Is there life in the universe, and if so has it visited Earth?

[CEL]

Here is the opinion of an astronomer about the subject.
http://blogs.discovery.com/space_disco/2008/11/ufo-alien-plait.html
Since he is a skeptic, some people will say he has an agenda. He probably has, but he knows about what he is talking.

 

[Pythagorean]

Here is the opinion of an astronomer about the subject.
http://blogs.discovery.com/space_disco/2008/11/ufo-alien-plait.html
Since he is a skeptic, some people will say he has an agenda. He probably has, but he knows about what he is talking.

It's a pretty convincing argument. Just to be clear, he's not a skeptic about alien life whatsoever. He's a skeptic about it having visited Earth:

Manmade satellites pass overhead several times an hour, and some brighten tremendously as a solar panel or mirrored surface catches the Sun. Meteors blaze across the sky, ice crystal refract sunlight and moonlight, atmospheric effects make a distant object appear distorted and weirdly-shaped. All of these have been mistaken for alien spacecraft .

So I know that most people misinterpret what they see. But there's something else too. If alien spaceships are really out there abducting us and playing chicken with our airplanes, then you'd expect that people who spend more time looking at the sky would see more of them. And who spends lots of time looking up?

Amateur astronomers. They are dedicated observers, out every night peering at the sky. If The Truth Is Out There, then amateur astronomers would be reporting far and away the vast majority of UFOs.

But they don't. Why not? Because they understand the sky! They know when a twinkling light is Venus, or a satellite, or a military flare, or a hot air balloon, and so they don't report it.

That, to me, is the killer argument that aliens aren't visiting us. If they were, the amateur astronomers would spot them.

 

[CEL]

It's a pretty convincing argument. Just to be clear, he's not a skeptic about alien life whatsoever. He's a skeptic about it having visited Earth:

Very few educated people doubt that there is life elsewhere in the Universe. What some people, including Phil and I, don't believe is that ETs are visiting us.

 

[baywax]

Very few educated people doubt that there is life elsewhere in the Universe. What some people, including Phil and I, don't believe is that ETs are visiting us.

One way a civilization may have been able to reach this planet from theirs... light years away... is through some sort of utilization of the principal of superposition. Being there and here at the same time. Impossible to imagine at this moment for us puny humans. Is there anyway this could happen?

 

[CEL]

One way a civilization may have been able to reach this planet from theirs... light years away... is through some sort of utilization of the principal of superposition. Being there and here at the same time. Impossible to imagine at this moment for us puny humans. Is there anyway this could happen?

What do you mean by the principle of superposition?

 

[Pythagorean]

What do you mean by the principle of superposition?

I think he meant something besides superposition :P

 

[baywax]

I think he meant something besides superposition :P

The term "superposition" is used in this quote (from Paul Davies) to describe how a quantum particle can be in many places at once...

A quantum particle can be in a superposition of states - for example it may be in many places at once - whereas the "classical" world of observation reveals a single reality. This conundrum is famously captured by the paradox of Schrödinger’s cat, in which a quantum superposition is amplified in order to put an animal into an apparently live-dead hybrid state.

http://physicsworld.com/cws/article/print/23668

One might think that an advanced civilization could somehow create the same conditions with a ship or ship with lifeforms in it.

 

[Pythagorean]

The term "superposition" is used in this quote (from Paul Davies) to describe how a quantum particle can be in many places at once...
http://physicsworld.com/cws/article/print/23668

One might think that an advanced civilization could somehow create the same conditions with a ship or ship with lifeforms in it.

In my QM classes, I never interpreted that as the particle actually being in two places at once. At least, not the way you imagine it. It always seemed more to do with our lack of ability to know which state it was in until we measured it.

I was under the impression that in the higher QM classes, you actually treat the electron as "gas" so that it's just a less dense distribution covering a larger area.

 

[baywax]

In my QM classes, I never interpreted that as the particle actually being in two places at once. At least, not the way you imagine it. It always seemed more to do with our lack of ability to know which state it was in until we measured it.

I was under the impression that in the higher QM classes, you actually treat the electron as "gas" so that it's just a less dense distribution covering a larger area.

I see... like what I've read in PF about treating a photon as an infinitely stretched out beam(thats actually spherical).

