248jsc-after all that, and a little bit o'luck and then evolution in the 21st Century could happen

OK - maybe I'll get in trouble for this, but ...

I used to design nuclear reactor cores for a living, and I am a pretty hard-nosed scientific engineering type. Certainly, there is strong delusion of some sort attending these "observations" of ET.

My viewpoint is pretty old fashioned. I strongly believe the Earth was visited - by God, the divine Logos (Word - Logic) in Jesus Christ. And if you want scientific proof, just go to Jerusalem on Orthodox Holy Saturday around noon, and go into the Church of the Holy Resurrection (Holy Seplucre is the world's name for it). Or pick up a Bible for $20.00, and pour over it for twenty years, and be brutally honest with yourself when you read it.

Look a real ET would use remote observations or something, they wouldn't have their expensive inter-stellar FTL spacecraft breaking down, or hovering over government nuclear installations. The energy/logic/knowledge required for interstellar spaceflight is enormous, and why bother with the sort of antics sometimes reported?

That sort of ET is just plain evil. "Close encounters" always are attended by an evil smell. Certainly, there are strange observations, and not everyone making them is a complete nut. But they do not follow a consistent, scientific or logical pattern for rational scientific "explanations".

This is because they are not from a friendly intelligence (and I personally think Earthquake lights, methane and military aircraft account for 99.999% of all UFOs). The more sensational cases with professional military observations are possibly from an evil intelligence.

The Church has known about this for 2000 years. Believe, make the sign of the cross, say a prayer, and ET should go away.

andy

The question I always ask is "Why would aliens, ET's, etc, even want to come to poor little Earth?" We are a tiny blob of rock and water orbiting a completely average yellow dwarf star in the outskirts of the Milky Way galaxy. The only way you could know we are even here from any distance is from the radio signals we emit, and those didn't even start leaving the Earth until the 1930's with enough power to be heard.

Over the years we've increased the power and the number of frequencies, but those signals, since the first, have only been travelling into the galaxy for about 68 years. That means an alien civilization that can travel at light speed would have to be or pass within 34 light years of Earth to hear us and reach us. FTL stretches it out to the full 68 light years, but they'd really have to be listening out at the edge of that sphere of radio signals. Worse of all, with the expansion of cable and direct satellite communications, our signal is actually dropping off. It is possible that in 30 or 40 years we will no longer emit any signal into space strong enough for an alien species to detect.

Another line of thinking is our nuclear weapons and their tests would attract an alien. The problem is that same with radio, and we've only been using nukes for 59 years, so the gamma burst sphere is smaller than the regular radio sphere.

The odds that an inteligent civilization would be within the few hundred stars out of the hundreds of billions in the solar system to could possibly hear us is so small that I seriously doubt it has or will ever happen. All ET's are weather balloons, military aircraft, and crazy people.

__________________
...and we'll be saying a big hello to all intelligent life forms everywhere; and to everyone else out there, the secret is to bang the rocks together, guys...

John L, you said, "Why would aliens, ET's, etc, even want to come to poor little Earth?" and continued, “We are a tiny blob of rock…”

Why would humans want to visit a tiny blob of rock in the middle of the Pacific Ocean and study finches for a harrowing amount of time? Why would humans want to visit hunks of ice near both poles, enduring very unpleasant conditions to study penguins and microbes, and do this for half a century and more, with no signs of stopping? Why do sophisticated people spend huge parts of their lives visiting really primitive people? Illiterate, totally unaware of the wider world, with abysmal political and economic systems, living conditions so horrid it passes belief.

Life--the most unusual, complex and diverse thing one can find in the whole universe. What would any human give to study life that has evolved independently from us from the beginning of time? And what is the potential knowledge to be gained? Past imagining.

If ETs have any curiosity at all, any desire for new knowledge, new art, and a host of other talents, they’ll be very interested in other life.

ETs will rush here, because we are so very special.

Bob

John L, you said, “with the expansion of cable and direct satellite communications, our signal is actually dropping off.”

Where did you get this information from? Per the Statistical Abstract of the United States, 120th edition, Table 910:

From 1970 to 1998 the number of broadcast commercial AM radio stations in the United States increased by 11%.

FM broadcast stations increased 159%

And television broadcast stations increased 82%.

Per the United Nations Educational, Scientific and Cultural Organization, Statistical Tables and Culture Indicators, Table 3, worldwide radio ownership increased an average of 8½% annually from 1980 to 1997.

In what Brave New World does an approximate doubling of broadcast services in 28 years suggest a decline? A quadrupling of radio ownership in 27 years?


