Occam's Razor

entia non sunt multiplicanda praeter necessitatem

For those of you who don't read Latin, that translates as "entities should not be multiplied beyond necessity," and it's one of the most important concepts of logical thinking - Occam's Razor.

Occam's Razor (also known as Ockham's Razor, since it was named after William of Ockham, the 14th century Franciscan monk who first postulated it) is more commonly phrased as, "all other things being equal, the simplest answer tends to be the right one." This is usually applied when multiple theories are used to describe a situation; the theory that makes the fewest assumptions and the fewest entities tends to be the most accurate theory.

One of the main reasons we prefer simpler theories (according to philosopher Sir Karl Popper) is because simpler theories apply more broadly than complex theories, and thus they are more easily tested (and refuted). Since valid scientific theories can never be proven, only disproven, a theory that can be more easily tested and refuted is preferable to one that cannot be tested and refuted (in fact, theories that cannot be disproven are not valid scientific theories).

Occam's Razor is not a scientific theory. Rather, it is a heuristic method used for choosing among competing theories. While there is some risk of eliminating valid theories, probability theory and statictics argue in favor of Occam's Razor on the basis that all assumptions introduce possibilities for error. Thus, theories with more assumptions are more likely to be incorrect. Additionally, simpler theories will be easier to test and refute, bringing us back to the more complex theories that we originally bypassed.

If you have trouble remembering Latin (like I do), you can just keep in mind the KISS principle: Keep It Simple, Stupid.

Hey Buddy, Wanna Be an Astronomy Researcher (Again)?

Back in January, I posted my first Hey Buddy... post, introducing a service called systemic that allowed amateurs (like you and me) to contribute to astronomical research. I bring this up now to introduce a new program that will allow amateurs and school children to participate in a project to help map star visibility.

The program, known as the Great World Wide Star Count, allows citizen scientists and school children to record their observations of various constellations during the period of October 1-15. The event, which is free and open to everyone who wants to participate, is organized by the Windows to the Universe project at the University Corporation for Atmospheric Research (UCAR), in conjunction with planetariums and scientific societies across the country and abroad. Funding is provided by the National Science Foundation.

Bright outdoor lighting at night is a growing problem for astronomical observing programs around the world. By searching for the same constellations, participants in the Great World Wide Star Count will be able to compare their observations with what others see, giving them a sense of how star visibility varies from place to place. The observers will also learn more about the economic and geographic factors that control the light pollution in their communities and around the world.

This is a great opportunity to get involved in scientific research by enjoying a fun, educational family activity with your kids. I know I plan to participate!

Garage Researcher Makes Possible Breakthrough Discovery

If you've been reading this blog for a while, you know that I try to highlight opportunities for amateurs to help make advances in science and technology. A lot of people may think that the days of amateurs working on research in their basements or garages and making major discoveries is long past.

Those people would apparently be wrong. John Kanzius was trying to find a way to use radio frequencies to de-salinate saltwater more efficiently when he stumbled upon something rather surprising: the right combination of radio frequencies applied to the water caused the molecular bonds between the hydrogen and oxygen to weaken, releasing hydrogen gas. In other words, Kanzius found a way to allow salt water to become flammable.

The results were confirmed by Rustum Roy, a Penn State University chemist, and now Roy is seeking funding for the Department of Defense to conduct research into the possibility of using saltwater--one of the most abundant and easily accessible resources on the planet--as a fuel source. The scientists want to find out whether the energy output from the burning hydrogen - which reached a heat of more than 3,000 degrees Fahrenheit - would be enough to power a car or other heavy machinery.

We're Here... Where are They?

If, as some science-fiction novels and movies would have us believe, the universe is teeming with intelligent aliens, that begs the question: where are they? If they're out there, why haven't they come to visit us yet (and please, for the love of God, don't refer me to stories of alien abductions and UFOs)?

That question has been pondered many times over the years (most famously by Enrico Fermi in 1950), by many scientists far smarter than a lowly computer geek like me. The heart of the matter comes down to one question: just how common is intelligent life?

In 1960, Dr. Frank Drake proposed a method for estimating the number of intelligent species present in the galaxy by use of a mathematical equation, as follows:

N = R^* x f_p x n_e x f_l x f_i x f_c x L

Okay, you're saying, but what the heck does that mean?

