Review: Physics of the Impossible

Physics of the Impossible is a really great book. It goes into a wide variety of primarily science fictional topics in decreasingly order of likelihood and gets into how each works (so far as they do work with what we know now) and what it would take to make them possible. There’s just enough scientific background that I understood most of it and could stretch for the rest, with pointers for what to search for to learn more, which is always a good way to go.

Worth a read! One interesting point is how many of these seeded ideas for more stories in the future! Onward!

Below are my thoughts and some comments through the book. It’s non-fiction, so spoilers aren’t really a thing 😄, but I’d be happy to talk about any of these points.


I came to realize that these tales were simply impossible in terms of the science involved, just flights of the imagination. Growing up meant putting away such fantasy. In real life, I was told, one had to abandon the impossible and embrace the practical.

However, I concluded that if I was to continue my fascination with the impossible, the key was through the realm of physics. Without a solid background in advanced physics, I would be forever speculating about futuristic technologies without understanding whether or not they were possible. I realized I needed to immerse myself in advanced mathematics and learn theoretical physics. So that is what I did.

That’s quite a background!

Jules Verne wrote a novel in 1863, Paris in the Twentieth Century, which was locked away and forgotten for over a century until it was accidentally discovered by his great-grandson and published for the first time in 1994. In it Verne predicted what Paris might look like in the year 1960. His novel was filled with technology that was clearly considered impossible in the nineteenth century, including fax machines, a world-wide communications network, glass skyscrapers, gas-powered automobiles, and high-speed elevated trains.

Fascinating. I should read some Jules Verne.

Part I: Class I Impossibilities

Chapter 1: Force Fields

I. When a distinguished but elderly scientist states that something is possible, he is almost certainly right. When he states that something is impossible, he is very probably wrong.

II. The only way of discovering the limits of the possible is to venture a little way past them into the impossible.

III. Any sufficiently advanced technology is indistinguishable from magic.

– Arthur C. Clarke’s Three Laws

I’ve definitely heard the third before and the first is familiar, but the second is a fascinating addition. I like the idea behind all three of them!

This was a neat chapter. Most of it I was already familiar with, but knowing just how crazy some of the particular technologies have to be to work was both fascinating and sobering.

Chapter 2: Invisibility

Next, Maxwell asked himself the fateful question: if magnetic fields can turn into electric fields and vice versa, what happens if they are constantly turning into each other in a never-ending pattern? Maxwell found that these electric-magnetic fields would create a wave, much like an ocean wave. To his astonishment, he calculated the speed of these waves and found it to be the speed of light! In 1864, upon discovering this fact, he wrote prophetically: “This velocity is so nearly that of light that it seems we have strong reason to conclude that light itself…is an electromagnetic disturbance.”

Huh. Despite knowing the basic idea of how magnetic/electrical fields interact I … never made the connection to constant flux. That’s awesome.

To make Harry Potter invisible, one would have to liquefy him, boil him to create steam, crystallize him, heat him again, and then cool him, all of which would be quite difficult to accomplish, even for a wizard.


Another interesting chapter, mostly within the realm of what I was familiar with. Invisibility is power in theory… but gets really weird in practice.

Chapter 3: Phasers and Death Stars

There is no law of physics preventing the creation of a Death Star or light sabers.

Don’t need the rest of the chapter then!

But more seriously, I’ve seen some interesting conversations about lasers before, although I wasn’t aware that the really powerful lasers wouldn’t have a visible beam. That’s both awesome and terrifying.

Another unfortunate things I hadn’t known before:

Teller, of course, was the physicist who testified before Congress in the 1950s that Robert Oppenheimer, who had headed the Manhattan Project, could not be trusted to continue work on the hydrogen bomb because of his politics. Teller’s testimony led to Oppenheimer’s being disgraced and having his security clearance revoked; many prominent physicists never forgave Teller for what he did.

Oh politics…

And the idea of a Death Star destroying planets already felt ridiculous, but would it really be any better to ‘just’ vaporize the surface?

Chapter 4: Teleportation

But there was still a nagging question that haunts physics even today. If the electron is described by a wave, then what is waving?

Huh. And the answer being ‘probability’ is even wackier.

“Quantum mechanics calls for a great deal of respect. But some inner voice tells me that this is not the true Jacob. The theory offers a lot, but it hardly brings us any closer to the Old Man’s secret. For my part, at least, I am convinced that He doesn’t throw dice.”

Interesting wording. I wonder what Einstein really believed.