 

[ChadRichens]

I would find it far more likely that they wouldn't actually come and do research on a totally unknown planet that appears to contain life. Instead they would send AI Bots on ships to observe us.. possibly even treat us like we treat animals, not recognizing us as any more intelligent than an ant colony. they probably communicate in a totally different way, and think that us using these vibrations from our voiceboxes to form languages is cool, like we think bee's are cool for vibrating to make mating call sounds.
We're probably labeled as "Potential Intelligence" or something to that effect and they probably wouldn't make contact with us until we get a better grasp on ourselves morally and technologically.
We don't even have a grasp on concioussness, to them does that mean that we act just as any other animal?
We havn't harnessed the power of the forces of the universe, the fact that we can be creative and curious makes us no more advanced in their eyes, until we learn to stop pointless aggression towards each other, thinking about this, we really are no more than animals, just highest up the food chain for this measly little planet. Worth Observing? Sure, got to keep an eye out for if we actually do acsend to a higher intelligence of the world, but there's probably just as likely a chance of use blowing ourselves up before we ever get close, so why actually come here. It's not safe.
I think this is the logic our minds would probably use in the shoes of a civilization far more advanced than ours, /shrug

Arn't we teleporting things at some university?
on the atomic level i know, but still.. beam me up scotty isn't neccessarily out of the reach of plausable in a far more advanced version of us right?
So who's to say they don't teleport themselves back and forth through different galaxies?
I think Mr. Kaku has it right saying we're going to be far more advanced than we are in 2057, then these questions would probably be common knowledge, look at how far we've come in such a short time, what's next?, this is why I love science.

 

[CEL]

In my QM classes, I never interpreted that as the particle actually being in two places at once. At least, not the way you imagine it. It always seemed more to do with our lack of ability to know which state it was in until we measured it.

That has always been my understanding. The particle has a finite probability of being in a region of space. We only don't know where it really is until we measure it. That is the sense that the measurement changes the thing that is being measured. The probability becomes a certitude.
Even if we accept the notion that the particle is simultaneously at two different places, this does not mean that the same can happen in the macroscopic world. The laws of physics are different in the nano and the macro worlds.

 

[baywax]

Even if we accept the notion that the particle is simultaneously at two different places, this does not mean that the same can happen in the macroscopic world. The laws of physics are different in the nano and the macro worlds.

As far as we know. Life is stranger than fiction.

 

[DaveC426913]

Point of order: when did this discussion get sidetracked from alien visitations of Earth to quantum superposition?

I mean, I know it's on its 43rd page of posts, but still, it seems to be a pretty popular thread even on its intended topic.

[EDIT: Ah. A quick look reveals that it's just a few posts ago, in the https://www.physicsforums.com/showpost.php?p=1983082&postcount=670". I thought it was a while back. Carry on...]

 

[baywax]

Point of order: when did this discussion get sidetracked from alien visitations of Earth to quantum superposition?

I mean, I know it's on its 43rd page of posts, but still, it seems to be a pretty popular thread even on its intended topic.

[EDIT: Ah. A quick look reveals that it's just a few posts ago, in the https://www.physicsforums.com/showpost.php?p=1983082&postcount=670". I thought it was a while back. Carry on...]

Yeah, sorry DaveC426913... it was my own fault for trying to come up with a method by which "aliens" could have traversed the distances between solar systems and/or galaxies. Its still a problem (for us) to imagine the technology that could achieve such a feat. And its one reason why I believe the crafts that have been sighted and photographed are terrestrial in origin.

 

[Anticitizen]

This is a FANTASTIC site that goes deep into the hard physics surrounding many science (fiction) conceits, aggregated over the years from usenet. Here is the section on slower-than-light interstellar travel: http://www.projectrho.com/rocket/rocket3aj.html

Here's a random exerpt from a subsection on suspended animation passengers:

"Poul Anderson noted that there is probably a limit to how long a human will remain viable in cryogenic suspension (in other words they have a self-life). Naturally occurring radioactive atoms in the body will cause damage. In a non-suspended person such damage is repaired, but in a suspended person it just accumulates. He's talking about this damage happening over suspensions lasting several hundred years, during interstellar trips. This may require one to periodically thaw out crew members and keep them awake for long enough to heal the damage before re-freezing them."

