinite power. As you can imagine, this will cause you to be propelled forward with infinite velocity at the instant you turn it on. The parachute’s mass and air resistance will quickly cause an infinite strain in the parachute cords, and they will snap. You will also pass out instantly unless you are wearing an infinite-G-suit. You will then continue your infinite velocity forward motion until stopped by an immovable object and likely your body will be dispersed into an infinite number of small particles. Therefore, my answer to you is: Use a motor with less than infinite horsepower! Now, lets think this through a little more because I, Cassandra, consider the questioner a good and honest fellow and friend and would like to see him avoid the coveted Darwin award. It has been said that anybody who teaches themself to fly has a fool for an instructor. Let us view the process of finding the optimal horsepower as a closed-loop positive feedback system. In lay terms this might be described as “trial and error” guided by positive results. Unfortunately prior to reaching self-stable output, such feedback systems may oscillate considerably since the starting point is essentially random, and the output from a randomly selected HP value may just as easily cause no flight as it will a deadly overpowering. My vast information resources suggest that 15-30HP is the range normally used for PPG’s. Probably you want to start at the lower end of that if you are just trying to get off the ground and have no prior PPG experience. See http://www.wikifaq.com/Powered_Paragliding_(PPG) and other goodly sources of information on the interweb. Also keep in mind that Cassandra herself has not and would not set foot in a PPG, as those things are death traps!

Q: Dear Cassandra, Why do you speak of yourself in the 3rd person? do you have ‘issues’?

A: Dear Reader, Good question! I was a bit flummoxed as the standard guides to English grammar indicate using the 1st person for people and 3rd person for gods. Being a demi god, what’s a poor girl to do? For our second consultation, you might consider that Cassandra is merely a convenient pseudonymous persona for a collection of individual authors. All of whom have serious, serious issues.

Q: Dear Cassandra, Why is there air?

A: Dear Reader, Look out your window a moment. What do you see? Cars. as far as the eye can see, these cars swarm over the landscape, a pestilence of metal and plastic machinery covered in a rounded colorful shell that doesn’t melt in anyone’s mouth. The motive power for these vehicles is supplied by fuel and air, it takes about 15 cubic meters of air to burn one liter of gasoline. World oil usage is around 80 billion barrels per day, this means about 6×10¹² liters per year, which uses around 9×10¹³ cubic meters of air to burn it. Yes yes, all this math is mind-numbing but bear with me for a moment. How much air do we have? The earth’s diameter is around 12700km. Now, the density of air in the atmosphere goes down as you go up, so we’ll estimate that if you compacted the thinner air above us to all be at sea-level density, you’d have about 10km thick atmosphere. That yields about 5×10¹⁸ cubic meters of air in the atmosphere total. That’s it folks! So all this oil use is consuming about 1/50,000′th of the atmosphere every year (converting the oxygen part to CO2). Oh, but that was only for oil. What about coal and natural gas? Between those it’s 2x to 3x that amount. So over 50 years we’ll use about 1/300′th of the atmosphere (at current use rates). How much did you want to leave for your grandkids anyway? I hear that trees can convert some of that CO2 back to oxygen, do you think there will be any of them left? Well, to sum up if there wasn’t all this air around, we’d have run out long ago.

Q: Dear Cassandra, Can you explain the relationship between chip complexity and production cost over time?

A: Dear Reader, This relationship of yours is a very important one. At a basic level, the relationship is that it costs $1billion for the first chip, and $1 for each additional chip. It’s a good thing such economics don’t follow for the Backstreet Boys, or we’d have a billion of those too. Complexity in a chip means transistor count. Moore’s Law describes how this complexity changes over time, that is, it typically doubles in 18 months. There are similar laws describing the progress of other microelectronic devices, such as hard disk drive platter density and LED brightness. A commonly held misconception is that LED’s are vastly more efficient than other forms of lighting. It just isn’t so. Their efficiency only just exceeded incandecent bulbs around 2004. But they are improving following a rapid moore’s law, while incandescents have stagnated for 50 years, so LED lighting will take over the world shortly. Ok, back to the chips. The cost of each new generation of chip manufacturing plants keeps going up. It was around $1billion in 2000, it’s around $3billion now. Sooner or later, you won’t be able to make enough chips in a new plant to recover the construction cost. This will significantly slow the development of new generations of chip plants and cause the corresponding slowdown of moore’s law. As for the individual chips - just like software, movies and soda pop the vast majority of them just don’t sell very well. The first chip costs $1million to $1billion, but they don’t sell any more. That’s what you call ‘capital intensive product development’. I hear biotech can be even worse though. That’s *bio-tech*, not *beeyotch*. Beeyotch usually be less than $200/hour. So on average, do you think the successful chips make up for all the ones that didn’t sell? Turns out the sales from the few successful ones are just reinvested along with new capital into the next generation. Perhaps you had not realized that Investment Capitalism is a Ponzi scheme? Lets compare chips to some other investments. The first barrel of oil from a secured Iraq will cost the US at least $500billion (they are over $300billion so far, but based on spending it isn’t secured yet). Do you suppose that $500billion investment is going to be recovered? What else could $500billion have paid for? How about 200 brand new nuclear power plants - that would supply at least 40% of all US power (20% of US electrical power comes from the existing 100 nuclear plants). Some people think the Iraq war may end up costing $2 trillion. That’s more than enough to convert the US to 100% nuclear power, and these are conservative cost-per-plant estimates. Obviously you could buy quite a few solar cells instead too. How much does the US spend on alternative energy research? Less than $1billion per year. Perhaps a bit more would help reduce the need for these oil wars. Oh, and solar panels DO NOT require more energy to manufacture than they produce, that’s just more oil industry FUD. Solar panel energy recapture takes about 3 years currently, and will be down to half that in the near future according to NREL.

hot-tub hermit

August 3, 2006 on 7:38 am | In Uncategorized | No Comments

scrap metal & driftwood call the gods as well as any bronze or marble

living at the edge, a weekend walk through the albany landfill sculpture park. a few creative souls inhabit the park, apparently living off the abundant tangy morsels we carefully plucked from their prickly caretakers.  after some time we came upon a secluded tent marked with an omen: “don’t piss off the hermit, he speakes to god”. but a soulmate we found, his jumble of catameran bits stacked by his tent. a rumor had circulated that our own cat might be found - left at the beach as an homage to convenience and laissez-faire some months back. upon entry the hermit proved quite jovial and invited us to a party in some days time. the exterior of his hermitage did not hint at the wonders within - a full stone hottub in the roman style with inlaid tilework - all of his own make. after some discussion the hermit dashed off to locate a smoke, and we reflected in the tub (see above). what was to become of the boat? upon his return we made more direct queries, and soon we found our return hike slowed by a new beast of burden - our 7th catameran purchase in as many weeks. as usual, an entertaining time was had by all. storming the castle:
http://www.flickr.com/photo_zoom.gne?id=202975892&size=l