Category Archives: Physics

The Mysterious Nature of Light

January 15, 2014Categories, Physics, Universe Mysterieslouis del monte, nature of light, unraveling the universe's mysteries, wave particle duality of lightadmin

To almost everyone, there is nothing mysterious about light. In fact, the opposite is true. When we are in the dark and mystery abounds, the first thing we do is turn on the lights. So, why is “The Mysterious Nature of Light” the title of this post?

The first thing that makes light mysterious is that it can exhibit both the properties of a wave and a particle. For all of the Nineteenth Century, and for the early part of the Twentieth Century, most scientists considered light “a wave,” and most of the experimental data supported that “theory.” However, classical physics could not explain black-body radiation (the emission of light due to an object’s heat). A light bulb is a perfect example of black-body radiation. The wave theory of light failed to describe the energy (frequency) of light emitted from a black body. The energy of light is directly proportional to its frequency. To understand the concept of frequency, consider the number of ocean waves that reach the shore in a given length of time. The number of ocean waves than reach the shore, divided by the length of time you measure them, is their frequency. If we consider the wave nature of light, the higher the frequency, the higher the energy.

In 1900, Max Planck hypothesized that the energy (frequency) of light emitted by the black body, depended on the temperature of the black body. When the black body was heated to a given temperature, it emitted a “quantum” of light (light with a specific frequency). This was the beginning of Quantum Mechanics. Max Planck had intentionally proposed a quantum theory to deal with black-body radiation. To Planck’s dismay, this implied that light was a particle (the quantum of light later became known as the photon in 1925). Planck rejected the particle theory of light, and dismissed his own theory as a limited approximation that did not represent the reality of light. At the time, most of the scientific community agreed with him.

If not for Albert Einstein, the wave theory of light would have prevailed. In 1905, Einstein used Max Planck’s black-body model to solve a scientific problem known as the photoelectric effect. In 1905, the photoelectric effect was one of the great unsolved mysteries of science. First discovered in 1887 by Heinrich Hertz, the photoelectric effect referred to the phenomena that electrons are emitted from metals and non-metallic solids, as well as liquids or gases, when they absorb energy from light. The mystery was that the energy of the ejected electrons did not depend on the intensity of the light, but on its frequency. If a small amount of low-frequency light shines on a metal, the metal ejects a few low-energy electrons. If an intense beam of low-frequency light shines on the same metal, the metal ejects even more electrons. However, although there are more of them, they possess the same low energy. To get high-energy electrons, we need to shine high-frequency light on the metal. Einstein used Max Planck’s black-body model of energy, and postulated that light, at a given frequency, could solely transfer energy to matter in integer (discrete number) multiples of energy. In other words, light transferred energy to matter in discrete packets of energy. The energy of the packet determines the energy of the electron that the metal emits. This revolutionary suggestion of quantized light solved the photoelectric mystery, and won Einstein the Nobel Prize in 1921. You may be surprised to learn that Albert Einstein won the Nobel Prize for his work on quantizing light—and not on his more famous theory of relativity.

The second property of light that makes it mysterious is its speed in a vacuum. The speed of light in a vacuum sets the speed limit in the universe. Nothing travels faster than light in a vacuum. In addition, this is a constant, independent of the speed of the source emitting the light. This means that the light source can be at rest or moving, and the speed of light will always be the same in a vacuum. This is counterintuitive. If you are in an open-top convertible car speeding down the highway, and your hat flies off, it begins to move at the same speed as the car. It typically will fall behind the car due to wind resistance that slows down its speed. If you are in the same car, and throw a ball ahead of the car, its velocity will be equal to the speed of the car, plus the velocity at which you throw it. For example, if you can throw a ball sixty miles per hour and the car is going sixty miles per hour, the velocity of the ball will be one hundred twenty miles per hour. This is faster than any major league pitcher can throw a fastball. Next, imagine you are in the same car and have a flashlight. Whether the car is speeding down the highway or parked, the speed of light from the flashlight remains constant (if we pretend the car is in a vacuum). The most elegant theory of all time, Einstein’s special theory of relativity, uses this property of light as a fundamental pillar in its formulation.

Why does light have a wave-particle duality?
Why is the speed of light in a vacuum the upper limit of anything we observe in the universe?
Why is the speed of light a constant independent of the movement of the source emitting the light?

