Saturday, August 04, 2007
Your Saturday evening poll
I asked a question the other day, in a discussion about science fiction, that I thought trite but turned out to be new to my interlocutor: Which is the more awe-inspiring and mind-blowing notion, that there are many other species in our galaxy who have built technological civilizations, or that humanity is the only one? Well, which blows your mind more? Take the poll!
Of course, we will all appreciate and admire your elaborations in the comments.
22 Comments:
By 
, at
Sat Aug 04, 08:25:00 PM:
I'm an almost done with my Ph.D. in Physics, specializing in Cosmology, so I think I can offer some perspective, at least from an astrophysical point of view. (Yay for one hit out to right field for me!)
At the most basic level, we're just chemical compounds that replicate themselves in a very elaborate fashion. The atoms that comprise us are mostly H, C, N, and O, and a few heavier trace elements. Initially, the universe was too hot for atomic nuclei to exist, and it was one giant photon plasma. When the universe became cool/old enough, it underwent the epoch of recombination, in which all the hydrogen in the universe was formed. Later on, the first stars formed, and in the giant fusion power plants at their cores, heavier elements formed evenly throughout the universe. Successive generations of stars then produced the heaviest elements. So there's nothing special about the most basic building blocks of which we are made; they can be found pretty much anywhere.
There's also nothing really special about the environment in which we arose, i.e. the sun as a star, either. It's a pretty standard main sequence star; we know of billions of others like it.
I think it's a pretty safe bet that there's self-replicating chemical compounds somewhere else; we can conservatively estimate that our universe contains over 100 billion galaxies, and each of those contains over 100 billion stars. Even if you say that only stars similar to our sun could have planets that support life (which I don't believe is true), that's still 100 billion galaxies * 100 million stars = 10^15 candidate star systems. Most of those stars have been around for billions of years as well. So IMO the smart money is on extraterrestrial life out there somewhere, simply because our home in the universe is so utterly un-special.
Will we ever be able to contact extraterrestrial life? I'd say almost certainly not. SETI is a nice project and all, but unless another civilization happens to have sprung up within a few light years (which is definitely extremely unlikely), we'll never detect them. But who knows, someday we might discover that the laws of physics are different than we think they are...which is why you, the taxpayers, continue to fund basic research in physics! Hooray!
By 
D.E. Cloutier, at
Sat Aug 04, 10:07:00 PM:
Phrizz11, what about wormholes? Are they theoretically possible?
By , at
Sun Aug 05, 12:09:00 AM:
I was once told by one of my physics professors (about 31 years ago) that tachyons (hypothetical particles that supposedly travel faster than light) were absolutely impossible. So there goes that "faster than light stuff".
A lot of permutations of Einsteinian space suggest that a "wormhole" is possible, but it would be deucedly hard to find, and would probably be extremely dangerous to send living matter through.
Lorentz transforms predict the exponential increase in mass as you approach the speed of light, and that pretty much precludes us humanoids ever getting to a close to even a nearby star in a reasonable amount of time (like one lifetime).
Unlikely that the Universe is empty of other intelligent life, but it would likely be too far away to communicate with (perhaps centuries between "Hi" and "How are you?"), or either too backward or too advanced in the right time frame for us to find them (or them to find us). Criminy, we can hardly communicate with each other sometimes.
The Universe is surely not empty of other intelligent life, but we are truly alone. This should give us pause to cherish each other a little more than we do.
Afloat, and alone, in a Universe without end.
-David
By D.E. Cloutier, at
Sun Aug 05, 01:23:00 AM:
Thanks for the response, David.
By TigerHawk, at
Sun Aug 05, 07:09:00 AM:
If FTL drive is not available, then the solution, perhaps, would be to extend lifespans. If we conquered aging, or pushed human lifespans into the several centuries, intersteller travel at at a high percentage of the speed of light would become possible for individuals.
By , at
Sun Aug 05, 10:40:00 AM:
It seems pretty obvious that if there were other forms of intelligent life and we were capable of contacting each other, such contact would already have occurred.
Three possibilities exist: one, no other forms of intelligent life exist in the universe; two, other forms of intelligent life exist but as we are so completely different we cannot communicate with each other; and, three, we are not a form of intelligent life.
Ever hopeful, I vote in favor of numbers one or two.
By TigerHawk, at
Sun Aug 05, 10:46:00 AM:
I'm not sure I accept the premise -- we have not been in a technological position to "listen" for extraterrestrial communications for more than 75 years or so, and realistically less than that. That is a very small window. What if the last "hail" came through, say, 200 years ago? I'm not sure what a reasonable period of time would be, but according to one way of thinking about it we have not given it much of a chance.
