Futuristic transportation - the speed of light 1: solutions in science fiction

which is a diamond[1], Department of Electrical and Electronics Engineering, Faculty of Engineering, Ariel University in Samaria * The article was published in Issue 7 of the Cultural Affairs Journal - correct

introduction

In the vast majority of science fiction films and books, emphasis is placed on the means of transportation that will be used technologically, in the utopian (or dystopian) future. The said is also in the works dealing with the near future, and even more so - in the works dealing with the distant future.

In works dealing with the near future (for example Blade Runner from 1982 by Ridley Scott), the vehicle is the flying car, which allows forward and backward movement, like the cars we know, but also movement in the vertical direction (up and down). Such vehicles are also used in distant future series such as Star Wars (the first film in the series "A New Hope" was screened in 1977), where flying motorcycles are shown. Also in the famous television series "Star Trek" (first screened in 1966), the famous spaceship Enterprise is equipped with the space shuttle, which is a kind of flying bus. Today the dream of the flying car is not over, and Professor Stefan Klein has even developed one such a car . But the main directions of development of the futuristic car are other: electric and non-polluting drive (hybrid vehicles, and a car with only electric drive - by Tesla, for example), and the autonomous car that drives itself without a driver. This also appears in the cinema as, for example, in the movie "Batman" (1989)), but today it is developed by several companies; Among others, Tesla and Google.

In the films of the distant future, the emphasis is mainly on means of transportation used to move between planets and even between different stars in the galaxy. The most famous aircraft of this type is the starship ENTERPRISE, which is known to have embarked on a five-year journey to explore the planets in the galaxy and the extraterrestrial civilizations that developed in them. The original series, "Star Trek" (1966), has many sequels (Star Trek Next Generation, VOYAGER, ENTERPRISE, DISCOVERY and more).

The iconic "Star Wars" film series, on the three trilogies that make it up, is also based on a galactic culture with interstellar mobility. The series is about a Galactic Republic, whose capital planet Coruscant is, in fact, a city that covers an entire planet. The trilogies deal with the efforts of a dark and corrupt political order to take advantage of the weaknesses of the democratic regime (long bureaucratic procedures, governmental laxity and greed), to collapse and turn it into a galactic empire. The middle trilogy (1977) deals with the rebels' efforts to reclaim the lost republic. The first series (1999), in which a cinematic brilliance was released over twenty years after the second series, deals with the processes that led to the collapse of the empire, and the third series (2015), describes the political processes that took place following the victory of the rebels over the empire. Over everything hovers the struggle between the justice-seeking order, which is supposed to protect the republic and failed in the first trilogy (the Jedi Knights), and the dark order (the Sith). Of course, a galactic regime of any kind (Empire or Republic) is not possible without spaceships that make it possible to reach in a short time from one solar system to another.

Another series of books (the first of which was published in 1956), also describing a galactic empire, begins with the book "Holit" by Frank Herbert. In the future world of "Holit", the movement between the stars is made possible by physical and mental activities carried out by the navigators of the guild. These post-human beings depend for their activity on a drug that is only produced on one planet in the galaxy, aka the Sand Planet, so called because it is completely covered in sand, hence its strategic importance. The book is the first part of a trilogy by Frank Herbert, but after his death, his son, Brian Herbert, joined Kevin Anderson, and together they published many books describing the universe of Hulit, both in the eras that preceded the events of the original book and in the eras that followed. The book DUNE was even filmed in 1984 by director David Lynch. A new version of the film is expected to be released in Israel in 2021.

the technological difficulties

The creators of the movies and the TV series ignore, of course, the well-known fact of gravity, which is supposed to prevent those vehicles from flying. Although, today we know how to overcome gravity in different ways, starting with the use of gas lighter than air (hot air or hydrogen gas and helium), but because of the large amount of gas required for each mirror these solutions are impractical. The solution, currently used in aviation, is based on the movement of air above and below wings with a special geometry, which creates a pressure difference above and below the wing. The pressure difference on the wing creates a lifting force that opposes gravity. The lift force depends on the lift coefficient which in itself depends on the geometry of the wing and the speed squared. This is why airplanes have wings, and they need long runways to accelerate and reach a speed where the force of lift will overcome the force of gravity. In a helicopter, this speed is achieved by rotating the propeller (a collection of wings attached to a central axis) at high speed. Of course, it is not possible to organize the runways for the cars, nor is it clear where they will land.

