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Our future, our universe, and other weighty topics

Sunday, March 18, 2018

Hits and Misses of the Physicist Bloggers

For decades the late Stephen Hawking was the center of a kind of giant hype machine that portrayed him as the greatest living scientific genius. This hype was unwarranted for a scientist who never even won a Nobel Prize. Showing admirable persistence and diligence despite his severe handicaps, Hawking made some interesting contributions to the study of black holes. But his thoughts about topics outside of his specialty were often not very wise.

An example of his dubious thinking was his “No Boundary Proposal” about the Big Bang, that the Big Bang was not a boundary in space or time. The problem with this proposal is that it is the exact opposite of what nature tells us about the beginning. Everything we have learned about the Big Bang suggests it is as clear a boundary as you can imagine, a sudden beginning of time and space.

Hawking also repeatedly warned that machines might take over the world (a fear that is unwarranted for the reasons  discussed here).  He repeatedly urged that we need to leave planet Earth (not as good an idea as staying here and making sure that our planet stays in good health). He repeatedly sung the praises of M-theory, a wildly speculative theory for which no evidence has ever appeared. He also declared falsely and unwisely that “philosophy is dead.”

Physicist blogger Ethan Siegel (whose specialty is cosmology) has a post entitled “The 4 Scientific Lessons Stephen Hawking Never Learned.” He lists one of these lessons as Be humble about your own speculative, unproven ideas.” He states the following:

This is a pitfall that has afflicted many of the greatest minds throughout scientific history: to fall in love with their own fringe scientific ideas so thoroughly that you tout them with the certainty normally reserved for verified, validated, robust theories. Hawking's no-boundary proposal is speculative and unproven, yet Hawking will often (including in A Brief History Of Time) speak about it with the same certainty he'd speak about black holes....Unproven ideas should never be a substitute for legitimate facts, yet Hawking, in every book he ever wrote, never tells you when he strays from the confirmed-and-validated into this speculative realm, particularly where his own ideas are concerned.

Here Siegel is right on the mark. One of the greatest problems of modern scientific literature is that writers mix up speculations and established facts, packaging the whole mixture as “science.” And so many a dubious proposition and many a doubtful theory is sold to the public as “science,” as if such things were well-established. Such failure to distinguish between fact and theory goes on constantly in the literature of biology, psychology, physics, and cosmology. When people start a sentence with “Science says,” half of the time they will refer us to something that has not actually been established by observations or experiments. 

science speculation
Unfortunately, Siegel himself is often guilty of exactly this problem of falling in love with his own shaky scientific ideas so thoroughly “that you tout them with the certainty normally reserved for verified, validated, robust theories.” We see this repeatedly in his columns when he refers to the extremely speculative and very much unverified theory of cosmic inflation as if it were empirically established science, which it certainly is not. We also see this repeatedly when Siegel refers to the speculative theory of dark matter as if it were empirically established, which it is not. No one has ever directly observed any dark matter. In the same column that Siegel is criticizing Hawking for speculative excess, he refers to “everything we've learned since 1979 about the conditions that set up the Big Bang.” Nothing of the sort has actually been learned, and we know nothing whatsoever about any conditions that set up the origin of the universe.

Not only do we have no observations about anything occurring any time close to the Big Bang, but we have no observations (and will never be able to have any observations) of anything that occurred in the first 300,000 years of the universe's history. Scientists tell us that it was only at about 300,000 years after the Big Bang that there occurred what is called the Recombination Era, in which atoms first formed. During the first 300,000 years, particles were so densely packed that all light coming from those years must have been hopelessly scattered. As a scientific site tell us:

Because of the presence of the free electrons, photons were scattered around in all directions and could not travel far before changing their direction. Therefore the universe was "opaque".

We therefore will never be able to get any observations about anything that happened during the universe's first 300,000 years. The light from those years was hopelessly jumbled and scrambled by the density of the matter, as strongly as if you put your Microsoft Word document through a computer program that might thoroughly scramble its characters 100,000 times. As we will never be able to make observations of the universe's state in the first 300,000 years, all claims about the exact state at the Big Bang (or before it) will never be claims backed up by observations.

