1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Is there any way to prove Newton's law

  1. Mar 5, 2010 #1
    a Newton's law states that : F=m.a , but I realize that it belongs to our sense , but may be someone know more about this . if you have any explaination or proof , let me know :)
  2. jcsd
  3. Mar 5, 2010 #2


    User Avatar
    Staff Emeritus
    Science Advisor
    Education Advisor

    Forget about Newton's laws. Think about how you "prove" anything in science!

    There is no such thing as "proof" as rigorous as that in mathematics, i.e. a logical proof. There are such a thing as "valid" evidence! The fact that your house still stands is an evidence for the validity of Newton's laws. The fact that we can actually map and predict the location of celestical bodies (i.e. we shoot a space capsule here on earth, and months and years later, actually reach a planet that wasn't at that location months and years earlier) is another evidence for the validity of Newton's laws.

  4. Mar 5, 2010 #3


    User Avatar
    Science Advisor

    Ofcourse you can. Just say that gravity is entropic.
  5. Mar 5, 2010 #4
    What this guy said.

    In logic,
    there are direct proofs (if a goes to b and b goes to c then a goes to c),
    proofs by contradiction (you assume the opposite of what you want to prove, then work to find the contradiction in that),
    and proofs by induction (Tricky to explain in a single line. look this one up.)
    You can look those up.

    The types of proof that are not valid that are constantly used are:

    Proof by superiority = "The King said the sun is blue.. so the sun is blue." The story of "the emporer has no clothes" is a story that attempts to explain to children that this is not proof.

    Proof by Precident.
    "We have been doing this for 25 years this way... "
    It could have been wrong for 25 years... or incomplete, but if that is all you knew, then thats all you knew.
  6. Mar 7, 2010 #5
    Tell me if I’m wrong. The formula f=ma is a definition of force. You can’t prove a definition. You can ask, is it meaningful? I think it is not. Can you measure force? Well, if you can measure mass and if you can measure the acceleration then you can measure the force. Otherwise I don’t think you can. So I don’t understand Milgrom and I don’t understand Verlinde. What are they doing?
  7. Mar 7, 2010 #6

    Vanadium 50

    User Avatar
    Staff Emeritus
    Science Advisor
    Education Advisor
    2017 Award

    Ever seen a spring scale?
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook