We can't know to a certainty, of course, that some ET civilization isn't about to invade our planet, with or without the prompting of our electromagnetic signals. Most things bearing on the fate of humanity seem to have a certain level of uncertainty. The 'alien invader' with our name on it could be an asteroid, for all we know.

Considering the age of the galaxy, compared to that of our planet, it seems likely that a typical civilization in space is much older, and much more advanced than our own. Even if the light speed travel barrier can't be gotten around, somehow, these civilizations have still had more than ample time to thoroughly occupy our galaxy.

The question arises, then, why hasn't our planet been taken over, in all its long history? In that none of the possible ET civilizations has done so, there appears to be something very strong inhibiting such an outcome. I suggest the possibility that the galaxy is thoroughly tenanted, and orderly, and that our planet has the status of a cultural and biospheric reserve.

We already have such reserves in parts of our planet, in bits of the Amazon basin, for example, and in North Sentinel Island in the Andaman and Nicobar Islands group, in the Indian Ocean.

You raise some VERY good points. :) Thank you... I suspect you're quite right on fa rmore advanced civilizations, but also think the size of the universe may be helping in our being safe, so far. :)

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River Song (aka Linda Latte on planet Earth)
"Happy I-Phone girl on the GO GO GO"

A much more likely scenario as to why we haven't been visited is:

If there are other advanced civilizations they are spaced so far apart that travel is ruled out; and also, they couldn't find a planet worth visiting as they are also likely to be sparsely scattered in our Galaxy.

A much more likely scenario as to why we haven't been visited is:

If there are other advanced civilizations they are spaced so far apart that travel is ruled out; and also, they couldn't find a planet worth visiting as they are also likely to be sparsely scattered in our Galaxy.

So VERY true !!!!!!!!!!!

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River Song (aka Linda Latte on planet Earth)
"Happy I-Phone girl on the GO GO GO"

I wasn't thinking of travel in the sense of an excursion starting out from one star, and stopping off at another, if/when it's found to have an interesting civilization.

Human history starts out in a tiny corner of Africa, and ends up with us occupying nearly all hospitable, and many inhospitable places on this planet. The whole process took hundreds of thousands of years. A very wide variety of other forms of life on this planet have also expanded into new territory, when it was advantageous for them to do this.

For a more advanced civilization, spreading out into space, even at speeds well below that of light, would enable it to colonize all habitable planets in the galaxy is a period of time not too dissimilar to that of human territorial expansion on Earth. This was realized over sixty years ago by Dr. Enrico Fermi, and is the basis of the famous Fermi Paradox.

This would work with even only one other (elder) civilization in the galaxy, besides ourselves. This civilization would improve its odds of long-term survival, as they expanded their territory. Even if some worlds were destroyed by nearby supernovas, asteroid impacts, or the like, others could be far enough afield to escape harm.

like I said if the nearest habitable and life sustaining planet were 30,000 light years away then how would they get there and how would they know where they were going ?

The scientific consensus is reported to be that there are billions or tens of billions of habitable planets in our galaxy. This would indicate that they are much, much nearer one another than you suggest.

Even at our rudimentary level of technical civilization, we are already coming close to being able to discern which of the stars near us in space is likely to be hospitable to life as we know it.

The scientific consensus is reported to be that there are billions or tens of billions of habitable planets in our galaxy. This would indicate that they are much, much nearer one another than you suggest.

Perhaps. But let's remember that probability doesn't determine individual cases. If the "average" distance between habitable planets, however we chose to define them, is X, that doesn't preclude the possibility that the closest one to us is 3X, 5X, or 100X. We don't know that life evolves on every possible planet, or how often life my evolve into complex life, let alone technical civilizations.

We seem to be veering into a discussion of the so-called Fermi Paradox, and there's a Wiki entry that gives a good rundown of the many possible explanations. https://en.wikipedia.org/wiki/Fermi_paradox

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“Upon opening the box, Schroedinger's raccoon will be observed in one of three possible states; alive, dead, or really, really pissed off.”

The scientific consensus is reported to be that there are billions or tens of billions of habitable planets in our galaxy. This would indicate that they are much, much nearer one another than you suggest..

The current age of the earth is estimated as being about 4.5 billion years, while the age of the universe is about 14 billion years. The most advanced civilizations are likely those over 10 billion years of age. While the "kids" in the universe are our age, or less. Since these much older civilizations are at or out towards the edge of the universe, they are an unbelievable distance, in terms of light years, from us. This is likely why we've never been contacted. Why even should these very old civilizations even want to contact us? What have they got to gain?

Our galaxy, big as it is, to us, is but the tiniest fraction of the universe. Consider that a web search will show that "Astronomers say there are 100 billion to 200 billion galaxies in the universe." We are ONE galaxy among as many as 200 billion galaxies. Wow, huh? I really doubt that the scientific consensus is that there are "billions or tens of billions of habitable planets in our galaxy." The likely number, IMHO, may be more like 100,000 planets, with maybe, and a lot of luck, 1% of them being habitable, i.e., in the "Goldilocks Zone." The "Goldilocks Zone" defines an area around a star where the temperature, et al and the presence of water is conducive to life as we know it, i.e., human life. Of course, there may be intelligent life that is not carbon-based; we have no clue on that, yet.

This thread is quite interesting with many logical ideas being put forth and discussed. All of us maybe at least partially "right" in our views.

There is one thing that has not been mentioned by anyone. All of the posts, including mine, till now, have never mentioned ONE interesting thing and that is "Flying Saucers."

I suspect that only a small percentage of those posting here believe in their existence, but I do. As a teenager, in 1952, at White City Beach, in Cleveland, Ohio, USA, a time of many saucer sightings, I saw one, fairly close up, about 600 yards away, and at the time I was in the company of hundreds of other people who also saw it arriving at, and hovering above, a bath house on a hill for nearly a minute, and then quietly rising, while remaining level, at about a 45 degree up angle, and quickly vanishing in a burst of acceleration. It had the classic shape, and judging by the size of the beach house, it was about 100 feet in diameter. All of us were along a pier fishing at the time. We all stood up and pointed towards the hill and exclaimed. Those nearest the beach end of the pier rose first, and all others, in a ripple effect, rose up and pointed. The long pier was terminated in a break-wall. The ship that I and hundreds of others saw was definitely "alien." Why, you may ask? I would answer: "Because we have no round airplanes on Earth." We had no cell phones back then, and there were no phone booths anywhere within almost a mile of our fishing pier. No one could call a TV station or a newspaper. Everyone was stunned. We all went our own way and I doubt the incident was ever reported. I saw no mention of it in the "Cleveland Plain Dealer," a large local newspaper.

Saucers are REAL, as those lucky enough to see one close up, can attest to. Where do THEY come from? Geez, huh? They certainly have technology advanced far beyond anything we have. Are these ships from the edge of the universe, or could they possibly be "our" age? If they are, how could they have developed at a much faster rate then we have?

So much to ponder, huh? We know so little. I'm reminded of the quote from Shakespeare's Hamlet that says "There are more things in heaven and earth, Horatio than are dreamt of in your philosophy. ..."

Oh well...

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River Song (aka Linda Latte on planet Earth)
"Happy I-Phone girl on the GO GO GO"

Leaving out distant galaxies , our own is old enough that elder civilizations within it could easily be a billion years our senior. There are a number of legitimate scientific sources that give the estimated number of habitable planets in our galaxy. These estimates are available via a simple internet search. A high end estimate would appear to run as high as 60 billion.

If only a small fraction of those hold intelligent life, we're still talking about a very well populated galaxy. Since there has been far more than enough time for all habitable planets to be occupied by expanding civilizations, it appears that even this sort of figure may be very conservative.

I wouldn't rule out the possibility of visits from those other civilizations. Evidence of such visits is typically considered inadequate by science, but perhaps that's how things are arranged. Those supposed visitors may act so as not to disturb our societies too deeply and too suddenly. Your own experience appears to fulfill these requirements. There caution may be quite wise, as it appears to me that many are still very much inclined to fear the 'other'.

http://www.universetoday.com/103379/60-billion-habitable-planets-in-the-milky-way-alone-astronomers-say-yes/

There is one thing that has not been mentioned by anyone. All of the posts, including mine, till now, have never mentioned ONE interesting thing and that is "Flying Saucers."

I never know what to do with the UFO question, for the simple reason that there's nothing except a lot of anecdotal reports. Yes, many are from very credible people. A few are from people I know personally, and I don't doubt that they saw what they say they saw. But observation doesn't equal explanation. So maybe we're being visited or observed, or teased, but where can we take that? We can only speculate and try to sort out hoaxes and swamp gas. It's a dead-end issue, in a sense. I'm not a skeptic necessarily. I just don't think sightings inform us very much.

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“Upon opening the box, Schroedinger's raccoon will be observed in one of three possible states; alive, dead, or really, really pissed off.”

Extraordinary claims require extraordinary evidence. Where is a single artifact; where is the first habitable planet that could support life as we know it. Where is good video of a sighting --where is the report of the breaking of the sound barrier when these putative craft accelerate away at high speed ?

Where are the saucers now that there is widespread television and armies of camera carriers ?
And finally where is the decoded message from 50 years of listening to the cosmic radiation.

maybe tomorrow we will find these things--I tend to think not but enjoy looking none the less.

The problem for science, I think, could be that the scientific method isn't really applicable to a situation where the subject of investigation is intelligent, and technically accomplished enough to conceal or reveal itself at will, to whatever degree it sees fit, and at whatever time it chooses.

Extraordinary claims require extraordinary evidence. Where is a single artifact; where is the first habitable planet that could support life as we know it. Where is good video of a sighting --where is the report of the breaking of the sound barrier when these putative craft accelerate away at high speed ?

Where are the saucers now that there is widespread television and armies of camera carriers ?
And finally where is the decoded message from 50 years of listening to the cosmic radiation.

maybe tomorrow we will find these things--I tend to think not but enjoy looking none the less.

You are so right above. You mention "Where is a single artifact?" No one outside our government can say for certain, and those that know are not talking about Roswell in 1947. There likely are artifacts from that purported UFO crash but no way for ordinary people to prove it. Area 51 is sealed like Fort Knox was, if it still is? Any gold still stored there?

Your comment "Where are the saucers now that there is widespread television and armies of camera carriers ?" really makes me wonder. The majority of UFO sightings occurred in the late 1940's and thru the 1950's, and now, in past years, I've not heard anything. Why aren't the saucers around now? I speculate on one thing that may be the reason. The period of maximum UFO sightings, the 40's and 50's, occurred during the same time period as tests of atomic and hydrogen bombs by the USA and Russia took place. Maybe the "atomics," and the threat such weapons pose, drew the interest of extraterrestrials?

I dunno? All I can do is speculate as we all do. I only know what I saw on a warm summer day, along with hundreds of others, in 1952. Your point about "where is the report of the breaking of the sound barrier when these putative craft accelerate away at high speed ?" made me blink. :) Gosh, we heard nothing when that ship accelerated upwards. It was quiet. there was no sound when the craft was hovering over the beach bath house either, at least none we could hear at 600 yards; its possible there was a low hum up close, but no one was below it to confirm it. Maybe the craft did not reach the sound barrier when it accelerated? It could have stopped accelerating below the barrier and went into level flight?

Geez, so many logical questions, and logical speculation, but no real answers. :(

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River Song (aka Linda Latte on planet Earth)
"Happy I-Phone girl on the GO GO GO"

There was no UFO crash. It was the remnants of a silver-coated high altitude spy balloon that we sent aloft to listen for Russian A and H-bomb tests.

You can see pictures of the rubble out there on the internet. The government couldn't find it's own behind with both hands let alone keep such a secret.

There was no UFO crash. It was the remnants of a silver-coated high altitude spy balloon that we sent aloft to listen for Russian A and H-bomb tests.

You can see pictures of the rubble out there on the internet. The government couldn't find it's own behind with both hands let alone keep such a secret.

I have to disagree, but I won't fall for the government coverup of the 1947 Roswell crash. :) Admittedly, it has been 'hyped up' to the n-degree, by our government, and the media, most likely, but then that is typical.

What I witnessed in 1952 in Cleveland, Ohio, with many others, is the reason for my not agreeing. What I and others saw there was REAL, and lends credulity to the Roswell crash. If it hadn't been for THAT, I would likely have to agree with you because of the lack of evidence. But, no offense intended.

Stay here on Earth. It's the only planet with DARK CHOCOLATE !!

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River Song (aka Linda Latte on planet Earth)
"Happy I-Phone girl on the GO GO GO"

Stay here on Earth. It's the only planet with DARK CHOCOLATE !!

If so it's very understable that so many aliens are coming to us.
However how they get undetected by astronomers, the army and others is beyond me.

[quote]Stay here on Earth. It's the only planet with DARK CHOCOLATE !!

If so it's very understandable that so many aliens are coming to us.
However how they get undetected by astronomers, the army and others is beyond me.[/quote

Maybe DARK CHOCOLATE reacts differently on aliens than it does on humans? Perhaps it causes invisibility? I dunno. :)

I can EXPLAIN it to you but I can't UNDERSTAND it for you. :)

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River Song (aka Linda Latte on planet Earth)
"Happy I-Phone girl on the GO GO GO"

What I witnessed in 1952 in Cleveland,

I suspect that you were quite young then. I too seem to recall that on the streets of New York the older boys playing football would kick the ball up on the roof of the 5-and 6 story hi-rises on my grandmother's block and then crawl straight up the side of the building --hand over hand --to get the football back. Though this is a vivid memory i am sure that It was just an adolescent dream.

Looks like communication (sending/getting information) is limited to the speed of light after all.

Superluminal communication is believed to be impossible because, in a Lorentz-invariant theory, it could be used to transmit information into the past. This contradicts causality and leads to logical paradoxes.

https://en.wikipedia.org/wiki/Superluminal_communication