Most good scientists are deeply impressed by, and even excited about, how little we yet know, how much there still is to find out. Our science and technology are impressive accomplishments, but still very much in their infancy as compared to what is possible.
Imagine, if you will, a tremendously technologically advanced civilization, whose technology just continues to advance. What is the end point? What do they and their technology look like after billions of years of rapid technological advance? I think it is safe to say that we don't know. It clearly wouldn't be anything that we currently have the science or technology to understand. As Arthur C. Clarke wrote, "Any sufficiently advanced technology is indistinguishable from magic." We wouldn't understand this alien technology or what it did any more than Cro-Magnons would understand a wireless modem. This hyper-advanced civilization would presumably have explored ever nook, cranny and loophole in the physical laws that govern the universe and transformed their technology and themselves beyond recognition. We likely wouldn't even recognize it or them as technology or life. We might not even recognize them or their technology as normal matter or energy, although after billions of years they would likely have transformed large parts of the universe itself.
Which brings me back to how little we currently know. Modern cosmology assigns only 4% of the mass/energy in the universe to "normal" matter, the kind we know anything about. 22% is thought to be "dark matter" and the remainder, 74%, is "dark energy." We know little about dark matter and next to nothing about dark energy, except that they are necessary to make our equations work out. Putting to one side the plausibility that the equations are wrong, we are free to speculate on what is going on with that other 96% that we can't see but suspect is there. My preferred hypothesis is that the universe is 96% aliens. Which is a somewhat silly way of saying that other life-forms may have transformed some large portion of the mass and energy in the universe into forms we don't understand. Why should a civilization with the most advanced technology we can pretend to conceive of be expected to leave things as they found them? If conservation of mass/energy is one of the rules they can't get around, couldn't a big crowded universe of aliens be expected to convert a large portion of its limiting resource into whatever form allows them to use this resource most efficiently? Dark matter releases no detectable radiation, and as such leaks no mass/energy. This would also help to explain why SETI can't detect any aliens. A civilization that hoards mass and energy isn't going to go blaring electromagnetism all over the place.
Why under this hypothesis would 4% of the matter be left as boring old stars, dust, black holes and light? Perhaps these things serve some function for the dark aliens. Or maybe we, and everything we can see, are a designated nature preserve with strictly enforced limits on poaching. To try to answer this last question is to move from pure speculation to pure fancy, so your guess is as good as mine.
Showing posts with label cosmology. Show all posts
Showing posts with label cosmology. Show all posts
Tuesday, July 07, 2009
Wednesday, April 16, 2008
Argument of Science!
Listening to NPR this morning, I heard two stories which did an excellent job of articulating two opposing point of view, both wrong, which taken together helped me articulate to myself how scientific knowledge is formed, and the difference between a denier and a skeptic.
The first story was about an extremely bright 15 year old who sat down to read the science on global warming, decided she didn't believe humans were causing the change, and then set up a hugely popular website 'debunking' the climate change 'hysteria' and attacking the scientists who support it. She objects not only to their conclusions, but to their dismissal of those who make the arguments she makes.
The second was about the Pope, and his visit to the US. One of the main goals of this tour, and this pope, is the War on Relativism. The pope argues that in this modern era, people believe that there is no objective truth, that every viewpoint is equally valid, and therefore anyone can believe anything they want. He argues that if there is no objective truth, we are all lost in a swamp of uncertainty, and life is not only meaningless but unpleasant.
So the 15 year old thinks that anyone who looks at the evidence and makes up her mind should be taken seriously, and the Pope thinks we need to have one objective truth arbitrated by the Church. To my way of thinking, they are both wrong.
Science (as a process and a culture) is neither a free for all where every view is equally valid, nor a dictatorship where those in high status can pontificate and the 15 year olds have to listen. Science is, in the words of Ernst Mayr, "one long argument," but it is a highly organized argument. There are only certain ways one is permitted to advance one's viewpoint. One can present data, but one cannot engage in personal attacks (although Mayr himself was well known for questioning the intelligence of those who disagreed with him). One can criticize, or tear to shreds, the logic used by other scientists, but one cannot simply refuse to listen. One can question the motives of others, but then still has to look at their arguments. If evidence is legitimate, one has the responsibility to be open to being won over. Personal attacks like 'quack', 'pseudo-scientist', 'corporate whore' and so on are to be reserved for those who grossly violate these rules. The only way this argument ever reaches an endpoint is if everyone on one side is either won over or dies of old age. Even then, if someone thinks they have found new evidence that the world is in fact flat, they can reopen the argument. Science does not deliver absolute, unquestionable truths.
