Feynman on Scientific Method.
Summary
TLDRIn this thought-provoking discussion, the speaker delves into the scientific process of formulating and testing hypotheses. They emphasize the importance of making definite guesses that can be falsified through comparison with experimental observations. The speaker compares this process to opening a safe, where random guesses are futile; instead, precise substitutions are required. They highlight that existing principles are inconsistent, necessitating the removal of some to make room for new guesses. Ultimately, the speaker stresses the need for a rigorous approach, where vague theories are inadequate, and definite, testable hypotheses are essential to advance scientific understanding.
Takeaways
- 🔑 The key to science is comparing theoretical predictions to experimental observations, and discarding theories that disagree with experiments, regardless of their beauty or origins.
- 🚫 It is unscientific to demand proof of impossibility; science deals with likelihoods and probabilities, not absolutes.
- 🔄 Scientific theories can never be proven right, only temporarily not proven wrong, as future experiments may contradict them.
- ⏳ Even long-standing theories like Newton's laws can eventually be shown to be incomplete or slightly wrong.
- ❓ Vague theories that cannot make definite predictions cannot be proven wrong, and are therefore unscientific.
- 🧩 The challenge is not in identifying potential flaws, but in proposing precise, testable replacements that better align with observations.
- 🤖 Guessing theories is not a mindless process; it requires deep understanding and insight into the existing framework.
- 🚪 Simply proposing random changes or holes in established theories is unlikely to yield viable replacements.
- ♾️ There are an infinite number of potential alternatives, many of which are easily ruled out by existing knowledge and constraints.
- 🧠 Proposing truly novel, viable theories requires extensive effort, creativity, and a deep grasp of the subject matter.
Q & A
What is the key process for developing new scientific laws according to the script?
-According to the script, the key process for developing new scientific laws involves first making a guess or hypothesis, then computing the consequences or implications of that guess, and finally comparing those computed results to observations or experiments. If the guess disagrees with experiments, it is considered wrong.
Why is it important for scientific theories or guesses to be definite or precise?
-The script emphasizes that scientific theories or guesses need to be as definite or precise as possible. Vague theories can be made to fit any experimental result with some skill, making them unfalsifiable. Definite theories, on the other hand, can be disproven if their computed consequences disagree with experiments.
Can scientific theories or laws ever be proven absolutely right?
-No, according to the script, scientific theories or laws can never be proven absolutely right. Even if a theory agrees with all current experiments, future experiments with a wider range of conditions could potentially disprove it. Scientific theories can only be considered temporarily right until proven wrong by new evidence.
How does the script view the process of making guesses or hypotheses?
-The script suggests that making guesses or hypotheses is not a trivial or random process. It dismisses the idea of using a machine to make random guesses, suggesting that it is the opposite of a dumb man's job. The process of making good scientific guesses requires skill and insight.
What does the script say about suggestions or criticisms that propose holes or changes in existing scientific principles?
-The script mentions that the author receives many letters suggesting holes or changes in existing scientific principles, but it states that these suggestions are obvious to anyone working on the problem. The real challenge is not pointing out potential flaws but proposing precise replacements that work better than the existing principles.
How does the script illustrate the difficulty of making good scientific guesses?
-The script uses the analogy of trying to open a safe. It suggests that proposing simple or random guesses, like suggesting a combination of '10, 20, 30', is not helpful when someone is already working hard and has tried many possibilities. Making good scientific guesses requires in-depth knowledge and understanding of the problem.
What examples of scientific phenomena are mentioned in the script?
-The script mentions examples such as superconductivity (the phenomenon of metals conducting electricity without resistance at low temperatures), extrasensory perception, and astrological influences on determining the best time for dental appointments.
How does the script view the role of experiments in the scientific process?
-The script emphasizes the importance of experiments in the scientific process. It states that if a scientific theory disagrees with experimental results, it is considered wrong, regardless of how beautiful or smart the guess is or who proposed it. Experiments are the ultimate arbiter of the validity of scientific theories.
What is the example given in the script about a theory that was initially considered right but later proven wrong?
-The script mentions Newton's laws of motion for the planets as an example. While Newton's laws were considered right for a long time and could accurately predict the motion of planets, the slight error in the motion of Mercury eventually revealed the limitations of the theory after several hundred years.
What is the overall message or conclusion of the script regarding the scientific process?
-The overall message of the script is that the scientific process involves making definite guesses or hypotheses, computing their consequences, and comparing them to experiments. While theories can be temporarily considered right if they agree with experiments, they can never be proven absolutely right, as new experiments may eventually disprove them. The process of making good scientific guesses requires skill and insight, and experiments are the ultimate arbiter of the validity of scientific theories.
