I like Michael Crichton. I like his books, and I've enjoyed a couple of movies made from his books. He gave a speech in California not too long ago where he linked the search for extraterrestral life and the hype over "global warming". I have no substantive argument with the overall theme of that lecture
. It's a good lecture, and it does an excellent job of showing why we need to approach outrageous arguments with a demand for "good" science. I have some qualms, however, about how portions of that lecture will affect non-scientific readers, and about lumping some good science in with "bad" science or "junk" science. I feel that some of the links he describes are tenuous, and that some of his conclusions need to be taken skeptically. Some of what he says may be a disservice to truly dedicated scientists and scientific endeavor. I'd like to talk about one of those subjects in this article. I hope to discuss others in a couple of follow-on articles.
Let me first say that I am not a "scientist". I am a generalist - someone who's studied many subjects, each in varying depths, and not always formally. My military specialty, imagery intelligence, drove much of that study. My interest and just general curiosity, plus an insatiable love of reading, has driven even greater interests in many areas. I'm not without skills, training, or resources, but I'm not a formal "scientist".
I'm also a Christian, and a strong believer in Judeao-Christian philosophy as well as religion. I've studied a dozen or so other faiths, and many different denominations of Christianity, from Catholic to Mormon. I hold my own beliefs, based on the only factual method possible - the lifelong experience of a personal relationship with a Supreme Being I accept is God.
One of those areas I have a strong curiosity about is the possibility of intelligent life on other planets. In this, I have a minor disagreement with Michael Crichton: scientific theory requires us to establish a hypothesis, and test it in the laboratory of reality. It will either be supported or crushed by such experimentation. Sometimes our theories require modification, based upon evidence acquired during testing, but the entire process is just that: question, hypothesis (possible answer), testing, proof/rejection of hypothesis, re-evaluate, modify, start over. There is now scientific evidence of planets around other stars. With that, one has to assume that it is POSSIBLE that life may exist outside the planet Earth. As we learn more and more about the possibility of life existing on Mars, Titan, perhaps even in the 'air-oceans' of Saturn and Jupiter, we also have to consider that life may exist outside our solar system. It would be UNSCIENTIFIC to deny these possibilities.
I also believe, as a Christian that, since God did create the entire universe and everything in it, and that He set up the "natural laws" that govern it, our planet Earth is not the only one He created life upon. There are about 100 BILLION stars in our galaxy alone (Info from Encyclopedia.com
). There are millions of galaxies. It would be very strange indeed for God to go to all the trouble of creating all this real estate and then restricting life to one small planet. Since God has created life to fill every available niche on Earth, I think He did the same thing throughout the galaxy. One day we'll know for sure. I'd be very surprised to find that all the other planets in our area of this galaxy are devoid of life. I would also be very surprised to learn that, once we DO contact life on other planets in other solar systems, they didn't worship a God whose words are recorded in a book very similar to our Bible. That's a personal belief, based upon my personal religious experiences, and doesn't necessarily reflect what anyone else might believe.
The next part of the scientific
process is to either prove/disprove the hypothesis through research and the collection of empirical evidence. At this point, we can only do indirect experimentation. Nothing will ever be proven until we either find specific, undeniable evidence of the existence of such life, or we examine the entire universe and prove there isn't any. Both of these are tall orders, and will take generations to finish. We cannot determine that the entire process is a waste of time because the failure of the search over the past 30 or 40 years hasn't been successful. To do that would be to ignore the variables involved, and the complexity of the problem.
Unfortunately, the science itself has been fairly lax in establishing and refining its models as time elapsed and more information was gathered. The so-called Drake equation hasn't been updated, modified, or changed to account for increased knowledge gained in the past 45 years. Being more than 45 years old, I can truthfully say I KNOW from experience that the world has gone through at least three 'scientific revolutions' during that time. Some of the changes have filtered into the search for Extraterresteral life, but not enough. Drake's formula needs to be completely rethought.
For instance, we now know that stellar formation is a continuous affair, and that solar systems evolve: they are "born", they "age" over time, and they "die" as the "fuel" of their central star(s) is consumed. This is a constant, measurable process. We know that some stars go through this natural evolutionary process at different rates, mostly based on two factors: size and composition. We know that the key to technology is energy consumption - the ability to do more than just survive requires more energy, the ability to build complex structures takes even more, and the requirement of transportation to allow complex structures calls for even greater energy consumption. Unfortunately for the search for extraterresteral intelligence, there's even more we don't know.
We don't know, for instance, how binary and larger stellar systems would affect planetary development. We DO know that some binary systems have planets - that's been proven by astronomical studies. We're not sure how planetary development occurs, although at least we now know our star isn't the only one with planets. The only solar system we've been able to study in any great detail has been our own, and it keeps surprising us. In fact, what we DON'T know about planetary evolution and development is far greater than what we do, or even can imagine. I'm sure the Milky Way galaxy alone will give us more than a few surprises in that respect. Many excellent minds have worked on the problem, not all of them scientists.
In order to truly study the possibility of extraterresteral life, we have to break the problem down into its constituent parts, and solve each part of the problem. That hasn't been done - at least, it hasn't been done and reported in any of the scientific arenas I check (which doesn't include Scientific American or National Geographic, both of which have abandoned the principles that they originally followed).
What are the problems? Here's my list:
1. What is the life-cycle of each type of star, and what outside influences can influence that cycle?
2. What is the likelihood of any star, either independently or in a stellar cluster of two or more bodies, having planets?
3. What is the likelihood of any planet being in the approximate range of its primary to allow a liquid-water cycle to exist? (this will give us a likelihood of the number of planets that MAY be able to support life similar to human beings).
4. Are moons/tides essential for life to develop? If so, how do these affect the development of life? Can life develop on planets without moons?
5. Is there any other form of life that can exist: I.E., using chlorine instead of oxygen, silicon-based, etc?
6. What kind of planet/sun/system would be necessary to allow such development?
7. What is the minimum life-span considered necessary for INTELLIGENT life to develop (within a range)?
8. What factors could affect the development toward a technical civilization, either inhibiting it or promoting it?
9. How would this affect the developing intelligence's ability to communicate?
10. What other factors can affect technical development, the development of electromagnetic communication, or other attributing factors?
11. What outside factors (nearby novas, excess gas and dust in nearby space, etc.,) can affect the development of life and intelligence, and how?
Drake's equation needs to be refined. I'm not a mathematician, but I'll make a small stab at it. Here's the original equation:
N=N*fp ne fl fi fc fL
Where N is the number of stars in the Milky Way galaxy; fp is the fraction with planets; ne is the number of planets per star capable of supporting life; fl is the fraction of planets where life evolves; fi is the fraction where intelligent life evolves; and fc is the fraction that communicates; and fL is the fraction of the planet's life during which the communicating civilizations live.
First of all, we can discard quite a few stars. They're either too young or too old, or have gone through a catastrophic process such as a nova explosion or other disaster. So we have to have a sub-equation of N'=N-(Nv+Nd+Nq), where N' equals the number of stars that have the potential for life, after subtracting from N those stars that are too young (Nv) or too old (Nd), have nova'ed, or have been affected by some other force that would significantly reduce (possibly even eliminate) their capacity to sustain life, whether planets existed or not (Nq). Then we have to decide just how many stars have planets. We cannot eliminate ANY star that has planets just because it doesn't have the same kind of environment our plant has, because we don't know if other forms of life can exist. So we need a variable called fNp
, or the fraction of total stars that have planets. (At the moment, I can't think of a way for life to exist without planets, but it's theoretically possible. The "theory" part indicates there's a "possibility", but doesn't suggest a "probability" high enough to be worth worrying about at the moment.) I'd be much more inclined to expect life to develop in a more sheltered environment - I.E., a planet, and one with a relatively thick atmosphere sufficient to stop such dangerous life-threatening events such as gamma radiation, meteorites, etc, - which gives us our next variable, fNt
, or the fraction of planets that have a significant enough atmosphere to both support life and protect it from catastrophic disasters that would terminate it. Now we have a general idea how many places in our galaxy have the potential for supporting life.
Once we get to this point, we'd need a variable to establish how many planets where life COULD evolve, it actually did - Drake's fl, my fNl
. From there, we need to determine what percentage of planets where life evolved, it developed into intelligent life. Right now, this has to be a factor of "1", since the only planet we know of where life has developed, has also developed enough intelligence to worry about the question. We cannot refine that variable further until we have some scientifically acceptable evidence. Right now, we don't even know if life exists outside of our own planet. We have some intriguing studies that indicate it COULD have, but we cannot truly say that life has developed anywhere else but Earth. Because of that, we can't even say that the variable should be "1/9" (Earth/total number of planets in our solar system) - we DON'T KNOW. We need to do the scientific evidence-collecting to give us at least a chance to develop an approximation. Anyone trying to do that at the moment is just guessing, which isn't very scientific. Still, we need a variable to express what percentage (fraction) of planets where life developed also developed intelligence (fNe
), and what percentage of intelligent life developed sufficient technology to spread a signal beyond their own planet (fNx
). Once all these factors are calculated, we have a number, Ni
, of potential intelligent species with the technology to communicate with us. The final formula should look something like this:
We now have a formula that will tell us the potential for life to develop, and for that life to grow beyond the pond scum stage to an intelligence with the technical capabilities to communicate over vast distances between stars. Unfortunately, even with this formula, we have no way of assigning real values to each of the many variables. We also run into a number of other significant problems in our consideration:
A. Is the intelligence similar to ours, or very different?
B. Do these intelligent species function or think the same way we do?
C. Do they develop sufficient technology that they can express their intelligence in ways similar enough to ours for us to understand it?