But while you can argue anything you want, if your argument does not meet certain standards, it, and you, will be dismissed out of hand. Your statements must be logical, consistent with and based on data and must demonstrate knowledge of and meaningful response to what has been said and written before. If you want to argue that the world is flat, you'd better have a good explanation for all those data that seem to suggest a spherical Earth. And how a flat Earth came into being, and tides, and cosmology, and so on and so forth. There is a strong scientific consensus on the basic shape of the Earth (although there are bulges and deviations from sphericallity that still need to be better understood), because there is overwhelming evidence from a wide range of disciplines. The same can be said for the reality of evolution, the Holocaust, global warming, and a variety of other topics where the argument continues despite being settled in the minds of almost all scholars.
Those who oppose the consensus view on these issues generally point out that science is not "majority rule." As an example, the great majority of geologists long thought that plate tectonics was a ridiculous idea, and if the majority had ruled, we would have rejected what is now a foundational (possibly even bed-rock?) concept of geology, geography and evolution. It is therefore important to address this objection, because while true, it is a straw man. No reasonable scientist believes that truth can be arrived at through a popular vote of experts. That is not how the long argument works.
The relevant fact is not that the vast majority of informed scientists now accept plate-tectonics, but rather that we had that argument, and the plate-tectonics skeptics were unable to explain the data. Skeptics were converted, or gradually modified their views, or retired, and the number of supporters increased. The heroes in this story, from my perspective, are not those who believe because their teachers told them so, but those who were open minded enough to carefully change their minds.
We now accept plate-tectonics because the skeptics, being good scientists, had no choice but to look at the evidence presented, and there was eventually no logical way to cling to the view that continents are too big to move. "Eventually" being several decades.
So maybe several decades from now, we will have rejected evolutionary theory, decided that the Holocaust was just a historical ploy by the Jews for sympathy in their bid for an Israeli state, and realized that the global climate is just naturally cycling? Possible, but not likely, for several reasons.
First, plate-tectonics was a new idea that opposed everything humans had always assumed about our world. It was a hard idea to wrap a mind around. Creationism is not a new, radical and difficult to comprehend idea (my niece is dating a creationist who says he believes it because it is easier to understand than evolution, and his family believes it). Nor is a naturally controlled climate, or anti-Semitism. The idea of plate-tectonics overcame a distinct disadvantage these other ideas don't have.
Second, plate-tectonics took so long to gain acceptance partially because it took that long for technology to improve enough to produce convincing data. But during those decades, data gradually accrued. These other ideas have been around for decades, or millennia, and during that time the evidence has increasingly pointed against them.
Third, there was no lobby or faith pushing plate tectonics. No one stood to get rich or win political points by arguing that the crust of the earth moves and changes. Quite the opposite. The same cannot be said for Ahmadinejad, Bush and Exxon-Mobil.
Finally, and most importantly, there never was a body of data showing that the continents had always been in their current locations. That was the null hypothesis. We have enormous bodies of data supporting the reality of evolution, the Holocaust and anthropogenic climate change. Those who argued for plate-tectonics did not have to ignore or misinterpret a similar body of data presented by the other side. Scientific creationists (pseudo-scientists), scholarly anti-Semites (quacks) and professional global warming deniers (corporate whores) have to do exactly that. The only way to advance their views within the rules of the scientific process is to take all that data, and show us why it is fake or misunderstood. It is because they can't do this that they are disrespected. (Let me here be entirely clear that these insults are not intended to include either the pope or the teenager, both of who are honest non-scientists.)
The argument cannot be won, so there will always be Flat-Earthers, Static-Plate-ers, Creationists, and deniers of the Holocaust and Global Warming. And those people have the right to their points of view. And we have the responsibility to look at any new evidence they produce, if it really is new and it really is relevant evidence. We don't have to pay attention to people who, for the 5 millionth time, argue that the human eye is irreducibly complex and therefore there is a God. They violate the rules of the argument both by ignoring what has already been said, and by foregoing logic, and thereby forfeit their right to be taken seriously.