A physicist blogger with a large following is Lubos Motl, who has been blogging many times a month since 2004 at his site "The Reference Frame."  Motl's blog is a strange collection of physics, politics, and climate commentary, with many of his opinions being very dubious (but presented with a large amount of literary skill and style). Very strangely Motl is for supersymmetry (a theory for which there is no evidence), but opposed to standard ideas on global warming (for which there is a great deal of evidence). This is simply an example of how the assertions of a modern scientist may be very largely dependent on the scientist's personal tastes. On the plus side, I may note that Motl is a good person to have around when physicists start spouting nonsense about parallel universes, because he has shown his skill at debunking such speculations.

Another physicist blogger with some interesting content is Sabine Hossenfelder, who blogs at this site. In contrast to Motl, she has repeatedly criticized the theory of supersymmetry, a speculative physics theory. That seems appropriate, since all signs are that supersymmetry has been a great big waste of time. Thousands of scientific papers have been written advancing this ornate speculative theory for which no evidence has been gathered.

But Hossenfelder has repeatedly advanced a dubious account as to why physicists advanced the supersymmetry theory. She has often claimed that the theory was advanced because physicists find that supersymmetry is “prettier” or “more beautiful.” Referring to the supersymmetry theory in a recent post, she says,  “I explained many times previously why the conclusions based on naturalness were not predictions, but merely pleas for the laws of nature to be pretty.”

But it's not correct that the supersymmetry theory was advanced because physicists had some great longing for a beautiful or pretty theory. The supersymmetry theory (a very cluttered affair not at all beautiful) was advanced to explain away a particular case of fine-tuning in the laws of physics.

Here is how the wikipedia.org article on supersymmetry explains it:

In the Standard Model, the electroweak scale receives enormous Planck-scale quantum corrections. The observed hierarchy between the electroweak scale and the Planck scale must be achieved with extraordinary fine tuning. In a supersymmetric theory, on the other hand, Planck-scale quantum corrections cancel between partners and superpartners (owing to a minus sign associated with fermionic loops). The hierarchy between the electroweak scale and the Planck scale is achieved in a natural manner, without miraculous fine-tuning.

So the real reason the supersymmetry theory was advanced was to try to avoid a case of “miraculous fine-tuning.” This is a much different reason than creating a theory in hopes of making the laws of nature “be pretty.”

No evidence has shown up for the supersymmetry theory. So scientists are stuck with this case of “miraculous fine-tuning” they had hoped to avoid. In a previous post, Hossenfelder compared this particular case of fine-tuning to finding a cube balanced on one of it edges. She says she doesn't believe that “finetuned parameter values require additional explanation.” In that post she seems to speak as if she thinks people should not pay much attention to cases in physics where we find a cosmic balance so delicate that it's like a cube balanced on one of its edges. I disagree, and think that such cases (which must have an explanation other than chance) are weighty cosmic clues we should pay very much attention to.

Postscript: In a recent interview in Scientific American, cosmologist Martin Rees says that the cosmic inflation theory (not to be confused with the more general Big Bang theory) is a "good bet."  But we should call things a "good bet" only when we have some probabilistic basis for believing in their likelihood. For example, if you hear a 60-year-old suddenly died in his home, it would be a good bet that he died of a heart problem, because that's the most common cause of sudden deaths in the elderly. But there is no probabilistic basis whatsoever for calling cosmic inflation (a brief burst of exponential expansion of the universe) something likely to have occurred. For such a thing to occur (ending up with a universe like ours) requires so many special conditions and so much fine-tuning that it is wrong to be calling such a theory  "a good bet." The theory is better described as a "popular story."

At her blog Sabine Hossenfelder puts the cosmic inflation theory into context:

Theoretical physicists have proposed some thousand ideas for what might have happened in the early universe. There are big bangs and big bounces and brane collisions and string cosmologies and loop cosmologies and all kinds of weird fields that might or might not have done this or that. All of this is pure speculation, none of it is supported by evidence.  

