Is space-time relative or quantized?

When we look at light reflecting from an object such as a grandfather-clock, we see a time-delayed reflection through a radiation source, a photon. Our brains then process and turn that electromagnetic (EM) radiation into colours. So what our brains see is an interpretative description of electromagnetic radiation. If you are colour blind, you will see shades of grey; this is how matter looks before the human brain processes and adds colour.

So what is electromagnetic radiation? Electromagnetic radiation can be defined as: “Energy resulting from the acceleration of electric charge and the associated electric fields and magnetic fields. The energy can be regarded as waves propagated through space (requiring no supporting medium) involving oscillating electric and magnetic fields at right angles to each other and to the direction of propagation.“Source: Oxford Dictionary of Science, John Daintith, Elizabeth Martin, et al., 2005, Oxford University Press.

Electromagnetic radiation can be seen as a form of heat, and heat can be transferred from one body or system to another by electromagnetic radiation. We measure the amount of heat within any body or system as temperature. Temperature can be seen as a measurement of work, as the hotter something is, the more energy it has. Different forms of electromagnetic radiation are composed of varying forms of electrical charge (eV) and a corresponding frequency (Hz), with an associated wavelength λ in meters (m).

For example, Gamma-rays at the higher end of the electromagnetic spectrum are made of ionizing radiation and can have an eV of 10^6 with Hz of 10^20 and λ of 10^-12; very energetic and very small. On the other end of the spectrum is AM radio, which is made of non-ionizing radiation and can have an eV 10^-9 with Hz of 10^5 and λ of 10^3; sluggish and very long; as long as a cricket field. Light sits about ⅔  along the electromagnetic spectrum and each “colour” is a distinct frequency within visible light. A colour of visible light represents the amount of energy a photon has within the electromagnetic spectrum.

Heat can also be used to describe the amount of work energy that is contained within matter or a system. Just as matter cannot exceed the speed of light, no system or matter can reach absolute zero; both of these are absolute barriers and are tied to entropy and the arrow of time. This does no rule out weirdness, as quantum mechanics and relativity allow for strange things to happen.

Experimental projects in particle physics, such as at the Tevatron at the Fermi National Accelerator Laboratory in Illinois USA, and the Large Hadron Collider (LHC) at CERN in Switzerland, are used to smash particles together. The resulting collisions are studied to peek deeper into the structure of matter. By looking into the structure of matter, particle physicists hope to explain in more detail the very fabric of reality. Astronomers looking at observations of “black hole” candidates, quasars and other energetic stellar material, have discovered something strange happening.

Dark star (for want of a better term) objects in theory are supposed to emit high and low energy photons simultaneously. Photons being ejected by a quasar in gamma-ray bursts should arrive at the same time, as both are in theory travelling at the speed of light and should be emitted from the dark star at the same time. However observations since 1995 have detected that some higher energy photons are arriving after lower energy photons. Something in our knowledge is amiss.

Lee Smolin who works at the Perimeter Institute for Theoretical Physics in Canada is currently researching “relative locality“. Although relative locality is not a new idea, it is being looked at with new mathematical tools with an aim to incorporate quantum gravity. Smolin suggests that we live in “momentum space” and not relative space-time, as proposed by Albert Einstein with his theories on special and general relativity.

Although Smolin’s research is interesting, there already exists a problem that emerges from research work carried out by Stephen Hawking’s PhD thesis on “black holes” radiating energy (Hawking radiation) and evaporating. Prof. Hawking used quantum effects to explain how a “black hole” could evaporate after billions of years; this raises some uncomfortable questions. The most prominent question being: where does the information for objects that have fallen into a “black hole” go? Information doesn’t just vanish from a system; that would be akin to magic.

Smolin suggests “momentum space” surrounds “black holes”. Space-time becomes so fuzzy and uncertain that an observer looking at a spaceship falling into a “black hole” is not certain whether it has fallen in or escaped; the information becomes attainable. Smolin’s solution uses the “measurement problem” of Heisenberg’s uncertainty principle. This lost information becomes a paradox in itself, resolving the paradox of evaporating “black hole” information. But does it?

There are various explanations that could be used to describe why high energy photons arrive after their lower energy counterparts. For example, delays observed could be caused by the very properties of dark star objects themselves. Smolin and his colleagues research suggests a melding of General Relativity and momentum space; producing phase space. If Smolin’s research proves to be an accurate description, it could lead to paradoxes and improbable things holding true, such as time travel, improbability drives and explain that information can be just lost without consequence from evaporating black holes.

While this may sound more like speculative fiction rather than a testable and observable hypothesis, Smolin’s work throws up more questions than answers. Is the measurement problem there because of our inability to see higher dimensions? Do these extra postulated dimensions as hypothesised by theoretical physicists exist?

On the other hand, just because we cannot observe or perceive these extra dimensions, it does not mean that they are not in shadows buried deep beneath our perception threshold. When a particle of matter at the quantum level is measured accurately, are we observing its reflective shadow onto 4-dimensional space-time of an object that really exists in a higher dimensional plane?

If we could observe dark star objects close up, such as quasars, magnetars or black holes, would we see all of space and time being phase shifted? Would we see beyond all of the reflective shadows and view our universe in 8, 10, 11 or 13 dimensions? One could draw a conclusion that, “curved momentum space” is just quantum space-time from a different perspective. Within General Relativity, depending upon the view-point of an observer, what one observer sees as space, another observer will see as time; and vice versa. Space and time are unified into being two different sides of the same coin.

So is quantized space-time the same as relative space-time, with different observations arising from how it is viewed? If so, are we only seeing a corner of the puzzle and not seeing the whole picture; does the geometry of space-time hide away what is in the shadows? If higher dimensions exist and we could see them, would we see all of space-time as being quantized?

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