SETI: Science or Pseudoscience?

[Notrump]

Pseudo-Random Number Generators

.....i seem to remember that no generator we use is truly random...although i don't quite see why not....
If a program is set so that 0-9 each can be chosen with prob 0.1, and then that program is iterated n times to create an n long number....why is that not random?

So how would a computer determine a choice from a set of numbers with equal probability? It can't be commanded to do so. It must be programmed to do so. There's no roulette wheel inside. How would you program it?

Undoubtedly, the pseudo-random number routines have grown in sophistication since I was studying them about 27 years ago. Such a routine is a simple algorithm (algebraic formula) that first takes a seed number (X) as the independent variable and calculates the value of the dependent variable (Y), which becomes the first generated pseudo-random number. The formula could be something like Y = (131X + 101) MOD 256, with X from 0 to 255. Then that number (Y) is made the new independent variable (X) that is run through the same formula to determine the value of another dependent variable (Y) that becomes the second generated pseudo-random number. This process continues in similar fashion.

I learned this using a simple generator that produced pseudo-random numbers from 0 to 255. The resulting pattern looked random, but it repeated itself after every 256 numbers. It's actually a deterministic process that appears random, hence the term pseudo-random number.

Practical pseudo-random number routines would have to go through a huge number of repetitions before the pattern repeats itself. The trick is to understand the context in which the routines are applied to determine if they are appropriate. When I write card-dealing routines, I have to qualms about using a pseudo-random number routine that generates results with 17-decimal-digit accuracy. It would take a zillion years for the pattern of dealt cards to repeat.

 

[Notrump]

-- a typical "frontier" as it expands may consist of mainly the same technology that began the expansion. yes, the core worlds left behind have since become more advanced... but does the technology reach the frontier as fast as the expansion occurs?

Each wave of colonizaton from one planet to the next may be separated by thousands of years. It would not likely be due to a million-year master plan conceived on Earth. Each new world would likely be independent of Earth or other colonies of humans. Some humans living on another planet would only migrate again if ecological or economic conditions compelled it. The first earthlings inhabiting a new planet would have brought with them most of the science and technology of the planet they left behind. In a few thousand years they would have grown to millions if not billions of people. Even it they received no updates from their original planet, their own science and technology could have advanced just as much as if not more.

It's been estimated that if a single species expanded outward in just such a haphazard fashion, it could colonize the galaxy in a time frame between 200,000 and 20,000,000 years. That may be long before an alien technological civilization appears.

You may find the collection of articles in this book to be germane to the subject and quite interesting: Extraterrestrials: Where Are They?
Click this link for more info on the book: http://www.amazon.com/exec/obidos/ASIN/0521443350/crastro-20

Another good one: If the Universe Is Teeming with Aliens... Where Is Everybody? Fifty Solutions to Fermi's Paradox and the Problem of Extraterrestrial Life
Here's the link to its info: http://www.amazon.com/exec/obidos/ASIN/0387955011/crastro-20

 

[Notrump]

Your thesis is, they're more likely hostile; in that case, this is intelligence gathering. And that means that it is indeed worth your tax money.

The next sentence was left out of the quote of my words: "On the remote chance that they are right, I would certainly learn something."

In any event, my actual thesis was that they likely do not exist at all. Building up to that, I indicated that if they did exist, they would likely be hostile and would probalbly have eliminated us by now. Since they have not done so, the implication is that they do not exist. If that is so, they would be neither hostile nor benign.

I would have strayed too far from the subject if I had tried to make a political point that private funding is often more effective than public funding. Since SETI is operating and is privately funded, there is no need to divert federal funds from other worthy projects. If government meddling in the matter were the only way, then I might be more amenable to the notion of a modest amount of congressional funding to be voted upon every x number of years. Congress has started funding projects for the prevention of devastating asteroid or comet impacts. Such events may be unlikely in the near future, but I suspect that either attacks or peace offerings from extraterrestrials are far less likely. I would hate to see a substantial portion of those asteroid funds diverted to SETI.

 

[CACTUSJACKmankin]

My two cents regarding SETI

There are 7×10^22 stars in the visible universe alone. That's a really big number. The only thing on a daily basis that you encounter that is anything like that number is a mole, which still doesn't help conceptualize how huge that number is. If even a tiny TINY fraction (10^12) of those have planets with life on them then there could be thousands (probably a massive undersatement) of intelligent civilizations.

SETI has never claimed to find anything unlike bigfool-hunters(AKA craptozoologists), FUOlogists, and PIS researchers. And they would be foolish to jump the gun on the big announcement, that would risk everything that they've put into this project.

To me this is the only way to scientifically even attempt to conclusively prove the existence of ETI. I mean it's not like we're gonna be going out there like star trek in the forseeable future. So, until then this is our only way.

 

[gnome]

It's been estimated that if a single species expanded outward in just such a haphazard fashion, it could colonize the galaxy in a time frame between 200,000 and 20,000,000 years. That may be long before an alien technological civilization appears. http://www.amazon.com/exec/obidos/ASIN/0387955011/crastro-20

Actually that's a critical difference... I'd say if the figure was 200,000 years, it's a no-brainer... the first past the post gets the galaxy.

At 20,000,000 years, primitive primates can evolve into a technological society...

 

[Notrump]

Actually that's a critical difference... I'd say if the figure was 200,000 years, it's a no-brainer... the first past the post gets the galaxy.

At 20,000,000 years, primitive primates can evolve into a technological society...

Sorry, that was a typo. It should have been 2,000,000. But even with the 20,000,000 figure, I would submit it is unlikely that technological civilizations arise together in the galaxy within time frames less than that. The higher figure is still only 0.146% of the age of the universe. Yet tekkies with head starts greater than a mere 20,000 years (1/685,000 the universe's age) should have little problem eliminating the upstarts.

Also, only in one case has a primitive primate advanced toward space faring technology on Earth. As I suggested, on the galactic scale that may have been a freakish and unique occurrence.