# B Can you prove anything using the Scientific Method?

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1. Mar 13, 2018

### Varsha Verma

I am studying the scientific method and have come to the following conclusion.

Since X -> Y does not imply X is true (or real), it is impossible for the scientific method (SM) to prove that anything is true.

So like mathematics, the scientific method builds knowledge on axioms which cannot be proven to be true, like mathematics is built on axioms like the point which does not exist.

The scientific method only stats that "if something is true" then "something else is also true".

For example: If you push an object -> it will move says the SM. But it does not show that there is a force.
Another example: "Taking antibiotics" -> "Cures diseases". But it does not tell that disease causing germs exist.

Is this the correct view??

Last edited by a moderator: Mar 14, 2018
2. Mar 13, 2018

### phinds

The scientific method is not about "proving" anything, it is about how to develop theories that comport with observations and make predictions about future observations. You never prove anything in physics, that's a math thing.

3. Mar 13, 2018

### Staff: Mentor

Yes, this is well known.

I would say that the scientific method builds knowledge on experimental evidence, not axioms. But experimental evidence verifies or falsifies theories, it does not prove them.

It definitely does show it. Just because it isn’t proven doesn’t mean that it isn’t shown. And just because it isn’t certain doesn’t mean it isn’t knowledge.

I think that you are overemphasizing the importance of proofs in the development of knowledge

4. Mar 13, 2018

### Varsha Verma

I am a big fan of astronomy and cosmology and astrophysics. Particularly SETI project.

So, for example when these days scientists discover exoplanets using the SM like this (artist rendition),

they are saying that the planet is actually there, right??

Does the SM tell us that the planet is actually there, that it exists ? Because we cannot directly see it using a telescope.

5. Mar 13, 2018

### phinds

You are putting too much emphasis on the scientific method. OBSERVATIONS (and extrapolations from those observations) tell us that it is there.

6. Mar 13, 2018

### Staff: Mentor

Yes, and the evidence shows that the planet is actually there. It doesn’t prove it, but it does show it.

Directly seeing it with a telescope isn’t proof either.

7. Mar 13, 2018

### Staff: Mentor

Leonard Susskind said, "Physicists aren't interested in what is true, but rather what is useful."

What @phinds said is the kind of useful that Susskind meant.

8. Mar 13, 2018

### Staff: Mentor

Et tu phinds!

9. Mar 13, 2018

### Varsha Verma

I am a bit confused.

Because isn't prove and show the same thing.

In Google I looked at the meaning of "prove" and it says this:
Prove = demonstrate the truth or existence of (something) by evidence or argument.
Synonyms = show.

So, I think they are the same thing right?? To show something is there is also to prove it's there, right?

Or, when you say "prove" you mean like in the mathematical sense of "proof".

But when you search for the meaning of "proof" in Google I get the same thing:
Proof = evidence or argument establishing a fact or the truth of a statement.

So, when scientists using the scientific method and "show" that an exoplanet exist 1000s of light years away orbiting a star he is in fact giving us "proof" isn't it???
He is in-fact giving us "evidence or argument establishing a fact which is that a planet exists or the truth of a statement, the statement being that an exoplanet exists".

So, aren't all (show, prove, proof) the same same thing???

I feel it is the same thing.

If not, what is the difference between show and prove?

10. Mar 13, 2018

### Staff: Mentor

Yes, I thought that was the sense in which you meant it, particularly given how you used it in the original post. In any case, that is the usual meaning here.

A proof is the standard form of deductive reasoning. Science is based on inductive reasoning, hence it is not proof as you yourself mentioned in the OP.

You should re read your own statements regarding “proof” in the OP for context here.

Last edited: Mar 13, 2018
11. Mar 13, 2018

### Varsha Verma

Why is Directly seeing it with a telescope isn’t proof either???

We don't modify anything when we see things from a telescope, the light is the original light which came from the object, so it has to be real right?

12. Mar 13, 2018

### Staff: Mentor

Because it is still inductive reasoning, not deductive. Do you understand the difference between deductive and inductive reasoning? It doesn’t matter how strong the inductive argument is, it does not turn into deductive reasoning

13. Mar 13, 2018

### Varsha Verma

Well, I don't fully understand the difference between inductive and deductive reasoning.

Can you give a real life example of both with regards to Physics??

Also, is deductive reasoning superior to inductive reasoning?

14. Mar 13, 2018

### Varsha Verma

Hi, according to this page: https://www.livescience.com/21569-deduction-vs-induction.html

the scientific method also uses the deductive approach.

"The scientific method uses deduction to test hypotheses and theories. "In deductive inference, we hold a theory and based on it we make a prediction of its consequences. That is, we predict what the observations should be if the theory were correct. We go from the general — the theory — to the specific — the observations," said Dr. Sylvia Wassertheil-Smoller, a researcher and professor emerita at Albert Einstein College of Medicine."

But you said science is purely inductive???

15. Mar 14, 2018

### mjc123

Was it Thomson who gave the toast "The electron: may it never be of any use to anybody!"?

16. Mar 14, 2018

### Staff: Mentor

Desuctive reasoning is mathematical theorems or proofs. In science it is the part of the scientific method where you start with a theory and then generate a testable hypothesis. You prove mathematically that if the theory is correct then you will see some hypothesized observation in a given experiment. For example, Noether’s theorem showed that if the laws of physics are time invariant then energy is conserved.

Inductive reasoning is the part of the scientific method where you perform the experiment and compare the result to the hypothesis. Then, if the data matches the hypothesis you conclude, via inductive reasoning, that the theory is valid, at least in the domain covered by the experiment. For instance, if energy is conserved in an experiment then you would take that as experimental validation of your theory that the laws of physics are time invariant.