Lots of considerations like the above example that I never would've considered. Warning, if you're optimistic about space travel, the site will probably depress you. Its take on each subject is more or less irrefutable though.

 

[Ivan Seeking]

Yeah, sorry DaveC426913... it was my own fault for trying to come up with a method by which "aliens" could have traversed the distances between solar systems and/or galaxies. Its still a problem (for us) to imagine the technology that could achieve such a feat. And its one reason why I believe the crafts that have been sighted and photographed are terrestrial in origin.

So then you assume that we are essentially [nearly] as technologically advanced as any species can be?

 

[baywax]

So then you assume that we are essentially [nearly] as technologically advanced as any species can be?

I think its prudent to neither assume that we are as advanced as all other species nor to assume other species are more advanced. What would be prudent is to wait and find out.

In the mean time, we might want to discover the origin of the UFOs because they or their origin could pose a threat to democratic and humanitarian progress. In fact, you Americans could spend another trillion bucks on that kind of preemptive research to ensure democracy survives.

 

[Ivan Seeking]

Discovery of Methane Reveals Mars Is Not a Dead Planet WASHINGTON -- A team of NASA and university scientists has achieved the first definitive detection of methane in the atmosphere of Mars. This discovery indicates the planet is either biologically or geologically active.

The team found methane in the Martian atmosphere by carefully observing the planet throughout several Mars years with NASA's Infrared Telescope Facility and the W.M. Keck telescope, both at Mauna Kea, Hawaii. The team used spectrometers on the telescopes to spread the light into its component colors, as a prism separates white light into a rainbow. The team detected three spectral features called absorption lines that together are a definitive signature of methane.

"Methane is quickly destroyed in the Martian atmosphere in a variety of ways, so our discovery of substantial plumes of methane in the northern hemisphere of Mars in 2003 indicates some ongoing process is releasing the gas," said Michael Mumma of NASA's Goddard Space Flight Center in Greenbelt, Md. "At northern mid-summer, methane is released at a rate comparable to that of the massive hydrocarbon seep at Coal Oil Point in Santa Barbara, Calif." Mumma is lead author of a paper describing this research that will appear in Science Express on Thursday.

Methane, four atoms of hydrogen bound to a carbon atom, is the main component of natural gas on Earth. Astrobiologists are interested in these data because organisms release much of Earth's methane as they digest nutrients. However, other purely geological processes, like oxidation of iron, also release methane.

"Right now, we do not have enough information to tell whether biology or geology -- or both -- is producing the methane on Mars," Mumma said. "But it does tell us the planet is still alive, at least in a geologic sense. It is as if Mars is challenging us, saying, 'hey, find out what this means.' "

If microscopic Martian life is producing the methane, it likely resides far below the surface where it is warm enough for liquid water to exist. Liquid water is necessary for all known forms of life, as are energy sources and a supply of carbon.

"On Earth, microorganisms thrive about 1.2 to 1.9 miles beneath the Witwatersrand basin of South Africa, where natural radioactivity splits water molecules into molecular hydrogen and oxygen," Mumma said. "The organisms use the hydrogen for energy. It might be possible for similar organisms to survive for billions of years below the permafrost layer on Mars, where water is liquid, radiation supplies energy, and carbon dioxide provides carbon. Gases, like methane, accumulated in such underground zones might be released into the atmosphere if pores or fissures open during the warm seasons, connecting the deep zones to the atmosphere at crater walls or canyons."

It is possible a geologic process produced the Martian methane, either now or eons ago. On Earth, the conversion of iron oxide into the serpentine group of minerals creates methane, and on Mars this process could proceed using water, carbon dioxide and the planet's internal heat. Although there is no evidence of active volcanism on Mars today, ancient methane trapped in ice cages called clathrates might be released now.

"We observed and mapped multiple plumes of methane on Mars, one of which released about 19,000 metric tons of methane," said co-author Geronimo Villanueva of the Catholic University of America in Washington. "The plumes were emitted during the warmer seasons, spring and summer, perhaps because ice blocking cracks and fissures vaporized, allowing methane to seep into the Martian air."