(If you used a computer to graph the Schrödinger wave of your own body, you would find that it very much resembles all the features of your body, except that the graph would be a bit fuzzy, with some of your waves oozing out in all directions. Some of your waves would extend even as far as the distant stars. So there is a very tiny probability that one day you might wake up on a distant planet.)

And harnessing that is used in The Hitchhiker’s Guide. Make that next to impossible (but still possible) thing certain… and you can teleport!

Heh. They mention this two paragraphs later.

Chapter 5: Telepathy

ESP in general is in that category of things that would be fascinating if it were real but I can’t really square it with how it could work in our world.

Likewise Project Star Gate.

A long list of things that would be fascinating to be true…

Fun fact:

The MRI machine operates in the same way, except it is more precise. A patient’s head is placed inside a huge doughnut-shaped magnetic field. The magnetic field makes the nuclei of the atoms in the brain align parallel to the field lines. A radio pulse is sent into the patient, making these nuclei wobble. When the nuclei flip orientation, they emit a tiny radio “echo” that can be detected, thereby signaling the presence of a particular substance. For example, brain activity is related to oxygen consumption, so the MRI machine can isolate the process of thinking by zeroing in on the presence of oxygenated blood. The higher the concentration of oxygenated blood, the greater the mental activity in that part of the brain. (Today “functional MRI machines” [fMRI] can zero in on tiny areas of the brain only a millimeter across in fractions of a second, making these machines ideal for tracing out the pattern of thoughts of the living brain.)

I never really thought about it beyond ‘powerful magnets’. It’s interesting that the resolution is only roughly one voxel per several million neurons. That’s worse than I’d thought. Although reading it all I think would be way too much bandwidth.

Chapter 6: Psychokinesis

Shakespeare’s Tempest has psychic powers? Fascinating. Especially:

In fact, about 350 years after it was written, The Tempest was remade into a 1956 science fiction classic called the Forbidden Planet, in which Prospero becomes the brooding scientist Morbius, the sprite becomes Robby the Robot, Miranda becomes Morbius’s beautiful daughter, and the island becomes the planet Altair-4. Gene Roddenberry, creator of the Star Trek series, acknowledged that Forbidden Planet was one of the inspirations for his TV series.

The idea of this coming true with the work of brain/computer interfaces is something (in my opinion) to look forward to though!

Chapter 7: Robots

This seems an odd inclusion, but really it’s talking a lot more about AI than it is about robots directly, which I see as different fields. And we’ve done some pretty crazy things in the last decade so far as AI goes, but every advancement we make seems to make everything seem one step further.

Chapter 8: Extraterrestrials and UFOs

This falls into the category of things that I have to believe are true (that aliens are real) and would love to see (them visit us) but I’m not sure how the physics could possible work. Some day!

A few years earlier, in 1600, former Dominican monk and philosopher Giordano Bruno was burned alive in the streets of Rome. To humiliate him, the Church hung him upside down and stripped him naked before finally burning him at the stake. What made the teachings of Bruno so dangerous? He had asked a simple question: is there life in outer space? Like Copernicus, he believed that the Earth revolved around the sun, but unlike Copernicus, he believed that there could be countless numbers of creatures like us living in outer space. (Rather than entertain the possibility of billions of saints, popes, churches, and Jesus Christs in outer space, it was more convenient for the Church simply to burn him.)

Oy. It doesn’t get much better (from Wikipedia):

The Vatican has published few official statements about Bruno’s trial and execution. In 1942, Cardinal Giovanni Mercati, who discovered a number of lost documents relating to Bruno’s trial, stated that the Church was perfectly justified in condemning him. On the 400th anniversary of Bruno’s death, in 2000, Cardinal Angelo Sodano declared Bruno’s death to be a “sad episode” but, despite his regret, he defended Bruno’s prosecutors, maintaining that the Inquisitors “had the desire to serve freedom and promote the common good and did everything possible to save his life”.In the same year, Pope John Paul II made a general apology for “the use of violence that some have committed in the service of truth”.

Chapter 9: Starships

Before reading it, I expect FTL (probably impossible), warp drives (maybe, but requires exotic matter), and generation ships (super expensive but probably possible even now). Maybe cryogenics?

A bit further in: I didn’t think of engines! Ion engines and solar sails are perfectly possible. Nuclear pulse drives? A ramjet/collection scoop would have to be truly gigantic. Something exotic we’d probably need.

Kind of a bummer hearing that we’ll likely never have a space elevator. It’s such a cool idea (if insane technology). Rail guns would be neat though!

