1 - Do Scientists Always Agree? (w/ Andrew Woodman, Ph. D.)
1. Do Scientists Always Agree?
Cold Open: On this inaugural episode of Curioscity, we delve into a simple question: do scientists always agree? What is a scientist and what does that person do? Are there any misrepresentations of science or the work done by scientists? Are there examples where scientists disagreed, and it was a good thing? Let’s learn to be scientifically conversational.
General Learning Concepts
1) What is a scientist?
a. Science Council: A scientist is someone who systematically gathers and uses research and evidence, making a hypothesis and testing it, to gain and share understanding and knowledge.
b. Our definition: a person who asks questions.
2) What does a scientist aim to do?
a. Jere Lipps: To learn about things and processes around us. Utilize critical thinking, evidential reasoning, and to judge authority.
b. Joseph Schwab from the University of Chicago in 1960 wrote: Different scientists do different things. A mode of enquiry discredited by one scientist, dismissed at one time, discarded in one science, reappears and is fruitful in other hands, at other times, or in other sciences.
3) Misrepresentations of Science
a. Convoluted: Mathematics in high school might have soured some thoughts on math or even the physical sciences. In reality, scientists are able to understand their work because they have been trained to study it and most science is not out of the reach of the layperson.
i. Jere Lipps from the University of California Berkeley says: “…science, itself, need not be complicated, although it may be, just like so many other endeavors in our lives.”
b. Used Only by Scientists:
i. Phrases: Many people use scientific principles in order to further their work, relationships, goals, etc. Common phrases include “common sense” and “tried and true”.
c. Chocolate is Good, Chocolate is Bad: Chocolate has scientifically proven health benefits, some articles suggest, while others say sugar is unhealthy. There are differences in how the study is conducted, the element of chocolate is examining, the test subject, etc. Does this mean scientists disagree?
d. Scientific language: Scientific language occasionally comes off as “wishy washy” to non-scientists. In the podcast “Open Forum in Infectious Diseases”, Seth Mnookin (author, director of the graduate program of scientific writing at MIT) talked about how scientific language can be challenging to follow. “Well based on all of the evidence that we have, we’re reasonably confident that there’s no concern that vaccines cause autism that we know of at this point, etc.” In science that means, “Yeah, we’re really sure about this.” But in English that means, “Yeah we have no idea what we’re talking about and we’re about to find out that actually we’ve been doing something horribly wrong…”
i. Theory: A scientific theory is an explanation of some aspect of the natural world that has been substantiated through repeated experiments or testing. But to the average Jane or Joe, a theory is just an idea that lives in someone's head, rather than an explanation rooted in experiment and testing.
ii. Hypothesis: A hypothesis is a proposed explanation for something that can actually be tested. But "if you just ask anyone what a hypothesis is, they just immediately say 'educated guess,'” says Rhett Allain at Southeastern Louisiana University in a blog post.
4) Peer Review
a. What is Peer Review? Evaluation of scientific, academic, or professional work by others working in the same field.
b. Why is Peer Review Critical? What happens when there is no peer review? To assure you there is some level of scientific quality. No one can be an expert in everything; it takes years of ones’ life to become an expert in a very narrow range of things.
5) Famous Examples in Science where Disagreeing Pushed Us Forwards
a. Hershey-Chase Experiment: For a time, it was unclear that DNA was the “blueprint of life”, the molecule of heredity. Many scientists assumed that protein was the genetic material and DNA provided structure. The opposite was actually true. Some work by Oswald Avery at colleagues at the Rockefeller Institute showed that genes were DNA, but the experiments in question are known as the Hershey (Alfred Hershey) Chase (Martha Chase) Experiments which lead to a 1969 Nobel prize in Physiology or Medicine relating to the genetic structure of viruses for Hershey but not Chase.
i. Centrifugation: Centrifugation is a process used to separate or concentrate materials suspended in a liquid medium. The theoretical basis of this technique is the effect of gravity on particles (including macromolecules) in suspension. Two particles of different masses will settle in a tube at different rates in response to gravity. Centrifugal force (measured as xg, gravity) is used to increase this settling rate in an instrument called a centrifuge. Two common examples of the use of centrifugal force are: (1) When you do the "around the world" trick with a yo-yo, it is centrifugal force that makes the yo-yo body stay at the end of the string as you rotate it; and (2) When you wash clothes in a washing machine, it is centrifugal force generated in the "spin" cycle that forces water out of the fabric to facilitate faster drying. (CENTRIPITAL FORCE vs CENTRIFUGAL FORCE)
ii. Viruses that infect bacteria are called bacteriophage, or phage. The phage that was used for the experiment is named T2 and infects a bacterium called E. coli (period and a softball). The phage looks a little like a syringe. Let me tell you what we know now: it’s a protein exterior that fires its DNA into the cell, leaving the protein coat and stalk on the outside of the bacterial cell. Hershey and Chase radioactively labeled both the protein and the DNA separately, infected the cells, blended the cells to dislodge the phage particles from the bacterial cells, and centrifuged the bacteria and phage mixture.
iii. Conclusion: The active component of the bacteriophage that transmits the infective characteristic is the DNA. There is a clear correlation between DNA and genetic information. This pushed along the understanding of how DNA was the functional unit of heredity
6) Solicited Questions
a. Is it bad when scientists disagree? Aren’t facts facts? Excellent scientific American article about the proposal of atoms. John Dalton proposed this was true at the beginning of the 19th century, but in the 4th century BC Democritus, a philosopher, proposed a similar idea. The difference is that Dalton brought a body of evidence with him. There were still scientists that disagreed against that evidence; scientists can be wrong. There were some that refined the idea beyond what it was: are atoms “right”?
b. Why should I trust a scientist? Because as you might trust a tax accountant to save you time doing your taxes, scientists are specialized to do what they’re talking about. If you don’t trust a scientist and you’re thinking critically, you can look at their published data and determine yourself if you believe it or not and work to disprove their point or make a counterpoint.
Overall Useful Resource: https://undsci.berkeley.edu/resourcelibrary.php