So, all of that said, how would I reply to the young woman who doesn't believe in human caused climate change, and to the Pope? To her I would say, "It is great that you are getting into science, and you absolutely have the right to come to your own conclusions. Based on your statements, I believe you have misunderstood much of what you read, and been mislead by those with a financial interest in misleading the public. I encourage you to learn more about the conceptual fields on which the science rests." To the Pope I would say, "The days when the Catholic Church was the unquestionable arbiter of truth for western civilization are long gone. At no point in the foreseeable future will the Church, or any other entity, resume that role. I respectfully suggest you accept this and guide the church into a new and more constructive role."
The first story was about an extremely bright 15 year old who sat down to read the science on global warming, decided she didn't believe humans were causing the change, and then set up a hugely popular website 'debunking' the climate change 'hysteria' and attacking the scientists who support it. She objects not only to their conclusions, but to their dismissal of those who make the arguments she makes.
The second was about the Pope, and his visit to the US. One of the main goals of this tour, and this pope, is the War on Relativism. The pope argues that in this modern era, people believe that there is no objective truth, that every viewpoint is equally valid, and therefore anyone can believe anything they want. He argues that if there is no objective truth, we are all lost in a swamp of uncertainty, and life is not only meaningless but unpleasant.
So the 15 year old thinks that anyone who looks at the evidence and makes up her mind should be taken seriously, and the Pope thinks we need to have one objective truth arbitrated by the Church. To my way of thinking, they are both wrong.
Science (as a process and a culture) is neither a free for all where every view is equally valid, nor a dictatorship where those in high status can pontificate and the 15 year olds have to listen. Science is, in the words of Ernst Mayr, "one long argument," but it is a highly organized argument. There are only certain ways one is permitted to advance one's viewpoint. One can present data, but one cannot engage in personal attacks (although Mayr himself was well known for questioning the intelligence of those who disagreed with him). One can criticize, or tear to shreds, the logic used by other scientists, but one cannot simply refuse to listen. One can question the motives of others, but then still has to look at their arguments. If evidence is legitimate, one has the responsibility to be open to being won over. Personal attacks like 'quack', 'pseudo-scientist', 'corporate whore' and so on are to be reserved for those who grossly violate these rules. The only way this argument ever reaches an endpoint is if everyone on one side is either won over or dies of old age. Even then, if someone thinks they have found new evidence that the world is in fact flat, they can reopen the argument. Science does not deliver absolute, unquestionable truths.
But while you can argue anything you want, if your argument does not meet certain standards, it, and you, will be dismissed out of hand. Your statements must be logical, consistent with and based on data and must demonstrate knowledge of and meaningful response to what has been said and written before. If you want to argue that the world is flat, you'd better have a good explanation for all those data that seem to suggest a spherical Earth. And how a flat Earth came into being, and tides, and cosmology, and so on and so forth. There is a strong scientific consensus on the basic shape of the Earth (although there are bulges and deviations from sphericallity that still need to be better understood), because there is overwhelming evidence from a wide range of disciplines. The same can be said for the reality of evolution, the Holocaust, global warming, and a variety of other topics where the argument continues despite being settled in the minds of almost all scholars.
Those who oppose the consensus view on these issues generally point out that science is not "majority rule." As an example, the great majority of geologists long thought that plate tectonics was a ridiculous idea, and if the majority had ruled, we would have rejected what is now a foundational (possibly even bed-rock?) concept of geology, geography and evolution. It is therefore important to address this objection, because while true, it is a straw man. No reasonable scientist believes that truth can be arrived at through a popular vote of experts. That is not how the long argument works.
The relevant fact is not that the vast majority of informed scientists now accept plate-tectonics, but rather that we had that argument, and the plate-tectonics skeptics were unable to explain the data. Skeptics were converted, or gradually modified their views, or retired, and the number of supporters increased. The heroes in this story, from my perspective, are not those who believe because their teachers told them so, but those who were open minded enough to carefully change their minds.