Wednesday, March 14, 2018

Expedition: A Science Fiction Story

I authorize an expedition to the supply center,” said Frank. “Karen and Tom will be the expedition participants.”

Can I go too?” said little Steve. “I've never even been outside our building, least not that I can remember. I'm old enough to go.”

Going on an expedition outside our building is nothing to be taken lightly,” said Frank. “If you don't suit up right, and make all the preparations just right, you may find yourself cooked like a hot dog in the microwave. It's an oven outside this building. Are you ready to face that kind of danger, little boy?”

You bet I am!” said Steve.

Okay, we'll I guess you're finally old enough for something like this,” said Frank. “I guess we can use that expedition suit that your sister first used several years ago. Let me brief you on all the steps you need to execute the expedition successfully.”

Frank retrieved what looked like a space suit.

This is your expedition suit,” said Frank. “It will keep you from dying from all that heat outside.”

I'll put it on,” said Steve.

No, that's not the first step,” said Frank. “First, you strip off your clothes and apply cooling gel all over your body. The cooling gel and the expedition suit work together to stop you from being cooked to death.”

After applying the blue cooling gel all over his body, Steve put on the expedition suit. It fit reasonably well.

So you think you're ready to go outside?” asked Frank.

Sure, I'm ready,” said Steve.

No, you're not ready!” said Frank. “You haven't put on your backpack cooling device. Without that, you'll cook to death out there.”

Frank showed how to set up the backpack cooling device. He had Karen, Tom, and Steve test the radios of the expedition suits. The radios would allow them to talk to each other over the noise of the backpack cooling unit.

So it looks like you're all suited up,” said Frank. “So are you ready to go out the building?”

Sure,” said Steve.

No, you are not!” said Frank. “You didn't make a weather check for dust storms. If one of those things hit while you're outside, it could kill you.” 

After the weather check, and after Karen, Tom and Steve were all suited up, they exited the building. They set out toward their destination a mile away. 

Steve was delighted by all the sights around him. It was a bleak landscape, but for a little boy who could never recall being outside of the building where he lived, everything he saw around him was a source of wonder.

You ever get into trouble on a trip like this?' asked Steve.

Sometimes,” said Tom. “If your expedition suit starts malfunctioning, it can be scary. You may get a sudden dust storm. If you see one of those, then you have to turn around and go back.”

After a mile of walking, they reached the supply center, and went inside.

Okay, you can take off the helmet of your suit,” said Tom. It was nice and cool inside the supply center. After gathering their supplies, Tom asked Steve what they should do before going outside again.

I guess we just have to put on our suit helmets again,” said Steve.

No, it's more complicated than that,” explained Tom. “The cooling gel we put all over our skin got used up during our 1-mile walk over. So we have to take off our expedition suits, and reapply some fresh new cooling gel before we go outside again.”

They all took off their suits, reapplied the cooling gel, and put their expedition suits back on. Before exiting the supply center, Tom had a question for Steve.

So can we go outside now?” asked Tom.

Sure,” said Steve.

No, we haven't done our suit checks yet!” said Tom. “Remember, I told you before: every time before exiting a building, you check all of the indicator lights on your expedition suit to make sure it is functioning perfectly.”

After making the suit checks, Tom asked Steve one more question.

So now are we ready to go outside?” asked Tom.

I guess so,” said Steve.

No,” said Tom. “We didn't make a weather check for approaching dust storms.”

But we already did that when we set out,” said Steve.

I know,” said Tom. “But you've got to make the weather check for dust storms both when you set out, and when you start to come back from your destination.”

After the weather check was made, Tom, Karen, and Steve exited the supply center, and began the one-mile trip back to the building where they lived. The trip back was uneventful. After returning to Frank, they took off their expedition suits, and cleaned off the remainder of the sticky cooling gel on their skin.

Congratulations, kiddo,” said Frank to Steve. “Now that you've made your first expedition outside, I guess we won't think of you as such a little kid any more.”

All that hassle, just to get some food at the grocery store,” said Tom with a sigh.