Bob

Wow, Bob you have a lot of time on your hands. SO my first statement is that everyone has some sort of blind faith. Mine is my car. Even though I don't do anything right to it, I have faith that it will get me to where I'm going. Anyways, why can't some people that believe in Jesus leave the people that believe in Science alone. I am a spiritual person that believes in a higher power. Lord there has to be someone better than we are out there.

Second statement, we may live on a tiny piece of rock, but who says that people from another planet live on a planet larger than ours? Who says that they may not break down. Listen, in the 60's we shouldn't have even made it to the moon. We went because we felt like we could. What if the "aliens" have found a way to go really fast to come to other planets to look at the animals and it goes really fast but they forgot to get their oil changed?

This may sound dumb to some of you, but we keep deifying all of these supposed aliens. What if we aren't the red headed step child of the universe? What if the "aliens" that are visiting are the trailer trash of the universe?

Sorry it's late. i tend to go crazy at night

__________________
frijole cabesa

Dear sarahnade_me,

Sorry, I just wanted to admit my scientific bias up front. [That does however, beg the question as to why I have to subsidize the preaching of a scientific materialist religion to children.]

I do believe you are correct that these are not the upper-crust of the universe.

The major point however, is that it takes an inordinately sophisticated and expensive setup to break "the bars of time". While I think most UFO sightings are hogwash, there have been some rather consistent observations of ET over millenium - even by some recent professional observers.

Bobunf (the first response),

My point was that the aliens would need to know we existed to have any reason to come here. My point was that our signals into the universe leave a very tiny footprint compared to even this arm of the Milky Way. My point was that the odds of being noticed, like a lone and tiny atoll in the vastness of the Pacific Ocean, is very small unless there is a whole lot of aliens out there doing nothing but charting and exploring and filling the galaxy around us.

Bobunf (the second response),

I read a statement from somebody at SETI last week on New Scientist.com. The SETI guy talked about the conversion to wired and direct signal communications is (or would) reduce our signals into the galaxy until we disappeared. He was actually gald about this because he felt it explained why we haven't already picked up tons of civilizations. If they all eventually convert to more efficient direct communication methods then that would explain the lack of signals.

__________________
...and we'll be saying a big hello to all intelligent life forms everywhere; and to everyone else out there, the secret is to bang the rocks together, guys...

These omnidirectional signals from radio and television transmitters are probably not very easily detected signals from earth anyway so I think we haven't lost much in the way of announcing our presence. Highly directional radar and laser signals are much better beacons as the article notes. A highly likely method of supplying energy needed for a sizable vehicle to traverse interstellar distances is the highly directional beaming of chunks of the stars energy to the ship. If such exist, they should be easily detectable when sent our way.

__________________
For those inclined to oppose human meddling with the structure of the universe or the composition and configuration of objects and groups of objects within the universe, consider:
Whether there is a limit to the magnitude of a modulation of chaos below which order remains invariant? Or, is order but a fiction invented by perspectives applied over finite, however large, time intervals?

Gourdhead, you said, “we haven't lost much in the way of announcing our presence” and I think you’re right about this for the reason you stated, but more significantly, because the most important and easily detected signals we send are those having to do with atmospheric gases and other signals from the effects of life and of intelligence.

Also of some relation to all of this is that the amount of broadcast radio energy has not been declining, but has been going up.

How can it be that this fact is just ignored? Doesn’t reality have some relevance to these discussions?

Maybe if I put it in all caps? BROADCAST RADIO ENERGY HAS BEEN INCREASING THROUGHOUT THE TWENTIETH CENTURY.

John L, you said, “I read a statement from somebody at SETI last week “

But he was wrong, or at least there are very significant contrary indications. Even in the internet age does the truth never catch up with the lie?

This isn’t a hard thing to figure out. Oodles of reliable information are published from a huge variety of sources. It’s not a nuanced question, subject to all kinds of interpretation, but one subject to easy empirical investigation.

How can it be that we can’t get this very simple fact straight?

John L, I don’t think there are any tiny atolls “in the vastness of the Pacific Ocean” that haven’t been thoroughly investigated for interesting biological and other qualities. Not exhaustively, just thoroughly.

I don’t think the footprint of life is small at all—it’s been broadcast for about four billion years with an antenna of about 140 million square kilometers. Even we, before the end of the next dec-ade will be able to detect methane or oxygen producing life within 50 light years or so of Earth. By the end of the 21st century, it’s hard to imagine that capability won’t be extended to a distance of many thousands of light years.