Outlines
🔬 The Scientific Method and Hypothesis Testing
This paragraph explains the scientific method of making guesses or hypotheses, computing their consequences, and comparing them to observations or experiments. It emphasizes that a hypothesis is wrong if it disagrees with experiments, regardless of its source or the person who made it. The paragraph also discusses the example of flying saucers to illustrate that science is about determining what is more or less likely, not proving impossibilities. It mentions phenomena like superconductivity and extrasensory perception as cases where known physics may be incomplete. The key point is that while we can disprove definite theories through experiments, we can never prove a theory right because future experiments may prove it wrong.
⚠️ The Importance of Precise and Testable Theories
This paragraph highlights the problem of vague or imprecise theories that cannot be definitively proven wrong. It uses the example of a vague psychological theory about love and parenting to illustrate how such theories can be made to fit any experimental result. The paragraph emphasizes the need for theories to be as precise and definite as possible, with clear methods for computing consequences that can be compared to experiments. It also addresses the misconception that guessing in science is a random or automated process, arguing that formulating precise guesses or hypotheses is a crucial intellectual task. The paragraph concludes by discussing the challenges of starting from known but inconsistent principles and the futility of suggesting simple changes without providing precise alternatives that can be tested.
Mindmap
Keywords
💡Scientific Method
💡Hypothesis
💡Experiment
💡Observation
💡Definite Theory
💡Consequences
💡Falsifiability
💡Vague Theory
💡Probability
💡Computation
Highlights
The process of finding new laws in science involves making a guess, computing the consequences of that guess, and comparing those results to observations or experiments.
If the guess disagrees with experiments, it is wrong, no matter how beautiful or clever the guess is. This is the key to science.
Scientists aim to find the most likely explanation, keeping in mind that it may be disproven by future experiments.
Phenomena like superconductivity, initially unexplained, were later shown to be consequences of known laws.
Other phenomena, like extrasensory perception, cannot be explained by current physics, and if demonstrated, would prove the physics theory incomplete.
Any definite theory can be disproven, but theories can never be proven right, as future experiments may find them wrong.
Vague theories cannot be disproven, as any experimental result can be made to look like an expected consequence.
To be scientific, a theory must be as definite as possible, allowing for clear computation of consequences and comparison to experiments.
The problem is not identifying what might be wrong, but finding a precise replacement that works.
Simply suggesting holes or changes without a definite substitute is not helpful, as there are infinite possibilities.
Making guesses is not a dumb process, but rather a crucial part of scientific discovery.
Known principles are often inconsistent, requiring removal or modification, which must be done carefully and with a definite replacement.
Random suggestions, like trying specific combinations to open a safe, are not useful if they lack context and do not address the core problem.
The process of finding new laws is challenging and requires careful thought and precision, rather than random guesses.
The speaker emphasizes the importance of definite, precise theories that can be tested against experiments, as opposed to vague ideas that cannot be disproven.
Transcripts
situation now I'm going to discuss how
we would look for a new law in general
we look for new law by the following
process first we get it then we come
don't let that's what's really true then
we compute the consequences of the guest
to see what if this is right if this law
that we guessed is right we see what it
would imply and then we compare those
computation results to nature or we say
compared to experiment or experience
compare it directly with observation to
see if it if it works if it disagrees
with experiment it's wrong in that
simple statement is the key to science
it doesn't make a difference how
beautiful your guess is it doesn't make
even as smart you are who made the get
or what his name is if it disagrees with
experiment draw a tourist toy it's
therefore not unscientific to take a
guess although many people who are not
in science think it is for instance I
had a conversation about flying saucers
some years ago with lamely because I'm
scientific I know all about flying
saucers
so I said I don't think there are flying
saucers so the other my antagonist said
is it impossible that they were flying
closer can you prove it it's impossible
you know I can't prove it's impossible
it's just very unlikely that they say
you are very unscientific if you can't
prove it impossible then right how can
you say it's likely that is unlike well
that's the way that is scientific it is
scientific only to say what's more
likely and less likely and not to be
proving all the time possible impossible
to define what I mean I finally said to
him listen I mean that for my knowledge
of the world that I see around me I
think that it is much more likely that
the reports of flying saucers are the
result of them known he
rational characteristics of terrestrial
intelligence rather than the unknown
rational efforts of extraterrestrial
intelligence
it's just more likely that's and it's a
good guess and we always tried to guess
the most likely explanation keeping in
the back of the mind the fact that if it
doesn't work then we must discuss the
other possibility there was for instance
for awhile a phenomenon called
superconductivity that still is the
phenomenon which is that metals conduct
electricity without resistance at low
temperatures and it was not at first
obvious that this was a consequence of
the known laws with these particles but
it turns out that it has been thought
through caffeine up and it's seen in
fact to be a consequence of known laws
there are other phenomena such as
extrasensory perception which cannot be
explained by this known knowledge of
physics here and it is interesting
however that that phenomenon has not
been well established and
that we cannot guarantee that it's there
so if it could be demonstrated of course
that would prove that the physics is
incomplete of therefore it's extremely
interesting to physicists whether it's
right or wrong and many many experiments
exist which show it doesn't work the
same goes for theological influences if
