Science doesn’t prove a thing

“Your theory is then right? No, it is simply not proved wrong.”

In my first post I wrote about how a lot of people don’t understand what the scientific method is, and then I realised, I missed something of even greater importance. People don’t understand how science works.

How does science work? Well:

A scientist starts with a hypothesis – which is basically a guess to an answer of a question.  They then carry out a series of experiments and compare the results to the expected consequences if said hypothesis was correct.

The results either support, or reject, that hypothesis. Notice that the hypothesis is not proved, but simply supported.

I can blabber on but nobody can explain this better than the late Richard Feynman.

“You can always prove any definite theory wrong. Notice however we never prove it right”

Science gathers evidence

Hypotheses that have only been put through a few experiments are tentatively accepted. It is important for a hypothesis to be approached at different angles to truly discover if the expected consequences can hold true.

Once a hypothesis has been substantially tested, and it is widely accepted, it becomes a theory. Theories that have practically been tested to death, and are still supported, can advance into a paradigm.

Paradigms become the overarching theory of a discipline. E.g. Darwins theory of evolution pretty much governs all that is biology in one way or another.  However, even paradigms we cannot be 100% sure of. We can just say that it is extremely likely that it is correct.

Evolution governs all that is biology. (Credit: T. Michael Keesey via Flickr [CC BY-SA 2.0])

An opening for scepticism

Personally I think it is exactly this that causes so many people to be sceptical of science. As scientific knowledge grows and evolves, sometimes what was long thought to be correct, can suddenly change.

Maybe you saw on the 2nd  of August edition of New Scientist the blaring head line saying “FA(C)T. Did we really get 40 years of dietary advice wrong?” . This article discusses how saturated fats may not be as bad as originally thought. It’s these changes to ideas that people have commonly accepted that could confuse people. ‘Isn’t science meant to be facts?! Why would it change?’

This is nothing new though, theories are proved wrong all the time – throughout history. It was believed for thousands of years that life could arise from spontaneous generation as a theory developed by Aristotle. It was only later with Louis Pasteur’s experiments were Aristotles theories decisively dispelled.

Does anyone have any other good examples of theories that were long thought to be correct before being shot down by further research?

To be honest, I can understand how people that don’t understand this are so sceptical of science. In their eyes – science is always changing. But really, science is always evolving.

“… tomorrows experiment may succeed in proving what you thought was right, wrong.”

8 Responses to “Science doesn’t prove a thing”

  1. Ashton Dickerson says:

    @haamer – yeah that is another problem too! Sometimes the hypothesis that is supported.. could be doing more harm then good! Especially in medicine. But we can only make our best conclusions based on the evidence we have. All the more reason to continue research – so that we can be more confident in our conclusions!

  2. Ashton Dickerson says:

    @gmgo – great point! You’re exactly right. Also ather than saying this ‘might’ be the case which ‘might’ mean this.. they blow it out of proportion. I suppose that’s better for ratings!

  3. Ashton Dickerson says:

    @jrowland – It’s great to hear that you are in the habit of correcting people! It’s very important that people understand.

    Your blog post is a perfect example Jess! It amazes me that the story of dinosaurs is still growing.. even though its been millions of years!

  4. Ashton Dickerson says:

    @Chris Mawer – The other (and slightly different) example that immediately springs to mind for me is whether or not having an abortion leads to an increased risk of breast cancer. A key paper published in the 70s found possible links between abortions and breast cancer, while many other papers have reported that there is no link. The reason I bring this up is because certain political parties which oppose abortions have used this paper as evidence that they are dangerous. It is, however, so important to look at all the evidence combined together. Opposing sides are saying ‘the science proves it’ but it is most important to take a step back and look at the evidence with non bias eyes – and examine it as it is. The way science always intended. Here is a nice article that assesses the evidence we have as a whole for the abortion-breast cancer topic

  5. haamer says:

    True! Its happening a lot in genetics nowadays. In the same 2nd August issue , there was an article saying that a gene that was long thought to be curing a disease in a way had a twin. The twin was only recently been discovered. And it was causing more harm than good.
    So yeah….“… tomorrows experiment may succeed in proving what you thought was right, wrong.”

  6. gmgo says:

    This is something that they never address in newspaper articles- it doesn’t sound exciting enough. And since most of the general public get their news from newspapers and TV reports in 30 sec snippets there’s not enough time to mention “possibly” and “may be”.

  7. jrowland says:

    Great post Ashton! I think I’m one of those annoying people who always corrects everyone when they say that ‘science proved x…’. I think that a lot of people don’t really understand the scientific process, and that’s become more and more problematic (eg. the issues around climate science).

    I actually just did a post on how the old theories about dinosaurs have been superseded:

  8. Chris Mawer says:

    Hi Ashton. Nice article. There are many examples that come to mind, such as that the sun revolves around the earth (see Nicolaus Copernicus, De revolutionibus orbium coelestium, 1543.TL;DR … no, it doesn’t), and that the earth’s continents have been fixed in position forever (see Alfred Wegener, Die Entstehung der Kontinente und Ozeane, 1915 – TL;DR … no, they aren’t).
    Have you found any more contemporary examples?