We will point out that the solution of Professor Stefan Klein It is actually a small plane with folding wings. When the wings are folded the plane turns into a car. The expected use for such a flying car is for movement between airports that already have runways. The helicopter is an expensive vehicle, and its propeller is a danger. That's why he needs a wide and fenced surface to prevent injury to passers-by. This is an unacceptable solution for the average car user, but it is still being considered by developers of futuristic flying cars for example The Pop.Up Next In this solution, the propellers (there are four) are placed inside a round frame that protects the innocent from harm (like the familiar fans). Another solution for overcoming gravity is the rocket propulsion. The rocket propels itself upwards by ejecting material downwards. Since momentum (mass multiplied by speed) is conserved, the rocket itself increases its momentum by the same amount and in the opposite direction to the momentum of the material it emits. Since a change in momentum per unit of time is a force according to Newton's second law, an upward force is created, which, to the extent that it exceeds the force of gravity, overcomes it, causing the rocket to move upwards. A rocket solution for a flying car would, of course, require a huge amount of fuel (exhaust material) to be carried by the flying car, so this solution is also not acceptable.

Star Trek

The distances in space are enormous. As of today (2021), humans have only managed to reach the natural satellite of their planet (the Moon), and have also managed to send robotic vehicles to a neighboring planet (Mars), and even approach with the help of unmanned spacecraft and take close-up pictures of more distant planets (Venus, Jupiter , Saturn, Neptune). Recently, they even managed to go a little beyond the boundaries of the solar system in a journey that lasted for decades (VOYAGER project). To travel huge distances at high speed, huge amounts of moving energy are required, which are not technologically available even in the most advanced rockets (the kinetic energy of any body is equal to half its mass times the speed squared as long as it moves at a speed sufficiently lower than the speed of light).

Above that hovers the most basic limit of the speed of movement in nature, otherwise known as the speed limit of light. According to an accepted interpretation of the theory of relativity, no body or signal can exceed this speed, and any body with a non-zero mass requires enormous energy to approach this speed (the light particle photon has zero mass). For example, the closest solar system to our own is the Alpha Centauri system, which is 4.37 light years from our sun. This means that according to the concept of contemporary physics, under the most optimal conditions we cannot hope for a shorter than 4.37 year one-way trip to Alpha Centauri (probably much longer). The round trip is a story of at least ten years to the nearest solar system. The distance between the sun and the center of the galaxy is about 100,000 light years, so a journey to the center of the galaxy will not be less than 100,000 years. That is, if there was a galactic empire on the Milky Way, it would take us no less than 100,000 years to reach its central star. If at all such a star can be found near the center of the galaxy, which is a hostile area - saturated with radiation and in the vicinity of a huge black hole.

The simulated solutions

Science fiction writers and their screenwriters do not know, of course, what the physical principles are behind the technologies they propose. They hypothesize that in the future our physical understanding will be different than it is today. This is a perfectly reasonable assumption, if we look back at the changes that have taken place in the science of physics in the last 500 years since the days of Galileo Galilei, and of course, with the hope that the rate of development will not change. A counter argument is that we have already exhausted the technological possibilities when it comes to traffic, and no dramatic developments are expected in the future; For example, today's passenger jets are not faster than the planes of the XNUMXs.

But if we remain optimistic like the science fiction writers, it is possible that in the future flying cars will be able to fly with the help of "anti-gravity" - a concept that does not exist in the current physical understanding. Also, spaceships will be able to swallow the vast distances of space by "folding" the space, which shortens the vast distances in interstellar space that is carried out by the navigators of the guild in the universe of "Holit". By "jumps" made by the spaceships in the "Star Wars" films, or by the warp engine (WARP ENGINE), which distorts space, and enables speeds higher than the speed of light, in the "Star Trek" series and its sequels. Additional means are related to the use of a "black hole" and a "white hole", with the first being an entrance opening and the second an exit opening, and the connection between them makes it possible to significantly shorten the distances in space. Thus, for example, the spacecraft VOYAGER, in one of the sequel series of "Star Trek", moved to the fourth and farthest quarter of the galaxy by mistake, and the main part of the series deals with the attempts of the crew of the spacecraft to return home. Needless to say, although the existence of black holes has been proven with certainty, according to the current understanding of physics, no matter (and certainly not humans) can survive entering a black hole, and likewise, there is no way out; Certainly not a connection to a white hole on the other side of the galaxy.

Assuming there is room to move forward, the question of the expected rate of progress still remains. The screenwriter of the "Star Trek" series (Gene Roddenberry) was quite optimistic in the sixties, when he predicted the beginning of interstellar travel (solar systems) already in the nineties of the last century (twentieth century). He envisioned such journeys thirty years from his present. From our point of view, towards the end of the first quarter of the twenty-first century, it is clear that such journeys, if they occur, are expected not before the twenty-second century.

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[1] Professor Asher Yaholum is a physicist

to the second part of the article

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