What happens when science says one thing and you believe something different? Our brains are designed to fight such situations and we try to apply logic to justify our beliefs – we basically make stuff up so that we can continue to accept our beliefs.
One of the most common reasons to dismiss science, is to point out the fact that “science does not know everything”. If it does not know everything, then it might be wrong in all cases.
That seems logical, but it’s not.
Science Does Not Know Everything
It is true that science does not know everything. We are learned new things about the world around us every day and that new knowledge will change the beliefs we have today.
Given that fact, it seems logical that we don’t actually know anything. And if that is the case, science can’t be used to disprove any belief.
The problem with this argument is that it assumes all scientific knowledge is equally unknown and that is just not true. The idea that the earth is round is now almost certain – we accept it as a true fact. The latest information about how the brain works is very likely to be incorrect or at least partially incorrect. Every bit of scientific knowledge has associated with it a degree of certainty.
We never talk about this degree of certainty, but it is there.
Uncertainty in Scientific Knowledge
The uncertainty is a direct result of the scientific process. It is an iterative process – a fine tuning process if you will. An initial discovery is followed up by more research, by others, to verify the facts. Through this process a single idea is explored and better understood. So called facts are either verified or disproved.
Research is very much and ongoing process and new information is continually added to the pile of knowledge. Over time a given piece of knowledge is verified many times. During this process the level of uncertainty is increased to a point where it gets so high that we accept it as fact.
We now accept the fact that the earth is round – or at least most of us do – not sure about Trump?
Science Can Be Wrong
People who do not understand the scientific process make use of the fact that science is not always right to justify their beliefs. Here are some examples of comments left on this blog by people who will not accept our knowledge about Roundup.
“For 10 years it was widely accepted by MOST scientists that humans possessed 48 chromosomes. It didn’t make them right.”
“For about 50 years, there was no proof that smoking caused cancer and a host of other diseases; but that’s because the tobacco industry spent billions of dollars burying evidence and buying scientists to falsify results. They finally were found out but for decades we heard there was no evidence. My money says the same thing is true of Roundup.”
Clearly, there is a logical connection between our knowledge about Roundup, DNA, and tobacco smoke! I just can’t find it 🙂
These people were able to find a fact of known science which turned out to be false. Therefore all other scientific facts are also wrong. It allows them to justify their beliefs, without knowing any real facts about the subject matter.
Do Humans have 48 or 46 Chromosomes?
It is true that in the early 1900, scientists thought we had 48 chromosomes. It turns out we have 46.
Stanley M. Gartler (ref 1) has written a real interesting historical review on the subject where he says “Human chromosome numbers were determined in the 1890s, and by 1914 at least 15 investigators had published papers reporting the chromosome number in humans. With one exception, the counts were low, with most reporting 24 as the diploid number. The lone exception was Hans de Winiwarter, who reported a count of 47 from testes and 48 from fetal ovaries. As we now know, only Winiwarter’s counts were close to being correct, apparently because he realized the importance of fresh material and immediate fixation, to avoid the clumping of chromatin. Once the need for fresh specimens and immediate fixation was recognized, reports of low chromosome counts disappeared.”
What went wrong with science? Nothing really, scientists just did not realize that chromosomes change in old specimens. The data was refined over time – the scientific method worked as designed.
For the next 50 years scientists tried to determine the right number of chromosomes and usually came up with the number 48. Read Stanley M. Gartler’s article for some very interesting details.
One reason why it took so long was that human material was hard to come by. Stanley reports “Spermatogonial cells are one of the few sources of rapidly dividing human cells; in humans, such samples in the 1920s and 1930s were difficult to obtain. Malcolm Kottler, in his excellent history of the human chromosome counting story, relates that cytologists literally waited at the foot of the gallows in order to fix the testis of an executed criminal immediately
after death before the chromosomes could clump.”
It took almost 50 years and several scientific advances in DNA research to reach the conclusion that humans have 46 chromosomes. But this is not an example of science failing us. It is an example of the scientific method working.
Smoking Causes Cancer
The statement “For about 50 years, there was no proof that smoking caused cancer and a host of other diseases; but that’s because the tobacco industry spent billions of dollars burying evidence and buying scientists to falsify results” is not correct. It is true that the industry was not honest in its findings, but non-industry scientists warned about the connection between smoking and cancer in 1950 (ref 2).
The reality is that most people smoked and learning that they had a cancer causing habit did cause them to stop. Most politicians smoked and they did not want to quit, nor did they want to lose the tax revenue. This is a case where government simply did what the people wanted – they ignored the science.
There is another big issue here. When it comes to human health and studying long term effects, the science is very difficult to do. You can’t make 100 people smoke and then dissect them to see what happened. You have to wait until they die and then try to relate their death to the cause. But humans are complex and live a long time. There are no clean controls – there is lots of normal variation among people. Some people get cancer easily and others smoke all their life and never get it. Showing true cause and effect relationships in living organisms is very difficult. This is one reason that a lot of health studies end up being wrong.
One alternative is to do testing on lab rats and other organisms, but these results may or may not be true for real world conditions.
Human science is tough science and it takes many studies and a lot of time to increase the degree of certainty to a point where we can consider ideas to be facts.
Roundup and Degree of Certainty
The fact that we initially got the number of chromosomes wrong, or waited too long to do something about smoking are very poor arguments for not believing facts about Roundup or any other scientific facts.
The LD50 values for glyphosate have been well studied and scientists accept the data as fact – it has a real high degree of certainty.
The product has been used for over 50 years with no indication that normal exposure levels cause problems in humans or soil microbes. This is a less certain fac than the LD50 value, but 50 years is quite a long time and most scientists are now convinced that the degree of certainty is high enough to consider it a fact. Several large organizations such as the EPA and WHO (at least one division) have agreed that glyphosate does not cause cancer. This conclusion is based on the review of thousands of research studies.
Is there a chance that we don’t know everything about Roundup? Absolutely. But the degree of certainty for the above facts is now quite high and it is unlikely we will find a smoking gun.
Science Knows a Lot
The very nature of the scientific process guarantees that we don’t know everything. But over time it is self correctly and we increase the degree of certainty about things we think we know. At some point we have to believe in the facts science is telling us.
What alternative do we have?
- The chromosome number in humans: a brief history; http://www.nature.com/scitable/content/The-chromosome-number-in-humans-a-brief-15575
- Discovery of a Link Between Smoking and Cancer; http://www.news-medical.net/news/2005/07/25/11957.aspx
- Photo source: A-Z Quotes