What is Einstein’s Theory of Relativity?

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Classical vs. Modern Space and Time

Newtonian mechanics came out of a separation of space, time, and matter, which had not existed in European thinking previously. Early Greeks spoke of four substances called Earth, Water, Fire, and Air and did not recognize space and time as categories separate from substances. Until the time of Descartes—who talked about extended substance in his work, Meditations, published 41 years before Newton—it was assumed that space and time were attributes of substance. Hence, the separation of space, time, and matter was a huge leap forward in Newtonian mechanics.

Newton’s calculus depends on the separation of matter, space, and time because it speaks about the motion of an object in space and time and objects can move in space and time only if they are separate from space and time. The separation of space, time, and matter is still commonly assumed today, although these concepts underwent a serious transformation in the early part of the 20th century in Einstein’s theories of relativity. In this post, I will describe what Einstein was doing, why he was doing it, and where it eventually led him.

Special Relativity and Logical Positivism

Beginning with the Special Theory of Relativity, Einstein started substituting the word space with the word meter and the word time with the word clock. This was keeping in line with the Vienna school of philosophy called Logical Positivism which was trying to reduce all words to measurements. Logical Positivists wanted to purge philosophy of esoteric words such as beauty, justice, morality, truth, existence, and so on, and transform the meaning of all words to instrument measurable outcomes. The charge against these words was that they were metaphysics, not measurable by physical instruments.

Einstein took a leaf out of Logical Positivism and started applying it to metaphysical words within physics such as space and time. Nobody can see space and time. Even if we talk about distance and duration, which are parts of the metaphysical entities called space and time, we know their meanings through instruments like a meter and a clock. Therefore, Einstein replaced metaphysical words like space and time with the words meter and clock respectively. He wanted to create a Positivist physics free of Newtonian metaphysics.

The Special Theory of Relativity led to two outcomes called Length Contraction (LC) and Time Dilation (TD). Since these terms tend to confuse most people, therefore, to understand what they mean, we must substitute the word length with the word meter and the word time with the word clock. LC means that moving meters are contracted (i.e., become smaller). TD means that moving clocks are dilated (i.e., run slower). If we use a contracted meter to measure an uncontracted distance, then the result will be longer. If we use a dilated clock to measure an undilated duration, then the result will be shorter.

This is how Einstein made the formerly objective space and time, or distance and duration, observer-dependent. Two observers—let’s call them A and B—can measure the same thing while moving at different speeds. Each observer will get a different value of distance and duration because their meters and clocks are contracted and dilated differently. However, each observer will believe that they are stationary, and thus, they will conclude that their measurements are correct. The result of two measurements by A and B will produce two sets of values on the same reality. Nobody can say which of these two measurements is reality. They are both true and yet mutually incongruent.

General Formulation of Relativity

Each observer could still know if he was accelerating. Einstein removed that possibility by saying that we cannot even know if we are accelerating because the backward force experienced during acceleration can also be caused by a gravitational force. A gravitational force can bend a meter, not just expand or contract it. A gravitational force can bend a clock, not just expand or contract it. Therefore, in the general formulation of relativity—called the General Theory of Relativity—Einstein started talking about curved space and time different from LC and TD. Since these terms may confuse most people, therefore, to understand what they mean, we must replace the word space with meter and the word time with clock. Curved space means that our meter is curved. Curved time means that our clock is curved.

If we measure the world with a curved meter, curved distances will appear straight and straight distances will appear curved. An object may be moving on a curved trajectory but it will seem to be moving on a straight trajectory to some observers (whose meters are curved) and on a curved trajectory to other observers (whose meters are not curved). If we measure the world with a curved clock, objects moving forward may seem to be moving backward, because a curved clock will go slower or faster compared to other clocks. As a result, distances, durations, directions, and angles were all observer-dependent.