We now accept plate-tectonics because the skeptics, being good scientists, had no choice but to look at the evidence presented, and there was eventually no logical way to cling to the view that continents are too big to move. "Eventually" being several decades.
So maybe several decades from now, we will have rejected evolutionary theory, decided that the Holocaust was just a historical ploy by the Jews for sympathy in their bid for an Israeli state, and realized that the global climate is just naturally cycling? Possible, but not likely, for several reasons.
First, plate-tectonics was a new idea that opposed everything humans had always assumed about our world. It was a hard idea to wrap a mind around. Creationism is not a new, radical and difficult to comprehend idea (my niece is dating a creationist who says he believes it because it is easier to understand than evolution, and his family believes it). Nor is a naturally controlled climate, or anti-Semitism. The idea of plate-tectonics overcame a distinct disadvantage these other ideas don't have.
Second, plate-tectonics took so long to gain acceptance partially because it took that long for technology to improve enough to produce convincing data. But during those decades, data gradually accrued. These other ideas have been around for decades, or millennia, and during that time the evidence has increasingly pointed against them.
Third, there was no lobby or faith pushing plate tectonics. No one stood to get rich or win political points by arguing that the crust of the earth moves and changes. Quite the opposite. The same cannot be said for Ahmadinejad, Bush and Exxon-Mobil.
Finally, and most importantly, there never was a body of data showing that the continents had always been in their current locations. That was the null hypothesis. We have enormous bodies of data supporting the reality of evolution, the Holocaust and anthropogenic climate change. Those who argued for plate-tectonics did not have to ignore or misinterpret a similar body of data presented by the other side. Scientific creationists (pseudo-scientists), scholarly anti-Semites (quacks) and professional global warming deniers (corporate whores) have to do exactly that. The only way to advance their views within the rules of the scientific process is to take all that data, and show us why it is fake or misunderstood. It is because they can't do this that they are disrespected. (Let me here be entirely clear that these insults are not intended to include either the pope or the teenager, both of who are honest non-scientists.)
The argument cannot be won, so there will always be Flat-Earthers, Static-Plate-ers, Creationists, and deniers of the Holocaust and Global Warming. And those people have the right to their points of view. And we have the responsibility to look at any new evidence they produce, if it really is new and it really is relevant evidence. We don't have to pay attention to people who, for the 5 millionth time, argue that the human eye is irreducibly complex and therefore there is a God. They violate the rules of the argument both by ignoring what has already been said, and by foregoing logic, and thereby forfeit their right to be taken seriously.
So, all of that said, how would I reply to the young woman who doesn't believe in human caused climate change, and to the Pope? To her I would say, "It is great that you are getting into science, and you absolutely have the right to come to your own conclusions. Based on your statements, I believe you have misunderstood much of what you read, and been mislead by those with a financial interest in misleading the public. I encourage you to learn more about the conceptual fields on which the science rests." To the Pope I would say, "The days when the Catholic Church was the unquestionable arbiter of truth for western civilization are long gone. At no point in the foreseeable future will the Church, or any other entity, resume that role. I respectfully suggest you accept this and guide the church into a new and more constructive role."
Friday, June 01, 2007
Nobel Intent
I came across an interesting online journal that is worth checking out.
http://origin.arstechnica.com/journals/science.ars
Most relevant to existing lines of thought that have been brought up so far:
Black holes for everyone
Could entangled particles be linked by wormholes?
http://origin.arstechnica.com/journals/science.ars
Most relevant to existing lines of thought that have been brought up so far:
Black holes for everyone
Could entangled particles be linked by wormholes?
Friday, May 18, 2007
Family of Science
I won't make a habit of this. But I thought posting this here would give the reader some sense of the environment that leads a young man to grow up and start Blog of Science!