No one knows. We learned an enormous amount about light in the last hundred years. We know it is composed of photons (packets of energy) that have no mass, and when emitted instantaneously, they travel at exactly 299,792,458 meters per second—about 186,000 miles per second. This means they do not accelerate to that speed. They instantaneously exist at that speed. We know the speed of light is a constant independent of the velocity of the source that emits the light. Lastly, we know photons can exhibit the properties of a wave and a particle. The one thing we do not know is “why.”

Reference: Unraveling the Universe’s Mysteries, available at Amazon.com

Warp Drive – Time Travel to the Future – Science or Science Fiction?

December 16, 2013Categories, Physics, Time TravelAlcubierre drive, how to time travel, louis del monte, time travel to the future, Warp Driveadmin

Is a warp drive spaceship feasible? Mexican theoretical physicist Miguel Alcubierre thinks it is.

In 1994, Dr. Alcubierre published a 1994 paper, “The Warp Drive: Hyper-Fast Travel Within General Relativity,” in the science journal Classical and Quantum Gravity.

The Alcubierre drive appears to allow a spaceship to travel faster than light, but it requires the existence of negative mass to make the Alcubierre drive work. In principle, the drive works by contracting the space in front of the spaceship and expanding the space behind the spaceship faster than the speed of light. In this fashion, the spaceship rides like a surfer on a wave. As the space behind the spaceship expands faster than the speed of light, the spaceship appears to move faster than the speed of light. However, it does not. Only the space behind the ship is expanding faster than the speed of light. In this way, Dr. Alcubierre avoids violating the laws of special relativity, namely, that no mass can exceed the speed of light.

There is no law in physics that prohibits space from expanding faster than the speed of light. From this viewpoint, the Alcubierre drive has merit. The Alcubierre drive is a mathematically valid solution to Einstein’s field equations. However, requiring negative mass as part of the mechanism for the Alcubierre drive makes the theory highly speculative and, once again, beyond the reach of today’s science. As a side note, Dr. Alcubierre got this idea by watching Star Trek and its use of the warp drive.

Often today’s science fiction becomes tomorrow’s science fact.

This post is based on my new book, How to Time Travel (2013), Louis A. Del Monte.

The Quantum and Macro Level Follow the Same Natural Laws

December 11, 2013Categories, Physics, Universe MysteriesEinstein general theory of relativity, Einstein special theory of relativity, louis del monte, Quantum and Macro Level Follow the Same Natural Laws, Quantum entanglement, quantum mechanics, theory of everything, universe's mysteriesadmin

The two pillars of modern physics are quantum mechanics and Einstein’s special/general relativity. We generally use quantum mechanics to describe how reality behaves at the quantum level (i.e., the level of atoms and subatomic particles). In our everyday world, the macro level, we generally use Einstein’s special or general relativity to describe the behavior of reality. Thus, it appears we need two separate set of “laws” to describe reality, one for the quantum level and one for the macro level. In addition, quantum mechanics is incompatible with general relativity. This suggests that quantum mechanics may not apply at the macro level. However, in 2010, an important experiment suggested that quantum mechanics is applicable to the macro level.

What happened on December 2010? Scientists at the University of Santa Barbara, United States, published a paper “Quantum mechanics applies to the motion of macroscopic objects”. The University of Santa Barbara scientists made a clear demonstration that the theory of quantum mechanics applies to the mechanical movement of an object large enough to be seen with the naked eye. Now, before we go into the detail, just think about the implications and questions this raises if this proves to be true. Do macroscopic objects have a particle-wave duality? Can macroscopic objects be modeled using wave equations, like the Schrödinger equation? Will macroscopic reality behave, under the right circumstances, similar to microscopic reality? To approach an answer, let’s take a look at what the University of Santa Barbara scientists demonstrated.

Our story starts out with Dr. Markus Aspelmeyer, an Austrian quantum physicist, who performed an experiment in 2009 between a photon and a micromechanical resonator, which is a micromechanical system typically created in a silicon chip and sometimes an integrated circuit, which may or may not contain additional electronic integrated circuits. The micromechanical resonator can be caused to resonate, i.e. move up and down much like a plucked guitar string. The interesting part is Dr. Aspelmeyer was able to established an interaction between a photon and a micromechanical resonator, creating the so-called strong coupling (i.e. a strong and noticeable interaction), able to transfer quantum effects to the macroscopic world. This is the first recorded time in history that the quantum world communicated with the macro world.

So what happened at the University of Santa Barbara at 2010? Andrew Cleland and John Martinis at the University of California (UC), Santa Barbara, worked with Ph.D. student Aaron O’Connell. This team became the first to experimentally induce and measure quantum effect in the motion of a human made object. The work, released in March 2010, was voted by Science and AAAS (the publisher of Science Careers) as the 2010 Breakthrough of the Year “in recognition of the conceptual ground their experiment breaks, the ingenuity behind it and its many potential applications,” according to a AAAS press release.

