# Stephen Hawking, Slingshotting Satellites, RankManiac 2011, and more!

Mighty, patient readers of this fine blog - I apologize for having a short delay in the next blog post. In fact, there was so much that had happened within the past two weeks that it was hard to do anything else other than live out my life until I got a break! As you can tell from the title of the blog - my life at Caltech is anything BUT ordinary. There’s really no way any of these topics connect with each other at all - but that’s what makes Caltech great. The variety of opportunities to learn, educate, and socialize given the small community is impressive. Whenever you’re here, you always find yourself diversifying your knowledge and experience… So what first? Stephen Hawking.

PS: Why not visit RankManiac 2011 today?

# Stephen Hawking

Many of you have…

- heard of him
- seen him in person
- gone to his lecture
- sang him “Happy Birthday”

Wait, what? Yes, let me say *that* again - sang him “Happy Birthday”. Let’s start with this… Have I seen him in person?

Roger, Houston. Have I sung Happy Birthday to him?

Affirmative. In fact, this happened on January 8th, 2011 (he turned 69!) So, a group of Caltech students organized an event in which we met in front of his house just off the West end of campus. He seemed to enjoy it a lot - it’s usually hard to judge but we were told that he loved the surprise and that it was one of the many reasons he enjoys visiting Caltech. Yes, Stephen Hawking said he loves us. :-D

Anyhow… in the next week or so (I think it was 1.5 weeks after that) - he held two separate lecture events at Beckman Auditorium: linky (Why not visit RankManiac 2011 today?). The lecture was titled “My Brief History” and it basically chronicled the life of his parents up to his birth, then his life up to the present - putting focus on how he was raised and why he chose to go into Astrophysics-Astronomy area.

As you can see, the whole audience was packed full of my fellow undergraduate peers, graduate students, and post-docs - all anxious and waiting for the lecture to begin. But.. before that could happen, Kip Thorne came up to make a formal round of introductions and provide a little background into his relationship with Stephen Hawking - I’m sure he cracked a joke or two but I might’ve missed them.

That’s Kip Thorne on the left, Hawking on the right. So, I just happened to get the front row seat on the middle-right side of the auditorium which kind of blocked his face from us. I think the only people who were able to see him completely were those on the left side of the auditorium, but just being there was a fantastic experience in and of itself. The lecture lasted roughly an hour and 30 minutes with a question/answer session at the end (3 people’s questions were selected to be ‘presented’ and a pre-prepared answer was given by Stephen Hawking). All in all - Stephen Hawking is a brilliant mind, so the final picture I’ll give for this section…

Go check out RankManiac 2011 while you’re at it! And the next thing to talk about is…

# RankManiac 2011

So it seems like you’ve seen the (RankManiac 2011) link scattered throughout the blog post right? So, there’s this CS144 competition which is to literally spam ‘RankManiac 2011’ in an effort to get your particular website at the top of the Google rankings for that term. Obviously, you can find my website here: RankManiac 2011. This is being hosted on the UGCS cluster and it is 100% free and you get it forever (one of the benefits of enjoying life at the Math and Science playground of the nation). I can’t really explain the competition any better than the problem set - here’s the problem set from Adam Wierman’s CS144 “Ideas Behind the Web” class: linky. As you can see, the class competition boils down to getting the highest ranking on both Google and Bing compared to: TAs, other classmates, competition pages from previous years. As you can tell, it’s a LOT of work. If you would like to support me, just post the link anywhere - blogs, facebook, twitter, digg, reddit… And if you have the option to choose the title text, it helps to make it “RankManiac 2011” like I’ve done in this blog (for maximal linkability).

One of the things we just happened to do with RankManiac 2011 was post the introduction of Venerable House Video (for rotation 2010-2011) which was a spoof on the Fresh Prince of Belair linky. Something happened with that video that we didn’t expect to happen. It got over 10,000 views within the first 24 hours after posting it on BuzzFeed for RankManiac 2011! If you check out my RankManiac 2011 website, you can see a picture of the graph as it was starting to go viral. The current graph is much bigger now.