According to the team, the plumes were seen over areas that show evidence of ancient ground ice or flowing water. Plumes appeared over the Martian northern hemisphere regions such as east of Arabia Terra, the Nili Fossae region, and the south-east quadrant of Syrtis Major, an ancient volcano about 745 miles across.

One method to test whether life produced this methane is by measuring isotope ratios. Isotopes of an element have slightly different chemical properties, and life prefers to use the lighter isotopes. A chemical called deuterium is a heavier version of hydrogen. Methane and water released on Mars should show distinctive ratios for isotopes of hydrogen and carbon if life was responsible for methane production. It will take future missions, like NASA's Mars Science Laboratory, to discover the origin of the Martian methane.

The research was funded by the Planetary Astronomy Program at NASA Headquarters in Washington and the Astrobiology Institute at NASA's Ames Research Center in Moffett Field, Calif. The University of Hawaii manages NASA's Infrared Telescope Facility.

For images related to this finding, visit:

http://www.nasa.gov/mars

http://www.nasa.gov/home/hqnews/2009/jan/HQ_09-006_Mars_Methane.html
http://www.nasa.gov/mission_pages/mars/news/marsmethane_media.html

 

[phyzmatix]

I think its prudent to neither assume that we are as advanced as all other species nor to assume other species are more advanced. What would be prudent is to wait and find out.

If we're going to assume anything then I think it is prudent to assume that, taking into consideration the mind-boggling vastness of the universe, there are less advanced as well as more advanced species out there.

In the mean time, we might want to discover the origin of the UFOs because they or their origin could pose a threat to democratic and humanitarian progress. In fact, you Americans could spend another trillion bucks on that kind of preemptive research to ensure democracy survives.

"Independence Day" is only a movie. If any civilisation has the technology to cross the vast distances involved in space travel, then I can almost assure you that there will be very little (if anything at all) that us mere humans could do to protect ourselves in case such a civilisation decided on an aggressive policy.

Imagine the Spanish Armada set against a modern-day aircraft carrier group...

 

[phyzmatix]

http://www.nasa.gov/home/hqnews/2009/jan/HQ_09-006_Mars_Methane.html
http://www.nasa.gov/mission_pages/mars/news/marsmethane_media.html

The most intellectual comment I can come up with at the moment is "Awesome!"

 

[Denton]

Would it be plausible that methane is merely seeping out of the rocks, frozen or whatnot from times of long ago? I am no expert in anything lol, but its been there for millions of years, I'm thinking that if there were any trapped methane it would've leaked out long ago.

 

[DaveC426913]

Imagine the Spanish Armada set against a modern-day aircraft carrier group...

http://www.imdb.com/title/tt0080736/"

Nothin' like a couple of F-14 Tomcats in a dogfight with a couple of Zeros. (very short)

 

[phyzmatix]

http://www.imdb.com/title/tt0080736/"

Nothin' like a couple of F-14 Tomcats in a dogfight with a couple of Zeros. (very short)

Got to get hold of it!

 

[The Dagda]

Godwin! There is evidence for flying saucers, it's just not compelling evidence. But that's a judgment call made by each individual.

Even those most critical of the idea must first still examine the evidence before deciding that it can be dismissed.
And I think by comparing it to religions and other establishments, you are simply trying to stir the pot. It's one thing to believe in unfounded ideas - we all do to some extent or another - it's another thing how strongly one will stick to those ideas. I'm guessing your idea of religions and naziism involves preconceptions of zealotism, and I imagine you think the same way about UFO-believers, but there is no dirth of moderate UFO-believers out there, so your comparison is more inflammatory than it is substantive.

That's not true, there is overwhelming evidence for flying saucers and or UFOs but no evidence that they are alien in origin.

 

[Ivan Seeking]

That's not true, there is overwhelming evidence for flying saucers and or UFOs but no evidence that they are alien in origin.

UFOs clearly exist; most are explained in conventional terms. As for flying saucers, that is a subjective interpretation. It should be noted also that we are talking about anecdotal evidence.

 

[The Dagda]

UFOs clearly exist; most are explained in conventional terms. As for flying saucers, that is a subjective interpretation. It should be noted also that we are talking about anecdotal evidence.

Parapsychology is replete with anecdotal claims, do you think personally that anecdote is valid and if not why not?

 

[Ivan Seeking]

Parapsychology is replete with anecdotal claims, do you think personally that anecdote is valid and if not why not?

