We all have a pretty good understanding of what time is. We are born, we live our lives, and we die over a span of time. We perceive time as moving at different rates. Time seems to fly as our children grow up. We wish we could slow time down to enjoy our children before they grow up and move away. In other situations, time moves too slow such as when we are waiting for an ambulance to arrive to care for a heart attack victim.
While time may seem to flow at different rates at different times, we know that time flows at a constant rate. This rate is visible in the moving of the second hand around a clock or in the steady marching off the seconds on a digital watch. Time is probably the most constant and expected attribute of our existence.
But, do we really understand time? Is it something we just take for granted, or it there more to it? Surprising still, there may be more than one form of time. In this article, we will journey through the world of time. We will look at how time was perceived in the past, how physics views time in the present, and the possibility that time may exist in multiple forms.
Historical Development of Time
Since ancient times, mankind was more interested in how to measure the passage of time than the nature of time itself. In its most primitive form, time was measured as the passage of the sun from east to west across the sky. All life on Earth reacts to this daily cycle of day and night.
As mankind evolved from hunter-gatherers to farmers, there developed a need to know when to plant the crops. Early astronomers noticed the Sun followed a different path each day. The Sun rose and set at different points on the horizon each day. The point of sunrise moved steadily from north to south until it reached a specific point on the horizon. Then, the Sun reversed direction and moved south to north until it reached another specific point.
This cyclic movement of the Sun corresponded to the seasons of the year. In the northern hemisphere, when the Sun reached its most northern point, farmers knew it was time to plant their crops. Counting the number of days it took for the Sun to complete one cycle south and back north led to the development of the 365 day year.
In a similar manner, observations of the Moon led to another cycle from one full moon to another full moon. This helped to predict the tides and became the basis of what we now call months. These concepts of days, months, and years eventually caused ancient people to developed calendars. Some calendars, such as the Mayan calendar, had a year zero based on the creation of the world. These calendars allowed for the recording of events on specific historical dates.
Measuring time within a day took longer to develop. The Sundial provided an early attempt to measure time during the day. However, sundials only worked during the day and only when the Sun was shining. The ancient Egyptians developed a water clock that could measure the passage of time both day and night.
By the 11th Century, the Chinese were building mechanical clocks with an escapement mechanism. In 1657, the first pendulum clock was patented by Christian Huygens. The chronometer, which allowed ships at sea to accurately measure the passage of time, was invented by John Harrison in 1761. By the 19th Century, pocket watches were in common use. World War I led to the use of wristwatches so that soldiers could keep their hands free while checking the time. In the 1960’s, the Japanese discovered how to use vibrating crystals to track time leading to very accurate clocks.
Today, atomic clocks use the properties of the Cesium atom to track time to within seconds over millions of years. Time is now one of seven fundamental physics quantities defined by the International System of Units (SI). The “second” has been defined by SI as 9,192,631,770 cycles of an electron moving between two energy levels of the ground state of the 133Cs (Cesium) atom.
While the measurement of time has become more precise over mankind’s history, the nature of time took longer to develop. Historically, there were two competing philosophies. Gottfried Leibnitz in the 17th Century and Immanuel Kant in the 18th century argued that time was merely an invention of the human mind. It is neither an event or a thing. Time cannot be measured and cannot be travelled.
Isaac Newton, in the early 17th century held an opposite view. According to Newton, time was part of the fundamental structure of the universe. It was a dimension independent of events and along which events occur in sequence. Time figured prominently in Newton’s three Laws of Motion.
In the 19th Century, a series of scientists, concluding with Ludwig Boltzmann, developed the idea of entropy. Entropy is spontaneous changes that occur in our world. For example, it you pour cream into a cup of black coffee, the cream will spontaneously disperse throughout the coffee. Also, the hot coffee will spontaneously cool over time.
Entropy defines something called the Arrow of Time. The Arrow of Time is the name we give to the one-way nature of time. Our universe can only move from low states of entropy to high states of entropy. There is no way we can go backwards in time just like a cold cup of coffee will not spontaneously get hot and cream will not spontaneously separate itself from the black coffee.
Our Current Understanding of Time
Today, we have concepts of time from both the microscopic world of quantum mechanics and the macroscopic world of Einstein’s Theory of Relativity. According to quantum mechanics, time is not continuous. Rather, there exists a smallest unit (or quantum) of time based on the Planck Scale. The smallest interval of time, called Planck time, is 5.39 x 10-44 s.