I’ll try to post further updates as we get later in the competition up until when it ends in the middle of February. Check out the RankManiac 2011 site for some pictures (under Day 3).

# Double Pendulum

So, last Thursday in my Physics class, the professor talked about the double pendulum! He actually did a demonstration of it. What makes the physics of this type of situation interesting is, when analyzing using Lagrangian mechanics and making plots of the various total energies introduced to the system, one finds that the pendulum exhibits rich dynamical behavior that is completely predictable. For other energies, the pendulum is completely chaotic. So check out these videos. The first two show double pendulum motion when the angles are equal and when the angles are opposite (but with energy that gives predictable motion):

And this last video shows chaotic motion when the double pendulum starts off with a lot of energy (a specific range of energy which gives it unpredictable behavior).

# Slingshotting Satellites

This week (last week, this week, and next week) - my Physics Computational Laboratory is all about modeling the path of the Voyager spacecraft’s *Grand Tour*. There have been seven spacecraft sent to explore one or more of the outer planets: the two Pioneers, the two Voyagers, Ulysses, Galileo, and (most recently) Cassini. Among these, Voyager has gained a special place in the hearts of many enthusiasts of space exploration. It was launched on August 20, 1977, and it visited Jupiter, Saturn, and Uranus on its way through the solar system out to Neptune. The encounters with these four planets were carefully planned. Each planet was used to provide a gravitational assist for the spacecraft, setting it on course to the next planet on a route. In a gravitational assist, a spacecraft passes close to a planet; in the course of the encounter, the planet transfers momentum to the spacecraft, allowing a boost to higher velocities (with respect to the Sun). You might guess that the planets must be aligned in a very specific way to make this possible, and indeed such a felicitous alignment did take place in 1977 (the subsequent alignment, in 1997, was exploited by the Cassini mission). Taking advantage of the planetary positions, Voyager was able to make a Grand Tour of the outer solar system.

PS: Have you checked out my website RankManiac 2011 yet? Do it!

In the first week of this lab, we had to design an adaptive runge-kutta scheme. A runge-kutta scheme is a series of mathematical integrations (without actually integrating, but using the derivative / slope and evaluating it at points - think Riemman Sums) to compute the value of a function over various time steps which we allow our program to run. Runge-Kutta comes in various orders such as a first-order Runge-Kutta (also known as the Explicit Euler). In this lab, we’re dealing with a 4th order runge-kutta but the issue becomes an NP problem as the time required to: compute orbits of multiple planets, motion of satellites based on gravitational effects over a constant time step; increases exponentially. While a higher-order Runge-Kutta is better (because we can get approximately closer to the true value of our integration), it comes with a time cost. So the adaptive runge-kutta aims to fix this by taking a fixed ‘accuracy’ which we like to see our equations evaluated within. It computes the accuracy that our equations and determines whether the accuracy is sufficiently high (so it increases the time step, it knows the accuracy is good enough so it goes further out in time) or whether the accuracy is ridiculously low (so it decreases the time step to evaluate the function at more points in a low accuracy section of the orbit - maybe when the orbit is changing directions or something awesome and cool is going on at that particular time area). By implementing it, we are able to evaluate the voyager’s path. Here are some pictures of slingshotting voyager past Jupiter in this week’s lab - a confirmation that we were able to (a) program the adaptive runge-kutta scheme and (b) get the variables inputted accordingly. Next week, I’ll post pictures of the orbit of the solar system as well as the path of the voyager as it goes on the *Grand Tour*.

# Quick Update on Venerable OPI: Jurassic Park

So, this past weekend - it’s rained a tiny bit (more like a shower), but any amount of rain we experience basically requires that we shut down construction until it dries up again. Therefore, construction did not get as much done as we would have liked - but art did a LOT. Remember that crappy-looking T-rex/Alligator/Creature from a B-rated Sci-fi movie? Our very own Rebecca Lawler (she makes a comic for the Caltech newspaper) worked and labored on the t-rex until it started looking like something from my nightmares…

You have to admit - that is one mighty, fierce T-rex right there… That’s pretty much a short summary of my life in these past two weeks… Join me next time! PS: RankManiac 2011 has everything you ever wanted and more! Go spread it around!