Keep in mind that this is a science forum. For science in particular, anecdotal evidence is the lowest form of evidence and counts for almost nothing. From a personal point of view, some anecdotes can be very compelling, but only to the extent that they suggest that something may be worth a look. Nothing concrete can be derived exclusively from anecdotes. On the other hand, anecdotes may lead to interesting discoveries. After all, science begins with observations.

For example, for the Western world, the evidence for the great apes was once nothing more than anecdotes.

 

[baywax]

=Ivan Seeking:
For example, for the Western world, the evidence for the great apes was once nothing more than anecdotes.

Could we test each species to see if they're of terrestrial or extraterrestrial origin?

What markers would indicate a difference?

Would there be any way to tell if a species is from another planet/galaxy or a terrestrial one?

These questions harken back to the discussion about cross-pollinating planets and panspermia.

How would we know a 65 million year old species of plant... like a flowering one... is a product of Earth or a product of mars... on earth?

 

[Ivan Seeking]

Could we test each species to see if they're of terrestrial or extraterrestrial origin?

What markers would indicate a difference?

Would there be any way to tell if a species is from another planet/galaxy or a terrestrial one?

These questions harken back to the discussion about cross-pollinating planets and panspermia.

How would we know a 65 million year old species of plant... like a flowering one... is a product of Earth or a product of mars... on earth?

I am not aware of any evidence indicating that any species lacks a terrestrial genetic history, but the question of the origins of life is an open question. AFAIK, there is no evidence that favors the proposition that that life [allegedly heterotrophs] began here, as opposed to arriving here on some form of cosmic debris.

 

[baywax]

I am not aware of any evidence indicating that any species lacks a terrestrial genetic history, but the question of the origins of life is an open question. AFAIK, there is no evidence that favors the proposition that that life [allegedly heterotrophs] began here, as opposed to arriving here on some form of cosmic debris.

So if and when we point the finger and say... "alien"... we may just mean "we've been here longer" as has always been the case with "intruders" and "natives".

 

[Ivan Seeking]

So if and when we point the finger and say... "alien"... we may just mean "we've been here longer" as has always been the case with "intruders" and "natives".

AFAIK, that may be true. Some years ago there was even some thought that alien viruses or bacteria may still be raining down on Earth on regular basis, but I don't know if anything came of it. Obviously it has never been shown to be true.

 

[baywax]

AFAIK, that may be true. Some years ago there was even some thought that alien viruses or bacteria may still be raining down on Earth on regular basis, but I don't know if anything came of it. Obviously it has never been shown to be true.

Is AFAIK my new nic name?

I'm not sure how we could distinguish extraterrestrial from terrestrial. If they're single celled and roughly similar in morphology, including the RNA or DNA, it would be difficult. We have bacteria and viruses that can go dormant for centuries just like a space bourn one would do.

The clue may be in their membrane and the stresses it shows. edit... for instance.. burn marks from entry!

 

[Ivan Seeking]

Is AFAIK my new nic name?

AFAIK.

I just have to be careful since I'm not an expert. I always state what I believe to be true [if I have no idea I would say so], but I do make mistakes, and my information may be out of date.

I don't remember exactly how this applies, but there is one test that I read about that would show a microbe evolved under a sun emitting light having the opposite polarization of the light from our sun. I think it had something to do with the spiral in the double helix of DNA. But again I have to be careful here as I read about this many years ago [about 30 years ago].

 

[The Dagda]

I am not aware of any evidence indicating that any species lacks a terrestrial genetic history, but the question of the origins of life is an open question. AFAIK, there is no evidence that favors the proposition that that life [allegedly heterotrophs] began here, as opposed to arriving here on some form of cosmic debris.

Panspermia.

 

[The Dagda]

Is AFAIK my new nic name?

I'm not sure how we could distinguish extraterrestrial from terrestrial. If they're single celled and roughly similar in morphology, including the RNA or DNA, it would be difficult. We have bacteria and viruses that can go dormant for centuries just like a space bourn one would do.

The clue may be in their membrane and the stresses it shows. edit... for instance.. burn marks from entry!

Discovering left handed amino acids or right handed RNA/DNA on a comet or asteroid would do it.