Author Topic: Ep 21- Chad's Car Headlight Data Storage Solutions  (Read 2346 times)

Offline RedWurm

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Ep 21- Chad's Car Headlight Data Storage Solutions
« on: July 16, 2014, 03:10:42 PM »
Episode 21 posed the question of data storage using car headlights, and I've never been one to shrink from an impractically whimsical challenge that involves no real stakes. So, away we go.

The figures in this post will be based of a file size of 58,920,960 bytes (that's what iTunes says), recommended parking space sizes from the UK (http://masseguridadvial.com/FILES/Underground_Carparks_EN.pdf provided a lot of details), figures in metres and kilometres (that's what I learned in school), and a fair bit of guesswork (I have no practical knowledge in any relevant - and most irrelevant - fields).


Just park the cars side-by-side, it'll look pretty cool at least

With a standard, non-disabled parking space width of 2.5m multiplied by 471,367,680 cars (equal to about the last 9 years of worldwide car production), we have a line of cars 1,178,419,200m long.

That's over 3.9 light seconds, nearly 29.5 laps of earth's equator, and just over 3 times the average distance to the moon.


So national borders, oceans and access might be a problem, let's try a giant car park

We'll keep it nice and compact, and assume that it's a one-way system and that the cars turn outside the area we're measuring. The parking spaces are 2.5m x 4.8m, the bays are at 90 degrees to the aisle and the aisle is 6m wide.

Arranged in this fashion, we cover about 9216km^2, approximately the surface area of Cyprus, or half of New Jersey.
In a nice neat square each side would come close to spanning one degree of latitude


Not a huge amount of land if you put it somewhere nobody would ever want to go (is this where I make a New Jersey joke? I believe it's traditional in some cultures), but wouldn't it be better to have a handy multi-storey car park?

Well, it would mean I have to make a lot of assumptions to make the maths a bit quicker, but here goes...

Again, ramps and turns will be external to the main body of the car park. Pillars will be basically ignored, although in some designs they only add a little to the bay length, so it's not that ridiculous (until you look at the final numbers). Vehicle clearance is 2.1m, and then it's the floor of the next level, no additional space. I've had to take a wild guess at the height of the steel frames supporting the floor, but if the diagrams are more or less to scale I'm guessing 700mm from ceiling of one level to the floor surface of the level above isn't too silly.

I shall be building a giant cube, because platonic solids are as dramatic as they are impractical, and maths may be fun, but easy maths is quicker.

So, our nice, compact cube of headlight data storage is a mere 3km to a side. Which just happens to be 3.5 times the height of the Burj Khalifa. I may have needed to allocate more room for pillars.


Oh, and some speculation on power consumption. I've seen the figure of about 55 watts for a single headlight (more on full beam, less on newer types of bulb, I don't do cars tbh) which gives us 110 watts per car if we assume there are no other lights on. To power this would take just shy of 52 gigawatts, near to the peak power demand of the entire UK.

edit: Of course, that is the maximum possible power requirement, which is a file made entirely of 1s. The actual power will be around half that.
« Last Edit: July 16, 2014, 03:36:34 PM by RedWurm »

Offline scikopas

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Re: Ep 21- Chad's Car Headlight Data Storage Solutions
« Reply #1 on: July 21, 2014, 01:50:00 PM »
this is beautiful. I love the energy component particularly.  I wonder how much CO2 it would emit to play the entire episode...

I did a couple back of the envelope calculations on wolfamalpha+twitter, and got a similar result. 

Using some approximation of average area for a parking space including driving aisles, I calculated the parking lot would need to be 11371km^2 (4390mi^2) ~0.55*total area of Wales.    but if you are using a fiat 500 and you take off all the side mirrors and push them together (you'd probably have to use a crane), you can get it down to 3018km^2=1161mi^2. (~0.15 area of Wales). 
PhD student in Materials Science at Arizona State University currently working on high-temperature superconductors and quantum computers or something.
my (materials) science podcast: LASER (Let's Agree Science and Engineering are Rad!) twitter @scikopas