Remember that one time   How wrong that porsche enthusiast was    Ask me anything.    

just kidding, im back

October 1, 2014 at 9:33pm
6 notes


So, I’ve been away from tumblr for like ever basically. 

List of things that have changed:

  1. stopped doing epic drugs, prescribed or not
  2. sold my miata
  3. i am a developer on a real live app, released on the app store
  4. got a new job
  5. stopped being an alcoholic
  6. could give a damn now if people listen to my engineering advice
  7. did karting, as promised. was epic. 
  8. got old, feel even older 

Overall being away from tumblr was probably the best decision at the time. my life was steaming towards the shitter for a number of reasons, and I was basically insane at all times. Like, really insane. It was all the adderal and anti anxiety meds though, both prescribed. They really fucked with my appraisals of situations and anger management, during the same time I was on here, I was losing a lot of like real life friends. It was terrible. 

I just got sick of dealing with the miata, so I sold it for like 10 bucks. I have a normal car now, but I’m kind of saving up for a bike or to do another karting series, or who knows maybe I’ll breakdown and buy a sweet car and do hill climbs haha. I’m trying to find engineering work in Cali right now, and if that happens I’d definitely get another car. Probably an old Porsche or something nice though. 

I’m developing a game on the side of the app I’m working on with some other people. Working with others has been great. It kind of forces me to follow through, which I somewhat needed initially. 

I regret all the terrible negativity I birthed here for a long, long time. There was no call for it, and though a lot of it is hysterically funny, a lot was just mean and nit picky douchebaggery. Typical tumblr bs you see all the time, to the nth degree. But I can’t take it back, its who I was at the time. 



July 1, 2013 at 8:30pm
4 notes

how wrong that porsche enthusiast was…

Less practically,

Downforce for a car body is calculated by 

D = \frac{1}{2} \cdot (WS \cdot  H \cdot  \alpha) \cdot F \cdot \rho \cdot V^2

D = 1/2 ( Area (in meters^2) *angle of attack) * lift coefficient * air density (in kg/m^3) * volume ^2

lift coefficient is calculated the same way as drag coefficient, but instead of calculating for the frontal area, you calculate for the planform area, which is for a car much like a top down view, but would include any outward facing area, (like if you have a curve in your cars body, it is the area of the slice of the sphere that curve represents, not its top down length * width, fortunately planform areas are readily available for most cars) 

C_\mathrm L = {\frac{L}{\frac{1}{2}\rho v^2S}} = {\frac{2 L}{\rho v^2S}} = \frac{L}{q S}

Coeff of lift is given by  C= [2 * Lift force] /[fluid density * true airspeed^2 *planform area] 

Lift force is where it actually gets tricky(lol). See, Lift in this instance is derived from the Kutta-Joukowski theorem(it could be done other ways, i like this one because it is used by computer programs(NASA’s specifically) which usually means it is best), which approximates an airfoil as a cylinder moving in a fluid using a conformal map, which would be in this case the Joukowski airfoil. Fortunately, nasa has an animation of this, somehow.

But the java is broken for me, so I’ll explain. 

L = c \Delta P = \rho V v c =-\rho V\Gamma.\,

The lift force can be gotten, eventually(after a v long formal derivation),  from the density of the air,times the speed of the air on the slower side of the airfoil times the difference in speed with the faster side, times the section length, presumably in meters. For a car the chord length would be constant(unless you remove a bumper), whereas an aircraft wing usually has different lengths along it, getting thinner towards the outer part of the wing. 

true airspeed is the next, and I think last thing we don’t know. It is not simply the speed, because 

\mathrm{TAS}={a_0}\sqrt{{5T\over T_0}\left[\left(\frac{q_c}{P}+1\right)^\frac{2}{7}-1\right]}

where T is the static air temperature in K, T0 is the standard temperature at sea level (288.15K, don’t ask why) 


Tt is just temperature in K, M is speed in Mach so if you’re going 150 mph, thats 150/768 Machs or a Mach number of .1953125. You should use meters per second here though, 340.29 meters per second for mach, though its dimensionless, but since you’ve read this far, why the fuck not. 

qc is actually Dynamic pressure. the ratio of static pressure to dynamic pressure is known to be, with gamma equaling 1.4



\frac{P_t}{P} = \left(1+ \frac{\gamma -1}{2} M^2 \right)^\tfrac{\gamma}{\gamma - 1}

and so

\;q_c = P\left[\left(1+0.2 M^2 \right)^\tfrac{7}{2}-1\right]

Now I think we should have everything we need to compute downforce over a car body, given a speed, the angle of the car(probably in radians for these equations), the density of air is like 1.2ish kg/m^3


Using these equations you have to remember that we aren’t looking for lift but downforce, so if the Coefficient of lift is positive, that merely means that we’ve fed it not the lift force, but the downforce, which are computed in exactly the same way( density * min airspeed * airspeed delta * chord length). Aerodynamic downforce is a fairly subjective topic and so most things you will find will put fluid and continuum mechanics in terms of either actual fluids or lift, because of their use in aeronautics, i was surprised to find a downforce equation at all. 