What exactly did they do? They showed that a mechanical resonator (i.e. in this case a small metal strip that can vibrate freely), which was cooled to its ground state energy (ground state), works at the macro level. To understand how profound this is we need to understand the ground state. The ground state is the lowest fundamental level of energy of vibration a physical entity may have according to quantum mechanics. It is not zero energy, but close. A particle with zero energy would violate the Heisenberg uncertainty principle. We would know where it is and how fast it is going simultaneously! The act of putting a system in its ground state energy has never been done before. Their method was brilliant. They first built a mechanical resonator to the frequency of the microwave. Then, the resonator was physically connected to a superconducting qubit (i.e. a quantum system controlled with great precision, used in research of quantum computers). The set was then cooled to near absolute zero. But, how could they be sure that they were at the ground state. They used quantum qubit as a thermometer and demonstrated that the mechanical resonator contained no extra vibration. In other words, it had been cooled to a level equivalent to its ground state energy. At this point, the experiment is already in the history books, but wait an even larger punch line is coming.

The mechanical resonator is as close as possible to being perfectly still, i.e. the ground state. The scientists then added a single quantum of energy, a phonon, the smallest physical unit of mechanical vibration, thus the lowest possible level of excitement. What they observed next is astounding. When the mechanical resonator absorbed this fundamental unit of energy, the qubit and resonator became entangled quantum mechanically (i.e., quantum entanglement). This means that any change in the quantum state of one of them will be immediately cause a change in the state of the other.

Measurements of the vibrational energy showed that the results exactly followed the predictions of the quantum mechanics. The quantum level and the macro level, given the appropriate physical circumstances, follow the same natural laws. This one experiment may have put us one step closer to a unified theory of everything, the “holy grail” of physics.

Theoretical Foundations for Time Travel (Why time travel is possible!)

October 7, 2013Categories, Physics, Time TravelEinstein general theory of relativity, Einstein special theory of relativity, existence equation conjecture, gravitational time dilation, how to time travel, louis del monte, Theoretical Foundations for Time Travel, time dilation, why time travel is possibleadmin

This post is based on material from chapter 1 of my new book, How to Time Travel.

Einstein’s special and general theories of relativity underpin the science of time travel. They are briefly presented here as theoretical evidence that time travel is real. In addition, Del Monte’s existence equation conjecture is presented as theoretical evidence that time travel is real.

1. Einstein’s special theory of relativity—The scientific community considers the special theory of relativity the “gold standard” of scientific theories. It has withstood over one hundred years of experimental verification. In addition to yielding the most iconic scientific equation of all time, E = mc², it also gave us our first insight into the scientific nature of time and predicted time dilation, both conceptually and mathematically. Time dilation is the experimentally verifiable difference of elapsed time between two events as measured by observers, when either one or both observers are moving relative to each other at a velocity near the speed of light. It is an experimental fact that the second hand on a clock moving at a velocity close to the speed of light moves slower than a clock at rest. Time dilation is real and implies forward time travel. For example, if you board a spacecraft capable of traveling at 650 million miles per hour, a one-day journey measured by a clock onboard the spacecraft would be equivalent to the passage of one year on Earth. Time dilation experiments are routinely performed using particle accelerators, which we will discuss later in this chapter.

2. Einstein’s general theory of relativity—Numerous aspects of the general theory of relativity have been verified. For our purposes regarding time travel, it is important to focus on only two:

* Gravitational time dilation—Gravitational time dilation suggests that two observers differently situated from gravitational masses will observe time differently. For example, a clock closer to the Earth will run slower than a clock farther from the Earth. The stronger the gravitational field, the greater the time dilation. This has been experimentally verified using atomic clocks, and we will discuss the results later in this chapter.

* Closed timelike curves—There are numerous solutions to Einstein’s equations of general relativity that delineate the world line of a particle is closed, returning to its starting point. In the general theory of relativity, the world line is the path the particle traverses in four-dimensional spacetime. For example, when the particle starts out, it has four coordinates, three dimensional coordinates and one temporal coordinate. Here is a simple analogy. You are in a specific place, definable by three spatial coordinates, reading this book at a specific time, a temporal coordinate. If the world line of a particle returns to its starting point, the particle is said to have returned to its past, suggesting backward time travel is theoretically possible. However, to date, we have not been able to experimentally verify that this aspect of Einstein’s general theory of relativity is true. As previously discussed, there is evidence that the “arrow of time” can be twisted, and that events in the future can influence past events. However, this is not conclusive experimental proof that backward time travel is possible.

