Posted on 07/16/2018 10:04:54 AM PDT by PJ-Comix
t’s something people tell me all the time, and usually in hushed tones: “With a trillion planets out there, we really can’t be the only intelligent beings in the galaxy.” In other words, given the enormous amount of real estate in space, aliens are sure to exist. So why haven’t we found any?
I don’t dispute this straightforward idea because, after all, it underpins the search for extraterrestrial intelligence (SETI). But not everyone agrees. A recent paper by three researchers at the University of Oxford is throwing shade on those who feel confident that the cosmos is thick with extraterrestrials.
The Oxford academics were addressing a puzzle known as the Fermi Paradox, which describes the disconnect between our expectation of many worlds swarming with aliens and the fact that they remain undiscovered. Nearly 70 years ago, the celebrated physicist Enrico Fermi mouthed a deceptively simple question: “Where is everybody?” He made a quick estimate of how long it would take for any society bent on building an empire to colonize the entire Milky Way and realized it was only a few tens of millions of years, which is nearly 1,000 times shorter than the age of the galaxy.
This raised an obvious problem: There’s been more than enough time for aliens to spread out, and yet we don’t see them.
(Excerpt) Read more at nbcnews.com ...
Logical? Based on what evidence?
Have you seen this response?
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Let me see if I can answer your questions and perhaps change your conclusion.
First:
Earth is at just the right distance from the Sun so that it is warm enough for ice to melt, but not so hot as to boil and steam away. Water is also able, in this habitable zone (the so-called “Goldilocks” region), to both evaporate and condense at lower levels in the atmosphere, thus permitting a more even distribution of water and the cycle of water over dry land known as precipitation.
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While the earth is at a good distance, the Goldilocs region, most star/planet have planets in a similar region. While many red stars have planets closer than us to our sun it is ok because of the lower radiation of a red star.
Second:
For suns to spawn Earth-like planets they must have sufficient “metallicity,” which is necessary for the formation of terrestrial rather than gaseous planets.
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Mostly, except possibly in white dwarfs, stars do not spawn planets. The materials from planets come from dead stars that have gone into supernova and in the explosion fused light elements into heavy elements. Those heavy elements are shot out away from the exploding star at great speeds until they are captured by another star and end up rotating abound a star.
At one time in astrophysics it was thought that these heavy objects would form an “accretion disc and their weight would eventually ignite and become a star. This theory passed away about 40 year or so ago. the theory now is that the early universe was mostly if not entirely hydrogen.
The hydrogen fell together because of gravity and formed stars. In the early universe there were many very large stars that burned themselves up very quickly and their monster explosions seeded the universe with heavy particles from which the planets have evolved.
Many larger planets while having a rocky or metallic core are mostly gas. Planets closer to their star are mostly rocky and metallic. The vast majority of planet/star systems have some rocky planets in the Goldilocks region.
Third:
Earth is in a “habitable zone” within the galaxy as well. Closer to the center of galaxies, radiation and the presence of wandering planetoids make life there unlikely.
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We don’t really know where the habitable zones are in most galaxies including our own, yet, we make suppositions however and the habitability zone likely encompasses over half of the stars in most galaxies. As star systems get closer to the center of a galaxy they receive significant radiation from other stars which “could” have an effect on life.
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Fourth:
Earth exists in a disk-shaped spiral galaxy (the Milky Way) rather than in an elliptical (spheroid) galaxy. Spiral galaxies are thought to be the only type capable of supporting life.
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While there may be some who think that spiral galaxies are the only kind that can support life there are plenty of people that would disagree. To say something is “thought” to be could mean that one person thinks that. That does not make it so.
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Fith
Earth’s orbit around the sun is an almost perfect circle rather than the more common “eccentric” (elongated) ellipse. Steep elliptical orbits take a planet relatively close to and then relatively far from the sun, with great consequences for warmth and light. Earth’s stable, nearly circular orbit around the sun keeps our distance from it relatively constant, and hence the amount of heat and light does not vary tremendously.
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While not perfect earths orbit is not highly eliptical. The orbit being not perfect actually is a major factor in creating our ice ages.
Most planetary systems evolve in nearly circular orbits, it is simply a factor of time. While a new planet may be highly elliptical the orbit smooths out over time. There is a lot more about time that will affect a planet. In the early stages of the life of a planet it is unlikely that advanced life could develop. The planet needs to cool, the atmosphere needs to stabilize and other factors that aren’t likely to happen until the orbit has pretty well rounded out.