This is a lot of math, even for me, who is used to doing this. In one of my college exams for essentially applied fluid and continuum mechanics it was open book and take home, but it took literally days to finish, working all the time. Other students would be like yeah take home sounds nice, but no, no. Not at 4 in the morning on your seventh redbull.  

To save yourself 28 hours and perhaps 6 redbulls, all you really need to know is how a change will effect the outcome. 

For instance, chord length. Lets say someone was to reduce the length of a wing, or perhaps their car body in some way. Lets say removing their bumper, just for instance. 

c = chord length, the length of the aerodynamic planform

L = c \Delta P = \rho V v c =-\rho V\Gamma.\,

chord length multiplies into L, the lift force or in our case, the Lift down force, assuming the vehicle is angled and adjusted in terms of the venturi principle to prevent lift(mostly being smooth on the bottom, and low at the front-not necessarily venturi ‘tunnels’),


 (the following picture and equation basically means fast air, low pressure under constriction, in this case by the cross section; low pressure sucks things down in our case, why 80s f1 cars were so low, the h means pressure, delta h is the change in pressure head, lower is less pressure, like a waterfall, higher water has more pressure) 

p_1 - p_2 = \frac{\rho}{2}\left(v_2^2 - v_1^2\right)


which race cars usually are. Unmodified street cars will default to lift actually(or eventually, in terms of speed, at 800 miles per hour there will be enough air moving under a toyota camry to rip it off the ground), but we are examining relative downforce here. 

coefficient of planform lift is

C_\mathrm L = {\frac{L}{\frac{1}{2}\rho v^2S}} = {\frac{2 L}{\rho v^2S}} = \frac{L}{q S}

which means a smaller L means a smaller Cl,

Downforce is given by, where F = Cl 

D = \frac{1}{2} \cdot (WS \cdot  H \cdot  \alpha) \cdot F \cdot \rho \cdot V^2

so a larger lift coeff, means a larger D

or a shorter c means a smaller L, which means a smaller Cl, which is the same as F, which means a smaller D, for downforce(nominally a paradox, smaller lift coefficient and lift force means smaller downforce). So, reducing cord length will reduce downforce, in this example, where planform area per cord length is relatively slight, compared to an airplane wing. 

To see how changes happen over different speeds or other numbers ,you could put this all into excel, or program an applet ( lol so 2002, crazy NASA). 

consider other resulting changes, like in this case, no bumper means planform flows eventually moving around bluff objects(wheels, engine) and will create turbulent vortexes and slow down the speed of the air under the car, raising the under car pressure and lowering downforce still(and creating alternating eddys depending on the mach number lol), so our model is not perfect because it is depending on us to account for all changes in some way, which is why computer models are used to calculate things, but just knowing how changes interact can get you a lot further than most people, especially in racing where most people go by what they feel, not science. 

to really get the full picture you would need to do about five of these, accounting for each aspect of change across changing variables(of different aero elements-perhaps speed for racing), and then if you have a spoiler or front wing, you need to do the same for that, so computer modelling is the way to go for anything quite serious. 

another thing to consider is that fluid and continuum mechanics are very much a work in progress, 2 of the (1,000,000 dollar reward) millenium prize problems are basically fluid mechanics questions, looking to prove things on a very core level(i worked on one of them). for this instance that doesn’t mean much though, we aren’t ever going to get accurate enough to notice without a wind tunnel and an f1 team, but maybe this will help you pick out spoilers or suspension settings (like rear and front ride height). 

June 30, 2013 at 11:14pm
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Malcolm Gladwell: Choice, happiness and spaghetti sauce | Video on →

In many years of internet I have never found a comment section that was not submerged in ridiculous debates, until now.

edit: like, look at it, its like a scientific discovery. the comment section is actually having an intellectual discussion about the video, with very little chaffing/arguments. 

2 notes
Reblogged from sefsar

The Web


Few people really understand the web. Most –and it’s very easy to fall into this trap– see it as some sort of entertainment tube defined by suits in high places. They sit consuming, frustrated, bored with the listings, the programming as it were. But this isn’t how it works.

