some stuff I need to do in zero-g

• Point to the enemy’s gate
• Somersault
• Bring some space Legos to float around in front of me
• Bring a Nalgene of water and turn it upside-down

past v present in US space

Ranges depend on whether you measure from the first or last flight of a program that was active over some time period.

Past achievements in space exploration:

• First US satellite in orbit to first man in space: 3 years
• First US satellite in orbit to first man in orbit: 4 years
• First man in orbit to first Moon landing: 8 years
• Moon landings to LEO space station: 1-4 years
• Moon landings to LEO Space Shuttle: 9-11 years
• Pioneer 10 to Voyager 1 and 2: 5 years

Current vision of space exploration:

• First LEO Space Shuttle to LEO space station completion: 19 years
• From LEO Space Shuttle to Moon landing: 10-29 years
• From LEO Space Shuttle to Mars landing: 17-36+ years
• Cassini to Europa Jupiter System Mission: ~10 years

Where did the ambition go?! Maybe I will help re-inject some this summer.

Dear BSG: usually you have a lot of realism, but

• naked
• singularities
• can
• not
• exist.

a subset of stuff George Will does not understand about science

• An average alone is not sufficient to quantify a statistical distribution.
• Two points are not, in general, sufficient to characterize a trend.
• Fluctuation and variation in a dataset is normal and should be expected.
• Experimentally, a single counterexample is not sufficient to invalidate a hypothesis.
• Repeatable counterexamples, however, are.
• Data showing temporal variation on two dramatically different timescales indicate that two different processes influence the data.

ways I have seen vectors denoted in papers and books since coming to grad school

• italic
• bold italic
• italic with over-arrow
• italic with under-arrow
• italic with over-harpoon
• italic with overbar
• italic with underbar
• italic with under-tilde

Potential reasons why humans might be viewed as the pinnacle of evolution on Earth

1. Humans can now affect their own evolution.
2.  Humans can now affect the evolution of other species in a controlled manner.
3.  Humans can affect the evolution of the planet.

Some things that life apparently does not need

1. Oxygen
2. Sunlight
3. Fixed nitrogen
4. Organic molecules

http://www.physorg.com/news142777731.html

Hellooooooo, life in space!

meteorite thin sections

1. 

   PCA82506

2. 

   PCA82506

3. 

   EETA79001

4. 

   ALHA78040

We only have one. Take care of it.

• 

  Earth from 31 million miles away (Deep Impact image)

• http://antwrp.gsfc.nasa.gov/apod/ap080903.html
• “Deep Impact,” indeed.

science, creationism, and “open-mindedness”

I recently had a discussion (actually, my first-ever intelligent discussion) with a creationist. Our discussion was, mainly, about the nature of the debate rather than any specific points — after all, neither of us was going to convince the other. However, one of his main contentions was that so-called “evolutionists” were close-minded in nature and desperately clung to the theory of evolution when there are scientific problems with that theory.* Some responses:

• The purpose of science is, in fact, to discriminate. It sorts out theories that accurately explain existing phenomena and predict the future behavior of the universe from those that do not provide sufficient explanations or make inaccurate predictions. It is not “close-minded” to reject a hypothesis that has been disproved many times over during the past hundred-odd years. This is just science doing its job! If, each time we educated a new scientist, we had to start from scratch without any established theories, we would still be at the level of the ancient Greeks. Very optimistically. Then again, it is the Platonic tradition to disbelieve observations of the physical world, so maybe that’s where the creationists want us.
• Logically, to prove a hypothesis, we must either find an analytical proof based on irrefutable premises or show that the hypothesis is true for every single possible case. A frequent contention by scientists is that creationism cannot be placed on par with a scientific theory because it has no predictive power. But ah-ha, say the creationists, Dr. Russell Humphreys, Ph.D., used creationist premises to make predictions about the magnetic fields of Uranus and Neptune that were borne out after Voyager II. This proves that creationism has predictive power. Not so, I say! It proves only that creationist premises (and many barely-justifiable assumptions) lead to a prediction that is consistent with the physical world in a single case. Creationists will have to show a lot more predictions than that to demonstrate that they have a scientific theory on their hands. In fact, I challenge them to use Genesis to make accurate (or any) predictions in the biological sciences, rather than in a specific application of magnetic theory that is so underdeveloped at present that scientists have had to revise it every single time a probe visits an outer planet. Is it really so close-minded to expect logical rigor when arguments are presented as scientifically rigorous?
• On the other hand, disproving a hypothesis requires only a single counterexample. By this test, creationism has been disproved many times over by various methods that date the Earth, Solar System, galaxy, and universe to far greater ages than the ~6000 years nominally required by creationism. In fact, Judeo-Christian biblical creation can be refuted on these grounds taking as a premise nothing but the inerrant truth of the bible: Genesis contains two creation myths, each of which is mutually exclusive of the other (different initial conditions, order of events, and duration of events). By the premise, both must be taken as true, however, if either one is true, then the other must be false. Since either one (or both) creation myths is false, the premise must be false. Ergo, neither myth can be treated as fact. Again, all I am applying here is the simple logic of implication; I am not necessarily closing my mind off to all alternatives. I even opened myself up to the creationist premise of the literal truth of the bible.
• The theory of evolution has, well, evolved since the time when Darwin first postulated it. This is because science often uncovers phenomena that elucidate a new aspect of a field, and existing theories must be revised to account for that data (see previous remark about gas giants). In other words, when a theory cannot explain some data, scientists revise the theory (sometimes extensively). Thus, we do not “cling desperately” to evolution, since the theory itself has been repeatedly modified. However, creationism, by virtue of coming out of a supposedly irrefutable bible, has never been modified to fit new data. Rather, creationists “desperately cling” to their belief by re-interpreting the data to fit the existing theory. Well, I exaggerate slightly — creationism was modified to fit observed data once: by a guy named Darwin, who allowed that God must have created life through the process of evolution.
• One thing that creationism will never be able to do is use the scientific method to provide a convincing inductive argument for biblical creation. To do this, creationists would have to take as a premise not the literal truth of the bible, but the accuracy of observation and their ability to draw logical conclusions from those observations. They would then have to use their observations alone to show that, logically, the most likely explanation for the data is that the world was miraculously created 5768 Earth calendar years ago and that the creator was their preferred god. First, I note that they do not currently take this approach — rather, they work backwards: take bible as true, go find evidence to support that premise/conclusion. (Creationists often obfuscate their argument by building their conclusions into their premises.) Second, and more importantly, there is no way creationists could support their theory in a scientific manner. There are two reasons why I know this. One — available data (e.g., the age of the Earth, Solar System, galaxy, and universe as obtained by radioisotope dating, measuring the speed of light, plate tectonics, measured sedimentation rates, crater counting, timing formation models for Solar System or galactic features, etc) do not support the theory. Two — even if creationists could show that the universe was <6000 years old, they would still have to show that it was created in a six-day period by a god (who they would also have to show the existence of, by logical interpretation of data). This is scientifically impossible unless said god were to appear and submit to observational tests. Here, creationists usually go back to invoking their bibles, which is where they build their conclusions into their premises. Now, I may seem unnecessarily harsh: What does all this have to do with open-mindedness? My point is simply that even if I give the creationists the benefit of the doubt, their theory does not stand up to truly scientific analysis and, in fact, they could not arrive at their theory through the methods of science. Whether scientists are “open-minded” or not has nothing to do with the validity of creationist theory.

* Many creationists have latched on to the term “evolutionist” to describe anyone who believes in a non-biblical creation; that is, that evolution guides the development of life and that the universe is >5768 years old. Essentially, the term applies to most scientists. However, I reject the use of the word “evolutionist” because it seeks to portray evolution as a belief system rather than a scientific theory. I do not believe in evolution, rather, I am convinced of evolution, perhaps of the punctuated equilibrium variety, by a preponderance of evidence. Furthermore, my convictions that the theories governing relativity, radioactive decay, plate tectonics, etc, are sufficiently accurate to date the formation of the Earth, Solar System, and universe are not dependent on my being convinced of evolution.