Quantum mechanics also recognizes three basic symmetries of particles – charge, parity, and time. Charge involves reversing the charge of an elementary particle to create antimatter. For example, an electron has a negative charge. Its antimatter particle is the positron with a positive charge. Parity involves reversing the spin of a particle (e.g. left-handed spin to a right-handed spin). Time involves reversing the Arrow of Time. Supposedly, time-reversal involves detecting a particle before it is produced in a particle accelerator. However, this form of detecting a time-reversed particle has never occurred.
Theoretically, if you reverse all three basic symmetries of particles, you would create a universe with the exact same properties as our own universe. This universe would follow an opposite Arrow of Time. However, current science has no way of understanding how this reversed universe would exist.
Einstein, and his Theory of Relativity, has a different twist on the concept of time. In his General Theory of Relativity, Einstein argued that time was an integral part of our universe. His “spacetime” model consists of the three spatial dimensions of length, width, and height. However, spacetime also includes the temporal dimension of time to make our universe a four-dimensional system. As a temporal dimension, objects move and change state over time, but time itself has no velocity.
Incorporating time into his gravitational computations, Einstein was able to generate a significantly better calculation of the precession of the perihelion of Mercury’s orbit. The previous best calculation was based on Isaac Newton’s Universal Gravitation formula which presupposes a three-dimensional universe without a time dimension.
The most controversial aspect of Einstein’s view of time, however, is his concept of time dilation. Time dilation was first introduced in Einstein’s Special Theory of Relativity. The concept was expanded to gravitational time dilation in his General Theory of Relativity.
In developing his Special Theory of Relativity, Einstein made the following assumptions:
- The Principle of Relativity,
- The Principle of Invariant Light Speed,
Our universe has no concept of standing still. Everything exists in its own Inertial Frame of Reference and is in relative motion to everything else. The Principle of Relativity states that every experiment will yield the exact same result in every Inertial Frame of Reference. Also, you cannot perform an experiment to determine in which Inertial Frame of Reference you exist.
The Principle of Invariant Light Speed states that photons move in the vacuum of empty space at a constant speed. That constant speed is the universal constant, c, which the International System of Units (SI) defined in 1983 to be 299,792,458 m/s. As an aside, the SI redefined the length of the meter at this same time to make the value of c an exact measurement.
Einstein was obsessed with the fact that the universe must have some universal constant to make up for the fact that nothing stood still. Einstein assumed that c was that universal constant and that photons provided a constant value upon which everything else could be measured. It must be noted that the Principle of Invariant Light Speed is only an assumption and cannot be proven.
One consequence of assuming both the Principle of Relativity and the Principle of Invariant Light Speed is time dilation. Time dilation is the concept that moving clocks run slower. Einstein expresses the idea in a thought experiment called the Travelling Twins Paradox. Supposedly, if one twin went off travelling at high speed through space and the other twin stayed on Earth, then the travelling twin would return to Earth much younger than his twin that stayed behind.
Physicists of today absolutely believe in time dilation. However, the general population has their doubts. It is true that GPS satellites must compensate for time dilation to synch up with clocks in other satellites and ground-based GPS systems. Also, every time dilation experiment ever performed with atomic clocks has confirmed that moving clocks do run slower than stationary clocks.
Clocks, however, are based on a technology that mimics the assumptions made by Einstein. Every clock has an oscillator that mimics Einstein’s assumption of invariant light speed. Clocks maintain this oscillation no matter how fast the clock moves relative to other clocks (i.e. Principle of Relativity). The combined assumptions of Relativity and Invariant Light Speed does cause time dilation to occur. However, this does not prove that time dilation exists in nature. For that to be true, Einstein’s assumption of invariant light speed must be true in the universe.
The Theory of Time
There is a new theory being proposed that offers an alternative explanation of our universe that does not involve time dilation. This theory is called the Theory of Time, which makes the following assumptions:
- The Principle of Relativity
- The Principle of Non-Constant Light Speed
- The existence of a Spatial-Time Dimension in the Multiverse
The Principle of Relativity in the Theory of Time is the same as Einstein’s assumption in his Theory of Relativity. The assumption of non-constant light speed is based on two changes to Einstein’s Principle of Invariant Light Speed. First, the Principle of Invariant Light Speed argued that the speed of light was independent of its source and never changed. The Principle of Non-Constant Light Speed argues that the speed of light is dependent on the speed of the light source. The second change is that photons have a mass-equivalence that causes them to accelerate and decelerate in the presence of gravitational forces.
