Archive | Uncategorized

RSS feed for this section

When Will the First Earth-like Planet Be Discovered?

With news of new extrasolar planets being released nearly weekly, there is a general feeling that we are in the midst of a singular moment in cosmic discovery. And the news a few weeks ago of a planet that is about the same size as Earth has provided the sense that the discovery of a planet truly similar to Earth – one that could actually sustain life – is on the horizon.

But can we actually predict when the first Earth-like planet will be discovered? In a forthcoming paper in PLoS ONE (to be published October 4th), Greg Laughlin and I attempted to do this. This paper, A Scientometric Prediction of the Discovery of the First Potentially Habitable Planet with a Mass Similar to Earth, uses the properties of previously discovered exoplanets, including the year of their discovery, to estimate when the likeliest time of this potentially habitable planet will be discovered. (Greg writes about our paper here).

Spoiler: early to mid-2011.

Of course, it’s a bit more complicated than that, but here’s an overview of what we did. Using the properties of previously discovered exoplanets, we developed a simple metric of habitability for each planet that uses its mass and temperature to rate it on a scale of 0 to 1, where 1 is Earth-like, and 0 is so very not Earth-like. Plotting these values over time and taking the upper envelope yields a nice march towards habitability.

Using a simple bootstrap sampling analysis, we calculated when a logistic curve fit to such an upper envelope would get to a habitability of approximately 1. And the likeliest time is early to mid-2011, or more precisely, early May 2011. Of course, there are precision considerations, but we are heartened by recognizing that our method shows a 75% chance of such an announcement by the end of 2013 (which is when many astronomers predict such a discovery), and that February 2011 is when we are due for a large release of data and announcement by NASA’s Kepler mission. Our method, using only previous discoveries, accords well with such informed estimates.

Now, we wait and see how close our prediction actually is to reality.

Update: The paper has been officially published at PLoS ONE and can be found here.

Samuel Arbesman, & Gregory Laughlin (2010). A Scientometric Prediction of the Discovery of the First Potentially Habitable Planet with a Mass Similar to Earth PLoS ONE (in press) arXiv: 1009.2212v1

A Probe’s Descent to Titan and Earth

Greg Laughlin has a great post at about detecting life on other planets, including Titan (a moon of Saturn, not a planet). He discusses the descent to the surface of Titan by the Huygens probe (which did not find evidence of life) and contrasts this with a similar hypothetical descent to a randomly chosen location on Earth. A fun and thoughtful read with striking visuals.

Moore’s Law in Robotics

In an interview, Rodney Brooks discusses a fun and very clear example of Moore’s Law in robotics – how fast they  move:

When I first came to the United States, I was sort of a gopher for Hans Moravec, who has been part of the robotics institute here at Carnegie Mellon for many years. Back then he was out at Stanford. In 1979 I remember working late at night with him when no one else was using the mainframe, and his robot would go autonomously through a crowded room. It took the robot six hours to go 20 meters. Ian Horswell, one of my graduate students at MIT, built a robot named Polly in 1992. It would give tours of the lab. It could operate for about six hours and go 2,000 meters. In the DARPA Grand Challenge in 2005, robots went 200 kilometers in six hours. So over a 26-year span, there were 13 doublings in capability, if you measure it as the distance a robot can go autonomously without human intervention in six hours. We have seen Moore’s law in action.

(via @pomeranian99)

Depressing Quote in the WSJ

In an article in today’s Wall Street Journal about men who take their video game girlfriends to actual vacation destinations, there is this sentence from someone who plays these games:

“There isn’t a lot of romance in my life and this helps me cope with some of the loneliness,” said Mr. Fukazawa with a chuckle.

Somehow the chuckle makes this sentence even more depressing.

Pac-Man Dossier and Trapping Ghosts

Jamey Pittman has written the Pac-Man Dossier, no doubt the most comprehensive article on the history and mechanics of Pac-Man. It includes such gems as how to trap the ghosts within their little home:

The more astute reader may have already noticed there is subtle flaw in this system resulting in a way to keep Pinky, Inky, and Clyde inside the ghost house for a very long time after eating them. The trick involves having to sacrifice a life in order to reset and enable the global dot counter, and then making sure Clyde exits the house before that counter is equal to 32. This is accomplished by avoiding eating dots and waiting for the timer limit to force Clyde out. Once Clyde is moving for the exit, start eating dots again until at least 32 dots have been consumed since the life was lost. Now head for an energizer and gobble up some ghosts. Blinky will leave the house immediately as usual, but the other three ghosts will remain “stuck” inside as long as Pac-Man continues eating dots with sufficient frequency as not to trigger the control timer.