Suppose a species develops communication technology not based upon radio waves: would they detect and understand the function of ours? If they developed some other way to communicate, would we be able to detect that communication? Would we even look at it as a signal? There are too many variables here to express in a simple equation, yet none can be ignored.
To top it all off, we have to have some way of determining if a particular intelligent civilization is in a similar technological stage to actually recognize a signal, and respond to it. This is a situation that, in our society, is in constant flux. Radio is just a little over 100 years old. Television is less than 70. Microwave radiation (radar, etc) is about the same age. More and more data is being carried by fiber-optic cables, rather than radio signals. Advances in technology are changing the world we live in daily. How can we even begin to consider the technological development of a different intelligent species?
When all these questions are evaluated, we see there is no simple way to determine if intelligent extraterrestral life exists, or if it does, that we can detect it. We've only been using radio waves for communication for just over 100 years. No extraterresteral civilization farther away than say, 150 light-years, could detect those signals - they haven't arrived yet. They'll have to be in the portion of their development where they have the technology to acquire the signals, and not so developed they would ignore them. They'd have to have the curiosity to actually be interested in looking for signals, and have the ability to detect them. When - if - they do detect the radio "noise" the planet Earth has poured out over the last 100+ years, they will be extremely weak (inverse square law), and have to be filtered out from other stellar background "noise". THEN they'll have to recognize the signal as being intelligent communication, instead of just an unusual, natural source. Then they'll have to devise some way to interpret the signals. For early radio and other wireless signals, that will be a major achievement for ANY species.
Of course, the same problems apply to us, and our search for signals from outside our planet and solar system. That doesn't mean the search is "unscientific", only that it's difficult, and the time needed to actually do the "test/evaluate" part of the hypothesis COULD take not years, but centuries.
The time it may take to actually do a sophisticated search for extraterrestral life throughout our galaxy could be tens of thousands of years, depending on whether we maintain the technical capability of doing so, and if we maintain the interest, and if we're restricted to slower-than-light movement. Our galaxy is approximately 100,000 light-years across, and we are about 25,000 light-years from the center. The farthest portions of our galaxy are therefore 75,000 light-years away. Our radio waves won't get there for another 75,000 years, nor can theirs get here before then. The entire galactic center and the majority of the "arms" are in the way, making it difficult for any intelligible signal to actually make it all that distance.
This is where the scientific process broke down with the search for extraterresteral life: unreasonable expectations, failure to constantly refine and re-express the basic scientific fundamentals of the search, and a failure to communicate the extent of the difficulties involved.
Most people today have unreasonable expectations about many things, including scientific knowledge. Part of the problem is that scientific breakthroughs have been occurring at breakneck speed in many, many fields. Unreasonable expectations arose from failure to clearly define the problem, and the means of examining that problem, to both the people and their leaders. I'm sure it's difficult to get funding for something that may not show ANY results for generations. Failure to show positive results is deemed a failure of the project, which is also false. There are many reasons why we may not have found a signal from beyond our planet, including all those questions I listed that need to be answered. There are too many variables, there are too many areas where we don't have the tools to truly conduct the research to answer the questions, and we haven't committed enough time or energy to answer the questions. Maybe we need to spend more time, more resources, and more effort in the search, or maybe we need to slow down, redefine what we're trying to do, and go about it differently - more slowly, in a different manner, using different parameters, or something we haven't even thought of yet. It's just one more of several million questions we can ask ourselves, and try to find the answer. Writing it off as a lost cause because we can't "imagine" getting results would be self-defeating.
I think the scientific community needs to do some serious rethinking about the search for extraterresteral life, and should provide some more information to the general public. If someone has already updated Drake's Equation, maybe that updated formula needs to receive greater publicity. Maybe a good, open debate on the subject should be encouraged (I know there's a space on the Space.com website to discuss it, but that's not general circulation. Some astrophysicist capable of writing to the general public needs to start a blog!).
Any question we can think of is worth pursuing an answer for. Some questions are easier to answer than others. Mankind has used fire for at least 25,000 years, yet we're still learning about how it can affect us and our world. The search for evidence of another intelligent species is based on the question "is anyone else out there?". We don't have the capability today to answer that question. We don't have the capability today to even define the parameters needed to make a reasonable assumption, other than "it's possible". It may take us another ten years, possibly even ten centuries, to develop even rudimentary capabilities to answer those questions. We rushed into a project to "find" supporting evidence, without fully defining the problem, and some scientists involved in the project allowed unreasonable expectations to be raised, and gain enough ground that people were disappointed when those expectations weren't realized. It may not be the most serious scientific question facing us, but it shouldn't be brushed off as "poor science". We can afford to allocate at least some resources for continuing to investigate the question, to search for data to help us evaluate our equations, and see if they truly are worth following. And who knows, it may one day provide us with some surprising answers.