The theory of relativity has little to do with metaphysical space and time and everything to do with the measurement of space and time using material instruments like meters and clocks. Since material objects are elongated, compressed, twisted, and bent under the gravitational force, therefore, the result of using them for measurement can also be elongation, compression, twisting, and bending. There was no other meaning to space and time if we restricted ourselves to physics rather than metaphysics.

Observer-Dependent Measurements

While these things were going on in the theory of relativity, there was a parallel development called quantum theory under which light transformed from waves to particles. A wave uniformly spreads to all locations in space and by that spreading everyone comes to know of the existence of something that emits light. But a particle goes to only one place and we detect the presence of something by detecting a particle of light—called a photon. Thereby, everyone could know the existence of everything when light was a wave. But everyone cannot know the existence of everything when it is a particle. Each observer will occasionally know of the existence of something—if and when a photon arrives at that observer’s measuring instrument. Thus, knowing whether something exists also became observer-dependent.

If we combine the principle of relativity with the quantum principle of occasional detection, then there are two measurement problems: (a) each observer in the universe cannot know of the existence of everything, and (b) if and when they know of its existence, what it is, is also observer-dependent.

The reason that quantum and relativity theories could not be combined is because relativity transformed space and time into a continuous field and quantum mechanics transformed matter into discrete particles. A unified theory requires the same thing to be both continuous and discrete but there is no known method to acheive this at present. The best viable solution is that we quantize space and time, and make locations in space and time discrete particles. However, that will destroy calculus which depends on the smoothness and continuity of space and time.

Einstein’s Idealistic Position in Physics

The crucial innovation in relativity theory is that space and time are also matter. However, they are not the kind of matter that we call quantum objects. The former is continuous and the latter is discrete. How can we reconcile these two kinds of matters into a single unified theory without a contradiction?

The answer is easy—treat relativity matter as an observer’s senses and quantum matter as the observed objects. It requires us to say something profound, namely, the words space and time are tied to our senses and constitute the goggles through which we see a quantum word of sensed objects. Einstein came to this profound conclusion when he started talking about Kantian Idealism in which space and time were an observer’s “synthetic a priori” categories not objective “realities out in the world”. It doesn’t mean that objective space and time are absent. It just means that the objective space and time are the metaphysical noumena that cannot be known. We can only know the physical phenomena.

While Einstein agreed with Kant that space and time were observers’ goggles to see the world, he did not agree with the Kantian idea that everyone wore the same type of goggles. In Kantian Idealism, space and time are hardwired categories in our minds and everyone must see the world in the same way. In Einsteinian Idealism, everyone is wearing a different type of goggles. Nobody can say whose goggles are better. For Kant, words like meter and clock have a universal meaning. But for Einstein, meters and clocks can be contracted, elongated, curved, or straightened. The results of the measurements were also different. Nobody can know if their meters and clocks are shorter, longer, curved, or straight. No observation can be said to give us a truer picture of reality. All measurements were now observer-dependent.

Philosophy Lags in Philosophical Terms

Unfortunately, there are no words for the observer-dependent perception of reality in the Western philosophical lexicon. The classical philosophical words are Realism and Idealism. Realism means objective truth and Idealism means subjective truth. There is no word for an objective truth being differently perceived by each observer. Therefore, when we describe physics in ordinary language, we run into the problem that the Western philosophical lexicon does not have the appropriate word for the observer-dependent perception of reality. Some people might therefore incorrectly equate this to pure Idealism while others might think that it is the rejection of any kind of Realism.

Physics is indicating neither pure Realism nor pure Idealism. There is some reality—otherwise, there would be no meaning to science. But the numbers we plug into the equations of science are observer-dependent. Because of quantum theory, every observer may not see everything. Because of relativity theory, every observer may see the same thing differently because their senses are like longer, shorter, curved, or straight meters and clocks. Thus, we reject both pure Idealism and pure Realism.

