Induction and Science

In that excerpt from Principia, Newton is talking about the method that he used to derive his laws and that he proposes as a model for what would later come to be known as science. He describes the very inductive method you seem to believe has no value in science.

No mind-reading necessary:

• Scientists tell us they use inductive reasoning.
• Philosophers of science tell us scientists use inductive reasoning.
• Many examples of scientific laws and theories cited in this thread require inductive reasoning to justify their claims of universality.

As far as I know, you and Jon are the only ones making the claim that scientists don't use inductive reasoning. And from what I've seen so far, niether of you has provided any compelling evidence to support your remarkable claim. I noticed you mentioned a few philosophers, but I didn't see any references to specific writings of theirs that support your claim.If I've missed something, please help me out.

He probably woudn't get tenure if he waited for his ideas to come in a dream or in a package under the Christmas tree. But perhaps he could sit in an orchard and wait for an apple to fall on his head.

It's interesting that you chose to respond to that one sentence but have not responded to the point of my post, which asked you for some references to support your claim.

No. Force, mass, and acceleration are properties of the world. They -- and their relationship expressed as F=ma -- were discovered through observation and experiment. Using induction, this law of nature was assumed to apply to all relevant instances anywhere in the universe -- past, present, and future.nwr is confused about what a standard is. Newton's laws can be used to develop standards when scientists agree to plug certain values into an equation. Unlike laws, standards are not assumed to be universal; they are conventions and can be changed at any time by mutual consent.To say that a law of nature exists to serve as a standard would be like saying height exists to calibrate rulers.

I agree that it is possible that intelligent life forms from Planet Arcturus might discover different properties of nature, and their F=xyz might be equally valid -- or perhaps even more accurate and useful than F=ma.Nonetheless, Newton discovered laws that tell us something true about the world. Is there room for improvement? Of course there is. Quantum mechanics and general relativity have already shown that. I disgaree with your implication that F=ma is tautological. F=m/a is also a definition, but it is false.Induction is used to universalize F=ma. If my 2,000 lb. Chevy runs out of gas and I push it with all my might, I may find that I can get it up to 1 mile per hour over a distance of one block. From this I can calculate the net force I am capable of applying. Maybe tomorrow my 3,000 lb. Ford will run out of gas. Now that I know how much force I can apply, I can calculate the acceleration that I can expect to achieve. But without inductive reasoning, I would have no reason to believe that F=ma will apply to my Ford on Tuesday just as it had applied to my Chevy on Monday.In fact, thanks to induction, I can use F=ma on Arcturus, notwithstanding the Arcturans' F=xyz. I don't think anyone in this discission has asserted that scientists use induction only. I'm certainly not asserting that. But induction is used often. And until someone comes up with something better, it is a necessary part of the scientific method.Edited by Stephen Push, : No reason given.Edited by Stephen Push, : No reason given.Edited by Stephen Push, : No reason given.

It doesn't matter what standards you use, as long as you are consistent. You cannot state the hypothesis in dynes and report the result in newtons, unless you apply the appropriate conversion factor. Regardless of what standard you use, if your methodology was flawless, if your results contradict Newton's laws of motion, and if your results can be replicated, then we must conlcude that Newton was wrong.

I don't see that it matters whether you use the metric system or internationally standardized time. A second is a second, assuming we are talking about a single point of reference (e.g., one spot on the surface of Earth). That's not the most precise way to calculate a second, but it should suffice for most purposes. What exactly are you measuring? Actually, Earth's rotation is slowing down. Since you haven't reported any data or explained exactly what it is you are measuring, I would have to say that you have not presented any results that support your conclusion.Edited by Stephen Push, : No reason given.

I was giving him more credit than that. Perhaps I was mistaken.

Read message 396.

You are confusing convenience with compatibility. Mean solar time is convenient because it is more constant. But true solar time is compatible with Newton's laws if you account for the elliptical orbit of Earth, the tilt of its axis, and other causes of fluctuations in the length of the day. What point are you trying to make here concerning inductive reasoning and Newton's laws? In fact, both the deceleration of Earth's rotation caused by the Moon and the acceleration caused by earthquakes can be explained with Newton's laws.Edited by Stephen Push, : No reason given.Edited by Stephen Push, : No reason given.

"Swan" in not an abstract entity that you can define any way you like. The term refers to a group of species of birds. You could not have seen all individuals of these species, so any statement that "all swans are white" is necessarily based on induction. A 1997 study that involved 231 paired observations of crows in Davis, California, was titled, "Crows Do Not Use Automobiles as Nutcrackers." Please note the study was not titled, "231 Crows in Davis, California, in 1997 Did Not Use Automobiles as Nutcrackers." The authors used inductive reasoning to make the claim that their conclusion applies to all crows, everywhere, all of the time.This type of inductive reasoning is typical of scientific studies. I could cite hundreds of examples if I thought you would take them seriously. The ideal gas law is used every day by scuba divers around the world to avoid a potentailly fatal buildup of real nitrogen in their blood. They trust their lives to inductive reasoning.

No. Mean solar time averages out cyclical fluctuations to provide a more constant standard. Using true solar time and accounting for the elliptical orbit of Earth, etc., does not ignore the fluctuations, it explains them.But I think your statement above reveals a lot about your view of science. You think it's all about definitions, standards, deduction, appearances, opinions, and guesses. You apparently don't appreciate how science can explain and predict.Edited by Stephen Push, : No reason given.

You can call the swan exmaple artifical all you want, that doesn't make it so. You might want to read about the Black Swan Theory.As a matter of fact, Europeans did use inductive reasoning to conclude that all swans are white, until Dutch explorers discovered black swans in Australia in 1697. The original reports were published in the 1970's. The study that refuted those reports was conducted in the 1990's. Crows have an average life span in the wild of 7-8 years. Thus it is highly unlikely that the crows observed in the 1997 study were the same individuals observed in the original reports. Without inductive reasoning, the authors of the 1997 study could not have made a valid claim of having refuted the studies conducted two decades earlier on different crows.More generally, almost all biological studies use inductive reasoning. When researchers study the genetics of fruit flies, for example, they are not interested only in the individual fruit flies in their lab. In fact, they are not interested only in fruit flies generally. They are trying to understand genetic principles that can be applied to other sexually reproducing species, including humans.Edited by Stephen Push, : No reason given.Edited by Stephen Push, : No reason given.

I think you are wrong about nwr's position. If you craft the standard properly, the results of your observations and experiments will, by definition, always appear to be in accordance with the standard. But I'm not sure what, if any, role nature has in the process.Didn't they teach you anything at Imperial College?