On 17 March 2014, the science and technology blog of the prestigious newspaper The New Yorker announced, “A scientific breakthrough lets us see to the beginning of time.” Lawrence M. Krauss, renowned physicist and author of A Universe From Nothing: Why There is Something Rather than Nothing, commented in his article on the news that went around the world, heralding a landmark moment in the history of science.

A team of scientists, astrophysicists and physicists, in an experiment called BICEP2 (Background Imaging of Cosmic Extragalactic Polarisation 2), carried out over nine years at an astronomical observatory at the South Pole, reported that they had discovered undeniable traces of a much sought-after phenomenon in astrophysics: gravitational waves. It was also announced that the method used to make the discovery had provided an important confirmation of the theoretical model of Big Bang cosmology, and would allow the first moments after this primordial explosion—the moment of creation for modern astrophysics—to be studied experimentally.

When you don’t find gravitational waves…

If we imagine space and time as the surface of an ocean, gravitational waves can be thought of as ripples in that ocean. More precisely, gravitational waves are theoretical ripples in space-time, first predicted by Albert Einstein in 1916 on the basis of his general theory of relativity. Like electromagnetic waves, which are produced by the oscillation of an electric charge, it is thought that a sufficiently strong oscillation of a very massive object should produce gravitational waves, which carry energy in the form of gravitational energy.

The direct experimental observation[1] of gravitational waves has been a scientific goal intensively pursued over the last decades, through high-precision interferometry experiments in complex and expensive laboratories such as LIGO (Laser Interferometer Gravitational-Wave Observatory in the US) or VIRGO (part of the European Gravitational-Wave Observatory). These experiments aim to measure the tiny effect that a gravitational wave should have on the spectrum of a very long laser beam as the wave passes through the detector space.

So far, these efforts have been unsuccessful, and for good reason: gravity is by far the weakest of the four known fundamental forces, 1027 times weaker than the next on the list, the “weak force.” As a result, even the gravitational waves predicted by the theory are extremely weak and difficult to observe. For example, if we consider the gravitational interaction between the Earth and the Sun, the effect of the energy loss due to the gravitational waves generated should cause the Earth’s orbit to shrink by 3.5×10-20m per year, which is about 1/300th of the diameter of a hydrogen atom[2]. The effect is therefore completely negligible for our planet for a long time to come, but this is not thought to be the case for other imagined cosmic interactions.

So what are the detectable sources of gravitational waves in the Universe? Supernovae and the merging of binary systems of exotic celestial bodies (such as neutron stars, magnetars, black holes, etc.) are thought to be two of the cosmic events that could produce gravitational waves energetic enough to be detectable from Earth.

The fact that the most sensitive interferometry experiments to date have failed to detect such waves is puzzling to researchers, as the precision of the devices is reaching the limit at which they should be able to detect them. The lack of detection has put pressure on theorists and posed problems for one of the most successful theories in astrophysics: Albert Einstein’s theory of general relativity.

… you search for alternative approaches

In this context, efforts were made to prove the existence of gravitational waves by means other than direct observation. In the search for sources of gravitational waves strong enough to be detected in some way, researchers have turned their attention to what is believed to be the most energetic event in the history of the universe: the primordial explosion, or the Big Bang.

No one expects to detect the gravitational waves that would have been produced by the Big Bang, which is thought to have taken place 14 billion years ago, but they can look for the traces that such powerful gravitational waves might have left, traces that could be visible today.

BICEP2 researchers came up with the idea of studying the Cosmic Microwave Background Radiation (CMB) because it is thought to be a direct remnant of the Big Bang that is still visible in the Universe today. According to the theory, the Universe’s background radiation was created at the end of a very short, violent and poorly understood period called inflation, which is thought to have occurred just 10-35 seconds after the Big Bang, when space itself was thought to have “expanded” at an unimaginably rapid rate.

Mathematical theories that attempt to model inflation predict that extremely strong gravitational waves must have been generated during the inflation itself, and that these may have imprinted the background radiation of the universe with certain light polarisation patterns that are observable today. However, these possible polarisation patterns of the background radiation are not only due to the theory of relativity, from which the search for gravitational waves originally started, but primarily to quantum effects that are believed to have operated only under those extreme conditions of inflation that cannot be reproduced or even sufficiently explained today.

It should be emphasised once again that, while the interferometric experiments mentioned at the beginning of this article are direct approaches to the detection of waves now propagating through our space, the search for the effects of gravitational waves in the polarisation of the background radiation of the Universe is par excellence a historical research approach in astrophysics: an indirect, statistical exercise in the interpretation of an “object” considered to be extremely old (the background radiation of the Universe), in order to reveal the traces of the factors that are thought to have acted at the time of its formation.

