2: Bootstrap Paradox
A Bootstrap Paradox is a type of paradox in which an object, person, or piece of information sent back in time results in an infinite loop where the object has no discernible origin, and exists without ever being created. It is also known as an Ontological Paradox, as ontology is a branch of philosophy concerned with the nature of being or existence.

– Information: George Lucas traveling back in time and giving himself the scripts for the Star War movies which he then goes on to direct and gain great fame for would create a bootstrap paradox involving information, as the scripts have no true point of creation or origin.

– Person: A bootstrap paradox involving a person could be, say, a 20-year-old male time traveler who goes back 21 years, meets a woman, has an affair, and returns home three months later without knowing the woman was pregnant. Her child grows up to be the 20-year-old time traveler, who travels back 21 years through time, meets a woman, and so on. American science fiction writer Robert Heinlein wrote a strange short story involving a sexual paradox in his 1959 classic “All You Zombies.”

These ontological paradoxes imply that the future, present, and past are not defined, thus giving scientists an obvious problem on how to then pinpoint the “origin” of anything, a word customarily referring to the past, but now rendered meaningless. Further questions arise as to how the object/data was created, and by whom. Nevertheless, Einstein’s field equations allow for the possibility of closed time loops, with Kip Thorne the first theoretical physicist to recognize traversable wormholes and backward time travel as being theoretically possible under certain conditions.

Movies: Examples of bootstrap paradoxes in the movies include Somewhere in Time (1980), Bill and Ted’s Excellent Adventure (1989), the Terminator movies, and Time Lapse (2014). The Netflix series Dark (2017-19) also features a book called ‘A Journey Through Time’ which presents another classic example of a bootstrap paradox.
Books: Examples of bootstrap paradoxes in books include Michael Moorcock’s ‘Behold The Man’, Tim Powers’ The Anubis Gates, and Heinlein’s “By His Bootstraps”

3: Grandfather Paradox
5 Paradoxes Of Time Travel ExplainedThe Grandfather Paradox concerns ‘self-inconsistent solutions’ to a timeline’s history caused by traveling back in time. For example, if you traveled to the past and killed your grandfather, you would never have been born and would not have been able to travel to the past – a paradox.

Let’s say you did decide to kill your grandfather because he created a dynasty that ruined the world. You figure if you knock him off before he meets your grandmother then the whole family line (including you) will vanish and the world will be a better place. According to theoretical physicists, the situation could play out as follows:

– Timeline protection hypothesis: You pop back in time, walk up to him, and point a revolver at his head. You pull the trigger but the gun fails to fire. Click! Click! Click! The bullets in the chamber have dents in the firing caps. You point the gun elsewhere and pull the trigger. Bang! Point it at your grandfather.. Click! Click! Click! So you try another method to kill him, but that only leads to scars that in later life he attributed to the world’s worst mugger. You can do many things as long as they’re not fatal until you are chased off by a policeman.

– Multiple universes hypothesis: You pop back in time, walk up to him, and point a revolver at his head. You pull the trigger and Boom! The deed is done. You return to the “present,” but you never existed here. Everything about you has been erased, including your family, friends, home, possessions, bank account, and history. You’ve entered a timeline where you never existed. Scientists entertain the possibility that you have now created an alternate timeline or entered a parallel universe.

Movies: Example of the Grandfather Paradox in movies include Back to the Future (1985), Back to the Future Part II (1989), and Back to the Future Part III (1990).
Books: Example of the Grandfather Paradox in books include Dr. Quantum in the Grandfather Paradox by Fred Alan Wolf, The Grandfather Paradox by Steven Burgauer, and Future Times Three (1944) by René Barjavel, the very first treatment of a grandfather paradox in a novel.

4: Let’s Kill Hitler Paradox
Similar to the Grandfather Paradox which paradoxically prevents your own birth, the Killing Hitler paradox erases your own reason for going back in time to kill him. Furthermore, while killing Grandpa might have a limited “butterfly effect,” killing Hitler would have far-reaching consequences for everyone in the world, even if only for the fact you studied him in school.

The paradox itself arises from the idea that if you were successful, then there would be no reason to time travel in the first place. If you killed Hitler then none of his actions would trickle down through history and cause you to want to make the attempt.

Movies/Shows: By far the best treatment for this notion occurred in a Twilight Zone episode called Cradle of Darkness which sums up the difficulties involved in trying to change history, with another being an episode of Dr Who called ‘Let’s Kill Hitler’.
Books: Examples of the Let’s Kill Hitler Paradox in books include How to Kill Hitler: A Guide For Time Travelers by Andrew Stanek, and the graphic novel I Killed Adolf Hitler by Jason.
5: Polchinski’s Paradox
American theoretical physicist Joseph Polchinski proposed a time paradox scenario in which a billiard ball enters a wormhole, and emerges out the other end in the past just in time to collide with its younger version and stop it from going into the wormhole in the first place.

Polchinski’s paradox is taken seriously by physicists, as there is nothing in Einstein’s General Relativity to rule out the possibility of time travel, closed time-like curves (CTCs), or tunnels through space-time. Furthermore, it has the advantage of being based upon the laws of motion, without having to refer to the indeterministic concept of free will, and so presents a better research method for scientists to think about the paradox. When Joseph Polchinski proposed the paradox, he had Novikov’s Self-Consistency Principle in mind, which basically states that while time travel is possible, time paradoxes are forbidden.

However, a number of solutions have been formulated to avoid the inconsistencies Polchinski suggested, which essentially involves the billiard ball delivering a blow that changes its younger version’s course, but not enough to stop it from entering the wormhole. This solution is related to the ‘timeline-protection hypothesis’ which states that a probability distortion would occur in order to prevent a paradox from happening. This also helps explain why if you tried to time travel and murder your grandfather, something will always happen to make that impossible, thus preserving a consistent version of history.

Books: Paradoxes of Time Travel by Ryan Wasserman is a wide-ranging exploration of time and time travel, including Polchinski’s Paradox.

Animals bring Advantages to Ecosystems

The existence of trophic levels in ecosystems is a well-established concept. A question that seems to never have been asked is, why are there trophic levels in the first place? Why was there a need to expand the original two-component model of producer and decomposer? What was the irresistible force that created the need for animals?

Teleologically speaking, the reason animals came into existence was to facilitate nutrient movement to the decomposers that would increase recycling and increase ecosystem productivity. Their advantage to the ecosystem was greater power output.

A Non-teleological Explanation 

 The first ecosystem consisted of a single-celled eukaryotic producer and a bacterial decomposer. In these first, two-component ecosystems, an autotrophic eukaryotic population produced biomass, and when the older individuals died, they were eaten by decomposers, the prokaryotic bacteria. The first ecosystem feedback loop emerged from the circulation of nutrients released by prokaryotic bacteria and their uptake by eukaryotic cells necessarily in a restricted environment where feedback was possible.  Autocatalytic interactions in the feedback system allowed ecosystems and the organisms they contained to grow in size and power output. Some eukaryotes experienced beneficial mutations that allowed them eat autotrophic cells as a source of energy. That proved easier than to capture solar energy themselves. These became the progenitors of animals.

Once the first consumer (animal) evolved and reproduced, there was competition among the offspring for resources. The offspring that succeeded were the ones with the greatest power output, because they could win the competition for energy. By chance, one group of single-celled consumers banded together in a tube through which plankton-like autotrophic cells would flow. This proved to be a much more efficient way to capture autotrophs, and so this type of animal enjoyed a selective advantage. Throughout evolutionary time, animals increased in complexity around the tube that gave rise to the gastro-intestinal tract.  This increased even further their power output.

Ecosystems

The addition of animals to food chains resulted in a longer food chain and increased biomass of ecosystems. The benefit to ecosystems was increased power output and greater stability.  The combination of autotroph, consumer, and decomposer in this enhanced energy flow enjoyed a selective advantage over cells that were unattached and free-floating or systems with only two nodes.

Migration to Land

In terrestrial systems, nutrients are often the limiting factor for plant growth, so it is important for plants to conserve nutrients. They do this by synthesizing compounds in their leaves that protects them from microbial decomposition. That is good for the plant, but bad for the ecosystem because it slows down nutrient recycling in ecosystems. When plants shed leaves with defensive compounds, nutrients are released very slowly into the soil, and as a result, productivity of the plants declines. But when the first animals appeared, their digestive systems were able to break down the compounds, and nutrients were released back into the soil in a soluble form available to plants. Nutrient cycling was increased and this benefitted the ecosystem.

Ruminants

Ruminants are one of the most diverse and successful groups of mammals. Their ability to acquire nutrition from plants that contain chemical or mechanical defenses is due to fermenting of the leaves through microbial actions in a rumen that facilitates digestion. This may underlie their success in competition with other mammalian species. Breakdown of recalcitrant plant material by microbes in the rumen results in excrement in which nutrients are soluble or almost so. Ruminants are one of the most diverse and successful groups of mammals. Their ability to acquire nutrition from plants that contain chemical or mechanical defenses is due to fermenting of the leaves through microbial actions in a rumen that facilitates digestion. This may underlie their success in competition with other mammalian species. Breakdown of recalcitrant plant material by microbes in the rumen results in excrement in which nutrients are soluble or almost so.

Insects

Insects, of course, are also animals. Like mammals, they also speed-up recycling of nutrients Shredders wander the stream bottom looking for vegetation that has fallen into the water. Using their tearing mouthparts, they rip and shred the leaves as they feed.

Grazers and scrapers are animals that specialize on feed on the biofilm layers. They use rasping mouthparts to scrape the biofilm and algae off of the rocks and vegetation.

Dung beetles feed on feces of higher animals and accelerate the release of nutrients from the feces.

Conclusion

 Life in ecosystems could very well exist without animals. It is just that animals increase the energy-storing capacity and nutrient recycling ability of ecosystems, thereby increasing the probabilities for survival of ecosystems and their embedded species.

Facts in Science

A scientific “fact” is something that is always true, everywhere in the universe. A few years ago, a student of mine became curious about established “facts” in ecology. We searched the literature and found lots of “hypotheses” but could not find one where a hypothesis was proven true always and everywhere. (Jordan and Miller 1996). We found one in physics that always has been valid when observations are restricted to time spans greater than one millionth of a second and to locations within our solar system. Under these conditions, there has never been any known observations of an exception to the first law of thermodynamics. It states that energy cannot be created or destroyed, only altered in form. Another law of physics is gravity, which is based on the fact that two bodies in the universe interact with each other. Other than those, there are few facts anywhere in science. Even the second “law” of thermodynamics is not a fact but a statistical statement. Boltzmann showed that because certain processes do not seem to occur – for example the spontaneous conversion of heat into mechanical energy – does not mean they are impossible, but extremely unlikely. In microscopic systems consisting of only a few molecules, the second law is violated regularly, but in macroscopic systems which consist of vast numbers of molecules, the probability that entropy will increase becomes virtual certainty.

A practical way to look at scientific “facts” is to consider them as hypotheses with a high probability of occurring. Much of science consists of testing a hypothesis that one group of objects (experimental group) is significantly different from objects in a control group. Objects can be people, animals, or non-living objects. The more individuals comprising each group, the higher the statistical confidence of the outcome. A good place to look for facts is in the “hard” sciences. Hard science is often considered to be more rigorous, that is, it can better ascertain “facts” than soft science. Newtonian physics is the most rigorous of the sciences simply because it has the good fortune to have a very good statistical base. Each physical object used in an experiment such as determining what metal is the best conductor of electricity consists of billions and billions of experimental objects (atoms) for each metal tested.

The sequence of scientific fields from hard to soft would be: Newtonian physics, Chemistry, Biology, Ecology, Economics, Social sciences (sociology, anthropology). In the field of chemistry, the statistics, while not as good as in Newtonian physics, still are good enough that many hypotheses are considered facts. Take for example the periodic table of elements, considered by most scientists to be confirmed. In reality, the periodic table is a probability table. In an ordinary mixture of hydrogen gas, 0.0156% of the atoms are deuterium and 10 ^-18 % are tritium. As a result, the atomic weight of a gas in a tube labeled hydrogen may be 1.00000, or it may be 1.00784. In the social sciences, small sample size is the problem. In contrast to Newtonian Physics, quantum physics considers interactions between only two atoms.  Predictions have been only as good as predictions of the outcomes of a coin toss.

Facts in Biology

A problem in biology is that of hierarchy. A “fact” at one hierarchical level of organization is a probability at a lower level. At the organismal level of biology, a species is a fact. Ways of defining species include karyotype, DNA sequence, sequence, morphology, behavior or ecological niche.  Between closely related species, these characteristics vary along a continuum.  A species is not a fact but merely a conglomeration of probabilities. If in my field studies of birds, I capture an individual that I don’t recognize, I can test its DNA and compare the result to a known data bank. Depending on the similarity of the best match, I can determine the probability that my catch belongs to a known species. At the level of DNA, the concept of species is based on probabilities. Functional processes such as photosynthesis that also are a fact at the organismal level of organization are probabilities at the biochemical level where myriad metabolic pathways comprising photosynthesis are subject to alteration by chance mutation, to random mistakes, or to interference by disease.

Institutional Facts

There is a distinction between scientific facts, and institutional or administrative facts that are simply a convention that enables humans to organize their existence.  Institutional facts are used routinely in court. I had beer with Andy Capp at the Rose and Crown the night of a crime is an institutional fact that can be verified by the bartender. His testimony indicates a high probability that I did not commit the crime. However, institutional facts are not always certain. The prosecution might bring a witness who testified he was at the Rose and Crown the night of the crime and never saw me, just someone who looked like me.

It is a fact that in 1930, my grandmother owned a house in Tilset, East Prussia (part of Germany). That fact could have been verified by looking at town’s property records.  However at the end of the second World War, East Prussia became part of Russia. My grandmother along with all other Germans were deported to refugee camps in Denmark, and her house was given to a Russian.  So it no longer is a fact that my grandmother owns that house. History has a way of changing institutional facts.

The first European explorer visiting Africa who labeled an animal with a long neck a “giraffe” did not make a scientific discovery.  He merely applied a label.  Labels are not scientific facts but simply administrative conventions. Many people believe it is a fact that the sky is blue. “Blue” is not really a fact but merely a word that we use to communicate the sensation we have when looking at the sky on a clear day.

 Is There Truth?

If there is doubt as to what constitutes a fact, how can we ascertain “Truth”?  Truth has been defined as that which is in accordance with fact or reality, but if institutional “facts” are nebulous, and scientific “facts” are merely probabilities, what does this say about “Truth”?   Except for thermodynamic laws, “Truth” is a probability. 

Literature Cited

Jordan CF, Miller C (1996) Scientific uncertainty as a constraint to environmental problem solving: large-scale ecosystems. In: Lemons J (ed) Scientific Uncertainty and Environmental Problem Solving. Blackwell Science. Cambridge Mass. p 91-117

Most people would say that “time” is something measured by a clock. Physicists, in an attempt to be more precise, say that a second is equal to 92 billion vibrations of a cesium atom. Digital clocks are based on the vibrating frequency of a quartz crystal in the shape of a tuning fork. All digital watch designers use the same frequency, one that is too high for use to hear. At this frequency, the prongs vibrate 32,768 times every second. However, clocks, vibrations of cesium atoms and quartz crystals are merely a measure of time. They do not regulate the speed of time, nor even inform us about the nature of time.

Time is an artificial human construct, based on the rotation of the Earth on its axis, and the rotation of the Earth around the sun. It offers a convenient way to schedule meetings. On a space ship beyond the solar system, there is no sun rise nor sun set, but the crew still uses clocks to indicate bed time, meal time etc. But if their clocks suddenly stopped, would time still exist out there in space?  Time as conceived here on Earth would not exist. The rotation of planet Earth light-years away from where they are in space would be meaningless for the crew.  Nevertheless, the crew does get older, so obviously time is passing for them. They are beyond the solar system and without functioning clocks or cesium atoms. Their only measure of time for them is their rate of metabolism, the rate at which they age.

What Regulates the Speed of Time?

Your age is defined as the amount of time that you have experienced. The amount of time you have experienced is equal to the number of times you have lived through a rotation of the Earth around the sun. As I write this, I am 87 years old according to Earth time. I have experienced 87 rotations.  If I were living on Venus, time would pass more quickly. I would age faster, since a year on Venus is equal to only 225 Earth days. I would be 141 years old (365/225 = 1.62. 1.62x87 = 141). If I were living on Mars, time would pass more slowly, and I would age more slowly. A year on Mars is equal to 687 Earth days, so I would be 46 years old (365/687=.53, .53x87=46).

Does this mean that if I wanted to live longer, I should move to Mars?

No, because time as we think about it here on Earth is relative to this planet on which we are living. If I lived on Mars, and thus was 46 years old, I still would look and feel like an 87-year-old on Earth. If I lived on Venus, I still would take a walk every day, even though I was 141 years old.

So from the point of view that time is relative, we could say that the speed of time depends on the planet on which we live.  But from the point of view of aging, it is not at all relative. It is deterministic, and depends on the rate that our biological systems deteriorate, and that depends on the speed of entropy, the tendency of everything to disorganize and decompose. Time will end when entropy is maximum.

Space-Time

Einstein concluded that space and time, rather than separate and unrelated phenomena, are actually interwoven into a single continuum that spans multiple dimensions. Gravitational pull regulates the speed of time throughout the universe. The closer one is to a black hole, the slower that time will pass.  If a space ship left planet Earth, passed close to a black hole, and then returned, the crew would have aged less than people remaining on Earth. The crew’s great grandchildren may have already passed away.

The Speed of Time

Thermodynamic theory says time is the rate of entropy, the rate of energy transformations from energy in the form that can perform work to dissipated energy, commonly known as heat. What determines the speed of entropy? Odum and Pinkerton (1955) proposed that the speed of entropy depends upon the efficiency with which energy in a system is transformed. In living creatures, energy is transformed from high quality glucose to heat during metabolism. In a system with high efficiency transformations, the speed of entropy is faster than in a system with low efficiency transformations. Between humans, there is only a small variation in the efficiency of transformations.  However, between humans and other animals, the difference in efficiency can be much greater. For example, dogs age about five times faster than humans because the efficiency of their energy transformations is higher.  The efficiency in elephants is lower.

But now suppose that neither I nor any other living creature ever existed. Would there still be such a thing as time?  The answer would have to be no, because there would be nothing to disorganize or decompose.  If only lower forms of life existed but not humans, would time exist? The answer would have to be yes, since the existence of time depends on the energy transformations in living bodies.  The existence of time depends on the existence of living beings. If all life on Earth suddenly ended, there would be no such thing as time.  

Some scientists say that time is independent of life. Entropy is continually degrading our solar system, and the sequence of events that contribute to the degradation is the essence of time. So the rate that the sun is burning out is a measure of time, but that is not a very practical measure. Others say that the rate that the universe is expanding is a measure of time.  They say that the universe is about 13.8 billion years old. The problem here is that our solar system did not exist until 4.5 billion years ago, and life did not exist until about 3.8 billion years ago. Before then, there was no such thing as a “year”. If time does not exist in the absence of life, or before the birth of the solar system, how can astronomers say that the universe is about 13.8 billion years old? It is a meaningless statement.

Alien Life

Could evolution of life in a distant galaxy have proceeded more rapidly than evolution here on Earth? This could mean there are more intelligent forms of life elsewhere in the Universe with greater capabilities for space travel. 

From outside the Universe, the speed of time is absolute, so all life has had equal time to evolve. But according to Einstein, time is relative and depends upon the movement of galaxies in space relative to each other. A billion years could pass more rapidly in a distant galaxy relative to a billion years here on Earth, so creatures that exist there today would have had more time to evolve.   But while there could be higher forms of life in other galaxies, it is unlikely they could visit us because the galaxies are moving away from us at the speed of light or faster. Within our galaxy, there could be forms of life that evolved as they did here on Earth, but the nearest exoplanet is 4.2 million light years away.  It would take evolutionary time to get there.

Ecological Significance here on Earth

Why, as an earth-bound ecologist, am I interested in time and how the speed of time is regulated? Because it bears upon Odum’s hypothesis that it is the efficiency of energy transformations that regulates the speed of time, and that management of resource systems such as agriculture are more efficient when energy transformations are slower (contrast industrial agriculture where transformations are fast but inefficient, with organic agriculture where transformations are slower but more efficient). His “Optimum Efficiency for Maximum Power Output” means the efficiency of a system that is maximizing power output (productivity), such as a monoculture of corn supplied with high inputs of fertilizers and pesticides. It is a low efficiency system compared to an organic farming system with low energy inputs and high efficiencies of energy conversions but lower power output.

Reference

Odum, HT, Pinkerton RC 1955. Time’s speed regulator: The optimum efficiency for maximum power output in physical and biological systems. American Scientist, Vol. 43, No. 2 pp. 331-343

 Why does Life Exist?

Most religions explain life as existing because of God’s will. That explanation is fine if it gives comfort to people but it is not a scientific explanation. A scientific explanation is harsher and colder, and leaves us with a displeasing answer as to “Why are we here?” Unlike religion, the purpose of science is not to give comfort.

Gradients

Nature abhors a gradient. Gradients exist when energy or pressure enters one part of a system and is discharged at another. When you suck on a straw inserted in a glass of water, the water rises in the straw because of the pressure gradient caused by a vacuum. Thermodynamic theory says that life exists because nature abhors the energy gradient between solar energy entering the Earth and heat energy reradiating into the atmosphere. On Earth there is an abundance of plant, animal, and microbial life. By converting solar energy into biomass, these organisms reduce the energy gradient between solar energy entering the ecosystem, and heat reradiating out into space. Life is reducing the gradient.  Nature “wants” there to be life on Earth.

Nature “wants” there to be life is a teleological statement. A scientific way to say it is that 4 billion years ago, in geothermal vents there existed both a strong energy gradient and a rich mixture of inorganic chemicals. These chemicals came together in millions of different combinations, but by chance, one combination had the ability to absorb chemical energy and transform it into heat. Thus occurred the first living organism, which incidentally reduced the energy gradient in the vent.  On a lifeless planet such as Mars, there is a strong energy gradient between solar energy hitting the surface and the heat reradiated from the surface. Nature “wants” there to be life on Mars, but is stymied because of lack of water.