Cosmology and our View of the World
That's not Science, Lead: Willem deVries
2/6/2006
Summary by Matthew Lubicki
That's not Science
Ben-Ari’s definition of a theory:
“A scientific theory is a concise and coherent set of concepts, claims, and laws (frequently expressed in mathematical terms) that can be used to precisely and accurately explain and predict natural phenomena. A theory should include a mechanism that explains how its concepts, claims, and laws arise from lower-level theories.”
How concise should a theory be?
The idea of the t-shirt test: a theory
should be able to fit on a t-shirt. However, this is very ambiguous and left
most people unsure about this “rule.” It was more confusing than
clarifying because there are too many variables such as font size and such.
Gravity: Do 4 equations make a theory or does more have to be explained?
Do we need to define all of the terms
within the equations? Can we assume that the audience is intelligent enough
to understand it? Perhaps a theory should include everything so that a person
reading it for the first time can understand it.
On the other hand a theory needs to be repeatable and constant rather than having many stipulations and requirements that it relies on. For example, if this law works only if the sun is at the right angle and the weather is slightly cloudy, it cannot be called a law.
What counts as a theory?
With so many “theories” out
there already, the question is what counts as a theory. Is 1+1=2 a theory, or
is it just an addition equation? Is contemporary physics or biology a theory
or a set of theories? The discussion led to a debate over how small a theory
should be, that is, can it be E=mc2 or is it necessary to explain all of the
terms?
How mathematical should theories be?
Physics is very mathematical, but what about biology, psychology, sociology, etc. Can theories in biology be defined using only mathematics? Biology uses mathematics, but it is hard to say if it can be defined using only mathematics like physics can. Are these other areas (biology, chemistry, etc.) trying to look like physics? Physics envy? Are they trying to use mathematics just for the sake of using mathematics, maybe because it seems to strengthen a theory.
Universality
Scientific theories have to be as universal
as possible, but how universal is that? For example, biology (theories in biology)
does not affect places where there is no life, so how can it be universal?
Science is explanatory, but what is it to explain something?
The traditional view was that explanation
was done by deduction
Traditional View:
Statements of Initial Conditions
+ Statements of General Laws
The Explanandum
What is a an explanation? Several comments led to a definition that if you can explain x than you can make a prediction about x or a retrodiction about x. Also, the discussion led to questioning whether or not “mathematics” on their own are an explanation of anything or if it is just numbers.
There are levels of explanation: i.e. explaining why it rains to a 3rd grader
as opposed to explaining it to a PhD student.
There should be a “right” answer whether you’re explaining
it to a 3rd grader or a PhD student.
Complete explanation vs. Partial explanation
-The goal of science is to produce the complete explanation, not just a piece of the explanation. However, that is done by coming up with piece explanations first.
Is this equation a prediction?
F = G m1 m2/r2
Ben-Ari says that if you let an observation run then the theory should predict
the result.
Is time involved with predictions? The prediction from the Big Bang was that
background noise should be heard or observed at close to 3 degrees Kelvin. That
is what was observed.
Scientific theories necessarily have explanations, i.e. the Newtonian theory of gravity explains motion. If something doesn’t explain something, then it cannot be a theory.
What makes something a law? The example of pennies in a pocket was brought
up: One can say that they have pennies in their pocket, and it can be true,
but that doesn’t make it a law, so that brings out the question of what
makes a law. Laws give us the right to make inferences.
The universe has regularities, and
natural laws work with those regularities, if the regularities are not there,
then science can not happen.