What is Reality?

For most people there is a kind of reasonable answer: "Reality consists of things like tables, chairs, trees, houses, planets, animals, people, etc., which are made of matter." We might be inclined to add some seemingly abstract terms like space and time, and the totality of all these "real" things would be called "the universe."

Some may perhaps think that this is not the whole of reality. In particular, the question arises about the reality of our mind. Should we not include conscious experience as something real? And what about concepts like truth, virtue, or beauty? Of course, some people can take a stubborn, materialist standpoint and regard mentality and all its properties as secondary to the material real. After all, our mental states are (so the argument would go) simply emergent features of the construction and behaviour of our physical brain. We behave in certain ways only because our brain acts according to physical laws — the same laws that are strictly followed by all other pieces of physical material. Conscious mental experience accordingly ultimately has no more reality than the material that underlies its existence.

This materialist view began 2500 years ago. At that time Democritus assumed that the universe is composed of the smallest particles, the atoms (Greek átomos, the uncuttable, indivisible), which move in empty space. He said: "Only apparently does a thing have a colour, only apparently is it sweet or bitter; in reality there are only atoms and empty space." Democritus was one of the founders of modern science.

Astonishingly, it took another 2400 years until finally a young scientist named Einstein seemingly provided the proof that atoms really existed, for they elude our perception. Even many respected scientists 120 years ago still believed that atoms did not exist. Einstein used Brownian motion for his proof and could even calculate the size of atoms.

Mathematics became the language in science with which "reality" is described. Mathematics is usually described as a science that examines abstract structures created by logical definitions, using formal logic, for their properties and patterns. This way of investigating "reality" seems plausible to us, for it is ultimately based on everyday experience: one apple plus another apple are two apples, divided by two people is one apple per person, and when they have been eaten, zero apples remain. A problem arises when this kind of logic is confronted with infinities.

The Infinite

Also 2500 years ago there lived another genius named Zeno, who with many thought experiments demonstrated the imperfection of logic and rational thinking. The most famous of his paradoxes is the paradox of Achilles and the tortoise: Achilles runs twice as fast as the tortoise, which is given a head start of 100m (a head start of one stadium is probably what has been handed down, and Achilles runs 12 times as fast as the tortoise, but the exact values are irrelevant to the argument).

Achilles can demonstrably never catch up with the tortoise, for when he has caught up with the tortoise's head start, the tortoise is already 50 metres further on, and when he has then reached that mark, the tortoise is already 25 metres further on, and so on ad infinitum. This paradox can also be reversed.

Take, for example, a stick, cut it in the middle, cut this half again in the middle ad infinitum. An infinitely large number of pieces would have to yield an infinitely long stick.

For our logical thinking it is indispensable that boundaries are drawn. In the above case one could argue, for example, that one could only split a drop of water down to the water molecule. By setting a boundary here, one can define water as H2O.

If we do not set a boundary, our thinking loses itself in infinities and becomes inoperative: the Planck units mark a limit for the validity of the known laws of physics. One must assume that for distances smaller than the Planck length (about 10 to the power of -35 metres) and times shorter than the Planck time (about 10 to the power of -43 seconds), space and time lose their familiar properties as a continuum. Every object that would be smaller than the Planck length would, on account of the so-called uncertainty relation, have so much energy or mass that it would collapse into a black hole. Physicists therefore half-jokingly call the Planck units "units of God."

Our Limited World

What our mind needs in order to operate are boundaries that are drawn abstractly. Science attempts to grasp reality by defining, i.e. limiting. To create definitions means to create images, e.g. theories and concepts. But true or absolute reality, the primordial ground of all being, that is, God, is far beyond all limitations and definitions, and therefore beyond all images. Hence the strict prohibition of images in the second of the Ten Commandments, and the general prohibition of images in Islam: images are dead constructs, while reality is life.

A film appears like reality and suggests movement. But a film is only a sequence of images (normally 24 per second), which our brain then seamlessly assembles. Each individual image in itself is exactly defined, and the rapid sequence simulates movement. Our thinking and all scientific theories are therefore not a depiction of reality as such, but snapshots that indeed give the appearance of being in conformity with reality, just as a film also feigns reality, but in reality consists of dead images. The result lies openly before our eyes: a destroyed world cut through by boundaries, where everything is put into its respective drawer, including ourselves. Our true self is in no way identical with all the selfies we take of ourselves.

The Solid Ground Erodes

Science has indeed established in various experiments that consciousness changes reality, e.g. in the famous double-slit experiment, the quantum Zeno effect, or also in time as an emergent phenomenon of quantum entanglement. Consciousness shapes and changes reality, perhaps it even creates reality. This at any rate is what Professor Robert Lanza of Wake Forest University School of Medicine in North Carolina believes. He calls his theory "biocentrism" and further claims that time and space would be merely tools of our mind. Then death would also be merely a mental construct in a world without spatial and temporal boundaries.