Looking for the footprints of intelligence is harder, but I feel confident that very clever people will figure out ways to tease out the signals of wide scale agriculture, industrial activities, and other effects of intelligent beings in ways we haven’t even imagined, yet.

I also think advanced ETs will be as capable as us

Bob

It would take detemined searching and very sensitive instruments to detect the emissions that Earth gives out;
see
http://www.faqs.org/faqs/astronomy/faq/par...section-12.html

the 300 metre Arecibo telescope could detect our tv transmissions no more than 0.3 light years away.

I expect advanced civilisations will have bigger instuments, but in the unlikely event that there is a civilisation on Alpha Centauri at our current level of technology, they could not detect our broadcast messages at all.

Only tight beamed messages, like those sent from Arecibo itself, or high powered radar beams could be detected at such distances.

__________________
Orion's Arm . The Starlark . Voices: Future Tense- Novella Contest Issue! . OA Flickr set

We are no longer in the 20th century, Bob. The direction communications technology has been taking for the last 5 years has been toward direct signal and wired, both requiring less power than the old omni-directional technology. The article I cited is refering to the growth of this trend in reducing the amount of signal that escapes both the Earth and the solar system.

Quote:

Originally posted by Bobunf also said@ I don’t think there are any tiny atolls “in the vastness of the Pacific Ocean” that haven’t been thoroughly investigated for interesting biological and other qualities. Not exhaustively, just thoroughly.

I was speaking metaphorically. The size of the Pacific Ocean is a poor comparison to the vastness of intra-galactic space. My point is that there are somewhere between 100 and 500 BILLION stars in the Milky Way, most of which are red and yellow dwarf stars. There has to be a very compelling reason to pick which you would visit, and a drop off in our radio emmissions would take away a prominent reason. Even at half the speed of light you are talking about decades of travel just to reach nearby stars. I would want to know there was something worth seeing before I took off on a multi-decade flight to another solar system.

<!--QuoteBegin-Bobunf furthermore said
I don’t think the footprint of life is small at all—it’s been broadcast for about four billion years with an antenna of about 140 million square kilometers. Even we, before the end of the next dec-ade will be able to detect methane or oxygen producing life within 50 light years or so of Earth. By the end of the 21st century, it’s hard to imagine that capability won’t be extended to a distance of many thousands of light years.[/quote]Your assumption is that our atmosphere has almost always been Nitrogen-Oxygen with Methane, CO2 and such, which it hasn't, but I agree its been that way for at least half a billion years - a long time even in my book. But seeing those emmissions, seeing the actual Earth next to the brightness of the Sun is no simple task. You would have to assume that the aliens in question are curious enough to look, have technology sufficiently advanced enough to see, be close enough to our solar system to see, and then have the motivation to spend decades traveling sub-light just to pay us a visit. And why would they come here and not make contact after such an immense journey? You figure if they're smart enough to see the Earth for what it is in the multitude of other stars in this section of the galaxy alone, to hear our weak and now diminishing radio signals leaking out into space and recognize them for what they are, and to have the technology to do all this and then actually reach us, then they'd probably be smart or powerful enough to come up with a way to introduce themselves when they finally did arrive without scaring us to death, causing a global panic, or driving us to try to blast them out of the sky.

__________________
...and we'll be saying a big hello to all intelligent life forms everywhere; and to everyone else out there, the secret is to bang the rocks together, guys...

John, you said, “The article I cited is refering (sic) to the growth of this trend in reducing the amount of signal that escapes both the Earth and the solar system.”

Is there any data at all—anything whatsoever—that supports this assertion? Even if we can’t yet access 21st century data about the number of AM, FM and TV broadcast stations and their energy output, is there something? Anything? Has there been a decline in the sales of radio receivers? A collapse in the price of broadcast radio or television stations? A sudden opening of available frequencies?

I didn’t think so.

I’ll make a prediction: When the date is available, it will be found that the number of FM, AM and TV broadcast stations operating in 2004 was more than in 1998 or 1997—the years I cited. And don’t get confused about the difference between absolute numbers and market share.

The idea, with zero supporting data, that, “We have cable so there is less broadcast” is just fuzzy thinking. And the statements about decline are just sloppy. What's meant is that the speaker thinks a decline will occur or is occurring. To which, if properly stated, I would reply, "Well, maybe, let's see."

But we haven't seen yet, and this is no slam-dunk. Technologies don’t necessarily replace each other. We have airplanes; but we still have trains, automobiles and busses traveling to identical destinations. People still ride horses.

In 1995 more candles were produced in the United States than in 1800. Sorry, I don’t have any data on that subject for the 21st century.

It's not nice to write obituaries about entities (like broadcast radio and television) until there's a least some hint they may not be completely healthy. Who was it who said, "The report of my death has been greatly exaggerated?"

Bob

John, I didn’t make any assumptions about an oxygen-nitrogen atmosphere. My understanding of the history of Earth’s atmosphere is that it has consisted primarily of nitrogen for at least four billion years with concentrations generally exceeding 80%. About 2.3 billion years ago the first oxygen revolution occurred and the concentration of oxygen rose to about 12%, an unmistakable indication of photosynthesis and life.

Before there had been a concentration of methane of about one-tenth of one percent, which the oxygen pretty much removed causing the first snowball Earth Ice Age. I understand that methane in that concentration at Earth’s temperature would be an indicator of life—and this signal was transmitted from about 4 billion years ago to about 2.3 billion years ago.

About 600 million years ago oxygen increased to about 20% of the atmosphere.

Thus the signals sent out that life exists here may have been:

Methane in biology requiring concentrations: from about 4 billion to about 2.3 billion years ago.
Oxygen at a 12% concentration: from about 2.3 billion to about 600 million years ago.
Oxygen at a 20% concentration: from about 600 million years ago to present.

I did notice an error in my previous post: the area of the surface of the Earth is about 600 million square kilometers, not 140 million.

Bob

John, you said ”But seeing those emmissions (sic), seeing the actual Earth next to the brightness of the Sun is no simple task. You would have to assume that the aliens in question are curious enough to look, have technology sufficiently advanced enough to see, be close enough to our so-lar system to see”

I am making an assumption here: that advanced ETs will be at least as capable as us, and will have been so for awhile. But isn’t that like the definition of an advanced ET?

In the next decade NASA’s Terrestrial Planet Finder and the European Space Agency’s Darwin missions are designed to do just that: see those emissions next to the brightness of their Star. We’re curious enough to look; we have technology sufficiently advanced to see; and we’re close enough to several hundred stars.

If we can do this now, of what will we be capable in 2100? Or 2200?

If we can do it, how hard can it be for ET?

Bob

Oxygen in a planet's atmosphere is no guarantee of biological origin, neither is methane;
All four outer gas giants have detectable levels of methane, while oxygen was detected in the atmosphere of HD 209458b;
oxygen can be expected in any planet which has water and is exposed to high UV levels; photolysis will split the water, and the hydrogen component may evaporate if the escape velocity allows; this will produce an abiotic oxygen atmosphere.

__________________
Orion's Arm . The Starlark . Voices: Future Tense- Novella Contest Issue! . OA Flickr set

Eburacum45, you said, "oxygen can be expected in any planet which has water and is exposed to high UV levels; photolysis will split the water, and the hydrogen component may evaporate if the escape velocity allows; this will produce an abiotic oxygen atmosphere."

From the University of Michigan’s Fall 2004 course “Global Change, Evolution of the Atmosphere-Structure and Composition, Current Lectures” by Professor Perry Samson.

“Photolysis of water vapor and carbon dioxide produce hydroxyl and atomic oxygen, respectively, that, in turn, produce oxygen in small concentrations. This process produced oxygen for the early atmosphere before photosynthesis became dominant.

“Oxygen increased in stages, first through photolysis of water vapor and carbon dioxide by ultraviolet energy and, possibly, lightning:
H2O -> H + OH
produces a hydroxyl radiacal (OH) and
CO2 -> CO+ O
produces an atomic oxygen (O). The OH is very reactive and combines with the O
O + OH -> O2 + H
The hydrogen atoms formed in these reactions are light and some small fraction excape to space allowing the O2 to build to a very low concentration, probably yielded only about 1% of the oxygen available to-day.”

1% is a lot less than the 12+% oxygen concentration Earth has had for 2.3 billion years. I think our advanced ETs will be able to figure this out. 12+>1.

Bob

Eburacum45, you said, “neither is methane. All four outer gas giants have detectable levels of methane”

Methane is still detectable in the atmosphere of the Earth. Even with all the oxygen—a conse-quence of the activity of still extant methogens, and another indication of life.

As for more than 2.3 billion years ago, my understanding is that the probable amount of methane in the Earth’s atmosphere was in excess of 0.1%, an amount that could not have existed for more than a few tens of thousands of years, not alone billions, without biological activity, because of the photolysis that will occur in the upper atmosphere releasing hydrogen to space.

Again, I think advanced ET will be able to figure this out.

Bob