Reflections on Life

A physical mirror reflects an exact copy of ourselves. However, in a cosmological mirror, things may not be what they seem. Do we have a cosmological reflection? Would it be a good idea to physically meet them? What makes them and us unique?

The Reality of Chirality:

The concept of multiple universes existing parallel to the one we live in is an attractive idea. Whilst the possibilities are endless and perhaps complex. Consider for now the possibility of there being just one simple universe, a perfectly reflected mirror universe.

To begin with we must consider the properties of reflective symmetry. If an object is not symmetrical its mirror image is non-superimposable, as one cannot be perfectly overlapped onto the other, this means the object possesses handedness and is therefore chiral. The term chiral stems from the ancient Greek word ‘kheir’ meaning hand. A pair of human hands are mirror images, yet non-superimposable, they are therefore chiral. Lets now consider chirality in the scientific realm…

Physical Chirality:

Chirality is fundamental to nature and is all around us, it even exists in the very small building blocks of life as we know it:

Box 1: Chirality extends into biological sciences; a) DNA molecules possesses left and right-handed chirality, b) Amino acids coded from this DNA are chiral.

Biologically our own DNA is chiral, the double helix structure in box 1a can fold as a clockwise or anticlockwise spiral, the DNA present in life on Earth is folded in an exclusively anticlockwise manner.

Chirality also exists in the molecular world. The amino acid depicted in box 1b coded from DNA which generate complex protein structure and biomolecular machinery is also chiral. Life as we know it selectively uses only one form of chiral amino acid, to this day no one knows why DNA and amino acids fold in this manner.

The two chemical examples in box 1a-b are chemically indistinguishable from their mirror images, they possess the same amounts of atoms, atom types and connectivity. However, they interact with polarised light differently.

In physics polarised light is also considered chiral, this polarisation arises from the oscillation of a charge field associated with light which creates magnetism. The movement of this charge can occur in a clockwise or anticlockwise manner, this is called optical rotation and can be used to measure the purity of a chiral mixture experimentally:

Box 2: Polarised light is non superimposable and is therefore chiral. It is used to distinguish between the biochemical examples in box 1.

The chiral nature of polarised light as depicted in box 2 can be a likened to the orbit of the planets in our solar system, all planets are bound to the sun which is travelling around a supermassive black hole in the centre of the milky way galaxy, much like polarised light the planetary orbit trails will be reflected in a non-superimposable manner. Interestingly, our orbit around the sun is anticlockwise in nature. Could our own solar system be chiral?

Chirality on the subatomic level becomes more abstract as we now have to consider the properties of matter and mirror matter. The over simplified particles in box 3a-b may look classically similar in shape. However, these particles possess properties such as spin and charge:

Box 3: Subatomic particles have chiral characteristics; a) spin and b) mirror matter.

In box 3a the particle can spin in a clockwise manner, whilst its mirror image spins in an anticlockwise manner, this spin is non-superimposable, this is referred to as spin parity.

Subatomic charge on the other hand is not traditionally reflective, instead the colour charge of a particle is inverted in a non-superimposable manner, much like a polaroid image negative. The mirror reflection of normal matter is called antimatter and is depicted in box 3b.

In particle physics spin reflection must also come with colour charge inversion, this is referred to as charge/parity conservation. But what has all this got to do with mirror universes? To answer this, we must now turn to physical cosmology…

Cosmological Chirality:

Gazing upon ourselves in a mirror it can be observed that our own hands are non-superimposable. On a chemical level DNA and amino acid molecules are non-superimposable, even the spin and charge of sub atomic particles which make up these molecules are also non-superimposable.

When all of this is considered the mathematical theory of a mirror universe works with the added caveat of time reversal. Does this mean time is chiral?

Box 4: In order for a mirror universe to theoretically exist, time reversal must be applied, does this mean time is chiral?

However, this is surely suggestive? In box 4 from our reflections point of view time will be perceived as positive and our own as negative. Perhaps this is also true for particles? A positively charged electron seems bizarre in our realm, yet in a mirror universe this could be perfectly normal? Antimatter could simply be a reflection of matter travelling backwards in time.

Some theories even suggest negative time must also come with negative mass and as a result, mirror universes should be gravitationally linked together given the attraction between mass. Although the gravitational interaction between matter and antimatter is still highly disputed, and the elusive gravity particle has no mass or charge and therefore no antimatter equivalent, it does possess spin and therefore could possess chirality.

Using the examples discussed it is entirely conceivable that in a reflective mirror universe; DNA coils in a clockwise manner, all chiral chemical compounds exist as the non-superimposable counterpart, subatomic particles possess the opposite spin, every particle is reflected as the antimatter equivalent (where applicable) and finally, time and mass exist in a reversed manner. All of which are linked gravitationally.

If this is true then what would a mirror universe look like given that time and mass are mathematically reversed? Does a mirror universe explain the dominance of matter over antimatter in our universe?

If we were to observe the mirror universe wouldn’t we merely observe the chiral antimatter equivalent of ourselves staring back at us? Would polarised light meeting each other from each universe simply cancel out? Wouldn’t time therefore observe itself and stop? What would negative mass look like?

Whilst the issue of matter dominance over antimatter in our universe could be beautifully explained by the existence of such a concept, surely meeting oneself in the mirror universe would be catastrophic given that matter and antimatter cancel each other out upon contact?

One hypothesis for the location of a mirror universe is that it exists on the other side of a black hole, this is known as a white hole, the opposite of a black hole, Here, light and matter are not consumed but instead are ejected at the speed of light. The idea is that everything consumed by a black hole in this universe is reflected into a mirror universe via a white hole:

Box 5: Does a chiral universe exist as a result of a black hole and white hole?

Another similar idea to that of the depiction in box 5 is that a mirror universe was created during the beginning of time. A recent study has suggested that the cosmic microwave background radiation is polarised and thus possesses a ‘handedness’. Perhaps this universe we’ve come to know and love is a reflection and we are the chiral counterpart to another universe as depicted in box 6?

Box 6: Does a chiral universe exist as a result of the big bang at the beginning of time? The cosmic microwave background radiation is believed to be polarised.

For now, this remains a hypothesis, white holes have yet to be detected, and our mathematics fails when gravity becomes infinite inside a black hole or at the beginning of time.

The origins of chirality in nature are also a mystery. Some speculate that chirality on an Earth biochemical level originated from cosmic coincidences such as, the proximity of passing neutron stars as our primordial soup hurtled towards Earth via an asteroid, or via the interaction of molecules with cosmic rays themselves. Others believe that chiral systems small or large maybe chemically the same, on a deep subatomic level one is merely more energetically stable than the other.

The Chirality of Reality:

Culturally the mirror universe is occasionally explored in sci-fi. In particular, the Futurama episode “I dated a robot” depicts the Planet Express crew observing themselves in a mirror universe waving back dressed as cowboys. In the popular Star Trek series an entire galactic quadrant is reflected under the villainous Teran empire dictatorship. However, the normal timeline depicts the progressive nature of the United Federation of Planets.

Whilst these may not be true reflections of a mirror universe, it does explore the idea of choice. Unlike a reflective binary mirror universe, consciousness is perhaps independent from chirality, which would mean a mirror universe may look completely different all together. Whilst we ponder and speculate for now, it is up to us to make the best of the universe we currently reside in.