But there are problems with the rail gun. It accelerates objects so fast that they usually flatten upon impact with the air.

Oh. 😄

Chapter 10: Antimatter and Anti-universes

… atomic bombs are only 1% efficient? Huh. Crazy. That actually came up in Black Rain and Paper Cranes. Amusing how things overlap.

There are so many very big numbers in this chapter. Huge machines to store a few antiprotons, the universe basically being a rounding error, etc. Good times.

Part II: Class II Impossibilities

Chapter 11: Faster than Light

Ah, so it wasn’t in Chapter 9, but rather here. FTL is one of those things that I really do want to see be true. The universe is just so mind boggling big and weird, I want to see everything! Or at least make it possible.

But… there’s the crazy idea that it’s not even possible because that would lead to paradoxes in time travel. We do have hints though:

One can calculate that the universe originally expanded faster than the speed of light. (This action does not violate special relativity, since it was empty space–the space between stars–that was expanding, not the stars themselves. Expanding space does not carry any information.)

That’s always been kind of a cool solution to me. And makes me wonder if we can abuse that: can we bend space around and ride on it somehow? Ah, there it is on the next page, stretching space. But how does that get around the ’not carrying information bit’? I guess if the space that’s stretching isn’t the space with the ship in it?

In any case, there was another cool idea (that I feel like I should totally write a story about):

Since Alcubierre first proposed his theory, physicists have discovered a number of strange properties. The people inside the starship are causally disconnected from the outside world. This means that you cannot simply press a button at will and travel faster than light. You cannot communicate through the bubble. There has to be a preexisting “highway” through space and time, like a series fo trains passing by on a regular timetable. In this sense, the starship would not be an ordinary ship that can change directions and speeds at will. The starship would actually be like a passenger car riding on a preexisting “wave” of compressed space, coasting along a preexisting corridor of warped space-time. Alcubierre speculates, “We would need a series fo generators of exotic matter along the way, like a highway, that manipulate space for you in a synchronized way.

Chapter 12: Time Travel

There are really two problems with time travel:

  1. How do we do it?
  2. What is the result

1 is interesting enough, but what I really like thinking about is 2. When you travel in time, do you end up changing the future (you came from)? Does time resist change (somehow)? Do you create parallel realities? I like the latter two, but there are interesting story ideas in each of these.

Chapter 13: Parallel Universes

A nice companion for time travel! And there’s a lot of very weird physics when you get into strings and higher dimensions and weird particles and all that.

One of the interesting things I took out of this was a sort of writing prompt: the idea that Heaven and Hell are parallel realities that evolved separately. And that perhaps you can have ‘groupings’ of realities that are tied together, so you can have parallel trios of us/Heaven/Hell in different configurations.


This is the so-called “anthropic principle.” The weak version simply states that our universe is fine-tuned to allow for life (because we are here to make this statement in the first place). The strong version says that perhaps our existence was a by-product of design or purpose. Most cosmologists would agree to the weak version of the anthropic principle, but there is considerable debate over whether the anthropic principle is a new principle of science that could lead to new discoveries and results, or whether it is simply a statement of the obvious.

Part III: Class III Impossibilities

Chapter 14: Perpetual Motion Machines

An interesting chapter. Zero point energy comes up in Stargate all the time “Zed.P.M.!”

Also, paraphrasing the Laws of Thermodynamics as:

“You can get something for nothing.” (First Law)

“You can’t break even.” (Second Law)

“You can’t even get out of the game.” (Third Law)

…is pretty amusing.

Chapter 15: Precognition

It really comes down to time travel though, no? So it’s strange that this is here versus with Chapter 12.

You do get wacky things like:

So Feynman revealed the true secret of antimatter: it’s just ordinary matter going backward in time. This simple observation immediately explained the puzzle that all particles have antiparticles partners: it’s because all particles can travel backward in time, and hence masquerade as antimatter. (This interpretation is equivalent to the “Dirac sea,” mentioned earlier, but it is simpler, and it is the explanation currently accepted today.)

I wonder if that’s why there’s matter at all though (the reason that more matter was seemingly created/survived the initial moments of the Big Bang).

Epilogue: The Future of the Impossible

The Standard Model is often called a “theory of almost everything.” Assume for the moment that we can shut off gravity. Then the Standard Model becomes a perfectly sound theory of all phenomena besides gravity.

Heh. That’s quite a way to end. Physics gets weird in the edge cases.