By , at
Sun Aug 05, 11:35:00 AM:
"Three possibilities exist: one, no other forms of intelligent life exist in the universe; two, other forms of intelligent life exist but as we are so completely different we cannot communicate with each other; and, three, we are not a form of intelligent life."
With respect, there is a fourth possibility. Let me give you a hint:
Interview with famous scientist:
Q: Is there any reason to think life could not exist elsewhere is the universe.
A: No, it is quite possible, and even likely that it does.
Q: Could any of that life evolve to intelligence?
A: We know of no reason why it could not, since it did here.
Q: Could those intelligences develop space travel?
A: Since we are in the process of doing so, I would have to assume they could.
Q: Could they travel to other worlds. like ours?
A: Well, we have travelled to another world, the Moon, admittedly a small baby step.
Q: Could they be far ahead of us in that respect?
A: Yes, they could - even if they were a few thousand years older than us, a blink of an eye in the evolution of our world, they could do things we could only perceive as magic, I suppose.
Q: Could they have come here already?
A: Certainly, it is possible they could have.
Q: What do you think about those who say they have seen things they interpet as alien spaceships?
A: They are all crazy idiots and fakers!
By Dawnfire82, at
Sun Aug 05, 12:29:00 PM:
Very pithy, but insert a rational thought there at the end.
Q: If there really was a space alien civilization with the means and interest of visiting Earth, can you think of any reason why they would buzz corn fields, kidnap farmers, and mutilate cows instead of, say, contacting world leaders by radio?
A: No.
By , at
Sun Aug 05, 02:01:00 PM:
Unfortunately there's really not much hope that we'll ever contact an alien civilization, unless the signal will be transmitted by some unknown mechanism. For us to receive a radio signal from another star system inside our galaxy, the power level of that signal would have to be some fraction of the output of the star itself, so we could detect a modulation in the signal coming from the star. Unfortunately, we don't just have to communicate with another star system, but we have to compete with the stars we live next to!
To put some numbers on it, the sun's power output is about 10^26 W. A 1 megaton nuclear weapon generates about 10^15 J of energy. Even if we detonated every nuke on earth in the space of 1 second we would barely produce a 1 part per billion blip in the radiation coming from the sun.
Unless there's some really crazy new technology/physics out there waiting to be discovered, which would let us compete with (or mess around with) a star's output, SETI will probably never discover anything.
By , at
Sun Aug 05, 02:12:00 PM:
We (some elements of the human race) have been able to communicate via the E-M spectrum for about 100 years. As TH said, we have been able to listen, intelligently, for less than that time, and only intermittently. Regardless of the life form and their advancement, they would probably use some portion of the E-M spectrum to communicate, not knowing the technological development of the possible receiving civilization.
So,a bubble of about 100 light years in radius from our planet, may have heard us. In that radius has to be a race that is
1) Technologically advanced enough to hear us. Mankind has been 'cvilized' for thousands of years, but only had E-M technology for about 100 years.
2) Actually paying attention, and interested
3) Is not so Xenophobic (a distinct possibility) to respond
4) Doesn't have some ethical qualm about contacting us, as in "Star Trek" non-interference Prime Directive.
When the outbound E-M wave from Earth is 1000 light years away, maybe there will be a statistically significant chance of meeting some of those criteria.
Carl Sagan (and others) seemed to feel that contact with a technologically advanced civilization would validate or vindicate many of their personal views and intellectual ideas; somewhat like what some kinds of Christians believe about 'Angels'.
We should be careful what we wish for; it's possible that an extra-terrestrial civilization would be so advanced and so...alien..., as to cause huge social disorder and trauma among human beings if we had contact. All of our accomplishments and knowledge might be trivial to them.
-David
By , at
Sun Aug 05, 02:15:00 PM:
Yeah, what Phrizz said about the power requirements, too.
I once read something about dumping large amounts of an unusual element (say Technetium) in the Sun to temporarily change its spectra, as a way of signalling an advanced civilization "Here we are!"
-David
By D.E. Cloutier, at
Sun Aug 05, 03:57:00 PM:
Well, keep at it, guys. I would like customers on other planets. The global marketplace on earth seems rather small to me these days.
By , at
Sun Aug 05, 05:25:00 PM:
TH: I answered 'A' on the vote, but with reservations. I didn't like the word "only".
On the other hand, it did inspire me to write this.
I'd say the odds have it.
Doc
By Assistant Village Idiot, at
Sun Aug 05, 09:37:00 PM:
Just to be irritating, I will point out that what blows my mind the most is that both possibilities are used as an argument against the existence of God.
We are hard to please...
