Proof in Science

As seen previously, scientists sometimes need to take a leap of faith and propose ideas that cannot be verified yet. Sometimes we do not have the means to empirically observe the evidence we need to prove our theories. Years later, with the advancement of technology and progress in other areas, these ideas might be proven wrong, or right. ​The latter was the case for Einstein, who predicted the existence of gravitational waves as part of his general theory of relativity. This part of the theory (gravitational waves) was widely accepted within the scientific community, but until recently, we had no empirical evidence of it yet. Nevertheless, in 2015, 100 years after Einstein's initial predictions, scientists have been able to spot the first gravitational waves. In an article by TIME magazine, Jeffry Kluger observes that "humanity’s genius, as often happens, was a big step ahead of humanity’s machines." He continues to cite scientist David Shoemaker from MIT: “It is remarkable that humans can put together a story, and test it, for such strange and extreme events that took place billions of years ago and billions of light-years distant from us.”

Within the natural sciences we rely heavily on sense perception and reason. Advancements in technology have allowed us to create better tools to observe, but there is still much we cannot access through our (limited) human frame. Some inventions, such as the microscope, telescope and magnifying glass are arguably mere extensions of human sense perception.

Others, go beyond that and "some evidence is produced by processes so convoluted that it’s hard to decide what, if anything has been observed." (plato.stanford.edu). "The role of the senses in fMRI data production is limited to such things as monitoring the equipment and keeping an eye on the subject. [...] If fMRI images record observations, it’s hard to say what was observed—neuronal activity, blood oxygen levels, proton precessions, radio signals, or something else. [...] Furthermore, it’s hard to reconcile the idea that fMRI images record observations with the traditional empiricist notion that much as they may be needed to draw conclusions from observational evidence, calculations involving theoretical assumptions and background beliefs must not be allowed (on pain of loss of objectively) to intrude into the process of data production.'" If we need to resort to tools that go beyond mere observation through senses (because of additional manipulations and calculations), this may affect the validity and neutrality of empirical data.

Observation can indeed be less passive or receptive as what we might think. It also takes great skill and practice to conduct correct scientific observations (especially when we access tools such as microscopes or telescopes). Our assumptions and wishes may also influence what we see. If are desperate to find evidence for something, chances are we will find it. We may fall in the trap of confirmation bias or selection bias.

We could count the hits and forget the misses. With inductive reasoning (which is intrinsic in the scientific method) comes the danger of hasty generalisations. We may conclude things based on insufficient observations. Nevertheless, it is not possible nor desirable to observe everything all the time. Within the natural sciences, the concept of evidence might encompass more than just empirical evidence and empirical evidence may mean different things in different situations.

The sound of 2 black holes: https://youtu.be/egfBaUdnAyQ

Telescope takes first ever image https://youtu.be/e_ouNnbLmic

What is invisible: https://youtu.be/8EUy_82IChY

Although we place a lot of trust in scientific findings, one should not forget that sometimes even the greatest scientists can be wrong. What was once considered genuine scientific knowledge may currently be discarded. The scientific method places much emphasis on peer review and falsification. This process aims to improve the veracity of scientific claims. We should be wary when scientists refuse their hypothesis to be tested by peers. This may indicate that they have something to hide, such as unethical or erroneous methodology, data manipulation or unfounded claims. Some scientists have even become guilty of scams and hoaxes such as the Piltdown hoax.

The drive to come up with ground breaking scientific discoveries has led some researchers to tamper with data and evidence. The more recent case of Andrew Wakefield and the MMR vaccine highlights the importance of peer review and the questioning of expert opinion in the field of the natural sciences. To verify scientific knowledge, we should ideally be able to repeat experiments. However, some great scientific hypotheses cannot be tested through experiments with observable data. Our sense perception is not perfect, despite the enormous advancements in technology. It is also practically impossible to repeat experiments infinitely. In that sense, Popper proposed that scientists try to falsify (prove wrong) each others' ideas and findings. For example, if a scientist claims that metals expand when heated, other scientists are invited to actively prove that this is not true. They should look for situations in which metals do not expand when heated, for example. This process of falsification aims to ensure the validity of scientific knowledge. It also leads to the improvement of some scientific knowledge, as theories can be refined, for example.

Generally, we do not accept scientific knowledge that is not supported by a wider scientific community. Sometimes individuals can be right, but over time, the wider community usually catches on. Peer review is very important. When one expert claims something is scientifically true, his/her peers will review the validity of the claims. This can happen through verification or falsification. Within the scientific community, we do not accept a claim by an expert simply because s/he is an expert. Someone's word is simply not enough. Nevertheless, falsification as well as verification are limited. This is partly due to problems with induction, reasoning and observation, which all play an important role within the scientific method.

As our scientific knowledge advances, we may have to revise previous ideas. Our understanding of atoms and human DNA has evolved considerably over the last century, new elements have recently been added to the periodic table, and the list goes on and on. Our knowledge sometimes expands and we can fill in the gaps of the knowledge maps (for example when the previously predicted elements of the periodic table have been discovered). Sometimes, we have to rewrite the knowledge maps because previous maps were inaccurate. For example, phrenology or the theory of harmony have been removed from our scientific knowledge map. In this sense, scientific knowledge arguably improves over time. It becomes better, more accurate and more expansive.

This progress is not necessarily gradual. It can happen in shocks and waves. Sometimes we have to revise our entire way of scientific thinking and a paradigm shift occurs, as described by Thomas Kuhn.

When competing theories co-exist at one point in time, it is not always easy to decide which one should survive. We could use some general guidelines, however. A theory that explains most data and a theory that can predict what was not observed yet before is often a good theory. For example, Mendeleev had predicted the existence of several undiscovered elements. A theory that is not backed up with much evidence from experiments and data is not usually regarded as very scientific. Theories like climate change and the theory of evolution seem to have withstood the test of time and are generally accepted today. We can find many historical examples of where the scientific world had actually accepted the wrong theory (e.g. the geocentric model).

It seems that scientific progress can be made possible by the continual testing and falsification of theories. This is what makes science different from a dogma. Interestingly, some incorrect theories have their value as they sometimes give rise to the creation of new theories and scientific discoveries. Not all current scientific theories will be accepted in the future and it is perhaps a good thing that experts often disagree within a scientific disciple. The scientific community has an obligation to analyse the acceptability of scientific knowledge claims and theories,\ through peer review and falsification. The wider community should check under what circumstances we should or shouldn't accept expert opinion and not blindly accept catchy headlines of the popular press.