First, there are a lot of stars. Our galaxy is called the Milky Way and consists of between 100 and 400 billion stars. Our sun is a star orbited by a number of planets and asteroids. Many of those other stars are probably orbited by planets as well. The most current estimates indicate that there are 100 to 200 billion galaxies in the universe. That's a lot of stars, planets, and moons. Galaxies tend to be separated by distances much larger than their dimensions. Most planets and moons are probably hotter or colder than the Earth, have much more or less gravity, or have an atmosphere unlike ours, for example composed of hydrogen, helium, or carbon dioxide, or no atmosphere at all, but in all those trillions of planets, some are probably Earth-like.
As for other life, I would think that there is. They have done experiments for decades which show that complex organic compounds tend to form spontaneously in water oceans containing the types of chemicals presumed to be present. Current theories of evolution suggest that given a soup of organic chemicals and enough time, life forms spontaneously.
Once life exists, does it eventually develop intelligence? The force of natural selection tends to change life to be more effective at staying alive, and I doubt that in all that immense space we are so unique as to be the only life to have evolved intelligence.
Physicists currently estimate the age of the universe to be about 13.8 billion years, but our own solar system is not that old. It is believed that our solar system is 2nd generation, formed from the remnants of stars that lived, died, and exploded, scattering their materials back into space. Therefore, other stars and planets have been around much longer than our star or the Earth.
If there is a fair amount of life in the universe, and if the universe is very old, I would guess that there have been many intelligent species and many civilizations, most based on life forms not much like humans. Although some features of our bodies and brains may be based on universal principles, for example, bilateral symmetry, there are simply too many forks in the road of evolution, in which the path chosen was by chance, to get many creatures who look like us again.
Given the immensity of the universe it seems impossible for Earth to be the only planet with life form of any kind. I'm sure there has to be planets with the precise climate elements necessary to sustain life. The main thing I think would have to be water. When thinking of the Earth in relevance to the universe we are just another atom in a large body. I agree with you about symmetry comment. Everything in the universe seems to be in harmonious balance ..even when chaos ensues things find a natural order. Cycles of destruction exist but they also have a rhythm . Amazing to think the universe is still expanding
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rosborne979
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Wed 11 Dec, 2013 07:52 pm
@Brandon9000,
Brandon9000 wrote:
It is believed that our solar system is 2nd generation
Not to nitpick but our sun and solar system are probably 3rd generation.
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rosborne979
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Wed 11 Dec, 2013 08:12 pm
@Brandon9000,
Brandon9000 wrote:
Physicists currently estimate the age of the universe to be about 13.8 billion years, but our own solar system is not that old. It is believed that our solar system is 2nd generation, formed from the remnants of stars that lived, died, and exploded, scattering their materials back into space. Therefore, other stars and planets have been around much longer than our star or the Earth.
If there is a fair amount of life in the universe, and if the universe is very old, I would guess that there have been many intelligent species and many civilizations, most based on life forms not much like humans.
The first generation stars were very large and simple (mostly hydrogen) and short lived. It's estimated that the first generation was probably measured in millions of years, not billions.
The second generation would have involved smaller more complex stars (formed from the heavier elements released from the first round of novae), with significantly longer life spans, maybe 5 to 10 billion years.
The third generation of stars (and stellar disks) would likely have been even more complex with rich arrays of heavier elements (like our solar system).
The reason I point all this out is that the chemical processes of life, and the other variables involved in evolving multicellular life may be more prevalent in higher generation stars (and stellar disks). If this is the case, then it's possible that 3rd generation stars are the vanguard of life-forming systems, and that we may also be one of the earlier technological species to have come along.
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Brandon9000
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Wed 11 Dec, 2013 08:45 pm
Okay, good point. But there is a nearly infinite amount of stuff to experience out there, and in my opinion, it's worth exploring. If we could go to these places, we would probably find things that are absolutely amazing, things that are awesome in a good way, and other things that we would wish not to have seen. I guess my point is that the potential for finding interesting things out there is immense.
As for technical species, bear in mind that even 100 years is very long in terms of the development of technology.
I'm not arguing against exploration at all, I'm 100% up for it. I'm just making note of conditions which might tell us what to expect.
As for exploration, I think we need to figure out the most effective way to start, and to me that means exploring our own solar system first before putting in a large effort to get out to other stars. Otherwise it's like saying you want to explore the oceans when all you have is a snorkel and a pair of swim fins; it isn't going to be effective. If we wanted to explore the oceans and all we had was snorkel and fins we would do best to start at a reef somewhere, and in our solar system, the "reef" is the moons of Jupiter and Mars (in my opinion). So I think we should be starting our more adventurous explorations there and getting really good at it (and learning a lot more about surviving in space) before we try to go outside the system. For more conservative explorations I think we're probably going to have to start with our own Moon (again) and Mars.