The experiment…

We are now ready to assess what the BICEP2 team discovered. If we were to look at the sky with the naked eye on a starry night in the microwave wavelength, we would see the background radiation of the universe as a pale and fairly uniform glow across the sky. But if we looked more closely, we would see that there are small variations in the intensity and polarisation of this light across the map of the sky, and these variations can be measured and analysed. After nine years of extremely fine measurements of the visible background radiation map of our sky, statistical analysis of the polarisation of this radiation has shown a correlation with a polarisation pattern that theory suggests could have been produced by primordial gravitational waves at a moment in time called inflation. In statistical terms, the R-value of the correlation is 0.22, where R=0 would indicate no correlation and R=1 would indicate a complete correlation.

This is essentially the result: R=0.22! After years of hard work, the researchers happily announced at the press conference that they had found important evidence for inflation and had even mapped the primordial gravitational wave tracks in our sky. The news was quickly picked up by the world’s press, and popular science articles began to appear in abundance…

…and the euphoria that accompanied it

One of the reasons this news has been so enthusiastically received by the scientific community is that it somewhat mitigates the failure to directly detect the gravitational waves that are supposed to be propagating through space. The most important reason, however, is that the discovery from the South Pole provides a much-needed confirmation for the theory of inflation, given the rather poor list of evidence to date. It also promises to open up a new avenue for investigating the first moments after the Big Bang, by studying the effects of the gravitational waves generated at that time.

To assess the situation correctly, it must be said that although the correlation found by BICEP2 is better than what the researchers expected, we are talking about a small correlation factor in absolute value for some extremely sensitive measurements that have not yet been confirmed by any other independent experiment. Moreover, as already mentioned, the result is mainly the result of a statistical analysis of a historical phenomenon, and not of a direct observation of an actual phenomenon.

Caution, scepticism…and doubt

The purported traces of primordial gravitational waves are intended to add an essential building block to the theoretical construction of the naturalistic paradigm at one of its weakest points, namely the theory of inflation after the Big Bang. However, few readers of popular science articles know how long, arduous, and complex the chain of interpretations, assumptions, and constraints is that links the tangible observation of “R=0.22” to the announcement at the press conference: “Detection of gravitational waves and proof of inflation”. Therefore, this article presents the theory behind the experiment with a degree of caution and scepticism.

There is reason to consider a healthy dose of doubt, which is always welcome in science. And in this case, such doubt is justified by the problems posed by the theoretical underpinnings on which this discovery depends and into which it fits. It is perhaps surprising to know that, despite the excitement and certainty with which new discoveries are heralded, so far we have a theory of Big Bang cosmology that claims to explain an unimpressive 5% of the universe, about as much as we can actually observe; the rest being 23% dark matter and 72% dark energy. For an overview of the history of the Universe and some of the main weaknesses of this perspective, read the contents of the following section.

The history of time from the perspective of modern astrophysics

  • About 14 billion years ago, “something” (the Big Bang) exploded out of “nothing”. Apart from the obvious difficulties of naturally conceiving the birth of something from nothing, the main reason for proposing this hypothesis was the observation by the American astronomer Edwin Hubble in the 1930s that celestial objects seemed to be moving away from us. If we consider that the Earth is not the centre of the Universe, it follows that the tendency to move away is widespread among all celestial objects. If we also consider that this dynamic has always been this way, it follows that at some point all the matter in the universe was concentrated in one place, hence the theory of a primordial explosion. But even if there’s no other way to explain the apparent distancing of celestial bodies from us, is it absolutely necessary to extrapolate it over billions of years to a primordial moment?
  • In a tiny fraction of time after the Big Bang, space expanded exponentially and the distribution of matter became more even: this is the “inflation” that produced the background radiation of the universe. It is not known exactly why this happened, or by what physical process. All that is known is that without this inflationary episode in the first second of the universe, the relatively uniform distribution of matter in the universe cannot be explained.
  • By 380,000 years after the explosion, the Universe had cooled sufficiently to become transparent to light, and thus to the background radiation of the Universe. At this point, the universe consisted only of hydrogen, the simplest possible chemical element.
  • The first stars begin to form about 400 million years after the Big Bang, and continue to form at a frenetic pace to this day. Billions of galaxies would each produce billions of stars through accretion (the gravitational accumulation of cosmic gas and dust), although the process by which a globular cloud of gas and dust can give rise to a star is still a hotly debated topic in astrophysics.
  • The existence of these natural thermonuclear reactors, called stars, leads to the production in stellar cores of chemical elements heavier than hydrogen but not heavier than iron. Elements heavier than iron are produced only in stellar explosions and supernovae, and are scattered into space to help form other stars and planets, and so on. This is the theory of chemical evolution, which explains the presence of chemical elements other than hydrogen in the universe.
  • Since the rotational profiles of galaxies obtained from direct astronomical observations do not match the predictions of gravitational theory, it is thought that over 23% of the Universe is made up of “dark matter”, which has not yet been identified as anything other than a missing ingredient without which the observed rotation of galaxies cannot be explained.
  • The same separation of celestial objects that led to the proposed Big Bang reveals another surprise: the trend of separation seems to be accelerating rather than slowing down! This can only be explained by the fact that 72% of the Universe is made up of “dark energy”, which has not yet been identified as anything other than a missing ingredient without which the accelerating separation of celestial bodies cannot be explained.
  • On one of the planets orbiting a certain star in the Universe, about 12 billion years after the Big Bang, under unclear chemical and energetic conditions, the first living cell appeared from non-living chemical components. Biological evolution is thought to have begun, in spite of all the probabilistic calculations showing that both the spontaneous origin of life and evolution by natural selection are mathematical impossibilities[3].
  • About 200,000 years ago, 14 billion years after the Big Bang, intelligent life, i.e. us humans, is thought to have appeared on this planet. In the last 2-3 millennia, we humans have developed spectacularly in terms of technology, and in the last few decades we have become capable of detecting and understanding the signs left by the phenomena that occurred in the first moments of the universe.