Religious Origins of Objective Reality

But there is more to the problem than just the absence of a philosophical term for the situation in physics. To understand it, we have to step into the history of Christianity, more specifically, the Biblical claim that all humans are children of Adam and Eve, and they have inherited their sinful nature. Due to their sins, they cannot know the truth on their own and truth can only be known through revelation.

For over 1500 years, after the dawn of Christianity, the idea of sin prevented any rational inquiry into any natural subject. Everything had to be known through the scripture and whatever was not in the scripture was unknowable. Alternatively, even if something was knowable but if God had not given us something in scripture, then He did not want us to know it. Trying to know something that God did not want us to know was an act of defiance.

The problem of sin and evil was solved by John Locke when he said that the human mind was a tabula rasa or “blank slate” at birth. We cannot overestimate the importance of these two words because they washed away the inherited sin and evil in Christianity. Every human was now pure and he or she could know the objective truth about the world. All doubts about sense perception accuracy were resolved by saying that we will derive our knowledge of the world through instrument measurements and not sense perception. All doubts about mental cognition were resolved by saying that we are born pure at birth. Thus arose the dogma of objectivity at the dawn of Enlightenment. But it was destroyed in the early 20th century by the advent of quantum and relativity theories. The situation has remained more or less stagnant since—which is close to a century now.

Applying Sāñkhya Concepts to Physics

In Sāñkhya philosophy, both senses and their objects comprise three qualities called sattva, rajas, and tamas. The senses are continuous but the sense perceptions are discrete. Therefore, if we were looking for something that is both continuous and discrete, then it is the three qualities. These senses constitute our personal space and time, loosely equivalent to Einstein’s contracted, elongated, curved, or straight meters and clocks. Our sense qualities contaminate our perception to create a distorted picture of reality. The truth can be known by purifying our senses.

The senses are neither permanently impure as in Christianity nor are they pure at birth as per John Locke. Every observer is not equally impure. The variation in impurity is due to the presence of sattva, rajas, and tamas in the senses. Since this impurity can be removed, therefore, it is possible to know the truth. The relativity of perception is due to impurity and absolutism of perception is due to purity.

The issue of selective perception can also be understood based on qualities. Every observer cannot see everything because the senses contaminated by one quality can only see things in that quality.

However, the impurities in the senses are not constant. The type and extent of impurity in the sense changes with time. A common example in Sāñkhya is seeing the rope as a snake. We don’t always see the rope as a snake. We don’t always notice the rope. Thereby, the idea of reproducibility in science is also rejected because the instruments (or senses) are changing which changes the results of measurement (or observation). This is well-known via the varying results of measuring the same thing repeatedly. However, experimental sciences disregard all such the variations as instrument errors and environmental changes.

Corresponding to the Lockean idea of tabula rasa or “blank slate”, there is a process of cleansing the mind in Sāñkhya, called cheto darpan marjanam. We aren’t born clean slates. Nor are we eternally impure. Everyone is not equally impure. Nor is the impurity constant over time. Different observers have greater or lesser impurities. Even those impurities increase and decrease over time. However, through a process of cleansing, we can obtain a pure mind. When the mind is completely purified, then the objective truth can be known. Until then, the perception is distorted based on the type of impurity in the observer.

Recapitulating the Discussion

Let’s summarize all these things discussed thus far into the following easily digestible points:

  • Everyone cannot perceive everything that exists due to quantum effects
  • Everyone does not see the same thing in the same way due to relativistic effects
  • Even one person cannot see the same thing consistently due to time effects
  • Our senses are like elongated, shortened, curved, or straight meters and clocks
  • The meters and clocks are altered by the presence or absence of matter
  • Our senses are also modified based on changes in time, place, and situation
  • The modification of the senses depends on the type of impurity in the senses
  • But if we purify the senses then everyone can perceive everything consistently
  • That unchanging vision of all that exists can be called the absolute truth
  • The senses are continuous whereas the sense perceptions are discrete
  • Both senses and their perceptions are created from the three qualities
  • Using these qualities, we dissolve the continuity vs. discreteness paradox

The Synthesis of Realism and Idealism

When we include senses in the vocabulary of science, then we have to think of dreams as well. During a dream, discrete sense perceptions emerge from the senses. When the dream ends, the sense percepts merge into the senses. An external world is not necessary for sense perception due to the possibility of dreams. However, when an external world affects us—such as during waking—then the process of sense perception must be just like dreaming.

