S C I ENCE FICTI ON
Pop Science
Science Fiction to Science Fact: A Look at Sci-Fi’s Favorite Innovations SCOTT GLADSTONE
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cience fiction has captivated the minds of young readers for generations, inspiring the curious to dream of time travel, cloaking machines, tractor beams, and any technological advancement imaginable. Avid fans of science fiction share a collective desire to live in a world with these technologies. Some have even used science fiction as a steppingstone to a career in developing and investigating their childhood pastimes, determining the feasibility of Asimov’s and Verne’s ideas. While most technologies of science fiction remain decades or centuries away, these fantasies contain real scientific concepts. Some are even closer to becoming reality than most would believe.
Time Travel TARDIS: Time And Relative Dimension in Space. Any fan of the popular British series Doctor Who can tell you TARDIS is the name of the iconic, 1960’s police-box spaceship that the Doctor and his companions use to travel around the universe . The machine is able to bend space and time, granting the travelers access to anywhere and any point in history. While a device with that type of potential is not yet within reach, no individual needs a time machine to experience time travel (1). At the most basic level, every living being is a traveler of time. We all spend our lives progressing in four dimensions: the well-known length, width, and depth dimensions of space and the more enigmatic fourth dimension of time. Space cannot exist without time and vice-versa; each dimension serves as a measureable check on the others, collectively forming the basis of the space-time continuum (2). Thus, each individual travels through space differently and takes a unique path through time. This is the most basic explanation of the relativity of time principle and helps to clarify why some things appear to progress faster than others. One of the most cited examples of this time-relativity phenomenon is the observation that global positioning satellites appear to gain a third of a billionth FALL 2012
Image courtesy of Alain Riazuelo. Retrieved http://commons.wikimedia.org/wiki/File:BH_LMC.png (accessed 25 October 2012)
Figure 1: Gravitational distortions caused by a black hole in front of the Large Magellanic cloud. This phenomenon reflects the interconnected nature of space and time.
of a second every day (1). With the Earth as a reference point, time seems to move faster in orbit due to the increased distance between the satellite and the center of mass of the Earth. The planet’s mass applies a regressive gravitational force on space and, due the interconnection of space and time, also applies the same force on time (3). This effect is known as gravitational time dilation (3). Time relativity and gravitational time dilation apply most clearly in modeling hypothetical travel around a black hole. A black hole is a massive, infinitely dense point where gravity pulls so strongly that not even light can escape. A small object with the mass of four million suns is a good analogy for a black hole (4). Theoretically, if orbit around a black hole were possible, time would be experienced at half of Earth’s normal rate. A five-year journey around the black hole Sagittarius A would seem like a decade to those on Earth (1). While we can consider the possibilities of faster temporal progression, the more interesting aspect of time travel is not to the
future, but to the past. Many physicists hold the belief that time is a linear chain of cause and effect dominated by the law of causality: every action causes a specific response and reaction. Scientists cite this law as the reason that time travel is impossible. For example, it would be difficult to imagine a reality in which an individual could die of a gunshot wound before being shot (1). Yet, if this causality theory is disregarded, room can be made for theoretical ideas such as an Einstein-Rosen bridge, more commonly known as a wormhole. A wormhole is a “tube” that connects two regions of spacetime and is believed to be formed by the attractive masses of two black holes (5). The idea is that if someone fell into one side of a wormhole, he or she would exit in a different part of space-time. Assuming that the time traveler’s body resisted being torn apart and the immense energy needed to make this travel was overcome, there are several paradoxes that still exist (1). Consider the following situation: a man travels back in time today 25