The four of them were living in Phoenix, Arizona in the southwestern United States in the year 2160. Once populated by more than a million people, the heat-scorched city now had a population of only 4,300, and all of them dressed up like astronauts when they dared to travel outside.

Saturday, March 10, 2018

Paradoxes That Puncture Professorial Pretensions

Many of our professors are very pretentious people who claim to have an understanding of many deep questions of time, space, life, matter and energy. But there are quite a few paradoxes suggesting that such academic figures may know very much less than they claim to know. Below is a list of some of these paradoxes.

The Faint Young Sun Paradox. It is believed that life appeared more than three billion years ago, in an event that would have required liquid water on the surface. However, models of the sun's evolution indicate that the heat output of the sun should have been much lower billions of years ago. Based on such models, it seems that it should only have been about about two billion years ago that the Earth started getting enough heat for liquid water to exist on its surface.

The Fermi Paradox. Our galaxy contains many billions of planets. In billions of solar systems there should be a situation where a planet roughly the size of the Earth exists at a suitable distance from the closest sun, resulting in a surface that is neither too hot nor too cold for life to appear. But despite all these opportunities for life to appear, decades of searches for radio signals from extraterrestrials have produced no successes. The Fermi Paradox can be succinctly stated by asking: where is everybody?

The “Mind from Matter” Paradox. It is typically believed that the human mind results from arrangements of matter in a brain. But mind and matter are two totally different types of things. We can imagine without a paradox mental things producing mental outputs, and physical things producing physical outputs. But it seems paradoxical that a material thing could ever produce a mental output.

The “Winding Problem” Paradox. A large fraction of the universe's galaxies are beautiful spiral galaxies. Spiral galaxies rotate, taking about 200 million years to make a full rotation. But stars in the outer parts of a spiral galaxy should take much longer to rotate than stars closer to the center of a galaxy (just as planets in the outer solar system have much longer years than planets in the inner solar system). This differential rotation should spoil the spiral shape of a galaxy after after 500 million years. But such galaxies have apparently managed to keep these spiral shapes for many billions of years.

The “Protein Origin” Paradox. In a cell proteins are produced by little structures called ribosomes. But ribosomes are themselves made up largely of proteins. So if proteins are built by ribosomes which themselves require proteins, how could proteins ever have originated?

A ribosome, with its proteins shown in green

The Matter/Antimatter Asymmetry Paradox. The prevailing Big Bang theory of the universe's origin maintains that in its first minutes the universe consisted of highly energetic particles of energy (photons) packed together at a very high density. Whenever two very energetic photons collide, they produce equal amounts of matter and antimatter. The Big Bang therefore should have produced equal amounts of matter and antimatter. But in our universe we see abundant amounts of matter, but no naturally existing antimatter.  

The Short Lifetime of Synapse Proteins Paradox. The leading theory of memory storage maintains that memories are stored in synapses in the brain. However, it is known that the proteins that make up synapses have short lifetimes, having an average lifetime of no more than a few weeks. How could synapses be storing memories that can last for 50 years when all the matter inside synapses is being rapidly replaced, with such rapid turnover?

The Paradox of High Mental Function in Highly Damaged Brains. Our professors assert that our minds are produced purely by our brains. But it sometimes happens that humans have normal or almost normal mental functioning even though they have lost very much or most of their brains due to disease. See here for some examples.

The “You Need a Language to Establish a Language” Paradox. If the first language were ever to get established among humans, there would have to have been some process by which a complicated set of rules got promulgated and established among a group of people. But (as discussed here) it seems that no such rules could ever have been established and promulgated unless a language already existed.

The “Inferiority of Primitive Speech” Paradox. Before any language was spoken, humans would have lacked the vocal adaptions needed to speak in an intelligible manner. Before such adaptions existed, hand gestures would have been a greatly superior way of communicating. But why then could spoken speech ever have originated, and been used instead of a hand-gesture language? See here for more on this paradox.

