Its Trouble...

Tuesday, September 01, 2009

Possible type of Alien Lifeforms (Part 2: Exotic Amino Acids)

For the most part, life on Earth uses the same set of nucleotides (amino acids) to form the basis of their DNA. In all, almost all known life uses 20 particular amino acids. These are often classified by their bases as A (adenine), C (cytosine), G (guanine) and T (thymine). These are the basic building blocks of DNA. They are also used to build proteins. Of course, from a certain point of view, DNA is just a really long protein.

How DNA uses these amino acids is described by Paul Davies in his article Are Aliens among Us? published in Scientific American, Dec 2007. He states, "The genetic code is based on triplets of nucleotides, with different triplets spelling out the names of different amino acids. The sequence of triples in a gene dictates the sequence of amino acids that must be strung together to build a particular protein."

Alien lifeforms may use exotic amino acids that are far different than the ones used by life on Earth. It is possible that the set of amino acids we use may not even appear on other worlds. Evidence by scientific study suggests that there are many other forms of amino acids that may be useful (or at least available) for other types of life. Evidence of exotic amino acids on other worlds has come from meteorites. Also, others have been synthesized in the lab.

Other lifeforms from other worlds may be completely different from us while still using the same basic DNA structure we use. A question remains, would life formed by exotic amino acids be all that much different than Terran life in appearance? Would the exotic amino acids lead life to evolve along completely different paths that we as yet have not conceived?

Reference: “Are Aliens Among Us?” by Paul Davies, Scientific American December 2007

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Saturday, August 29, 2009

What are the odds of Humaniods evolving again?

Humans take human-level intelligence for granted. So much so, that our humanoid form seems to prevail any of our notions of intelligent life on other worlds. Images of Greys, EBENs and other aliens have the same general plane symmetry body plan as us, with two arms, legs, a torso, a head, symmetric features, two eyes, mouth, nose holes, brain, etc. But what are the chances of life evolving in this way again, either on another world or evolving again here on Earth after humans are gone?

The major problem with this is that life goes through a great number of changes as it evolves over time. At each point, a very specific set of criteria sets the stage for what is eventual deemed successful adaption and what comes to the end of the line. Given what little we know right now, it seems unlikely that changes at each step will follow the same path twice in different ecosystems and different worlds.

Sure, we do have convergent evolution, where multiple species evolve the same abilities in separate epochs and ecosystems. But is human-level intelligence something that will happen naturally again? Is having two legs, two arm, a face, etc, something that happens naturally as a matter functionality? Could there be intelligence as advanced as ours, but in a completely different form?

We don't know anything concrete regarding evolution of life on the cosmic scale. For years it was assumed that the form of our Solar System was common, and that is what makes life elsewhere likely. We exist; there's nothing special about us; therefore life like us exists elsewhere. This is a bit silly since we have no data to support that. In fact, when we started finding planets in other star systems, the Solar System model proved to be quite unusual.

Maybe our understanding of evolution is still incomplete at the cosmic scale. Maybe traits we see in Terran life are common on other worlds simply because these adaptions are the most successful in general, regardless of specific ecosystems that may exist. Before people start declaring this or that is unlikely, let's collect data and find out.

Start sending probes to other star systems and poke about. The probes will take a long time to get where they're going, but so what. Unless we humans kill ourselves off (or nature does it for us), our posterity should be around to receive the results of our efforts, so that they can figure this out with actual evidence, instead of relying on unscientific guesses (see Drake's Equation).

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Possible types of Alien Lifeforms (Part 1: Mirror Life)

On Earth, life uses what is called right-handed DNA. Right-handed DNA uses left-handed amino acids, sometimes described as homochiral. The fact that all lifeforms on Earth use Right-handed DNA suggests that all life here is descendant from a common group of ancestors.

Why does the difference matter? If single cell members of mirror life (with left-handed DNA) are placed in a nutrient broth consisting of only left-handed amino acids, the lifeforms will not be able to thrive. The same is true of the reverse.

Mirror life is a type of lifeform that uses the same type of DNA structure, but where the DNA is left-handed. This type of life, in turn, used right-handed amino acids.

The possibly that life on other worlds may be mirror life is very exciting. If found, it would lend tremendous evidence that life is possible in other forms as well.

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Reference: "Are Aliens Among Us?" by Paul Davies, Scientific American December 2007

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Saturday, August 22, 2009

G8 Meet and Ride Aug 2009

Here are the photos from last weekend's San Francisco G8 Meet and Ride.

Here's a sample:

Wednesday, August 19, 2009

"Mommy, what's a keyboard"

Even with the explosion of the QWERTY keyboard being plastered on to almost every type of electronic device these days, I’m going to go out on a limb here and now to declare that the QWERTY keyboard will be obsolete within my lifetime. This prediction is not limited to the keyboard device I’m using to type this article. I’m referring to any type of letter based data input that takes the form of QWERTY. The beginning of the end for QWERTY is not the Dvorak keyboard. Nor is it speak [mis]recognition technology. In my view, the signal of the end is predictive text input.

Predictive text input is where a person enters there first couple of letters and then is presented with a word or list of words that most likely match the author’s intent. The author keeps typing until the correct word appears, then accepts the entry. On a cell phone number pad, each number represents 3 or 4 letters. Predictive test input can quickly find the desired word, often with the push of only a couple of numbers. In addition, more sophisticated systems will learn which words are most commonly used by the author and present those as first choices to the author.

With predictive text input, a person can drastically increase their typing capabilities. I’ve seen individuals text with cell phones numeric pads faster than what is even possible on a smartphone QWERTY keyboard. In fact, I would suggest that average wpm speeds of numeric pad texters with predictive text input even exceeds that of experienced typists on traditional full size keyboard devices. That’s not hyperbole, and I’m not kidding. The QWERTY keyboard’s current Golden Age will be over soon enough.

Tuesday, August 11, 2009

Road Trip, Santa Barbara

My wife and I took a relaxing road trip to Santa Barbara recently to beat the heat wave in Silicon Valley. The weather in Santa Barbara was cool in the 70's, and the sun came out in the mid-afternoon. Meanwhile, back at home, some areas hit 100's. Oh darn!