For reasons unclear to me, my family has chosen to comment on my recent post "Not the end of the world" elsewhere, rather than on Blog of Science, so I have reproduced our discussion here. GML is my father, KAL my mother and JAL my brother. The following messages are in approximately chronological order:
The great physicist Enrico Fermi pointed out that interstellar travel is not very difficult for a technologically advanced and rich civilization, as long as it is designed for travel times of decades or centuries (or longer if a big colony is sent in a "generation ship". Each new colony would then grow and develop for some centuries, even a millennium, and then send out new ships (first to scout and then to colonize), and that this process would spread a civilization about our galaxy in a fairly short time, astronomically speaking, perhaps a few million years. Surely, the idea goes, at least one species somewhere would do this. This led to his famous question, "Where is everyone?" Many answers have been suggested, but the relevant one here is self-destruction, probably not by a physics experiment gone wrong, but by war within the species.
Our species has been said to need a "Moral Equivalent of War" to give us some outlet for our natural aggressive and us-them tendencies. This MEOW idea appeals to me, but I am not clear what it would be.
-GML
Dad, correct me if I'm wrong, but it was my impression that ETs wouldn't need to travel between stars for us to notice them. I thought even the level of radio noise that we currently produce would be plenty for us to notice if anyone were producing it within a few zillion light years. So the fact that we haven't heard anything (despite SETI and other projects looking for non-random radio signals) suggests not just that no one out there is traveling, but that no one out there is using radio waves, i.e., is technically advanced at all. Is that not right?
-JAL
There are a lot of assumptions we are making here.
Of which these are a few:
1. We are assuming that an advanced civilization uses radio waves to
communicate. Why do we assume this? We think we are advanced, and we
use radio waves. Perhaps radio is grossly inferior to something else we
ain't thought of yet, so nobody uses it.
2. They don't care if we hear them or not. Why do we assume this? We
don't worry about ETs detecting us, so we think they don't care if they
are detectable or not. Perhaps for one reason or another, many
civilizations consider it unwise or undesirable to broadcast their
presence.
3. We assume that if they are out there broadcasting radio, we would
pick up the signal. I don't know how far off we could pick up
broadcasts from a planet transmitting like Earth, unless we
specifically targeted that point in space, but I assume it is a
relatively small section of the galaxy.
4. We assume that if we picked up their signal, we would recognize it
as nonrandom. Given that we have no idea what form life on other
planets would take, it seems hubristic to assume that we would
recognize their transmissions as a sign of intelligent life.
5. We assume that if they picked up our signals, they would then
continue behaving in a way that would allow us to detect them. Imagine
there are technologically advanced aliens 100 light years away. They
detect rapid environmental change on earth, infer a rapidly developing
early technological civilization that behaves rather voraciously. Until
they know more, do they want the aliens (us) to know they are there?
The overarching point is that we know too little to know anything
except that we don't know. If we assume we are looking for ourselves,
which is what we often assume, we are wrong. The aliens are not going
to be biologically, psychologically or technologically familiar. they
are not going to live in a niche that would be amenable to us, and they
are not going to develop all the same technologies or develop them in
the same order. They are not going to have the same weaknesses and
strengths. They are not going to be in the same phase of develoopment,
or a similar one, to where we are. They are not necessarily going to
match our current definitions of either intelligence or life. It is fun
to speculate about and make up hypotheses, but we don't know enough to
draw any conclusions or moral lessons from. We know that either there
is no one out there, or that they are undetectable given our current
technology, or for one reason or another we have failed to detect them,
or have failed to notice detecting them. Everything else is SciFi.
-DAL
There is no reason why alien "life" should be carbon-based, or have discrete "bodies," or use the same senses we do (light, sound), or be on the same size scale as we - they might be miles across or microscopic or made up of filaments - or need the same amount of ambient radiation, heat, pressure, or environmental stability. There need not even be "individuals" with separate lives and separate mortalities. Probably some relatively fluid medium is needed - it would be hard to imagine solid rock being able to assume the complexity necessary for communication and reproduction. Otherwise I think that most human thought about the topic uses way too many chauvinistic assumptions. Long, thin necks and three-fingered hands, indeed!