Confused? Here’s the video:

Differentiating Skill and Luck in Financial Markets with Streaks

Speaking of luck, we just released a paper onto SSRN about luck and skill entitled Differentiating Skill and Luck in Financial Markets with Streaks. This paper, which I worked on with Andrew Mauboussin (a brilliant high school student who worked in our lab this summer), examines the relationship between skill and luck using mutual fund performance streaks. This builds on some of my previous work in baseball hitting streaks (a popular article here), using the assumption that streaks are good determinants of skill: when luck meets extraordinary skill, you get very long performance streaks. But when luck meets middling skill, very long streaks are generally absent.

The question we tried to answer in this paper was whether or not the distribution of streaks in the financial world over many decades could be explained by the overall performance of the market plus luck (via a Monte Carlo simulation), or whether these long streaks are longer than simply expected by chance and are indicative of true skill. Spoiler: there is skill involved in mutual fund performance, at least according to our methodology. But you’ll have to read the paper to find out the details.

For further reading, here’s a great discussion of skill and luck by Michael Mauboussin entitled Untangling Skill and Luck (pdf). Here’s one fun part from the article:

There’s a simple and elegant test of whether there is skill in an activity: ask whether you can lose on purpose. If you can’t lose on purpose, or if it’s really hard, luck likely dominates that activity. If it’s easy to lose on purpose, skill is more important.

Andrew Mauboussin, & Samuel Arbesman (2010). Differentiating Skill and Luck in Financial Markets with Streaks SSRN:

Luck and Genetics

At the recent Comic-Con in San Diego, a number of people were asked what they thought the greatest superpower is. Stan Lee, the creator of Spider-Man and Fantastic Four (among many others), said it was ‘good luck’, because nothing can go wrong if you have good luck:

It turns out that the science fiction writer Larry Niven has actually explored what it would mean for there to be a gene for good luck. In his stories, a species of alien breeds various other aliens for different traits they deem beneficial. Humans, while neither the strongest or the smartest, are considered inherently lucky. So these aliens actually engineer a series of lotteries, where the human winners are preferentially able to have children, with the implication in the stories being that the luckier people are the ones who get to reproduce more. And in this way, humans are selected for luck.
While of course, this doesn’t make sense genetically, it is fun to think about. Niven even explores what the end-point for a species would be, when everyone is lucky and almost nothing can go wrong, in the story Safe at Any Speed. And for further discussion of other types of luck-bending situations, see the Harry Potter potion Felix Felicis.

Unexpected Parenthetical Statement in WSJ

The Wall Street Journal, with its ever-entertaining journalistic style, has yielded another gem. In today’s paper, there is an article about how the University of Michigan has announced a smoking ban in its stadium (click through for the fun headline). The article has the following sentence, containing one of the more unexpected parenthetical statements:

Following a $226 million renovation that added new luxury boxes and suites, Michigan Stadium, nicknamed the Big House, now seats 109,901 people, more than at any other U.S. college. (Asked whether the numeric palindrome was deliberate, Mr. Madej said, “Believe it or not, the answer is no.”)

The Internet for Dummies, First Edition

I was going through some of my books recently, and I came across my copy of a first edition The Internet for Dummies, from 1993. Reading this book took me back to the first download my father and I ever made: Plato’s Republic, via a university telnet. We were so excited by it, we jumped up and down. The current edition of this book is the twelfth, and one can assume it has undergone quite a number of changes.

The original edition explains TCP/IP networking, email, FTP, gopher, telnet, and WAIS. And there are sentences like this: “Most UNIX systems also include a different, somewhat incompatible telnet-like program called rlogin.” As a friend noted, what might have been considered a dummy back then is a veritable power user now. There is also a section on the Web, but it is eight pages long, and discusses a text-based browsing program, as the first graphical browser was still a year away.