By , at
Sun Aug 05, 10:40:00 PM:
See Rare Earth
Paleontologist Peter Ward and astronomer Donald Brownlee think all of us should feel lucky. Their rare Earth hypothesis predicts that while simple, microbial life will be very widespread in the universe, complex animal or plant life will be extremely rare.
Ward and Brownlee admit that "It is very difficult to do statistics with an N of 1. But in our defense, we have staked out a position rarely articulated but increasingly accepted by many astrobiologists."
Renowned paleontologist Ward (Univ. of Washington), who has authored numerous books and articles, and Brownlee, a noted astronomer who has also researched extraterrestrial materials, combine their interests, research, and collaborative thoughts to present a startling new hypothesis: bacterial life forms may be in many galaxies, but complex life forms, like those that have evolved on Earth, are rare in the universe. Ward and Brownlee attribute Earth's evolutionary achievements to the following critical factors: our optimal distance from the sun, the positive effects of the moon's gravity on our climate, plate tectonics and continental drift, the right types of metals and elements, ample liquid water, maintainance of the correct amount of internal heat to keep surface temperatures within a habitable range, and a gaseous planet the size of Jupiter to shield Earth from catastrophic meteoric bombardment.
By , at
Mon Aug 06, 12:30:00 AM:
(Actually, after some further thought the power requirements are not quite as dire as I had stated, since the sun is by far not as loud in the radio as in the IR and higher wavelength bands. But it's still a large amount of power.)
By , at
Mon Aug 06, 12:35:00 AM:
Remember SUPERMANS home planet of KRYPTON exploded and thats why we have the MAN OF STEEL
By , at
Mon Aug 06, 01:19:00 AM:
"Very pithy, but insert a rational thought there at the end.
Q: If there really was a space alien civilization with the means and interest of visiting Earth, can you think of any reason why they would buzz corn fields, kidnap farmers, and mutilate cows instead of, say, contacting world leaders by radio?"
A: No.
My comment is not merely "pithy". It addresses a very real deficiency in the investigation of a very prevalent but controversial phenomenon.
Exactly how does you response, which vividly demonstrates the prejudice that I have tried to illustrate in my little dialog, serve to refute my contention?
Or do you consider that all UFO reports involve objects that "buzz corn fields, kidnap farmers, and mutilate cows?"
Far from inserting "a rational thought here at the end", you have smugly illustrated my point that there is little logic in how this subject is investigated. Thank you.
ps. Brownlee's and Ward's book, which I have read, advances a hypothesis. I doubt it's validity, but it is a hypothesis nonetheless - your comment is merely a retort designed to preclude serious discussion.
By , at
Mon Aug 06, 05:27:00 AM:
Phrizz11: "Unfortunately there's really not much hope that we'll ever contact an alien civilization, unless the signal will be transmitted by some unknown mechanism. For us to receive a radio signal from another star system inside our galaxy, the power level of that signal would have to be some fraction of the output of the star itself, so we could detect a modulation in the signal coming from the star. Unfortunately, we don't just have to communicate with another star system, but we have to compete with the stars we live next to!"
Slow down, kid. You assumed the need to radiate continuously in all directions on all frequencies. Don't do that. :-)
The problem of signals in a noisy environment is a problem for EEs, not cosmologists, and it is one they solved some time ago. Besides, outshining the sun is easy:
(1) Aim. Don't radiate over 4pi sr, radiate over 1 nsr at a time, pointed right at a nearby star. That gets you 10 OOM.
(2) Go off-peak. Going from 10000 cm-1 to 0.1 cm-1 gets you another 10 OOM.
(3) Flash. Don't radiate CW, pulse the signal.
(4) Go narrow-band. Nature doesn't have a lot of monochromatic sources. Just ask Joe Taylor.
Bottom line, these guys say a Sun-size 5800K black body emits 5.8 kW from .10000 to .10001 cm-1 in a 1 nsr cone. Jeez, WPRB puts out more power than that, CW. Add in clever modulation/coding, and you've got yourself an interstellar signaling system.
TigerFizz
By , at
Mon Aug 06, 09:00:00 AM:
TF: Yeah, I guess you're right, I hadn't really thought it through
very carefully. Thanks for the correction.
By D.E. Cloutier, at
Mon Aug 06, 04:08:00 PM:
TigerFizz: "Slow down, kid."
Phrizz11: "Yeah, I guess you're right, I hadn't really thought it through very carefully."
Well, there's the answer to Anonymous Lawyer in the TigerHawk post "Big law firms are very harsh places" on August 1.
http://tigerhawk.blogspot.com/2007/08/big-law-firms-are-very-harsh-places.html