-KAL
Interesting point. There are several factors to consider. The radio-based SETI and similar programs (mostly piggy-backing onto other equipment since Senator Proxmire made fun of it and got the U.S.Gov't to make it illegal to spend gov't money for it) make various reasonable (but not necessarily correct) assumptions about what frequencies would be used, as most free of background noise, etc., but at moderate interstellar distances such signals would be very hard to sort out, anyway. Also, higher-tech systems than radio (tachyons, gravity waves, links through space warps, etc.??) could be used, so lack of radio broadcasts does not mean lack of high technology. Another thought is that any sensible advanced species would carefully refrain from broadcasting its location, for fear of hostiles killing off possible competitors. No-one really knows, but the pay-off could be so great, technically and intellectually, that it seems worthwhile to put a little money into listening for interesting patterns; even if we do not find ETs, we may hear some natural phenomena worth knowing about. This has already happened, as when the pulsars (at first jokingly termed LGM for Little Green Men) were discovered.
-GML
Dan is quite correct in all his points, except perhaps in regard to our ability to recognize non-randomness. This is based on mathematics, mainly, not on biology or (I hope) human psychology. I certainly think that mathematics is universal; though I have no non-human examples as evidence. I believe that in some sense we discover mathematics, and do not just invent it.
-GML
Once mathematics is applied to trying to recognize patterns in real data, it becomes science, and all the limitations that come with science apply. We have to look at a particular set of time scales on a particular set of frequencies for a deviation from some mathematically defined but psychologically chosen null hypothesis. And all that means we don't really know if we could detect an alien deviation from random.
Regarding mom's point, it is very true, there is no reason to assume life on other planets would be carbon based. I wouldn't dismiss some sort of solid state lifeform though. Silicon can do amazing things.
-DAL
How about my idea that "life" elsewhere may accept very different conditions re solid/not solid "body" (or no actual body at all), tolerance/requirements for temperature conditions or radiation exposure, apparent passage of time per actual time passage, inevitability of mortality, use of other senses than sight/hearing, etc? Perhaps we haven't heard from anyone because we are actually very atypical in our characteristics and wouldn't think of the more common communication modalities. Or maybe no one else is out there and we are truly unique. Sometimes I think we exist only because the universe requires at least one set of observers in order for it to exist.
-KAL
Very true, that any collisions that CERN will make have happened, more powerfully, many times out in space, with no-one to register and measure them.
The Big BAng, from what I read, supposedly did not create any mass-energy, hard as that is to believe. The idea is that the expansion of the universe is, in proper physical book-keeping, measured in negative units, while the mass-energy is in positive units, and that these just cancel each other out. As you note that Stephen said, "on a minute scale the universe is a froth of energymass popping in and out of existence, but that these things were usually so small and numerous they mostly canceled each other out, leaving the energymass in the universe very close to
constant." Larger sized quantum fluctuations are shorter-lived than smaller ones, and if the universe is thought of as a nearly-zero mass virtual particle, it can last a very long time. Mass-energy versus time is one of those complementary trade-offs found in quantum physics, such as (knowledge of?) a particle's momentum vs. (knowledge of?) its position.
-GML
So we can get de novo mass-energy as long as we are willing to accept an equal amount of de novo space-time with it?
-DAL
Yes, in a sense, we can get more mass-energy along with more space-time, but only in a new universe, I gather. A prominent current theory is that black holes create new baby big bangs which then expand as full fledged universes; if the characteristics of a given universe leads to lots of black holes, that kind of universe will end up with lots of descendant universes with similar (but not identical) properties, leading to universes with successful characteristics (physical constants, etc.) becoming more numerous and predominating, in a Darwinian fitness paradigm. This theory is supposedly testable by figuring out what set of physical constants, etc., should be most successful in making black holes of the right sorts, and seeing how well this matches our universe.
-GML
But Darwinian evolution requires:
1. Mutations leading to variation
2. Heritability of that variation
3. Fitness differentials based on the heritable mutations
With regard to black holes as baby universes, we have no reason to assume 1 or 2, only that if 1 and 2 were to be true, that 3 could be true.
Also, your last comment implied that in order to be stable, a big bang event would have to result in something that in some strange sort of reckoning had zero mass. Black holes are not known for having zero mass.
There also seems to be the difficulty that black holes are not closed systems. Mass can go in and through quantum variation of location, evaporate off. Universes on the other hand are generally thought to be closed.
