January 27th, 2008 § § permalink
God said, “Cancel Program GENESIS.” The universe ceased to exist.
— Arthur C. Clarke
The Universe as a virtual machine or a simulation is a very old idea. Even outside of science, many culture have thought of the material existence as the dream of a god.
Christianity has always dealt introspectively with questions about the relationship of God and the Universe. For example, if only God existed before time and space, where is the Universe in relation to God, and whether the Divinity had to limit Himself when He created the Universe.
More recently, with the rise of favorable conditions, many people have started to devote more time to this kind of exploration–which is a very natural curiosity I may add, considering we all want to know how and why we are here, in this particular time and state.
So it’s no surprise that a recent article, The Physical World as a Virtual Reality, attempts to frame the virtual reality question in light of modern physics. The article is the result of a scientist’s exploration about the implications of a virtual Universe within our current physics framework.
It’s a fascinating reading although no conclusion is given, and no attempt is made to create any mathematical models around the questions present–something I doubt is possible now, and which, in fact, may not be ever possible. Of course, if we were able to prove that the Universe is a simulation, the implications would be civilization-changing (Simulacron-3 / The 13th Floor are very good fictional explorations of those themes).
But more interesting than that would be attempts to hack the code of the Universe, changing and introducing new laws. One could imagine an infinite series of Universes, each running their own giant simulations and experiments.
Of course, that begs the ultimate questions: if we are in a simulation, which form do take blue screens of death?
February 28th, 2003 § Comments Off on World of Mathematics § permalink
Eric Weisstein’s World of Mathematics is an incredibly cool math encyclopedia “intended for students, educators, math enthusiasts, and researchers”. The entries cover a lot of subjects in the main areas of this beatiful science, and some of them are quite comprehensive.
The only problem I found with it is that I can’t stop reading the entries…
January 3rd, 2003 § Comments Off on Mt. Etna § permalink
Astronomy Picture of the Day has an incredible photo of Mt. Etna taken from the International Space Station.
I used to visit the Astronomy Picture of the Day site daily because of photos like that. When I changed jobs in 2001, I lost most of my bookmarks and forgot about the site. Time to bookmark it again.
December 25th, 2002 § Comments Off on Racism in science § permalink
In a visitor‘s blog, I found a pointer to a The New York Times article about a study that supposedly identified five main human populations, based on scans of the human genome. According the scientists that made the study, those five population groups broadly correspond with popular notions of race. I think we already have sufficient trouble fighting racism, and now a study is claiming that races do really exist.
I see some problems with the conclusions the study reached. I don’t know how well the article presents those conclusions, but I will try to question some of the results below.
Firstly, the study found patterns in the DNA that correspond to five major geographical areas. From this, the scientists jumped to the conclusion that each of this groups is a race. I can understand what it’s implicit here, but it simply doesn’t follow. From what we know of history and biology, it’s obvious that cohesive population groups would slowly develop common traits across the centuries. Natural selection, genetic drift and social constraints can account for those common characteristics. Nonetheless, classifying those similarities as properties of “race” is just a semantic construct. Take the Americas, for instance. Their population is a result of heavy intermixing by people of Asian, European and African descent. But once the population stabilized, the common traits aforementioned started developing. As the study identified the Americas as one of the major population groups, or race, we would have to conclude that races are not static patterns, since the America’s population is composed of people of every conceivable descent. That fact alone would invalidate the conclusion that those groups are races.
Secondly, the study claims that, by using “self-reported” ancestry, it would be easier to identify the possibility of occurrence of some diseases, like sickle cell anemia in African populations. Sickle cell anemia is common in Africa because its carriers are immune to malaria, another common cause of death there. The rates of death by malaria and sickle cell anemia balance around 18%, because of natural selection. So, even with heavy mortality rates, sickle cell anemia is preserved in the population when it would tend to naturally select itself out of the gene pool. We can see that the environment is a factor in the genetic development of the population. In other cases, like the Amish population in the USA, the common traits developed are the result of intermarrying, driven by social constraints. It would be dangerous to presume too much on the basis of a broad generalization like the study proposes. More so if we consider two additional facts: genetic drift happens very fast in small populations and population mobility is higher now than in past centuries.
Thirdly, the articles says the markers analyzed have no particular function, and are free to change. I’d say they have no know function and nobody knows how changes in them would affect an individual. It’s unsafe to make such assumption and base conclusions on it.
Fourthly, it has been demonstrated that even among phenotypically related populations, there can be enough genotypical differences to make their components seem like they belong to far removed biological groups.
There are other points I could consider, but the article doesn’t give enough information to allow comments.
In short, even if the study conclusions are valid (considering the points above), it’s unfortunate that those scientists decided to associate the genome variations within the human species to races. There are a lot of people who would be delighted to have their prejudices about race confirmed in that way. To the credit of the article, it points the ethic problems with the study, and challenges the notions presented. I just wish scientists would be more careful when dealing with science where it touches the social problems of our world.
October 14th, 2002 § Comments Off on Movie physics § permalink
Ever wondered if a Texas-size asteroid could really be split in two with a nuclear blast in a 800-foot-deep hole as depicted in Armaggedon? If you did, you will like this site about insultingly stupid movie physics. It has simple reviews of mistakes movies make when it comes to displaying accurate science. For physics fans, it also has in-depth explanations of typical blunders.
October 7th, 2002 § Comments Off on New Frozen World Found Beyond Pluto § permalink
Slashdot: New Frozen World Found Beyond Pluto
“The new world, which has been dubbed Quaoar, is about 1,280 kilometres (800 miles) across. Quaoar orbits the sun ever 288 years and is 1250 Km wide, about the size of all the asteroids combined. This discovery is being hailed as the most important solar system discovery in the past 72 years.”