Former Michigan Congressman Vernon J. Ehlers, the first PhD physicist in the House of Representatives and the only one so far from the Republican party, died on August 15 at the age of eighty-three. His tenure in Congress (from 1993 to 2010) capped off a most impressive career as a scientist (specializing in studies of the nuclei of alkaline and post-transition metals), Continue reading “We Can Still Learn From Vern”
The first few years of the Millennium were dark ones for fans of hard science fiction. In 2001, Poul Anderson died, followed a few months later by his frequent collaborator Gordon Dickson. Then in 2003, Hal Clement, who did more than any other writer to develop hard science fiction as an identifiable sub-genre by introducing a new degree of scientific rigor in writing and helped make world-building an art form, also passed away. Between these two massive losses came possibly the most tragic of them all, as physicist and writer Charles Sheffield lost a brief but brave battle with an aggressive brain tumor in 2002. Although he had begun writing quite late in life, Sheffield had nonetheless quickly developed a reputation as one of hard science fiction’s finest practitioners, a prolific and versatile writer whose diverse stories and series combined, as Spider Robinson (who would name the spaceship in his Heinlein paste-up Variable Star after his late colleague and friend) said, “the scientific grounding of Clarke, the storytelling skills of a Heinlein, the dry wit of a Pohl or Kornbluth, and the universe-building prowess of a Niven.” I would also add that he possessed Gregory Benford’s skill at realistic and believable depictions of scientists and science at work…even as practiced many centuries from now. As wondrous and exciting as his many novels and short stories were, there was still the feeling that the best was yet to come; alas, as had been the case with Stanley Weinbaum three quarters of a century earlier, the cruelties of cancer once again stole us of a promise yet to be fulfilled, and we can only surmise as to what might have been. Continue reading “Countdown to Interstellar: The Warp Drive in Hard Science Fiction…1…Charles Sheffield”
Gregory Benford and Relativistic Effects
I once attended a talk given by renowned mathematical physicist Roger Penrose where he described binary pulsars as the most beautiful objects in the universe, as they fulfill every prediction made by the Theory of Relativity. Similarly, the stories of Gregory Benford are among the most beautifully written in science fiction, not just because of their prose but how they illuminate the laws and hidden facets of the universe. As a physicist himself, much of Benford’s science fiction is distinguished by both his keen observations of the lives of scientists and his finely detailed depictions of them at work, and his ability to vividly convey the sort of cognitive and sensory impressions that are part of their experiences. Continue reading “Countdown to Interstellar: The Warp Drive in Hard Science Fiction….2….Gregory Benford”
Writers of hard science fiction, that most rigorously realistic of the genre’s subdivisions, pride themselves on their unwavering commitment to scientific accuracy and adherence to the known laws and facts of the physical universe in their stories, yet they find themselves making a necessary exception for one of the most significant of all its invariants. Since the Theory of Special Relativity has established that nothing can move faster than the speed of light, which has only been further buttressed by experiment and observation, the practitioners of hard science are forced to bend their own principles slightly whenever their stories go beyond our own Solar System. Fortunately, the Great Einstein giveth as much as he taketh away, and the many fascinating predictions and outcomes of both Special and General Relativity have provided the “loopholes” many writers are looking for in trying to explain how their characters can traverse such great distances. In some instances, the stories are specifically about faster-than-light travel itself; the brand-new Christopher Nolan film INTERSTELLAR follows a well-worn path to the stars that science fiction writers have traveled many times before, attempting to explain how FTL or the “warp drive” in terms that are consistent with current scientific knowledge, and using it as a platform for both the stories and themes. Continue reading “Countdown to Interstellar: The Warp Drive in Hard Science Fiction….3….Poul Anderson”
The late, great Frederick Pohl opened Chasing Science, his wonderful memoir of scientific tourism, with an account of his visits to America’s national laboratories. Although the majority work under heavy security there is one lab, as Pohl notes, that always welcomes visitors with open arms: Fermilab in DuPage County, Illinois. It is there that the Top Quark was discovered, solidifying the Standard Model and establishing it firmly as the touchstone of modern physics, and it remained the country’s leading particle physics facility until the recent shutdown of the Tevatron accelerator. Even so, it remains a major research center as well as a popular tourist attraction in the greater Chicago area, and the recent documentary Science at Work provides a virtual tour of the lab for those of us who have wanted to but never had a chance to pay a visit. Continue reading “Movie Review: Science At Work”
There are many people that base what they know of the first 190,000 years of human history on Hollywood movies about cavemen rather than any academic research. The reality is that anatomically modern humans lived a hunting and gathering lifestyle exclusively for almost 190,000 years. They did this, not because they were too stupid to invent agriculture or that they had no idea what animal husbandry was, they lived that lifestyle because it was easy. In fact it was so easy a “caveman could do it”.
Got your attention?
Hunters and gatherers did not invent agriculture because it was a better lifestyle. The fact is that agriculture is not optimal for human health and it certainly is not as easy as hunting and gathering. Agriculture has a host of health and social problems that come with it that are extremely negative and the majority of these problems have not been overcome until relatively recently. This begs a question…If farm living is so much harder why would anyone do it? The answer is relatively simple, necessity. The first people who moved to the agricultural lifestyle did so because of ecological change, change in climate, and population pressures that occurred at the end of the last ice age.
There are myriad reasons why humans did not develop agriculture before or during the last ice-age, but for the most part the ready availability of prey animals and small population densities made agriculture less desirable. Around 12,000 years ago there was a perfect storm of change that forced humans to try something new. That something new was not inherently better than what had come before. The change in diet associated with agriculture probably led to thousands of early deaths and has led to centuries of gastrointestinal problems as human beings adapt to this new lifestyle.
But, but, but….you can’t possibly be suggesting we return to the lifestyle of hunting and gathering. No, that is not what I am saying. We could not return to that lifestyle even if the population wasn’t so large, or even if someone believed it was a good idea. The ecological factors that made it possible for people to subsist easily are no longer present. Vast herds of megafaunal prey animals no longer roam America and Europe and will not again in the near future. Secondly our technological society has finally begun to mature to a point where human beings are better off as agriculturalists than as hunters and gatherers.
This does not mean we can’t objectively look at the differences between the hunting and gathering lifestyle and the agricultural lifestyle so we can understand why humans chose each. There are several advantages to being a hunter and gatherer.
1) Medical- Medicine didn’t magically become better when people started living in villages in fact medical problems got much worse when we started living on top of each other. Diseases that were often avoided because of isolation suddenly became pandemic. To see this in action look at what happened in North America after Columbus. The Native Americans had arrived on this continent as hunters and gatherers in small isolated groups. The trip to North America acted as a natural bottle neck for disease. Very few diseases that infected humans were carried across. These band of hunters and gatherers were isolated from human disease vectors that had evolved in the old world. When these diseases were reintroduced they decimated the agricultural civilizations that had sprung up in North America. Without such killers as measles, chicken pox, even the common cold the population had never evolved resistance.
So, you have all those same injuries and illnesses that hunters and gatherers faced like hunger, broken limbs, etc plus more disease in agricultural society. This lasted until the early modern period and it was often exacerbated by a much larger population vying for fewer resources. Pray if you are ever dropped back in time before about 200 years ago. It is somewhere underpopulated.
2) Society- Contrary to pop culture the strongest person was not always “Boss Caveman”. I may need to remind you these hunter and gathering groups are simply extended or direct family groups consisting of father, mother, children, and grandchildren. Sometimes uncles,aunts and their children as well. Thirty people is the normal size of these bands. They are not states they are not even really tribal. Bands and family groups. There are no rules, rulers, kings, or serfs and government hasn’t been invented yet. Just because movies tell you that UGH was beating his tribe into submission doesn’t mean that was the norm.
As for WAR? What war? Can you call a fight between groups that max out at about 60 people a war? It is a conflict more akin to a family feud. Most Hunter and Gatherer groups, we have had the privilege to observe in the modern age don’t go to “War” they count coup of one kind or another. Sometimes they do kill somebody sometimes a people get hurt. That is the nature of being human. When compared to the horrors inflicted by agricultural societies?
I have had people call hunting and gathering societies communist utopias. They were not. They were neither Utopian nor were they communistic. In fact communism as we know it, in which individuals live communally for the welfare of the group, is an invention of agriculture. These hunting and gathering bands are the haven of the original rugged individualist.
The major advantage to living in large groups for these early people was child rearing. Children survive with more regularity in a settled society. Score one for “It takes a village”. As the population rises in these settled agricultural communities they soon exceed the normal number of people associated with hunting and gathering. You can support more people on less land with agriculture. Soon you have government and with government comes a type of power humans had never had over each other before. In a hunting and gathering society when the bands become too large and one group tried to dominate another they break apart and go their separate ways. This doesn’t happen for agriculturalists. They are tied to the land or they are dependent on specialized knowledge of others to survive. They can’t run away over the hill and survive without interference from the state.
Yes, we are better off today than 13,000 years ago but it took quite a bit of heartache to get here and we didn’t get here because agriculture was a better choice.
Saying that hunting and gathering is a better lifestyle choice than agriculture until the modern period is not Marxism projected backwards, if anything it is individualism projected backwards. Neither is it a “Noble Savage” fallacy. There is plenty of evidence that life was not always easy no matter which lifestyle you lived. Humans evolved to live a particular lifestyle. We lived in that lifestyle for tens of thousands of years and it was not lack of intelligence or imagination that kept us there it was simply easy…we all get in a rut sometimes.
Some popular misconceptions about paleolithic man.
1) Paleolithic Humans were prey for carnivores such as the cave lion, or the short faced bear. and lived in constant fear of their surroundings..false.
Human’s have been apex predators since before becoming anatomically modern. Large carnivores may have been able to kill the occasional human but archaeological remains suggest early humans hunted other carnivores much more often than they hunted humans.
2) Paleolithic Humans lived exclusively in caves…false. Caves were certainly utilized, but humans are very adaptable and probably lived in many different types of structures made from local materials.
3) Paleolithic humans were always dirty, hungry, and disease ridden…false. We dealt with disease above. As for being dirty we can’t really tell from the archaeological record, but we can surmise based on hunters and gatherers that have been studied. Bathing is a fact of life in most of these societies and cleanliness is often ritualized. As for hunger it really depends Archaeological evidence shows that many groups of hunters and gatherers went through periods of boom and bust from year to year, others are more constant in their nutritional intake. It almost always depends on the area in which the people lived and the abundance of food. Looking at skeletal remains of hunters and gatherers verses agriculturalists, hunters and gatherers are often in much better physical shape probably as a result of better diet (Hunters and gatherers actually work much less than agriculturalists so it isn’t from physical labor).
For more reading:
Mashall Sahlins’ study The Original Affluent Society goes into detail how hunter and gatherer societies functioned, http://www.primitivism.com/original-affluent.htm
And if you want to see a writer go a bit too far with the Noble Savage idea:
If mankind is going to reach for the stars, it is most certainly going to involve some way to travel faster than light speed. A recent post on this very site, reported the fact that certain scientists are considering warp drive as a possibility. I am skeptical of such things but then again I am not a scientist. My thoughts are that this is going to take a while regardless but there two basic schools of thought on how this is going to develop. 1) That we are going to have to colonize our own solar system and that through that colonization we may learn what it is going to take to head to new stars. 2) There are others though that propose that we skip the colonization of our own solar system because the prospects for terraforming, say Mars, are bleak at best. I suppose that there are those that think we need to just do both because we need to do it. These two opinions seem to be the basis though for all the rest. Myself, I take the first route, because I believe mankind has a lot to learn before it can reach to the stars.
Hypothetically, lets take a trip to a star with our goal to colonize a world on it and at the moment of arrival we need to face the problems in doing so. What is going to happen at that moment.
1) Conventional Drive Propulsion: Even to survey such a system to find a suitable world is going to require getting around that system far faster than we have been currently able to get around our own. Even if we send a robot drone to do this, it is going to have to move. Current missions to survey our own solar system have been slow and cumbersome taking years to do. Depending on how we arrive, we may need to survey the system quickly or far in advance. The need to get around a solar system quickly becomes apparent regardless because we can’t take all day finding the place to colonize. We might be able to use our faster than light propulsion for this but there is also a possibility that we may not.
2) Communication: The recent Mars mission highlighted this problem. Even in our own solar system time lag problems can be fatal. Even if we follow a mothership with drone survey ships model, time lag can be difficult to get the colony going right away. Some form of faster than light communication would be helpful, but more than likely we are going to have to deal with time lag and that means problems we are going to have to overcome. I would rather practice this closer to home before we start sliding to other stars.
3) Terraforming: It may be that as we send out robot ships out that we may to find much in the way of worlds we can colonize. There is a real possibility that we may not find something better than Mars. If so, I would rather have how to deal with such a world all worked out before I get there.
Then there are the issues of how we build such a colony ship in the first place. Questions arise: Do we have all the resources we need to do so here on planet earth or are we going to have to exploit other planets and moons in our solar system to have the materials we need? That means at least robot mining colonies to do this. What is the best way and place to build this starship. Building it in space would help, but that means manufacturing technology is going to have to go to no gravity or low gravity environs. The list of questions also includes environmental controls, life support, self sufficient technologies, etc. It is a long list of questions.
The main fact we have to face with this issue is that all we have done is gone to the moon and back and sent robot probes into or local neighborhood. All this qualifies us for is that we have gotten off our belly and are on all fours. We really have not even learned to crawl, let alone walk or run. It may be that there is a giant leap in the near future that will help, but we cannot count on it. In the meantime, questions can be answered by addressing the learning curve we need to face in the local neighborhood of our own solar system. It becomes a great testing ground and nursery to learn to crawl and then walk.
I am hoping to hear the other side on this one, because maybe their objections to this have merit. I am after all not a scientist or engineer. My thoughts are that we may have many barriers to break before we break the speed of light barrier and that to break them we may have to look and experiment in our own back yard first before the stars can be reached. I just don’t think this is going to be like dusting crops; it is far more complicated than what we would like it to be.
Life! You know it when you point at it but you find it difficult to say just what it is. What is it about an entity that make you say “That’s alive.”? What systems that we do not normally think of as alive have similar properties? What things that get described as life might it be better not to call life?.
I originally wrote this article to clarify my own thinking on the subject. I found the framework that I’m using here helpful. Others may come up with different useful descriptions.
The first question about life is “Is it a process or an entity, an activity or a thing?”. Is life a substance or force permeating living beings which is not present in non living entities? Or is life the activities that go on in living beings?
Well, the way you know if something is alive is by what it does. If it is inactive and unchanging one identifies it as being dead. This suggests that one should think of life as what goes on in a living being. One should only propose the existence of a life force if there is no other way to explain what is going on.
In the 1950s and 1960s we uncovered the physical bases of heredity and the energy transport mechanisms. Inheritance turned out to be coded on the nucleic acids, ribonucleic acid (RNA) and deoxyribonucleic acid (DNA). Energy was found to be transported by adenosine triphosphate (ATP). While much of the mechanism of life is not understood, there seems to be no reason to believe that any unknown principles of physics or unknown forces are involved.
(An aside. In the Nineteenth Century developments in biology and geology did sugges that there were gaps in contemporary physics. Evolution in biology and uniformitarianism in geology required a vast age for the Earth. Known energy sources could not explain how the internal heat of the Earth or the heat of the Sun was maintained over such a long period. This problem was solved with the discovery of nuclear energy.)
Life is a property of a system not of any individual part of a system. You cannot point to a molecule in a cell and say “That molecule is alive.”. A protein or lipid or carbohydrate molecule is the same inside or outside a living cell. One cannot look at any particular chemical reaction and say “This is life.”.
OK. So what is it about a system that has us saying “This cell or this organism is alive.”?
One answer I have seen is reproduction. However this by itself seems wrong. A sterile organism can still be alive. A worker bee is not dead. Neither is a pet that you have had sterilized.
The best candidate that I have seen is autopoiesis. This is self maintenance. An autopoietic process brings about its own continuation and the maintenance of the structure in which the process occurs. An autopoietic system replaces its components with new ones that it has created. This description fits cells and it also fits organisms. However it can be argued that it also fits organizations such as corporations, states and ant nests. These are not exactly what one thinks of when one talks about life.
I think we can say that all living systems are autopoietic but not all autopoietic systems are alive. Systems that we describe as alive are self-contained bounded physical systems rather than systems linked by a network of concepts. Thus life is a property of a definite physical body whose individual components were created by that body.
Reproduction of living systems uses the mechanisms of autopoiesis. New organisms are created by the living organism using components that it has created and organized into another autopoietic system. However a self replicating system does not have to be autopoietic. It can simply create copies of itself without maintaining itself or doing anything much except replication. It can also replicate itself by taking over another system and making that other system replicate it. Examples of this behavior are the activities of viruses and prions.
Living organisms do not live forever. To allow a kind of life to persist some members of a kind have to be able to reproduce that kind. Thus self-replication is a property of all types of entities that we normally think of as life forms. However not all members of a kind have to be able to reproduce. An organism can produce both sterile and fertile offspring. Bees and ants provide good examples of this.
Living cells are the most obvious examples of living systems. They are elaborate structures made up of organic matter, water and inorganic materials (mostly as ions in solution). They are maintained and replicated by physical and chemical interactions among the components.