Sixth:
Two nearby “gas giants” (Jupiter and Saturn) attract and catch many wandering asteroids and comets and generally keep them from hitting Earth. The asteroid belts also keep a lot of flying rock in a stable orbit and away from us.
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Actually just the opposite is true. The large gas planets knock asteroids out of the asteroid belts frequently where they would otherwise safely orbit. Objects from outside the solar system rarely approach our sun or earth.
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Seventh:
Our molten core creates a magnetic field that holds the Van Allen radiation belts in place. These belts protect Earth from the most harmful rays of the sun.
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This statement is very old science. Our rotating planet orbits through the magnetic fields of the sun. Our iron core moving through the field and rotating while it does produces currents that cause our magnet field. The molten portion of movement creating a field is insignificant. Mars is thought to not have a molten core and still has a magnetic field although not as strong as ours because it is farther away from the sun where the suns magnetic field has less effect on the planet iron core.
On a somewhat regular basis our magnetic field flips it seems now that it is always in conjunction with the flipping of the magnetic field of the sun. Often only one hemisphere on the sun will flip making as it were two magnets of the sun but when both hemispheres flip on the sun the earth field will also flip.
All stars have large magnetic fields, even white dwarfs and red giants. The closer a planet is to the star the stronger will be the magnetic field.
Our own sun is going through a change right now into what is called a solar minimum, actually a “Grand” solar minimum. This seems to happen every few hundred years. Grand solar minimums have drastic effects on our planetary magnetic belts because the size of the suns magnetic belt decreases as the sunspot numbers dwindle. It will come back again though just like all other stars and planet systems.
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Eighth:
Earth’s volcanism plays a role in generating our atmosphere and in cycling rich minerals widely.
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It is true that volcanic activity plays a part in the make up of our atmosphere but largely a detrimental affect. While volcanoes help us to find diamonds if we never suffered another volcano we wouldn’t miss it.
Volcanoes add more Carbon Dioxide in a few hours that man does in a few years. It is Carbon Dioxide which became food for plants once the plants appeared however it was their decay that produced a large percentage of Carbon Dioxide.
People complain today about Carbon Dioxide but it is the basis for life on this planet.
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Ninth:
Our sun is just the right kind of star, putting out a fairly steady amount of energy. Other types of stars are more variable in their output and this variance can utterly destroy life or cause it to be unsustainable due to the extremes.
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Most stars except the very large ones are very stable for billions of years. Many of the variable stars that have been identified by past astronomers have been found to be in binary systems and only seem to be variable because of their companion and their changing positions.
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tenth:
Earth’s fairly rapid rotation reduces the daily variation in temperature. It also makes photosynthesis viable because there is enough sunlight all over the planet.
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While our rate of rotation does help even out temperatures our atmosphere helps with that too. We have no way of knowing what a “normal” rotation for a rocky planet would be, it is likely that there are as many planets that rotate faster than us as there are planets that rotate slower. A somewhat slower rotation may have little or no affect or only reduce the habitability zone on a planet to equatorial regions.
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Eleven:
Earth’s axis is tilted just enough relative to its orbital plane to allow seasonal variations that help complex life, but not so tilted as to make those variations too extreme.
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This is just plain silliness, whomever told you that is just plain wrong. Life developed and flourished in the equatorial regions on earth where there are no seasons.
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Twelth:
Our moon causes tides that are just strong enough to permit tidal zones (a great breeding ground for diverse life) but not so severe as to destroy life.
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Actually the tides on earth are important because it stirs the oceans more than making a breeding ground. We hear a lot about moon tides and life but mostly the moon is not needed the Sun creates tides at about the same rate as the moon. Without the moon we would not have leap tides but there would still certainly be tides.
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I hope I have not offended you in what I have said above, that was not my intent, like Joe Friday used to say, “Just the facts, mam”.
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The Bible is loaded with direct statements that you appear to dismiss.
The corollary to the Fermi Paradox is the Dark Forest theory, which mostly says everyone is hiding because there are predators in the forest who make a meal, so to speak, of the unwary or careless, but do it in such a way that they are not noticed by other predators: for instance: launching a ‘seed’ from beyond the Ort Cloud which, when it reaches some point in the solar system, unfurl and convert the entire system into a two dimensional object.
Occam’s Razor applies. The most obvious answer is probably the correct one.
There’s a good chance that there are many planets with all kinds of life, but interstellar transit is a practical impossibility. If you believe in a creator you have to wonder why he would make such a huge universe and only fill one tiny part of it with life.
What are these people afraid of? If we are alone, so what?