The other type of exploration that's important is more radio astronomy. For exploring the galaxy I think it's more likely that we would be able to detect the evidence of another technological civilization long before we can actually get there (not to mention the fact that we don't know where to go until we've detected something). So I think better telescopes and space-based tools are a must for galactic exploration.
KLINGONS v PIONEER 10
(Stat Trek V: 'The final Frontier')
Translation: VIXIS- "Captain Klaa, we have a target in sight. A probe of ancient origin."
KLAA- "Difficult to hit?"
VIXIS- "Most difficult."
KLAA-"Good"
KLAA- "All weapons to my control. Scope!"
KLAA (after destroying it)- "Shooting space garbage is no test of a warrior's mettle. I need a target that fires back !"
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edgarblythe
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Thu 12 Dec, 2013 07:16 am
@rosborne979,
You are right, of course. Still I like the occasional deviation, such as Voyager One going into deeper space. Intriguing, to say the least.
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Setanta
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Thu 12 Dec, 2013 07:51 am
Some things seem obvious to me. One is that the best way to explore our galaxy would be self-replicating machines. The costs in energy and materials to send out manned missions would be far too high. Beyond that, i don't think we can reasonably assume that there is any way around the speed of light. That means that even with time dilation, there is little prospect of a manned mission retrieving information, and the crew then returning to the earth in good health. The most that manned missions could accomplish would be to explore our local, galactic neighborhood, and even the the crew would have to resign themselves to the the thought that their loved ones and their acquaintance will all be dead when they return.
Of course, with machine exploration, we are still bound by the speed of light as well. Any information retrieved by mechanized exploration will still take hundreds or thousands of years to get back to the earth. Don't mistake me, though. I don't consider that a good reason not to make the effort.
By the way, self-replicating machines would probably need to take at least enough materials to replicate themselves at least once, it not two or three times. We can count on other star systems having "asteroid" belts.
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edgarblythe
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Thu 12 Dec, 2013 08:47 am
The only reason I can see to send people into space beyond the solar system would be a sort of ark. A desperate move to avoid extinction, or merely an experiment. In the latter, the travelers may or may not expect to return.
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Romeo Fabulini
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Thu 12 Dec, 2013 09:52 am
Incidentally if the light-speed barrier is impenetrable, making prolonged space travel impossible, perhaps telepathy is another way of making contact (assuming the speed of telepathic thought is instantaneous).
Perhaps all these alleged UFO abductions and close encounters that we hear about are simply the result of a human picking up an alien telepathic message from across the universe.
But the human brain can't unscramble it correctly, so it triggers hallucinations in which the contactee thinks he sees aliens and spacecraft etc.
A traveler can reach another star in a reasonable amount of time from his own point of view if he can get close enough to light speed, but should he choose to return, years will have passed at his planet or point of origin.
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rosborne979
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Thu 12 Dec, 2013 02:11 pm
@rosborne979,
rosborne979 wrote:
If we wanted to explore the oceans and all we had was snorkel and fins we would do best to start at a reef somewhere, and in our solar system, the "reef" is the moons of Jupiter and Mars (in my opinion).
Oops, I meant the moons of Jupiter and Saturn, not Jupiter and Mars. Not that those two little rocks orbiting Mars wouldn't be interesting, but I'm sure Titan has a lot more in store for us
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rosborne979
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Thu 12 Dec, 2013 02:22 pm
@Setanta,
Setanta wrote:
Some things seem obvious to me. One is that the best way to explore our galaxy would be self-replicating machines.
I think simple non-replicative machines would still be good for exploration even if they can't yet replicate.
Self Replicators are great if you want to initiate a "blanket" type of broad exploration, but targeted exploration points could be handled pretty well by advanced robots (a bit more advanced than we currently have).
All I can say is Wow? Did you discuss this with your sister ( the cow as you call her) or come up with this all on your own?
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Setanta
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Thu 12 Dec, 2013 04:52 pm
@rosborne979,
That would true for near-by objects. However, for distant objects, even at significant fractions of light speed, the probe would require at least centuries to reach their destination. Cyber systems would need to be shielded against cosmic radiation, and, let's face it, we don't know what long-term exposure would do to the vehicle. The vehicle might need to stop for minor or even extensive repairs. That's one reason i day they'd need to carry a good deal of material with them.
One of the consequences of the speed of light being a limit we cannot exceed, or one which it would take us thoudands of years to find a " work-around" may be that we will never be able to explore very much. This is also why, essentially, even if there are other technological intelligences out there, we are going to always be alone. If there were such a civilization on a planet orbiting Antares, for an example, if they send out a message saying " we are here, is there anyone else out there?" (although why they would send such a message to the galactic boondocks would be a poser), it would take ten thousand years for the message to reach us. If we were to receive such a message and beam it back (assuming we could even recognize and interpret the message), it would be another ten thousand years before they heard our "Yes, we are here" reply. Twenty thousand years ago our ancestors were living in the stone age--a very lot can happen in twenty thousand years.
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