 

So, regardless of the physical veracity of this discovery, for the average person looking in from outside the scientific profession, the following question is legitimate: what makes the long string of assumptions, unknowns, and untestable interpretations that turn “R=0.22” into “gravitational waves” and “cosmic inflation” into “certainty” for scientists around the world? Where our instruments can make measurements, the results are often at odds with theoretical predictions: galaxies are spinning too fast, stars are moving away from each other at an accelerated rate, not a slower one, comets appear to contain no water, and planets show complex, unexpected interactions with the solar system environment. These are just some of the mysteries of the fascinating field of astronomy, mysteries that contradict theory through measurement and direct experimentation. Why, then, is that part of astronomy that deals mainly with events that are difficult to verify and almost beyond the reach of experiment, clothed in such certainty?

There are many people who argue that the hypothesis of a primordial explosion also requires a primordial cause, namely God. There are also many scientists who believe that the need for an original cause is illusory, since every cause requires its own cause, and they are therefore comfortable with the idea of a spontaneous universe created by its own action. The fact is that with the Big Bang cosmology people are for the first time truly free and unencumbered to believe whatever they want, and no longer necessarily bound by the need for a creator. Big Bang cosmology does not directly exclude God as a possible creator of the universe, it simply makes Him unnecessary for those who choose this path. In this respect, the need for certainty with which this theory is approached, despite all its faults, weaknesses and inadequacies, is only natural.

At the same time, it seems that doubt and scepticism are all the more negligible the further the object of study is removed in time, space and access for direct experimentation. The seductive power of the naturalistic paradigm for modern humans thirsting for certainty can hardly be underestimated. This grandiose approach promises an explanation for everything, from the beginning of the universe and its subsequent development, from the beginning of life and its subsequent development, all the way to the meaning of life and the destiny of the universe: an overview of tens of billions of years, which people, so tiny in time and space, perceive as giving them the necessary meaning and significance for their own existence.

There are many question marks about this theoretical framework that humanity painstakingly struggles to create, but the seduction of the idea that one day we will be able to explain everything without needing God is greater than the question marks. In this regard, it is instructive to read how Lawrence M. Krauss concluded his article in The New Yorker: “For some people, the possibility that the laws of physics might illuminate even the creation of our own universe, without the need for supernatural intervention or any demonstration of purpose, is truly terrifying. But Monday’s announcement [the BICEP2 announcement—editor’s note] heralds the possible beginning of a new era, where even such cosmic existential questions are becoming accessible to experiment.”

Footnotes
[1]“There is some indirect evidence for gravitational waves. In 1993, the Nobel Prize in Physics was awarded for the observation of effects attributable to gravitational waves in the interaction between two exotic celestial bodies, thought to be a pulsar and a neutron star in very close orbit.”
[2]“https://en.wikipedia.org/wiki/Gravitational_wave:_Orbital_decay_by_gravitational_radiation.”
[3]“In 1966, at the Wistar Institute, Philadelphia, USA, at what became known as the Wistar Symposium, a group of eminent mathematicians challenged the evolutionary biology community by expressing their doubts about the theory of evolution (neo-Darwinism) from the point of view of probability theory. Simply put, the overall conclusion was clear: evolution by natural selection, according to neo-Darwinian theory, proposes probabilities that are simply impossible to support quantitatively, in other words, mathematically.”

“There is some indirect evidence for gravitational waves. In 1993, the Nobel Prize in Physics was awarded for the observation of effects attributable to gravitational waves in the interaction between two exotic celestial bodies, thought to be a pulsar and a neutron star in very close orbit.”
“https://en.wikipedia.org/wiki/Gravitational_wave:_Orbital_decay_by_gravitational_radiation.”
“In 1966, at the Wistar Institute, Philadelphia, USA, at what became known as the Wistar Symposium, a group of eminent mathematicians challenged the evolutionary biology community by expressing their doubts about the theory of evolution (neo-Darwinism) from the point of view of probability theory. Simply put, the overall conclusion was clear: evolution by natural selection, according to neo-Darwinian theory, proposes probabilities that are simply impossible to support quantitatively, in other words, mathematically.”
Anna Bliokh

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