Physics of the Impossible

According to Kaku, technological advances that we take for granted today were declared impossible 150 years ago. William Thomson Kelvin (1824–1907), a mathematical physicist and creator of the Kelvin scale said publicly that “heavier than air” flying machines were impossible. “He thought X-rays were a hoax, and that radio had no future.”[4] Likewise, Ernest Rutherford (1871–1937), a physicist who experimentally described the atom, thought the atom bomb was impossible and he compared it to moonshine (a crazy or foolish idea). Televisions, computers, and the Internet would seem incredibly fantastic to the people of the turn of the 20th century. Black holes were considered science fiction and even Albert Einstein showed that black holes could not exist. 19th century science had determined that it was impossible for the earth to be billions of years old. Even in the 1920s and 1930s, Robert Goddard was scoffed at because it was believed that rockets would never be able to go into space.[4]

Such advances were considered impossible because the basic laws of physics and science were not understood as well as they would subsequently be. Kaku states that “as a physicist [he] learned that the impossible is often a relative term.” By this definition of "impossible", he poses the question "Is it not plausible to think that we might someday build space ships that can travel distances of light years, or think that we might teleport ourselves from one place to the other?"[4]

Each chapter is named by a possible, or improbable, technology of the future. After a look at the development of today's technology, there is discussion as to how this advanced technology might become a reality. Chapters become somewhat more general towards the end of the book. Some of our present day technologies are explained, and then extrapolated into futuristic applications. In the future, current technologies are still recognizable, but in a slightly altered form. For example, when discussing force fields of the future, Dr. Kaku writes about cutting edge laser technology, and newly developed plasma windows. These are two of several technologies, which he sees as required for creating a force field. To create a force field these would be combined in a slightly altered form, such as more precise or more powerful. Furthermore, this discussion on force fields, as well as on the pantheon of highly advanced technologies, remains as true to the original concepts (as in how the public generally imagines advanced technologies) as possible, while remaining practical.[5][6] Kaku concludes his book with a short epilogue detailing the newest frontiers in physics and how there is still much more to be learned about physics and our universe.

Kaku writes that since scientists understand the basic laws of physics today they are able to perceive or imagine a basic outline of future technologies that might work. Kaku writes: "Physicists today understand the basic laws [of physics] extending over a staggering forty three orders of magnitude, from the interior of the proton out to the expanding universe."[5] He goes on to say that physicists can discern between future technologies that are merely improbable and those technologies that are truly impossible. He uses a system of Class I, Class II, and Class III to classify these science-fictional future technologies that are believed to be impossible today.

Bryan Appleyard considers this book to be a demonstration of renewed confidence in the possibilities of physics. He also sees the book as a depiction of how the public believes in an especially optimistic view of the future. Discussing the book's author, he writes, "Kaku, when on home territory, is an effective and gifted dramatiser of highly complex ideas. If you want to know what the implications would be of room-temperature superconductors, or all about tachyons, particles that travel faster than the speed of light and pass through all points of the universe simultaneously, then this is the place to find out."

To Appleyard, the fact that this book uses Sci-Fi technology to open the door to real science is interesting. However, he writes, it also has the added effect of making discoveries that might otherwise end up being obscure as giving us a feeling of being closer to that optimistic future. When bending microwaves around an object, rather than being just an obscure physics experiment, it creates a feeling that a Star Trek cloaking device is just around the corner. An equally obscure subatomic experiment means that soon we will be saying, "Beam me up Scotty." He writes, that in this regard, this book helps to “sustain our sense of an increasing acceleration into a future that must be radically different from the present.”[12]

According to Appleyard this radically different and better future "... is what lies at the core of this type of book. The future, conceived as some realm in which contemporary problems have been resolved, is the primary, though usually unacknowledged, faith" that people have always had."[12]

• The Physics of Star Trek, a similar book by the physicist Lawrence M. Krauss
• Metamaterial
• List of physicists
• Quantum teleportation
• Quantum energy teleportation
• Interstellar travel
• Superstring theory
• Supersymmetry
• List of theoretical physicists

• M. Kaku (2008). Physics of the Impossible: A Scientific Exploration Into the World of Phasers, Force Fields, Teleportation, and Time Travel. Doubleday. ISBN 978-0-385-52069-0.

• Review in The Independent
• Review in NewScientist.com
• 2057: Time Travel with Dr. Kaku
• Sci-Fi Science : Physics of the Impossible Series with Dr. Kaku