Jesus Camp

(For the sake of readers, I’ve decided to shorten controversial posts to get straight to the point. The following youtube link was from Cactaur.)

Aside from all the chilling ideologies rising in pockets of America, Jesus Camp could be one of the most ravenous wolves in sheep’s clothing. Apparently, some evangelical churches are brainwashing kids at a very young age to become soldiers in a war to convert America into a Christian theocracy.

As a Christian, however, I am strongly against it for two reasons.

1) Theocracies are biblically unsound. Jesus said that his kingdom was not of this world (John 18:36). He had no intention of conquering the Romans who were currently ruling over the Jews, and in fact has no intention of ruling over the earth until his second coming (Revelations 20). Meanwhile, America is a democracy, and in the least sense, submission to authorities (Romans 14) should mean abiding by the constitution and the liberties it provides.

2) From history, we know of two examples of failure: a) the Old Testament Jewish nation, and b) Roman Catholism. What happens when you mix religion and politics? You get a crucified Messiah, the crusades, and burning at the stake. You get priests who make up extrabiblical laws to present themselves as more “holy” than others. The truth is hidden; corruption and ignorance abound. If the evangelical “culture” is already attacking biblical messages, I’d imagine a repeat of history if they were to take over America.

Depressing image

Wow, now I’m really depressed. Even my precious Fourier Transform fails at love!

More can be found here.

Really Cool Traffic Paradox!

Did you know that shutting down a road can actually improve traffic in a city?

The phenomenon is known as Braess’ paradox, which states that adding an extra link/road in a network/city could increase overall latency. For a graph theorist, the idea is highly counterintuitive since all the previously existing flows still exist. The reason why this happens, however, is due to the Nash Equilibrium induced by SELFISH drivers. Yes, you know… like… EVERYONE?

Let’s use a simple toy example below (click to enlarge) [1]:

Here, let us assume that all traffic is flowing from s to t along two roads through points v and w. The total traffic is 1 unit (The traffic may consist of many smaller unit flows, e.g. 10 cars contributing 0.1 units of traffic each.). The function l(x) indicates the latency (say, in minutes) induced by x units of traffic along that road; hence in (a), the optimal traffic flow would be to have half the cars choose the top path, and half choose the bottom path. The resulting latency is 1.5 minutes for every driver.
Now, suppose a one-way street was built to connect v to w, as shown in (b). This street is infinitely wide and has no speed limit, and hence cars can essentially “teleport” from v to w with 0 latency. What is the new optimum? Surely, it is at least as good as the old optimum, and in fact it is the same as the old optimum. People could just pretend the one-way Warp 9 road does not exist. However, this will not happen if people do not cooperatively decide to do so. If no driver can communicate (in a friendly way) with other drivers, which is usually the case, the following occurs:

Suppose there are 10 cars. Car #1 sees that it can choose s->v->w->t and make it in 0.2 minutes. Car #2 sees that car #1 has chosen its route, but it sees that s->v->w->t is also beneficial because he can share the road with car #1 and still make it in 0.4 minutes. The same goes for the other 8 cars. In fact, no car will want to choose s->v->t or s->w->t at any time because it will ALWAYS be slower than chooseing s->v->w->t. (They are selfish after all.) Therefore, the result is that everyone chooses the same path, and everyone gets to the destination in 2 minutes.

Hence, adding an extra road causes everybody to lose 30 seconds. WEIRD HUH? So next time you see construction on the road, take a detour and don’t necessary expect a heavier delay than if construction did not exist. You might get to your destination faster!

Such is the price of anarchy.

[1] Tim Roughgarden , Éva Tardos, How bad is selfish routing?, Journal of the ACM (JACM), v.49 n.2, p.236-259, March 2002

Hello theory world!

Now that I have finished the worst part of my phd career, it’s time to blog publicly again! But why wordpress? Well, I felt like a conformist today, and everyone else has been switching over from xanga to wordpress. It definitely looks a lot better. =)
I recently received an Ipod as a gift from my bro and my mom for passing the quals. I was considering getting an FM transmitter to play it in the car, but from what I’ve heard, if you’re in a city like LA where the FM stations range all over the spectrum, the quality of your Ipod transmitter can be degraded by noise/interference. Anyone used this before? Do you recommend it?

Ok, this is about as systems as this blog will ever get. If you want your tech savvy news, go to slashdot. Or read some of my friends blogs. All you will find here is theory. Apply theory at your own risk. =)