-DAL
For reasons unclear to me, my family has chosen to comment on my recent post "Not the end of the world" elsewhere, rather than on Blog of Science, so I have reproduced our discussion here. GML is my father, KAL my mother and JAL my brother. The following messages are in approximately chronological order:
The great physicist Enrico Fermi pointed out that interstellar travel is not very difficult for a technologically advanced and rich civilization, as long as it is designed for travel times of decades or centuries (or longer if a big colony is sent in a "generation ship". Each new colony would then grow and develop for some centuries, even a millennium, and then send out new ships (first to scout and then to colonize), and that this process would spread a civilization about our galaxy in a fairly short time, astronomically speaking, perhaps a few million years. Surely, the idea goes, at least one species somewhere would do this. This led to his famous question, "Where is everyone?" Many answers have been suggested, but the relevant one here is self-destruction, probably not by a physics experiment gone wrong, but by war within the species.
Our species has been said to need a "Moral Equivalent of War" to give us some outlet for our natural aggressive and us-them tendencies. This MEOW idea appeals to me, but I am not clear what it would be.
-GML
Dad, correct me if I'm wrong, but it was my impression that ETs wouldn't need to travel between stars for us to notice them. I thought even the level of radio noise that we currently produce would be plenty for us to notice if anyone were producing it within a few zillion light years. So the fact that we haven't heard anything (despite SETI and other projects looking for non-random radio signals) suggests not just that no one out there is traveling, but that no one out there is using radio waves, i.e., is technically advanced at all. Is that not right?
-JAL
There are a lot of assumptions we are making here.
Of which these are a few:
1. We are assuming that an advanced civilization uses radio waves to
communicate. Why do we assume this? We think we are advanced, and we
use radio waves. Perhaps radio is grossly inferior to something else we
ain't thought of yet, so nobody uses it.
2. They don't care if we hear them or not. Why do we assume this? We
don't worry about ETs detecting us, so we think they don't care if they
are detectable or not. Perhaps for one reason or another, many
civilizations consider it unwise or undesirable to broadcast their
presence.
3. We assume that if they are out there broadcasting radio, we would
pick up the signal. I don't know how far off we could pick up
broadcasts from a planet transmitting like Earth, unless we
specifically targeted that point in space, but I assume it is a
relatively small section of the galaxy.
4. We assume that if we picked up their signal, we would recognize it
as nonrandom. Given that we have no idea what form life on other
planets would take, it seems hubristic to assume that we would
recognize their transmissions as a sign of intelligent life.
5. We assume that if they picked up our signals, they would then
continue behaving in a way that would allow us to detect them. Imagine
there are technologically advanced aliens 100 light years away. They
detect rapid environmental change on earth, infer a rapidly developing
early technological civilization that behaves rather voraciously. Until
they know more, do they want the aliens (us) to know they are there?
The overarching point is that we know too little to know anything
except that we don't know. If we assume we are looking for ourselves,
which is what we often assume, we are wrong. The aliens are not going
to be biologically, psychologically or technologically familiar. they
are not going to live in a niche that would be amenable to us, and they
are not going to develop all the same technologies or develop them in
the same order. They are not going to have the same weaknesses and
strengths. They are not going to be in the same phase of develoopment,
or a similar one, to where we are. They are not necessarily going to
match our current definitions of either intelligence or life. It is fun
to speculate about and make up hypotheses, but we don't know enough to
draw any conclusions or moral lessons from. We know that either there
is no one out there, or that they are undetectable given our current
technology, or for one reason or another we have failed to detect them,
or have failed to notice detecting them. Everything else is SciFi.
-DAL
There is no reason why alien "life" should be carbon-based, or have discrete "bodies," or use the same senses we do (light, sound), or be on the same size scale as we - they might be miles across or microscopic or made up of filaments - or need the same amount of ambient radiation, heat, pressure, or environmental stability. There need not even be "individuals" with separate lives and separate mortalities. Probably some relatively fluid medium is needed - it would be hard to imagine solid rock being able to assume the complexity necessary for communication and reproduction. Otherwise I think that most human thought about the topic uses way too many chauvinistic assumptions. Long, thin necks and three-fingered hands, indeed!