The revolutionary new idea in the Theory of Time is the existence of a Spatial-Time Dimension. Our universe still exists in a four-dimensional system consisting of three spatial dimensions and the temporal dimension of time. However, the Theory of Time postulates a fourth spatial dimension though which our universe is moving in the Multiverse. The Multiverse is a higher order space in which multiple universes are born, live out their lives, and die.
The Spatial-Time Dimension is still an assumption, but there are some serious facts unfolding from our space probes that suggest its existence. First, both the American WMAP probe and the European Planck probe have confirmed that our universe is based on Euclidean geometry. Einstein’s concept of spacetime is heavily dependent on our universe being non-Euclidean in nature.
If our universe is a three spatial dimension Euclidean system (we are excluding the temporal time dimension for now), then the Big-Bang must exist as a point in that system. However, the location of the Big-Bang is not a point in our sky. Rather, the Hubble Space Telescope has revealed through its Deep Field studies that the Big-Bang is at the farthest point in every direction of the sky. The only way this can happen in a Euclidean system is if there exists a fourth spatial dimension.
The Big-Bang is not a single point in the night sky because our three-dimensional universe has moved away from the point of the Big-Bang in the Multiverse. The concept of our universe moving within the Multiverse raises some possibilities. If we combine these four spatial dimensions with the temporal time dimension, we are living in a five-dimensional Multiverse.
Solids only exist in three-dimensions. This new fourth spatial dimension is only a dimension where objects move and change state over time. This definition should sound a lot like how I described the temporal time dimension within Einstein’s spacetime. The difference is that temporal time has no velocity. This new dimension, called the Spatial-Time Dimension, acts like time, but it has a velocity associated with it.
As we look at deep space objects the night sky, we are actually looking back along the Spatial-Time Dimension. For example, the Andromeda Galaxy is a mere 2.5 million light-years from Earth. We know this means we see the galaxy as it existed 2.5 million years ago. However, this also means we see where our moving universe existed 2.5 million years ago back along the Spatial-Time Dimension.
Einstein’s Mass-Energy Equivalence Equation, E = mc2, now has an interesting new interpretation. Current science does not give an explanation why the universal constant, c, is in this equation. However, we do know that it governs how energy, E, was turned into mass, m, at the time of the Big-Bang. Any mathematician will tell you this equation is an acceleration formula where matter was accelerated to speed c at the time of the Big-Bang.
Current scientific beliefs say this cannot happen because c is a limiting factor to the speed of mass. However, c is only a limiting factor if we believe Einstein’s assumption of the Principle of Invariant Light Speed and that we exist in only a three-dimensional Multiverse.
The Spatial-Time Dimension answers several perplexing issues in modern physics. For example, matter is always created in pairs – a particle of matter and a particle of antimatter. However, our universe consists mainly of matter. Where did the antimatter go?
Recall the earlier dilemma of the time-reversed particle. With our universe moving away from the Big-Bang at speed c, there is now room in the Multiverse for the Big-Bang to create two separate universes – our universe, and a second antimatter universe created with time-reversed particles. Both universes are moving along their own respective Arrows of Time in the Multiverse.
Time in Multiple Forms
The Arrow of Time is not determined by entropy alone, but mainly by the direction in which a specific universe is moving in the Multiverse. Twin universes are born together in a low-entropy state, and they move away from each other in opposite directions as they move to higher states of entropy.
Each universe evolves separately from its twin universe in its own Arrow of Time. Following the Principle of Relativity, there is no experiment we could perform that would indicate in which universe we exist. If we could see our twin universe, it would appear to be moving backwards in time. However, the two universes are moving away from each other at twice the speed of c. There is no way light from one universe would ever reach its twin universe. As a result, we can never see our twin universe.
Following this scenario farther, the Multiverse may continually be giving birth to twin universes. With each universe following its unique Arrow of Time, the Multiverse may be filled with multiple forms of time – each heading off in a different Arrow of Time.
With no gravitational forces opposing them, each universe will continue to move at speed c until each universe meets its ultimate demise. Einstein may be wrong in his assumption of the Principle of Invariant Light Speed. However, Einstein’s dream of c being a universal constant may be correct. Rather than c being the constant speed of light in the vacuum of empty space, c could very well be the universal constant for the speed of time.
Does anyone know how to measure the speed of a random photon?