Well, N is the number of intelligent alien species currently in our galaxy with which we might hope to be able to communicate.

R^* is the average rate of star formation in our galaxy.

f_p is the fraction of those stars that have planets.

n_e is the average number of earth-like planets that are capable of supporting life per star that has planets.

f_l is the fraction of the above that actually go on to develop life at some point.

f_i is the fraction of the above that actually go on to develop intelligent life.

f_c is the fraction of civilizations that develop advanced enough technology to release detectable signs of their existence into space.

L is the length of time such civilizations release detectable signals into space.

By multiplying out the values you think are probably correct for those variables, you can get an estimate of the number of intelligent, advanced civilizations currently present in our galaxy. And the best part is, our knowledge of the universe is growing all the time, so we can refine the values used in this model as time goes on.

Drake and his colleagues used the following values in 1961:

R^* = 10/year (10 stars formed per year, on the average over the life of the galaxy)
f_p = 0.5 (half of all stars formed will have planets)
n_e = 2 (2 planets per star will be able to develop life)
f_l = 1 (100% of the planets will develop life)
f_i = 0.01 (1% of which will be intelligent life)
f_c = 0.01 (1% of which will be able to communicate)
L = 10,000 years (which will last 10,000 years)

If you work out the math, you'll find that Drake and his team estimated that there are 10 intelligent civilizations in the galaxy capable of producing advanced communication signals that we should be able to detect.

In the past 46 years, however, we've already learned enough to refine the model somewhat. For example, Drake estimated star formation (R^*) at 10 stars per year, but studies by NASA and the ESA show that the number is closer to 6.

Drake himself wrote an article for Wired Magazine in 2004 about revising the information for his model as new data became available. Drake now believes that there are far more intelligent species in the galaxy than he did fifty years ago.

But if Drake is right, then Fermi's original question stands: Where is everybody?

PlanetQuest Update

Another update from Dr. Laurance Doyle on the status of the PlanetQuest group:

...Our lack of progress at the moment is a funding issue which we feel could be solved if we can get initial funding to a point where we can finish the alpha test version of the software and thereafter sign folks up to be supporting-founding members of PlanetQuest.

We do have sufficient astronomical data (stellar light curves) at present for a thorough test of the system and could accommodate perhaps up to 100,000 users for a year. This was previously my main concern. We have also carried the problem through from data acquisition to light curve model fitting (the transit detection algorithm) and therefore see no technical issues in the way of proceeding.

Most of our personnel, however, are also extremely busy people working in other businesses and on other projects, and so PlanetQuest has not received the attention lately that it needs to move forward as quickly as it could, because it is largely (although not entirely) a volunteer project at this point.

I would like to see it take off this year-that is, that we are able to release an alpha version of the Collaboratory and start to post key parts of our educational web site on a daily basis. I am involved in fund raising for PlanetQuest at present, and also writing a comprehensive business plan.

The overall project in execution is quite complex, but the basic overview ideas are readily understandable. After about seven years now since the initial idea, we are still unique in offering a project like PlanetQuest (which surprises me a little). Computational speed (i.e., Moore's Law) has gone up over a factor of 25 in that time, so we have had to collect a lot more stellar data. Our team is ready to proceed, then, as soon as we can get support for the final phase of the programming...

PlanetQuest is a worthy project to allow desktop users (like me and you) to contribute to the search for extra-solar planets that may harbor life. But in order to get the software working and continue their science, they need money. I gave them some a while back, but they obviously still need more.

A Perfect Launch

Endeavour's launch last night went off on-time and without any problems, which apparently only happens about 40% of the time for space shuttles.

Endeavour Launches Tonight

NASA's space shuttle Endeavour launches tonight at 6:36:36 PM EDT. Unfortunately, that will be 5:36 my time, and I will be at the gym, so I won't be able to watch it like I usually do. If you want to watch the launch, however, you can see it at Space.com.

Since the last time it launched, Endeavour has undergone a major overhaul replacing most of the key systems and updating the shuttle with the latest technology. When it launches, it will be the most advanced shuttle NASA has ever sent into orbit.