they were true that the Stars could
affect the day that it was good to go to
the dentist then that there's an America
we have that kind of astrology then it
would be wrong the physics theory would
be wrong because there's no mechanism by
understandable and principle from these
things that would make it golf and
that's the reason that there's some
skepticism among scientists with regard
to those ideas now you see of course
that with this method we can disprove
any definite theory you have a definite
theory a real guess from which you can
clearly compute consequences which could
be compared to experiment that in
principle we can get rid of any theory
we can always prove any definite theory
wrong notice however we never prove it
right
suppose that you invent a good guess
calculate the consequences to discover
that big consequence that you calculate
agrees with experiment the theory is
then right no it is simply not food law
because in the future there could be a
wider range of experiments you could
include a wider range of consequences
and you may discover then that this
thing is wrong that's why I laws like
Newton's laws for the motion of planets
less such a long time he guessed the law
of gravitation calculate all the kinds
of consequences for the solar system and
so on compare them to experiment and it
took several hundred years before the
slight error of the motion of mercury
was developed during all that time the
theory had been failed to be true wrong
and could be taken to be temporarily
right but it can never be proved right
because tomorrow's experiment may
succeed in proving what you thought was
right wrong so we never are right we can
only be sure we're wrong however it's a
rather remarkable that we can last so
long I mean
have some idea what your last so long I
must also point out you that you cannot
prove a vague theory wrong if the guest
that you make is fully expressed rather
bay and the method that you use for car
figuring out the consequences is rather
a little vague you're not sure I mean
you say I think everything's because
it's all due to Mughals and Mughals do
this and not more or less so I can sort
of explain how this work then you see
that that theory is good because it
can't be proved wrong if the process of
computing the consequences is indefinite
then with a little skill any
experimental result can be made to look
like an expected consequence you're
probably familiar with out another
fields for example a hates his mother
the reason is of course because she
didn't caress him or love him enough
when he was a child actually if you
investigate you find out that it's a
matter of fact he did love him very much
and everything was alright well then
it's because she was overindulgent when
he was so by having a vague theory it's
possible to get either resolved
not a cure for this one is the following
it would be possible to say if it were
possible to state ahead of time how much
love is not enough and how much love is
overindulgent exactly and then there
would be a perfectly legitimate theory
against which you can make tests it is
usually said when this is pointed out
how much love is and so on
oh you're dealing with psychological
matters the fees can't be defined so
precisely yes but then you can't claim
to know anything about it now I want to
concentrate from now on because I'm a
theoretical physicist and more the
lighter with this end of the problem as
to what goes on how do you make the
guesses
now as strictly as I said before not of
any importance where the guess comes
from it's only important that it should
agree with experiment and that it should
be definite as possible as definite as
possible but you say then is very simple
we've set up a machine a great computing
machine which has a random wheel in it
that makes the succession of guesses and
each time it guesses hypothesis about
how nature should work computer media
view the consequences and makes a
comparison to a list of experimental
results that has it the other end in
other words guessing is a dumb man's job
actually it's quite the opposite and I
will try to explain why
the first problem is how to start you
see our style thought with all the known
principles but the principles that are
all known are inconsistent with each
other so something has to be removed so
we get a lot of letters from people
always getting letters from people who
are insisting that we ought to make
holes in our guesses as follows you make
a hole to make room for a new guest
somebody says to you know you oh people
always say space is continuous but how
do you know when you get to a small
enough dimension that they really are
enough points in between it isn't just a
lot of dot separated by little distances
or they say you know those quantum
mechanical amplitude is you told me
about they're so complicated I'm sorry
what makes you think those are right
maybe they aren't right I get a lot of
letters with such content but I must say
that such remarks are perfectly obvious
and now well are perfectly clear to
anybody who's working on this problem
and it doesn't do any good to point this
out the problem is not what might be
wrong but what might be substituted
precisely in place of it if you say
first anything precise for example in
the case of a continuous space suppose
the precise proposition is that space
really consists of a series of dots only
in the space between them doesn't mean
anything and the dots are in a cubic
array then we can prove that immediately
is wrong that doesn't work you see the
problem is not to make to change or to
say something might be wrong but they
replace it by something and that is not
so easy as soon as any real definite
idea is substituted that becomes almost
immediately apparent that it doesn't
work secondly there's an infinite number
of possibilities on these of these
simple types it's something like this
you're sitting working very hard you
work for a long time trying to open a
safe and some Joe comes along who hasn't
doesn't know anything about what you're
doing or anything except that you're
trying to open to say because you know
why don't you try the combination ten
twenty thirty because you're busy you
tried a lot of things maybe you're
already fried ten twenty thirty maybe
you know that the middle number is
already thirty-two and not twenty maybe
you know that as a matter of fact this
is a five digit combination
so these letters don't do any good and
so please don't send me any letters
trying to tell me the thing is going to
work I don't I read them to make sure I
haven't already thought of that
but it takes too long to answer them
because they're usually in the class try
10 20 30
[Music]
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