Levinthal's Paradox. The proteins inside our bodies have complex three dimensional shapes. But in a DNA molecule that specifies the makeup of a protein, there is only a specification of the sequence of amino acids that make up the protein. Does a chain of amino acids somehow discover its three dimensional shape through some type of trial and error, settling on some shape with the lowest energy requirements? Not according to Levinthal's paradox, which points out that finding such an answer through trial and error would take many years – actually a length of time longer than the age of the universe. Instead a newly synthesized protein finds its characteristic 3D shape within a few minutes. The wikipedia article on this paradox inaccurately tells us that "the solution to this paradox has been established by computational approaches to protein structure prediction." This is not at all correct -- even using databases and high-speed computers, scientists can't accurately predict the 3D shapes of complex proteins (and cells don't have such databases and computers). 

The C-Value Paradox. There is no relation between the complexity of an organism and the size of its genome. Organisms much simpler than humans may have genomes larger than the human genome. For example, some amphibians and flowering plants have genomes 100 times larger than humans. Such a fact is completely at odds with the idea that the genome or DNA of an organism is some kind of blueprint for the organism.

The Natural Selection Paradox. Attempting to account for biological innovations, biologists offer as an explanation natural selection. But natural selection, which requires the existence of life, cannot account for one gigantic example of biological innovation: the origin of life itself. In fact, it seems that natural selection cannot in general explain any complex biological innovation, for the reason that such an innovation will not produce any survival benefit or reproduction benefit until it has already appeared.

The Paradox of Fast Retrieval of Old Memories. Accounting for short-term memory is relatively easy, since we can imagine that there is a kind of very small “scratch pad” storing things you learned in the last few minutes. A brain might be able to search that tiny little “scratch pad” very quickly. But how is it we are able to instantly remember information learned years ago, as contestants do so effectively on the TV show Jeopardy? If you have millions of items that you have learned, there would seem to be no way for you to instantly find an exact location in the brain where a memory was stored, nor would there be time within a few seconds to scan all of the items in your long-term memory to find a particular memory.

The Homochirality Paradox. Amino acids and sugars can exist in two forms: what are called left-handed forms and right-handed forms. The left-handed forms are kind of mirror images of the right-handed forms. In earthly life amino acids are all left-handed, and sugars needed for life are all right-handed. But when these chemicals are created through laboratory processes, they appear with left-handed versions and right-handed versions in equal numbers. The odds against life getting started with all amino acids left-handed and all sugars right-handed seem astronomical.

Paradoxes of the Origin of Sex. Sexual reproduction seems to offer no clear advantage over asexual reproduction. Also it is hard to imagine any progression that could have led to functional sexual organs that differ among males and females, as any change in the anatomy of one gender would be useless unless complemented with reciprocal changes in the other gender (with there being only an incredibly low chance of complementary random changes in both male and female occurring within a few generations).  For example, a mutation producing a little bit of a penis in an organism would not achieve fixation in the gene pool if it occurred when no organism in that species had any vagina; and vice versa.

The Cosmological Constant paradox. In outer space a vacuum is devoid of energy, as far as any astronaut is able to measure. But when quantum physicists add up the quantum contributions that should be made from what are called virtual particles, their calculations tell them that ordinary space should be very dense indeed – even denser than steel. This discrepancy between theory and observation is still unexplained.

The Double-Slit Paradox. The physical world outside of our bodies is supposed to be something existing independently of whether or not it is observed.. But one of the most famous experiments of modern physics suggests this may not be true. Experiments with passing light or electrons through a double slit consistently show an effect in which the outcome is completely different, depending on whether or not there is an observer.

Energy Conservation Paradoxes. It is supposedly a law of nature that mass-energy cannot be created or destroyed. This law is called the law of the conservation of mass-energy. But it seems that in the Big Bang, such a law must have been violated, with a huge amount of mass-energy suddenly coming into existence. Moreover, as the universe expands, more and more space comes into existence. We have been told many times that the expansion is not an expansion of matter within space, but an expansion of space itself. But every volume of space has its own tiny amount of energy, caused by a non-zero cosmological constant. This means that an expanding universe must constantly be leading to a creation of new space, and new mass-energy, with the total amount of mass-energy increasing every second. But how can this be, if there is a law saying mass-energy cannot be created or destroyed?