I am well aware of the fact we believe the speed of light in the vacuum of empty space, as denoted by the universal constant c, is 299,792,458 m/s. The International System of Units (SI) even redefined the length of the meter in 1983 to make this exact measurement possible. There have been countless experiments that have confirmed this value.
However, these countless experiments generally involve emitting a photon, bouncing the photon off a mirror (or a set of mirrors), and returning the photon back to a detector that is collocated with the photon emitter. The purpose for the collocation is so one clock is used to measure the elapsed time from emission to detection. This collocation eliminates the need to synchronized multiple clocks and also eliminates the dreaded time-dilation issue associated with clocks moving relative to each other. In other words, these experiments are all performed within the local Inertial Frame of Reference.
So, let me clarify my question. The key word in the question is “random”. Can we measure the speed of a random photon coming into our local Inertial Frame of Reference from a star in some far off Moving Inertial Frame of Reference? In other words, can we measure the speed of a photon that we did not emit in some controlled experiment?
According to modern scientific thought, the speed of this random photon is still going to be 299,792,450 m/s (i.e. the universal constant c). We have Albert Einstein to thank for this conclusion. It is called the Principle of Invariant Light Speed. This principle is one of the hallmarks of his Theory of Relativity. Einstein needed some universal constant to deal with a universe that has no stationary point in which to measure the velocity of anything. I would even go to the extent to say that Einstein was obsessed with the concept of the speed of light being a universal constant. However, I must remind everyone that the Principle of Invariant Light Speed is merely an assumption by Einstein.
Today, the scientific community thinks of Einstein as almost a god. Even in his lifetime, Einstein was the savior of the physics world. However, today’s physicists are not always historians. So, let’s examine the state of the physics world in the late 1800’s. Scientists in the 1800’s knew that sound used air as a medium for transporting sound waves. In the vacuum of space, sound cannot travel because it requires a medium in which to generate compression waves. However, no one knew the composition of outer space at that time. Since ancient times, philosophers believed there was a substance, called aether, that filled outer space and was the medium for transporting light waves. By the mid-1800’s, scientists still believed in the existence of aether.
In the 1860’s, James Clerk Maxwell developed his famous four equations that described the electromagnetic phenomena. His equations confirmed the speed of light that various scientists were trying to measure in various experiments. Maxwell proposed that light was an electromagnetic wave that could travel through empty space as a transverse wave. Suddenly, scientists needed to know whether light travelled through outer space using compressions waves within the aether, or whether they travelled through empty space as transverse waves.
This issue was settled in the famous Michelson-Morley experiments of 1887. If outer space was filled with aether, then it must flow around the Earth. The rate of flow would be different at different points in the Earth’s orbit. Albert Michelson and Edward Morley used a highly sensitive instrument, called an Interferometer, that measures minute differences in the speed of light moving in different directions. The experiment was repeatedly performed in different orientations at different points on the Earth’s orbit. In none of the experiments did they detect any difference in the speed of light. There are two points to keep in mind regarding the Michelson-Morley experiments. First, the Interferometer generated its own photons. So, again, we are dealing with the local Inertial Frame of Reference. Second, the Interferometer did not calculate the speed of the light. The Interferometer only looked for interference patterns generated by light moving at different speeds.
The results of the Michelson-Morley Experiments sent a shock wave through the scientific community. There was no aether in outer space, and light travelled through empty space without a medium. This revelation placed the physics world in a crisis. Scientists were already using redshift to measure the velocities of celestial objects. The belief that redshift measures velocities was based on the Doppler Effect. The Doppler Effect is based on a formula that includes the speed of the medium. Without a medium, the Doppler Effect for light does not function the same as the Doppler Effect for sound. Without an explanation of the Doppler Effect for light, there was no explanation for how redshift measures the speed of a celestial object.
It was into this crisis that Einstein proposed his Special Theory of Relativity in 1905. By assuming the Principle of Invariant Light Speed, the universal constant c could be substituted into the Doppler Effect equation as the speed of the medium. With that substitution, astronomers felt they were justified in using redshift to measure the speed of celestial objects. In 1929, Edwin Hubble published his now famous Hubble’s Law which not only related redshift to velocity, but also to the distance of the object from Earth. Hubble’s Law essentially states that, the farther an object is from Earth, the faster it is moving away from Earth.
