how does something become a law in science?

[vincentfromyay]

for example, when galileo (or whoever it was) first proposed that bodies will fall at the same rate in a vacuum regardless of mass, how many times did this have to be tested before it became accepted?

 

(also, is the above example a law?)

 

(and is it true that Aristotle had said the more massive object will fall faster than the less massive object?)

[Sensei]

Galileo had no idea about vacuum. He lived in 1564-1642. The first gas was discovered in 1766 (Hydrogen), 1772 (Nitrogen), 1773 (Oxygen), 1774 (Chlorine).

 

The main question: I guess so repeatable every time..

[timo]

There is no formal criterion for something to become a "law" in physics. The amount of testing required before something is accepted varies greatly. The people proposing something are often convinced after their first experiments . Things become interesting after the first other groups/people can reproduce the effects. Wide acceptance probably comes when many people successfully apply the idea for derived work (like successfully hitting towns with artillery ).

 

[BusaDave9]

A law of physics is what exists independently of human understanding.

A theory is our understanding of a law.

If a theory is proven to be correct it doesn't become a law.

 

Gravity is a law of physics. Newton wrote a theory of gravity. Later Einstein wrote his theory of gravity (General Theory of Relativity). Even though Einstein's theory is much different than Newton's that doesn't mean Newton was wrong. Newton's equations are still used to put a satellite in orbit.

Edited November 3, 2013 by BusaDave9

[swansont]

Laws are also limited to ideas that are or can be expressed as straightforward mathematcal relationships

[decraig]

Busa. You claim that there are objective laws of physics. Then where are these laws existent?

 

Historically, physicists became so sure of the objective truth of Newtonian mechanics, they began to call his axioms Laws with a capital L. Applying the word law, to a bunch of axioms was simply a mistake.

 

To be sure, Newtonian mechanics is wrong. This doesn't mean it is extremely useful, but still fails to have one to one correspondence with the results of experiment. I'm sure general relativity also fails.

 

It is the mood, these days, not to have so much hubris as to claim one theory or another to be a law of nature, or a law of God.

[Ophiolite]

It is my impression that calling something a Law is an archaic process. As the scientific method has evolved it has led to improved recognition that all results and theories are provisional. The continued use of the word law for something like Newton's Laws of Motion is a form, appropriately enough, of inertia.

 

As I say, this is an impression. What is the most recent Law any of you are aware of, ignoring anything from the Social Sciences? (Since anything from the Social Sciences usually is best ignored.)

 

Edit: I somehow failed to read the previous post. I see I have made much the same point as decraig. Excuse the repetition, but I'd still like to know when was the last time something was named as a law.

Edited November 15, 2013 by Ophiolite

[decraig]

Edit: I somehow failed to read the previous post. I see I have made much the same point as decraig. Excuse the repetition, but I'd still like to know when was the last time something was named as a law.

 

It's good to find agreement. Thank you.

[imatfaal]

Law of Large Numbers was mid 19th (although concept was Renaissance)

 

http://en.wikipedia.org/wiki/Bragg%27s_law - although I think the apostrophe is in the wrong place is early 20th

 

Hubble's Law was formulated in the 20s - so within a century of today

[gabrelov]

Laws exist even before we all exist. But remember if there are multiverse we cannot say law here applies there. Much like country with different law.

 

But the law is only limited to what we understand so far. Eg; Newton law and einstein law of gravity.

[decraig]

Laws exist even before we all exist. But remember if there are multiverse we cannot say law here applies there. Much like country with different law.

 

But the law is only limited to what we understand so far. Eg; Newton law and einstein law of gravity.

 

OK. This is interesting. It is my belief that Newtonian physics, Einstein gravity and all the rest are human inventions: Physics is not discovered but invented, in my way of thinking.

 

I still ask, where or when are these magical LAWS OF NATURE sequestered? Where are they?

If they are no where in space and time, Gabrelov, then these hypothetical laws would not be physical but metaphysical. Would you proposing that physics is metaphysical?

 

 

I think they are only a phantom (but secretly wish to discover what they are).

 

 

I remain in extreme contradiction; preaching one thing and passionately hoping for the alternate.

 

 

============================================

 

So with all this, where no one has a clue, where us humans, who pretend to intellectuallity, and can hardly pull it off---------------

Yet at the same time, we remain smug. We know better; the Universe created itself from nowhere and nothing, there is no God, and we can fathom anything.

 

B.S.

Edited November 23, 2013 by decraig

[BusaDave9]

 

It is my belief that Newtonian physics, Einstein gravity and all the rest are human inventions: Physics is not discovered but invented, in my way of thinking.