The web is no more or no less than what you make it. The web is only ever what you make it. So, make it.

absolutely agree,

the only problem is that the web is getting less diplomatic as a result of its size, paradoxically. this isn’t a criticism, its an observation that bothers me quite often. i worry the internet will turn into tv one day. 

the way search engines work its very hard to break into a new category as a website. for instance, unless we were blogging here i’d almost certainly never see this post. 

also even google’s method of rating and collecting web pages is somewhat antiquated. i mean how often do you link to things now with keywords and links? not often, and of the 60 or so ranking categories that happens to one of the, apparently, most powerful(by my experience and things ive seen/heard from within google). backlinks of all things, its amazing the whole thing works, and equally amazing how many people are seo experts, because usually they will not recommend something like a backlink building campaign and strategies therein. and then people like me don’t even work in seo haha. its preposterous, if random guy on twitter is an seo expert, im an seo grand imperial wizard knight samurai admiral and ive done 0 hours of search engine related work in like probably 1.5 years.

on top of all that, because of this discovery inefficiency people act less efficiently as producers of web content. if you think about it, there are really two content segments: one is really an information oligopoly, the other is people trying to break in which is more like direct competition. now very often i see small blogs trying to be big blogs, because viral discovery is really the only way up. the exception and probably most efficient segment in the current paradigm is probably tutorials because they tend to lend themselves to self categorization and niche viewership. 

the picture this paints is that there is a minority of producers who get most of the views, are trusted, etc. and the rest are worthless basically. tumblr, sadly, could be categorized the same way despite some semblance of a self categorization model. i have a small number of followers, and we like what eachother post, but we arent bringing in the views. its only going to be 10 or 20 percent of users who pull in most of the views.   

for a while ive been trying to think of a way to solve this, how to re democratize the web, but i dont know. some models would suggest that redemocratizing the web would simply make it a more efficient market and that merely the 20% of users would be closer to being the 20% of users people were looking for. content democracy but not communism. 

i guess ideally it would mean that less time invested in pondering the internet for things would lead to more discovery, more things to discover. i always hear about things id wish id heard about sooner, imagine if everyone feels this way, and what theyd do with that information.

sorry for anyone reading this, i know i am excruciating and boring with regard to such subjects, thanks for humoring me. needed a break from battling with blender. 

June 24, 2013 at 7:07pm
3 notes

i need tumblr today

its so damn hot i could fry an egg on my video card. and i live like right next to the ocean. i cant imagine 10 mi inland. 

June 17, 2013 at 11:25pm
4 notes

another update

I’m making a game. 

May 30, 2013 at 2:04am
7 notes

Quarterly Update 1/4

I’ve accomplished basically nothing besides drinking a bottle of vodka over the past 3 months in terms of tangible changes in my life. It was pretty good, stoli blackberri if you’re wondering. Split between tonic and powdered lemonade pairings. 

Of the intangible, my web app is coming along and I’ve learned some new tricks, and relearned some old tricks. I’m taking a look at some of the google glass stuff, mobile langs, and etc. I already know C to a point, so applying it is more about learning about the apple sdk(for the i-devices i mean, not glass), which is a task when taken to a great detail.  

I spend most of my time at work dreaming of working in some slightly less horrible arrangement. Some guy literally drove to work today from another company to explain to me how much of a complete douchebag I am, which is of course very true as you well know. After essentially agreeing with him, I asked him to leave.  The security guy was like damn. Good money, but this sort of job makes life taste bad. 

below I’ve diagrammed what I project for the next 6-12 months of my employment, in a concise infographic: 

the miata is fixed, after roughly 2500 dollars and 4 months. have a van now for karting as well. hoping to move more west in MA soon. ill let you know how shifter karting goes. 

i’m basically redoing some features of my app now for security sake and i’ll launch it by july-ish, in a primitive state.

well off to bed, and a quickly approaching hell. cheers, bitches.

March 11, 2013 at 11:58pm
12 notes

I am leaving tumblr for 1 year.

For various pressures of ambition, i must leave this place. I am a 0% or 100% person. I can only do 1 thing 100 percent, and its very hard to focus otherwise, and nothing gets done.

If you want to stay in touch, email me at brian (at) culdesak(dot)com 

tumblr has been great in recovering from a great siege in my life, I feel like from here the road is a building one and that alone will bring me happiness hence forth. I may update on progress via email (4 times over a year) but i will not actually sign in. 

tumblr is rife with creative people, and the people i follow are among the most creative, ingenious people ive come across. its really been awesome. i’ll be back eventually, but my life will be very different when i come back, one way or another, on March 12, 2014. 

hit me up on psn too if you want, though im on less often now there as well. 

I might be back sooner if things go well, but we’ll see. 

Come writers and critics
Who prophesize with your pen
And keep your eyes wide
The chance won’t come again
And don’t speak too soon
For the wheel’s still in spin
And there’s no tellin’ who
That it’s namin’
For the loser now
Will be later to win
For the times they are a-changin’.

2 notes
Reblogged from 6-66x39

I feel like being a genius has nothing to do with sweating, but I could be wrong.

the genius is in the execution, in as many words.


I feel like being a genius has nothing to do with sweating, but I could be wrong.

the genius is in the execution, in as many words.

0 notes

DIY Arduino powered Diesel ECU  →

saw on hackaday, this is a homebrew diesel ecu powered by arduino mega. very interesting, can work with certain bosch fuel pumps. 

heres the hackaday page: