Posted on 10/13/2009 8:14:47 PM PDT by Michael Barnes
Turn it around, and add to this that we've only been broadcasting for ~100 y means no one farther out than 100 c-y can see us, yet, even if they have large arrays in space and better signal separation technology listening for us. We have no evidence that there are habitable planets within 100 c-y. Give it a couple of thousand years.
As for civilizations that boast a 1.8 Gy technology lead over us: maybe they've already been here and gone. Maybe we've met the aliens, and they are us. I believe this was Francis Crick's conjecture. We have no real theory of abiogenesis on this planet, yet. Maybe there's a reason.
Incidentally, if the self-destruction scenario is true, given a fairly constant rate of development of new intelligent civilizations, then the odds of a civilization surviving are at least somewhat likely to go up over time, as you have civilizations figuring out that most previous civilizations must have self-destructed before them, and some therefore attempting to find ways to circumvent such self-destruction.
So what you're saying is, our existing technology could likely only detect signals broadcast within 250 light years? If that's the case, then that would cover only about 1/25trillionth of just the Milky Way. That could kind of explain the Fermi Paradox right there.
Absence of evidence isn’t evidence of absence.
Meanwhile, at exactly the same time, aircraft that were not made by humans were buzzing the White House and about 100 US Cities.
Life is extremely rare. Even excluding the vastness of space, life in the Solar System is rare by many measures. One could measure the proportion of living mass or living volume to its non living counterparts in our local neighborhood and come up with very small numbers.
Another possibility is that our SETI efforts are completely irrelevant to date. Our technology is too primitive to pick up interstellar communication.
Even so, they would still know that there's a planet here which has life from about anywhere in the galaxy, and they would have known it for a very long time.
Really? When there are billions of planets in the Milky Way, spread across 100,000 light years in 3 dimensions, and we've only been broadcasting long enough for our signals traveling at light speed to have even (weakly) reached 1/50trillionth of our galaxy?
Sorry, doesn't wash.
>>>just plug that Drake equation into an excel spreadsheet .... life in other galaxies? definitely outside our area code.
Moreso because the Drake Equation is incomplete. Additional factors can and should be incorporated into the calculation. Factors which drastically reduce the chances of alien technical civilizations.
The only thing certain is that the Drake Equation only offers a starting point for thought. Not answers. Not a single element of the equation can yet be quantified.
Drakes calculation posits as if all solar systems are created equal, leaving the matter of life in all cases to the same random percentages. Without regard for position in the galaxy, be they in the spiral arms or the dense core. Regularity of solar emissions is ignored, when a 1% plus or minus in output makes the difference between ice ages and scorched world. Distribution of heavy metals in the galaxy. And several similar omissions.
Its pretty obvious that Extrateressials are here. The evidence is all around. You can’t even turn on the science channels without some UFO show on. Independence Day runs all the time.
Ed Mitchell talks about it here. The DJ is a flake and annoying.
http://www.livevideo.com/video/C50A...l-claims-u.aspx
That link was dead. This is the link to Ed Mitchell who was the sixth man to walk on the moon.
http://www.livevideo.com/video/C50A9CA5569C45BB8D28FCE6E525A63E/astronaut-ed-mitchell-claims-u.aspx
How about the most simplistic answer of all: God created the Universe and decided to create humans on Earth—the rest of that stuff “out there” is for His amusement?
(don’t flame me, I’m a theology graduate)
Folks with an interest in the topic might find this scientist intriguing..
I love the analogy he draws of ant colonies next to the freeway.
They wouldn’t have to wait for our signals. They would almost certainly be able to read the chemical composition of our atmosphere.
Not even close. Unless a signal is beamed directly at us, we cannot pick up a transmission further away than about 0.8 c-y. To reach 250 c-y, we would need an antenna array with area 10^3 km^2 (if square, 30 km on a side).
If that's the case, then that would cover only about 1/25trillionth of just the Milky Way.
Milky Way Galaxy has dimensions ~10^5 c-y diameter x 10^3 c-y thick. Roughly has area 8 x 10^12 c-y^3. If we could see out to 250 c-y, that would be a volume centered at the earth of around 6.5 x 10^7 c-y^3, so if we could see out to 250 c-y, we would cover only 1/120,000th of the galaxy. This is small, but not as small as your estimate.
You also have only a temperature window from about 280-325 K.
Why do people consistently think that we should be able to somehow communicate with planets thousands of light years is beyond me. If it takes light a thousand years to get there then we should expect a response in, say, two thousand years.
why do these knuckleheaded authors keep talking about life in other galaxies (which I would think is completely irrelevant to this discussion)?
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