 

I still ask, where or when are these magical LAWS OF NATURE sequestered? Where are they?

 

 

What do you mean "where are these laws of nature"?

An apple would fall to the ground even long before any human existed. Gravity exists independently of human understanding. Einstein's General Relativity is his understanding of gravity. You can say Relativity is Einstein's invention and I'd have a hard time disagreeing with that but it's more accurate to say GR is his explanation of gravity. But it has proven to be a very accurate theory. Scientific theories come and go. The ones that can be verified and provide predictions are the theories that will stay around. These theories are the ones that most closely represent how the laws of nature really are.

Edited November 23, 2013 by BusaDave9

[gabrelov]

Yes an apple will fall before even humans existed. It was not invented by humans but is limited to what we understand. Eg: law of gravity of newton and einstein.

 

What they understand before is that due to mass that objects fall, even before gravity was discovered. The later comes law of gravity with objects of proportional mass and then came the curvature of fabric of space time. We did not invent this laws, this is the result of what we observed so far. If still people and scientist are not satisfied then it ends up as theory, but we may brand it as thoery but in reality its a law or vice versa, we brand it as a law but in reality its not.

 

If you are questioning how this laws existed, as I mentioned above AFAIk we cannot say at atmost 100% that all laws are really laws, we have to remember we have macroscopic and quantum level. Laws may not apply to the other. I would not want to guess how they existed for the first place, but rather we have to dig deep into the level of how everything begun, the constituents of this universe which in turn limits what we understand so far. There are still things we don't see remember, dark energy, dark matter, maybe they have effect on gravity. This is what I want to express.

 

What I wanna say: Don't limit yourself to what the laws says, sometimes they maybe exceptions and that is what science is all about.

 

Anyways that is why I love science, there is more out there than meets the eye. We have lot more to learn and that is why it is not boring, everyday we progress we learn and we discover new things, we also create history.

Edited November 26, 2013 by gabrelov

[BusaDave9]

... we brand it as a law but in reality its not.

 

I agree.

I think semantics is confusing this thread.

There are the laws of nature. These laws are absolute. We humans try to understand physics and will formulate theories. When our theories are proven to be correct we call them laws as if they are the exact representation of the laws of nature. I think that's overly arrogant. And telling from the posts on this thread, I think some of you agree with this. Kepler's "Laws" of planetary motion are very accurate. They were labeled "laws" as if they were the end all, be all, for explaining orbital motion. Later Einstein explained gravity as warped space-time.

 

I don't think we should ever use the word "law" for a theory, no matter how much we prove it to be correct.

[swansont]

I agree.

I think semantics is confusing this thread.

There are the laws of nature. These laws are absolute. We humans try to understand physics and will formulate theories. When our theories are proven to be correct we call them laws as if they are the exact representation of the laws of nature. I think that's overly arrogant. And telling from the posts on this thread, I think some of you agree with this. Kepler's "Laws" of planetary motion are very accurate. They were labeled "laws" as if they were the end all, be all, for explaining orbital motion. Later Einstein explained gravity as warped space-time.

 

I don't think we should ever use the word "law" for a theory, no matter how much we prove it to be correct.

 

Except that Kepler's laws, and later Newton's law of gravitation and three laws of motion, are not really theories, so that's not a mistake being made. There is no mechanism proposed to explain them, just the mathematical observation of behavior. And that's what a law is in science. Basically it's an equation that holds under certain conditions. A theory will explain why the law is there.

[gabrelov]

I would give another example that sometimes calculation cannot substitute to reality.

 

It was during the time when aicraft was trying to go past speed of sound.

 

Calculations showed that if an object tries to go beyond Mach 1, the drag will increase to almost infinity, thus requiring infinite thrust. So by then most of them agree no one can go faster than speed of sound. But an experiment using an aicraft doing a dive going mach 1 broke this theory, man can travel faster than speed of sound. They have to revise the calculations back then.

 

So for humans we try to understand something and thus we create theories maybe not just from observation but calculation but in reality we may have overlook some aspects of it that may totally change what we know so far.

 

Anyways actually we only call it laws of nature, this is a genral term for something, it is not name for some kind of formula or a single of observation. So we call it laws of nature because we cannot change it base on what we observe, it holds its own meaning for itself or we cannot define it.

Edited November 27, 2013 by gabrelov

[John Cuthber]

On a related note, what is the most recent "law" in science?

Is this a contender?

http://en.wikipedia.org/wiki/Hubble's_law

or this

http://en.wikipedia.org/wiki/Benford%27s_law

 

If you can find the recently defined "laws", perhaps you can see what made them laws rather than theories or whatever.