3. Del Monte’s existence equation conjecture—In summary, the existence equation conjecture is derived from Einstein’s special theory of relativity and predicts that a mass requires energy to move in time. If additional positive energy is added to the mass, for example, by accelerating it in a particle accelerator and increasing its kinetic energy, the mass will move more slowly in time. I interpret this as the fundamental explanation of time dilation. An interesting aspect of the existence equation conjecture is that it suggests adding negative energy to a mass will cause the mass to move backward in time. Since today’s science has been unable to produce and manipulate negative energy, this last point has not been experimentally verified. (Note: An entire chapter is devoted to explaining the existence equation conjecture in the referenced source, How to Time Travel)

Source: From chapter 1 of How to Time Travel: Explore the Science, Paradoxes, and Evidence (September 2013), Louis A. Del Monte (Amazon)

Image: Book Cover How to Time Travel

What is faster than the speed of light? Quantum Entanglement!

September 25, 2013Categories, Physics, Universe Mysterieslouis del monte, Quantum entanglement, Quantum entanglement faster than the speed of lightadmin

In 1905, Einstein published his now famous special theory of relativity. It is one of the pillars of modern physics. The special theory of relativity asserts that no physical entity can travel faster than light, since the energy required to enable such a velocity would be infinite. Most of the scientific community extended this concept to communication, asserting that no communication could take place faster than the speed of light. Generally, the scientific community regards light as the upper speed limit of the universe. Until recently, there was no data to contradict this widely held belief.

In 1935, a paper by Albert Einstein, Boris Podolsky, and Nathan Rosen described the EPR paradox (i.e., a thought experiment intended to reveal what they believed to be inadequacies of quantum mechanics) and several papers by Erwin Schrödinger shortly thereafter initiated research into an incredible feature of quantum mechanics, “quantum entanglement.” What made this feature of quantum mechanics incredible is that it appears to allow communication to occur faster than the speed of light. However, we are getting a little ahead of ourselves. Let us first understand what quantum entanglement is and how it relates to communication.

Quantum entanglement is a physical phenomenon that occurs when pairs of particles are generated or interact such that the quantum state of each particle is described relative to each other. Let us consider an example to illustrate this phenomenon. When an electron collides with a positron (i.e., the antimatter counter part of an electron), two photons are emitted. An unusual feature of quantum mechanics is the resultant photons are “entangled.” If one photon exhibits spin up (a component of its angular momentum), the other photon will exhibit spin down. They conserve spin. If you separate the photons and change the spin of either photon, the other will immediately change its spin in a manner to conserve spin. For example, if you change the spin of one photon from spin up to spin down, the other photon, even at a significant distance, will change its spin from spin down to spin up. In other words, they continue to conserve spin.

This phenomenon has been widely verified and the scientific community accepts it as a fundamental feature of quantum mechanics. In recent years, further experimentation related to quantum entanglement has shaken one of the fundamental pillars of modern science, namely, the speed of light as the upper limit that mass or information could travel. Recent experiments (Juan Yin, et al. (2013). “Bounding the speed of `spooky action at a distance”. Phys. Rev. Lett. 110, 260407) have shown that the quantum entanglement information transfer occurs at least 10,000 times faster than the speed of light. It might even be faster. Quantum mechanics holds that the quantum change occurs instantaneously. In other words, the separated particles act as if they were one, even when they are separated by a significant distance. “According to quantum physics, entanglement is independent of distance,” physicist Rupert Ursin of the Austrian Academy of Sciences said in a statement to livescience.com (reference below).

The phenomenon of quantum entanglement has been demonstrated experimentally with photons, electrons, molecules and even small diamonds. It is real and an area of active research in physics. There is no widely held theory within the scientific community that explains how the particles are able to communicate faster than the speed of light. There are numerous speculations, which I will not go into in this article in the interest of remaining factual.

Anyone who can explain quantum entanglement to the satisfaction of the scientific community is likely a candidate for the Nobel Prize. It has been a mystery for almost a hundred years.

Sources:

Wikipedia http://en.wikipedia.org/wiki/Quantum_entanglement
Livescience.com, “Space Station May Test ‘Spooky’ Entanglement Over Largest Distance Yet” http://www.livescience.com/28553-quantum-entanglement-distance-test.html
Unraveling the Universe’s Mysteries, 2012, Louis A. Del Monte (Amazon)

Image: iStockPhoto