I don’t believe so, I think that both are useful and have their value. The scientific method uses them together to advance knowledge effectively.

Yes

Did I? I don’t think so, but if I did, then my apologies. The inductive part is the part that distinguishes science from other disciplines like math or philosophy that exclusively use deductive reasoning. Science uses both. That is partly what makes it so effective at generating knowledge.

Last edited: Mar 14, 2018
17. Mar 14, 2018

### Varsha Verma

I still don't get this "deductive" part in in science.

Because you say that "you start with a theory and then generate a testable hypothesis". But, doesn't it happen the other way around. First all you have is the "hypothesis", right?? How can you have a theory first?? Because, from what I understand, a "theory" in science is " a well-substantiated explanation of some aspect of the natural world, based on a body of facts that have been repeatedly confirmed through observation and experiment. ".

So, I don't understand how you can start with a "theory" and end up with a hypothesis. Is this a special, rare thing in science??

Is science mainly "inductive"??

So, did Thompson, and Rutherford, Chadwick discover the atom, proton, neutron and electrons through the deduction process or induction process??

18. Mar 14, 2018

### Staff: Mentor

Part of the issue here may be that "proof" or "proven" can be used to describe the outcome of either inductive or deductive reasoning. Mathematical "proofs" are 100% true (or 100% false) and therefore "proven" whereas scientific theories can never be 100% true but can be said to be "proven" to a lower standard, similar to how a court case is won or lost based on a lower certainty.

19. Mar 14, 2018

### A.T.

It doesn't matter. What matters is that in the end you have a quantitative model that matches observation.

20. Mar 14, 2018

### Staff: Mentor

That understanding can confuse you. There are no language police to enforce uniform and consistent use of words like theory, law, hypothesis, and so on. For example, "Newton's Laws" versus "Einstein's Theories of Relativity." Use of law and theory in those contexts are just accidents of history.

Math can be precise, but natural language will never be precise.

21. Mar 14, 2018

### jbriggs444

Do not put so much emphasis on word choice. The word "theory" does not always mean some well confirmed and reasonably complete explanation for some set of facts. It can be used (as @Dale uses it above) to simply mean some arbitrary and tentative explanation whose correctness will need to be probed further.

Personally, I use the scientific method pretty much every day at my job (network troubleshooting). A user will come in with a complaint about some behavior. [Sometimes they will even have some symptoms more precise than "it's slow" or "it doesn't work"]. After verifying the symptoms, the first thing that one does is to try to come up with some theories that fit the observed facts. DNS failure? Asymmetric routing? Firewall policy? PMTU black hole? Intermittent packet loss? Inadequate buffering for the round trip delay? QoS bits being stripped off?, etc, etc.

If one cannot come up with a good theory, things get really difficult. You end up having to gather data blindly, hoping that a detectable pattern will emerge.

With a set of theories in hand, the next step is to see which can be ruled out or substantiated. This is where experiment comes in. One stops and thinks: "If this explanation holds, what resulting behavior can I test for?". So one tests DNS resolution, runs traceroutes and looks at routing tables, examines firewall logs and obtains packet captures.

All through the process, one has to keep in mind that all diagnoses are tentative -- every diagnostic test has weaknesses which can and sometimes will lead to false conclusions.

22. Mar 14, 2018

### Bandersnatch

Let's walk through an example.

You are an astronomer hunting for exoplanets. You have on hand a set of tools: mathematics and physical theories. These have been worked through earlier by other people, so you're not concerned with their validity - you know they've been either proven (in the case of mathematical theorems, relationships, etc.) or supported with evidence beyond reasonable doubt (in the case of physical theories). You assume they're correct.

Your tools in hunting for exoplanets would likely be geometric relationships, theory of gravity, theory of stellar structure, optics, etc.

So you observe a certain star, and see a dip in brightness. You then use all your tools to deductively formulate a hypothesis: given what we know about geometry, optics, gravity, and the star, we hypothesise that there should be a planet with such and such characteristics, in such and such orbit. The hypothesis gives some predictions - the star should have repeated and equal dips in brightness at such and such precise intervals. This lets you use induction to test the hypothesis against further observations, either falsifying or supporting it.

23. Mar 14, 2018

### Staff: Mentor

Hmm, science is an iterative process, so what comes first is a little ambiguous, but how could you have a hypothesis without a theory? A hypothesis is a prediction of the outcome of a particular experiment. On what basis could you make a prediction other than a theory?

That is a bad definition since it does not allow for new theories which are not yet well substantiated.

I don’t know what is your source for all of this, but it does not appear to be a very good source. Anything that teaches about the scientific method in general without describing the difference between inductive and deductive reasoning is suspect.

24. Mar 14, 2018

### Varsha Verma

I got it from Wikipedia: https://en.wikipedia.org/wiki/Theory

A new theory which is not yet well substantiated is still a hypothesis, right??

Hypothesis = a supposition or proposed explanation made on the basis of limited evidence as a starting point for further investigation

Like for example "String Theory" is actually "Sting Hypothesis", right??

But they use "String Theory" because I think it sounds good.

25. Mar 15, 2018

### Staff: Mentor

That does explain a lot.

Without getting hung up further on vocabulary. Your OP clearly started out with the idea of “proof” as a logical deduction, and correctly pointed out that by reliance on experiment the scientific method is based on inductive reasoning. Nevertheless, the result of inductive reasoning is still informative even though it does not constitute a logical deductive “proof”.

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