So, again, I ask the question. Does anyone know how to measure the speed of a random photon? Was Einstein correct in assuming the Principle of Invariant Light Speed. In Einstein’s own explanation of how redshift works within Moving Inertial Frames of Reference, Einstein appears to be violating another one of his assumptions – the Principle of Relativity. According the Principle of Relativity, one should get the same results when performing the same experiment in different Moving Inertial Frames of Reference. The fact that observed redshift will have different values in different Moving Inertial Frames of Reference directly violates this Principle of Relativity.
Einstein used only a few assumptions, like the Principle of Relativity and the Principle of Invariant Light Speed, to develop his Theory of Relativity. However, assumptions are the axioms of a mathematical theory. If you change one axiom, you change the whole theory. If the Principle of Invariant Light Speed is wrong, it changes Einstein’s Theory of Relativity significantly. For example, the Doppler Effect for light is not the same as the Doppler Effect for sound. Also, redshift does not measure the velocity of a celestial object.
I totally agree that the initial speed of light relative to its light source is the universal constant c. This is what we have measured in countless experiments. However, this statement only means the speed of light is dependent on the speed of its light source. Einstein’s assumption is that the speed of light is independent of the speed of the light source. I contend that scientists have never tested the independent nature of the speed of light. Measuring the speed of random photons would answer the question of whether the speed of light is dependent or independent of its source. If every random photon has speed c, then we have proof of independence. If the speed of random photons varies, then we have an argument for the speed of light being dependent on the speed of the light source. Instead of a constant speed of light, we now have a non-constant speed of light.
I know of three techniques used to measure the speed of an object:
- A radar signal can be bounced off an object. A succession of radar signals can then determine the velocity of an object. However, the Pauli Exclusion Principle states you cannot bounce a signal off a photon because a photon is not a fermion. A photon is a boson, and multiple bosons can occupy the same space at the same time.
- One can measure the momentum of a detected object. However, the Heisenberg Uncertainty Principle states that we cannot both detect a photon and measure its momentum simultaneously.
- We can also make two distinct observations of an object measuring the distance and time between the two observations. However, a photon is always destroyed when it is detected. The only way to measure the photon at a second point is to have a mechanism that re-emits a photon upon detection. The problem is the that the re-emitted photon will always have speed c relative to the speed of the emitter. The emitter has no way of re-emitting a photon at the same speed as it was detected. Hence, this process cannot measure the independence of the original photon from the speed of its light source.
I believe that the speed of light is dependent on the speed of the light source, and not independent of it. If Einstein can assume the speed of light is independent of its source, I can equally assume the speed of light is dependent on its source. This assumption of the non-constant speed of light is one axiom of my Theory of Time. I challenge the scientific community to prove my assumption is wrong.
As in a court of law, I am not looking for circumstantial evidence. Examples of circumstantial evidence include, but are not limited to:
- Experiments proving time dilation with clocks. I contend that time dilation is the result of Einstein’s assumption of independent light speed. Atomic clocks, as with any clock, has an oscillator that oscillates independent of the motion of the clock. As a result, atomic clocks, by their very design, will experience time dilation as illustrated by GPS satellites.
- Experiments proving time dilation in nature. I contend these experiments always have relativistic momentum hidden somewhere in the experiment. This relativistic momentum is always interpreted as relativistic mass times a velocity less than the universal constant c. I believe relativistic momentum should be interpreted as the zero mass of an object times a relativistic velocity that may be greater than c. Speeds are limited to c only because of the Lorentz Factor Einstein used in his mathematical theory, which, of course, is dependent on the assumed independent speed of light.
- Experiments dealing with the Doppler Effect for Light. I contend that scientists of today do not understand the Doppler Effect for Light. They always explain the Doppler Effect in terms of sound and then do arm waving to say the same thing happens for light. The fact is that it doesn’t necessarily do the same thing as sound unless you assume a constant and independent light speed of c. Since redshift follows directly from the Doppler Effect for Light, then redshift also depends on independent light speed.
I suspect it is impossible to directly measure the speed of an incoming random photon from a random star. That is why the Principle of Invariant Light Speed is only an assumption. But, if someone knows how to do it, I would like a reply from you. Also, if you have any indirect way, other than those listed upon, that proves the speed of light is constant and independent of its source, please leave a reply also. I do ask that you register with the website to leave a reply. I am trying to keep this a serious discussion and avoiding spammers.
Thank you for any and all serious comments pertaining specifically to the question asked. Again, the question is “does anyone know how to measure the speed of a random photon?”.
What is the Theory of Time? The Theory of Time is a new theoretical view on the nature of our universe. It is a physics…