-KAL
Interesting point. There are several factors to consider. The radio-based SETI and similar programs (mostly piggy-backing onto other equipment since Senator Proxmire made fun of it and got the U.S.Gov't to make it illegal to spend gov't money for it) make various reasonable (but not necessarily correct) assumptions about what frequencies would be used, as most free of background noise, etc., but at moderate interstellar distances such signals would be very hard to sort out, anyway. Also, higher-tech systems than radio (tachyons, gravity waves, links through space warps, etc.??) could be used, so lack of radio broadcasts does not mean lack of high technology. Another thought is that any sensible advanced species would carefully refrain from broadcasting its location, for fear of hostiles killing off possible competitors. No-one really knows, but the pay-off could be so great, technically and intellectually, that it seems worthwhile to put a little money into listening for interesting patterns; even if we do not find ETs, we may hear some natural phenomena worth knowing about. This has already happened, as when the pulsars (at first jokingly termed LGM for Little Green Men) were discovered.
-GML
Dan is quite correct in all his points, except perhaps in regard to our ability to recognize non-randomness. This is based on mathematics, mainly, not on biology or (I hope) human psychology. I certainly think that mathematics is universal; though I have no non-human examples as evidence. I believe that in some sense we discover mathematics, and do not just invent it.
-GML
Once mathematics is applied to trying to recognize patterns in real data, it becomes science, and all the limitations that come with science apply. We have to look at a particular set of time scales on a particular set of frequencies for a deviation from some mathematically defined but psychologically chosen null hypothesis. And all that means we don't really know if we could detect an alien deviation from random.
Regarding mom's point, it is very true, there is no reason to assume life on other planets would be carbon based. I wouldn't dismiss some sort of solid state lifeform though. Silicon can do amazing things.
-DAL
How about my idea that "life" elsewhere may accept very different conditions re solid/not solid "body" (or no actual body at all), tolerance/requirements for temperature conditions or radiation exposure, apparent passage of time per actual time passage, inevitability of mortality, use of other senses than sight/hearing, etc? Perhaps we haven't heard from anyone because we are actually very atypical in our characteristics and wouldn't think of the more common communication modalities. Or maybe no one else is out there and we are truly unique. Sometimes I think we exist only because the universe requires at least one set of observers in order for it to exist.
-KAL
Very true, that any collisions that CERN will make have happened, more powerfully, many times out in space, with no-one to register and measure them.
The Big BAng, from what I read, supposedly did not create any mass-energy, hard as that is to believe. The idea is that the expansion of the universe is, in proper physical book-keeping, measured in negative units, while the mass-energy is in positive units, and that these just cancel each other out. As you note that Stephen said, "on a minute scale the universe is a froth of energymass popping in and out of existence, but that these things were usually so small and numerous they mostly canceled each other out, leaving the energymass in the universe very close to
constant." Larger sized quantum fluctuations are shorter-lived than smaller ones, and if the universe is thought of as a nearly-zero mass virtual particle, it can last a very long time. Mass-energy versus time is one of those complementary trade-offs found in quantum physics, such as (knowledge of?) a particle's momentum vs. (knowledge of?) its position.
-GML
So we can get de novo mass-energy as long as we are willing to accept an equal amount of de novo space-time with it?
-DAL
Yes, in a sense, we can get more mass-energy along with more space-time, but only in a new universe, I gather. A prominent current theory is that black holes create new baby big bangs which then expand as full fledged universes; if the characteristics of a given universe leads to lots of black holes, that kind of universe will end up with lots of descendant universes with similar (but not identical) properties, leading to universes with successful characteristics (physical constants, etc.) becoming more numerous and predominating, in a Darwinian fitness paradigm. This theory is supposedly testable by figuring out what set of physical constants, etc., should be most successful in making black holes of the right sorts, and seeing how well this matches our universe.
-GML
But Darwinian evolution requires:
1. Mutations leading to variation
2. Heritability of that variation
3. Fitness differentials based on the heritable mutations
With regard to black holes as baby universes, we have no reason to assume 1 or 2, only that if 1 and 2 were to be true, that 3 could be true.
Also, your last comment implied that in order to be stable, a big bang event would have to result in something that in some strange sort of reckoning had zero mass. Black holes are not known for having zero mass.
There also seems to be the difficulty that black holes are not closed systems. Mass can go in and through quantum variation of location, evaporate off. Universes on the other hand are generally thought to be closed.
-DAL
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