Perception is described as waves in a pond in Yoga philosophy. Yoga Sutra 1.2 states: “The purpose of yoga is to end the modifications of the mind”, that are compared to waves in a pond. The pond can generate waves when a stone is thrown into it. Each pond can throw stones into other ponds—which is a sense of action. No pond throws stones into all other ponds—which is why everyone cannot see everything. Each pond is filled with a different liquid and each stone thrown into a pond has a different shape. Accordingly, the waves generated by stone-throwing into a pond are also different. The difference can be attributed both to the stone and the liquid in the pond. The pond is continuous, but the stones are discrete. The resulting waves are also discrete. This pond, stone, and wave theory is Sāñkhya.

The pond is the mind. Its ability to throw stones into other ponds is the senses of action. The mind’s ability to receive stones thrown at itself is the senses of knowledge. The ripples in the pond generated by stones thrown into a pond are the perceptions of senses of knowledge. The ripples in the pond that precede the throwing of stones into other ponds are the perceptions of senses of action.

Since there are many ponds, therefore, there is Realism. But because we know these ponds through the waves generated by the stones that they throw at us, therefore, there is Idealism. We are not seeing the other ponds. We are seeing the waves within a pond generated by the stones thrown at the pond by other ponds. Each stone carries an imprint about the pond that threw it. Each ripple in each pond is thus attributed to some external pond that previously threw a stone. This is how it becomes possible to talk about reality through perceptions.

Alternative Conceptions of Space and Time

There is an absolute space and time in the Vedic system that corresponds to the ground that contains various ponds. As new ponds appear and old ponds dry up, this ground for all ponds evolves. Within this absolute space and time are relative spaces and times that correspond to the individual ponds and the ripples in them.

All these ponds are organized hierarchically in an inverted tree structure such that when one pond throws a stone into another pond, the path to the other pond involves several intermediary ponds that lie at higher levels in the inverted tree. We can imagine a situation in which a stone thrown by one pond jumps through several ponds until it lands in the destination pond. The intermediate ponds are demigods. They can absorb the stones thrown by lower-level ponds ensuring that they never reach their destination. They can modify the shape of the stones thrown ensuring that what the receiver sees is different from what was originally thrown. They can also throw stones into ponds creating an illusion of reality or a dream which looks just like when there is actually a reality. The higher-level ponds also get ripples that correspond to their experiences. They can control each lower-level pond’s ripples.

Thus, reality is the inverted tree of ponds. The perception is ripples in each pond. We try to guess the reality by perception but it is very hard to know it because the ponds are filled with different liquids and the ripples in them are created by differently shaped stones. To know the reality, we have to purify the liquid in the pond and ensure that stones are not improperly modified in transit. Until that time, we will have perceptions that are not the truth, although they exist. The ripples in a dirty pond exist but they are not the truthful understanding of the inverted tree. Therefore, they are all called illusions. Only the ripples in the purified pond are called the truth. Thus, the world is both existent and yet delusional.

Anti-Realism in Science and in Sāñkhya

This idea of reality is consistent with all the anti-realism found in science. It reconciles what cannot be reconciled in modern science. It is not impersonalism because there are many separate ponds. It is not materialism because the ponds are minds rather than objects. It is not pure realism because the ponds are filled with dirty liquids. It is not pure idealism because the liquid in the pond can be cleaned.