A web site discusses this issue:

What’s more, there is an energy associated with any given volume of the universe. If that volume increases, the inescapable conclusion is that this energy must increase as well. And yet physicists generally think that energy creation is forbidden. Baryshev quotes the British cosmologist, Ted Harrison, on this topic: “The conclusion, whether we like it or not, is obvious: energy in the universe is not conserved,” says Harrison. This is a problem that cosmologists are well aware of. And yet ask them about it and they shuffle their feet and stare at the ground.

Tuesday, March 6, 2018

What Is the Most Preposterous Device in Science Fiction?

The world of science fiction is a world of strange and wonderful devices. Some of these machines are somewhat plausible, and others are very far-fetched. Let's look at some of these devices, moving from the fairly plausible towards the more unbelievable, ending up with the most unbelievable machine in the annals of science fiction.

A fairly plausible device is the hand-held energy-shooting device. In the Star Trek set of TV shows and movies, this takes the form of the phaser, a little ray gun. In the Star Wars movies the favorite hand-held energy device is the light saber. Given the progress man is making in developing high-energy lasers, both phasers and light sabers seem like something we may well see within a few centuries. Another type of very plausible device is the palm-sized communicator used in the original Star Trek series. We basically already have such a thing in the form of a cell phone.

Then there is the walking robot. In the Star Trek universe we see an example in the android named Data. In the Star Wars universe we see an example in the form of the walking android robot C-3PO. Neither are terribly implausible. It is very questionable whether we ever will have robots or computers that ever rival humans in intelligence. But we probably will one day have pretty good chat-bot software that could be hooked up with a robot body, resulting in something that allows a robot to talk in a way resembling human conversation. Since neither Data nor C-3PO really show any superhuman intelligence, such robots are not much of a strain on our credulity.

In the Star Wars universe, we have the large orbiting satellite called the Death Star, capable of destroying an entire planet. Such a device is not at all preposterous. A nation today could build a similar device, creating a huge satellite filled with nuclear weapons rather than some energy death ray. It is not much of a stretch to imagine a planet-destroying device that used a huge laser or pulsed-energy weapon.

In both Star Wars and Star Trek, we have hologram devices capable of projecting three-dimensional images that resemble human figures. In the Star Wars universe, this technology doesn't seem very sophisticated. But in the Star Trek universe, hologram technology is pushed to the max. Crew members of a space ship can enjoy something called a holodeck, which provides holographic simulations that include a surrounding landscape and three-dimensional figures that look just like real people. So if you're on a starship, you can walk into the holodeck, request a particular simulation, and then poof, it may suddenly be just as if you are on the beach on Tahiti, complete with scantily clad women surrounding you.

The basic idea isn't particularly unbelievable. If you were in a holograph room that included both holographic projectors on the floor, holographic projectors on the ceiling, and holographic projectors on the walls, we can imagine that this might create an illusion that made it appear just like you were in some entirely different place. The same technology could produce holograms resembling human figures. But in the Star Trek series, the holodeck users also seem to engage in tactile interactions with the holographic projections. A character may sit down on a holographic table, lie down on a holographic bed, or kiss and hug a holographic figure. I have no idea how such tactile interactions could occur using holographic technology. So we might put down Star Trek's holodeck device as something that is merely semi-plausible. 

A Star Trek gadget that seems increasingly plausible is the replicator device, capable of almost instantly producing any equipment or food.  The more 3D printing technology advances, the more plausible such a device seems. 

One staple of science fiction is the faster-than-light spaceship. In the Star Trek universe, we have something called a warp drive, that supposedly allows a spaceship to travel faster than the speed of light, by warping the space in front of the spaceship. In the Star Wars universe, spaceships travel faster-than-light by doing something called “jumping through hyperspace.” Although not totally preposterous, such devices are not very plausible. We know of no physics that would allow a spaceship to travel faster than light by warping space in front of it, nor do we know of any such thing as “hyperspace” that might allow spaceships to travel from star to star instantaneously. About the best you can say is that there conceivably could exist undiscovered physics that might allow such things to occur.