But this theory, even if underpinned with scientific proofs, is simply too revolutionary for people to be able to accept it. The notion that reality consists of elementary particles, as a house consists of stones, and is held together by concrete laws such as gravitation, is too deeply ingrained and psychologically reassuring.

Unfortunately, this solid ground is increasingly eroded by precisely that science which is actually supposed to prove that everything proceeds nicely in order according to rationally comprehensible laws, and is not dictated by an intangible God.

Already since Einstein's general theory of relativity a hundred years ago, human consciousness can no longer keep up with the latest scientific theories. Where as a human being one could still easily imagine Newton's concept of gravitation, that all bodies possess attractive force (especially pretty female ones), a human being can hardly imagine any longer that gravitation in reality arises from the fact that spacetime is curved. Richard Feynman, who could juggle with theories of quantum mechanics like hardly anyone else, once wrote: "I think I can safely say that nobody really understands quantum mechanics!" Or, put differently: "that nobody can really understand quantum mechanics," because our consciousness is not calibrated for such theories. One might just as well try to explain to a mole what Mount Everest looks like.

The double-slit experiment, for example, turns our ingrained notion of causality completely upside down. It works as follows: In principle, waves that pass through two narrow, parallel slits form an interference pattern on a screen. This applies to all waves, whether light waves, water waves, or sound waves.

But light is not only a wave, but also a particle, which is called a photon. So what happens when one shoots a single photon at the double slits? It turns out that, although there is only one photon, it still forms an interference pattern. It is as if the photon were moving through both slits simultaneously!

But it gets even stranger. By observing the double-slit experiment, the behaviour of the photons changes! The idea behind the double-slit experiment is that even if the photons are sent through the slits individually, a wave is still present that produces the interference pattern on the screen. The wave is a wave of probability, because the experiment is set up in such a way that the scientists do not know which of the two slits an individual photon passes through. If one tries to find this out by placing detectors in front of each slit to determine which slit the photon really passes through, the interference pattern does not appear at all. This also applies if one tries to set up the detectors behind the slits, and even if one splits the photon with a crystal and measures the second photon after the first has already reached the screen. Even if the second photon is detected after the first photon has hit the screen, it still ruins the interference pattern. This means that the observation of a photon can change events that have already occurred.

In the Swampland

What is currently happening in the research field of string theory, however, is even more abstruse. Scientists actually claim to have calculated that our universe cannot exist at all, but instead lies in so-called swampland, a region of inconsistent things!

String theory is an attempt to describe the entire universe under a single "theory of everything" by adding additional dimensions of spacetime and treating particles as tiny vibrating loops. Many string theorists claim that it is still the most promising concept for uniting Albert Einstein's dream, his general theory of relativity, with the contradictory microscopic world of quantum mechanics.

String theory defines all matter and forces as vibrations of tiny bundles of energy. The theory permits around 10 to the power of 500 different solutions, which form a diverse "landscape" of possible universes. String theorists such as Cumrun Vafa have been striving for years to place our universe somewhere in this landscape of possibilities.

Now, however, Vafa and his colleagues suspect that there can be no universes like ours in the string landscape! Reason: While the universe expands, the energy density in the vacuum of empty space must decrease faster than a certain rate. The rule seems to be true in all models of universes based on simple string theories. However, it violates two widespread views about the actual universe: it is both unthinkable for the accepted picture of the current expansion of the universe and for the leading model of its explosive birth. Telescope observations since 1998 suggest that the cosmos is expanding ever faster, which means that the vacuum of empty space must be permeated with a dose of gravitationally repulsive "dark energy." Moreover, it seems that the amount of dark energy permeating empty space will remain constant over time. The new conjecture, however, states that the vacuum energy of the universe must decrease. Vafa and colleagues therefore claim that universes with stable, constant positive amounts of vacuum energy, which are called "de Sitter universes," are not possible.

Since the discovery of dark energy in 1998, string theorists have struggled hard to construct convincing models of stable de Sitter universes. If Vafa is right, however, these efforts are logically inconsistent, since de Sitter universes lie not in the landscape but in the "swampland."

"The things that look consistent but are ultimately not consistent, I call swampland," he explained recently. "They look almost like landscape; one can be deceived by them. One thinks one should be able to build them, but one cannot."

"We lie in the swampland and actually do not exist at all? What kind of nonsense is that," most people will think. But what if this theory were right? Imagine one had been wearing virtual-reality glasses since earliest childhood, and then someone came along and told one that one was living only in an illusion and that this world did not exist at all. Could one accept that?

What if it were proven that our "I" is also merely an illusion?

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