Thus, all the positions are true in one sense and all the positions are false in another sense. The science that emerges out of this conception of reality involves the explanation and prediction of which stones will be thrown out of and into which ponds, and how those stones with either progressively cleanse the pond, or dirty it further. The former is the path to greater truth. The latter is the path to greater falsehood.

An understanding of Einstein’s work in relativity and quantum theories is another route to understanding Sāñkhya philosophy. Similarly, those who know Sāñkhya philosophy can also understand the problems indicated by Einstein’s work in relativity and quantum theories. If we know the scientific theories, the historical contexts that led to such theories, and the philosophies that motivated them, then the problems and solutions are easy. Without these, a caricature of scientific reality as objective observer-independent truth prevails.

Reinterpreting Relativity as Perception

The senses and the mind are not blank slates. They have innate tendencies. The senses and the mind are not also not interacting with everything in the universe at once. They are selectively, occasionally, and contextually interacting with different things at different times, places, and situations. The resulting perceptual results are far more complex.

Let’s apply this to the problem of speed of light measurements, where a beam of light is emitted toward a reflector and the reflected beam is absorbed by the emitter. The delay between the emission and absorption is used to measure the speed of light. But this is a classical physical view of reality. In the quantum view of the same reality, the photons are emitted, absorbed, and reemitted by the “reflector”. The time taken in absorption and reemission is not fixed because both involve a probabilistic quantum collapse, which doesn’t occur consistently. When the collapse comes earlier or later, the same distance would be divided by a shorter or longer time, and the resulting speed of light will not be constant.

Similarly, let’s apply this problem to the measurement of distance to galaxies. If photons arrive slower at the detector, then the detected intensity of light will be lower, which will be interpreted (according to the Inverse Square Law of Luminosity) as greater distance to the galaxy. Conversely, if photons arrive faster at the detector, then the detected intensity of light will be higher, which will be interpreted as shorter distance to the galaxy. Since the photon arrival is not uniform therefore the detected intensities are not uniform and the resulting distance measurements cannot be constant.

Understanding the Problem of Perception

Even to ensure a consistent speed or distance measurement, we have to ensure that the sender and receiver are sending and receiving photons consistently. There is no guarantee for that in quantum theory. The theory is compatible with both consistent and inconsistent emission and absorption of photons. Hence, no measurements are reliably repeatable. Every measurement is unique, and we cannot claim to know reality unless we can guarantee that the senders and receivers are themselves not behaving inconsistently.

LC and TD simply point toward the fact that some types of behaviors are more likely than others in some situations. When an object moves relative to another, the delay in photon arrival is, on average, higher. We might also say that an appearance of motion is created when the photon delay is higher. That higher delay results in time dilation and the clock appears to run slower. The measured reality seems farther from the measuring instrument, and is called length contracted. TD and LC are simply results of changing delay of photon arrival.

Thus, all problems come down to the probabilistic nature of quantum theory where photon emission is not consistent, a photon can be emitted sooner or later, which will then alter the speed and distance measurements, and no experiment can be called repeatable. Unless we understand the mechanisms of quantum emission and absorption, nothing can be said about the truthfulness or falsehood of an empirical measurement.

At present, physics assumes uniformity to probabilities over arbitrary chosen durations of time. For instance, if the probability of an event is 0.1, then one such event will occur over 10 smallest units of time measurement, and will remain consistently 10% of events over any arbitrary period of time. This is simply not true. Without this, there is no objectivity or repeatability.

Relativity is about the changing probabiliteis of events. A moving object is more likely to have delayed photon reception. Due to effects of other objects, some events are more likely to occur than others. All notions of objectivity have been destroyed by relativity and quantum theories. We have to now move toward understanding perception to solve these problems.

Cite this article as:

Ashish Dalela, "What is Einstein’s Theory of Relativity?," in Shabda Journal, June 8, 2023, https://journal.shabda.co/2023/06/08/what-is-einsteins-theory-of-relativity/.