Both Star Wars and Star Trek seem to rely on a type of device that is never discussed: an artificial gravity generator. For example, in the Star Trek universe, characters walk around on a spaceship on which there is normal gravity just like we have on Earth. We know of a very simple method that will reliably generate artificial gravity in a spaceship. The spaceship can have a spinning component that generates artificial gravity by centrifugal force, like the Jupiter-bound spaceship in 2001: A Space Odyssey. 

 You can get artificial gravity with a design like this

But the spaceships in Star Wars and Star Trek seem to have no design that would generate artificial gravity by centrifugal force. Maybe the assumption is that the ships are using some type of artificial gravity generator. But we know of no way in which a device could ever generate artificial gravity without using centrifugal force. This seems an area in which our science fiction falls short in the credibility department.

But what is the most ridiculous device in any major science fiction series? Here the booby prize must be given not to anything in the Star Wars universe, but instead to something in the Star Trek universe. The most preposterous device in any major science fiction show is the transporter device used on the starship Enterprise.

In Star Trek the transporter supposedly works by doing three things:
  1. A scan is made that reveals the exact position of all molecules in the person being transported.
  2. Over the course of a few seconds, that person's body is then dematerialized.
  3. Over the course of a few seconds, the person's body is then rematerialized or reconstructed at some distant location.
This is basically a “destroy and reconstruct” algorithm. The scan part of the process seems unrealistic. How could some machine possibly determine the exact state of all of the particles inside your brain? We can get a blurry look inside someone's brain by doing an X-ray, although there is radiation exposure whenever that is done. The radiation exposure of some type of “precisely scan all particles inside the body” would probably be prohibitive. Heisenberg's uncertainty principle tells us that you cannot determine both the position and velocity of any particle, casting the greatest doubt on the possibility of doing a scan giving you the exact particle information corresponding to a body.

In Star Trek someone can be transported or “beamed” from the transporter room of one spaceship to the transporter room of another spaceship. That's not the most laughable absurdity, because at least in that case you have a transporter machine on each end of the transport, one machine doing the scanning and de-materialization, and the other transporter machine doing the reassembly of the body. But in Star Trek people are also transported from a transporter room to the surface of a planet (where there is no transporter device), and from the surface of a planet (where there is no transporter device) back to the transporter room. But how could the process needed for the “from the surface of the planet” transport possibly occur from the surface of a planet, where there is no machine there to do the scanning of the person's molecular state? And how could the process needed for the “to the planet surface” transport possibly occur on the surface of a planet, where there is no machine there to do the reassembly of the body from the scanned molecular state? It's like imagining that you are taking a train to the middle of some country that has no trains or train tracks.

Any transporter device like that in Star Trek would also be a body duplication device. For once someone's molecular state had been scanned and kept in a machine, there would be no need to discard that information. The same information could be used to recreate a new copy of someone who had died – or any number of copies of someone. The result would be ridiculous scenes like this:

Mr. Scott: Bad news, Captain Kirk. A monster on the planet attacked and devoured Mr. Spock.
Captain Kirk: Why do you think that's bad news? Use your head, Scotty! When we transported him down to the planet, we scanned his exact molecular state. Just use that stored state to reassemble him in the transporter room. He'll be as good as new, and have no memory of what happened.
Mr. Scott: How silly of me not to think of that!

When creating the Star Trek series, Gene Roddenberry could have avoided the nonsensical idea of transporting people by disassembling all their atoms and reassembling them. He could have come up with the idea of a “wormhole transporter” that would have achieved teleportation by having people move through a time-space wormhole. The idea would be that some machine would generate a spacetime wormhole between the transporter and some distant location, and that your body is propelled through the wormhole to end up in some distant spot, without your body ever getting disassembled and resassembled. Although relying on undiscovered physics, such a teleportation system would have avoided the most absurd aspects of Star Trek's transporter mechanism, such as the idea that a body could be reassembled on some distant planet without there even being an assembly device on that planet.