We were alone before the question came up if we are alone.
and what does it matter if we are alone. We are making out okay and will continue.
What are these people afraid of? If we are alone, so what?
We were alone before the question came up if we are alone.
and what does it matter if we are alone. We are making out okay and will continue.
While I don’t believe biblically there is anything saying there is or there isn’t other life in the universe, I have a tough time believing it was created by a bolt of lightning hitting a primordial soup and creating a single cell organism that eventually evolved to become every plant and animal that has ever lived.
Still haven’t heard a credible evolution theory for an organism to evolve into having a penis and a vagina — at the same time!!!
Yes, next question.
While many red stars have planets closer than us to our sun it is ok because of the lower radiation of a red star.
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Red dwarfs emit frequent flares that would sterilize a planet.
Agree 100%. Fermi and them calculated that the chance of other life was extraordinarily high and thus came the question of where are they then. I tend to agree with you, if they dont want us to see/hear them then we wont.
There is another thought that maybe we shouldnt go yelling out across the cosmos looking for anyone as we might not like what we find, or want to be found.
Red dwarfs emit frequent flares that would sterilize a planet.
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Certainly no more than our own star. The flares of a red star would be nothing compared to our sun. The energy level on a red star surface are minuscule in energy content compared to a yellow star.
A red star is not dangerous because of flares. Red stars are at then end of their life cycle and their likely time until death can be counted in millions of years instead of billions. Red stars are burning helium, usually after starting a collapse that ignited the helium. The extra sudden ignition of helium is what causes the expansion in size. A red star total energy output would be higher than it was before it went red but the energy per square meter would be much less but now the red star has become huge compared to what it was.
If our sun were to start burning helium it’s diameter would likely encompass the orbits of Mercury and Venus and strip away our atmosphere. Mars might like that a lot.
After some millions of years however the helium would be exhausted and heavier atoms would start to be fused into more and more heavy elements until the fusion furnace could no longer support itself. The pressures that hold up the atmosphere would fail and the star would start falling in on itself. The star may convulse by starting to fall with the pressure of the falling star igniting heavier elements enough to sustain the pressure of the atmosphere again for a short time. This could happen several times or only once when vast amounts of matter are combined by fusion into heavy elements in a split second when the pressure of all this sudden fusion explodes the star and the star becomes either a white dwarf or if it was big enough a neutron star.
Any intelligent life near a red star would be looking for a new home well before any of that happened. the good news is that the star would be old and planets that had developed intelligent life would have had perhaps billions of years to develop the technology to either move the planet or move to another planet.
Don’t misunderstand what I say next. Any civilization that far advanced would be incomprehensible to us. To us they would be gods and have a level of intelligence and knowledge that we simply cannot even imagine. To them we would be no more than ants scurrying around building our little cities.
Trying to imagine God’s thoughts and intentions is as old as man’s existence, and is present throughout the Bible and Christian literature. I reject your silly attempt at judgement, and remind you that you are not qualified to speak for him.
There is another thought that maybe we shouldnt go yelling out across the cosmos looking for anyone as we might not like what we find, or want to be found.
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Perhaps but I suspect anyone so advanced to do anything about hearing us is advanced enough to know we are here and so far not dangerous to them.
Stories of advanced civilizations wanting our resources while making a good story could find all they need at home by harvesting the energy of their star. Once you really learn fusion you can make anything you need. Then again I don’t think we can begin to even imagine what they could do.
Boy, I would just be thrilled if somebody could tell me what the horse evolved from. Whenever I ask people, they just show me pictures of progressively smaller mammals that get less horse-like. I am willing to believe that God’s plan includes the ability of small vaguely horse-like mammals to evolve into our large modern, majestic horse. But nobody on earth can tell me the creature that evolved ito the small horse predecessor, let alone the marine animal that evolved from.
To believe totally in Darwin’s theory of evolution, that mammals evolved from invertibrate sea creatures, taks every bit as much raw faith as any religion does.
David Brin and others resigned from the board of SETI if I recall because they started ‘active SETI’ where they started powerful tight beaming to interesting points in the sky instead of listening. They supposedly had no debate, just started doing it.
Besides aggressive theories like the dark forest theory and ‘the berserker theory’ there could be passive explanations, like once everyone gets so technologically advanced they just fall into a virtual reality hole where reality is simulated perfectly and everyone lives in bliss or something. Or hard as it would be for us to imagine, the desire to explore could be exceedingly rare but sentience and life are not rare.
Freegards
More so if you ask me.
Yes, especially to the extent they don’t even realize it.
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