However the components of an autopoietic system do not have to be organic molecules or organic structures that are not alive by themselves. (A cell membrane is a universal part of all known living cells. Isolated from a cell it cannot be described as alive.)
The components of an autopoietic system can themselves be autopoietic systems. This is the case in multi-cellular animals, plants and fungi. These originated as multi-cellular colonies. The cells became differentiated into many types and organized into structures in new autopoetic systems. The cells can be isolated from an organism and grown by themselves in unorganized tissue cultures. The culture is not an autopoietic system though the individual cells that it is made up of are. A mouse is autopoietic system and the cells that it is made up of are also autopoietic systems. A tissue culture is not an autopoetic system though the cells making it up are.
Thus I think life can be regarded as recursive. It can exist on multiple levels. The life of a mouse is not the life of its cells though it depends on the life of the cells. One can make a case for even higher levels of autopoietic organization. For example a bluebottle (Portuguese man o’war) is a colony of multicellular polyps. There are several specialized types of polyp in a colony and an overall structure.
If autopoietic systems organize into a higher level system the individual components can loose the ability to maintain themselves. They can become dependent on their interactions with the other formerly independent systems. That is, living organisms can organize into a higher level living system and the lower level of life can then be subsumed into the higher level of life. This appears to be what happened when eucaryotic cells were formed. (Life can be divided in procaryotic and eucaryotic organisms. Procaryotes have relatively simple cell internal structures. Eucaryotes have elaborate membrane bound cell internal structures. Procaryotes are the bacteria and the archaea. The eucaryotes are the protists, the animals, the plants and the fungi. Protista is a grab bag including the simple eucayotes that don’t fit in the other kingdoms.) The eucaryotic cell probably formed as a symbiotic association of several different types of bacteria. Examples of cell organelles that were once independent organisms are mitochondria, plastids, flagella and cilia and the nucleus. I would not regard these as being autopoietic systems in their own right any longer.
Viruses probably have multiple origins. One of them is probably extreme simplification of parasitic bacteria.. If this is the case then living forms can evolve into self replicating systems that are arguably no longer alive. However I only know of this in entities that are parasitic on living organisms.
Another possible example of a higher level autopoietic system composed of autopoietic sub-systems is the biosphere of the Earth as a whole. The Gaia hypothesis regards the entire biosphere as a self regulating system. The hypothesis is that action of living organisms maintains the planet in a condition suitable for life. A system of feedback loops stabilizes the climate and and atmospheric composition etc. The main components of the system are bacteria. Other living organisms, the atmosphere, the hydrosphere and the outer layers of of the lithosphere could also be regarded as components of the system. Under this hypothesis the Earth would be an example of an autopoietic system that does not reproduce. The Gaia hypothesis is sometimes criticized as being a fuzzy mystical approach. I see it as a useful way of looking at a complex of feedback loops. It is a plausible, probably correct but unproven hypothesis.
All the known examples of life ultimately depend on aqueous organic chemistry. In principle this does not have to be the case. One sees many examples in science fiction of other kinds of life. Life with liquid ammonia or other solvents instead of water, life based on silicon rather than carbon compounds, metallic life forms, life based on nuclear reaction and so on. Some of these alternatives could be possible. Some probably aren’t. But that is for another generation to find out.
The ideas that I presented here most came out of What is life? by Lynn Margulis and Dorion Sagan. In turn the idea of autopoiesis that they used came from the Chilean biologists Humberto Maturana and Francisco Varela.
Neil Armstrong really needs no introduction. I don’t have words to tell you what his accomplishment means to me. His one small step is the greatest achievement man has ever made. His tiny step dwarfs the pyramids, it makes the great wall look like a picket fence. His small step is the kind of thing that not only transcends the bounds of this planet it transcends the barrier of race, religion, and nation. His step was a step forward for all mankind. Let us remember this hero of heroes. I have no more words…
Soon you will be able to purchase a 3-D television that requires no glasses and that allows you to view the 3-D screen from almost any angle. An article in Science Daily published yesterday outlines the new technological advancement. Current 3-D technology relies on the glasses integrating two different views of the scene into a three dimensional whole. The new technology takes the perspective into account from five or more points, allowing the viewer to view what is happening on the screen from many different angles. These autostereoscopic displays are able to create the three dimensional illusion through the use of technology that can track the depth of the room and the distance the viewer is from the screen. The computer then generates an image in real time based on this information.
These Televisions should be showing up in stores sometime next year. The science fiction dream of Tri-D TV without the glasses is finally here…..where is my damn flying car?