Rice University gets Newtons 3rd Law wrong

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Discussion Overview

The discussion revolves around the interpretation and explanation of Newton's Third Law of Motion as presented by Rice University. Participants critique the accuracy of the explanations and illustrations provided, comparing them to historical misinterpretations, and explore the implications of wording in the context of Newton's laws.

Discussion Character

  • Debate/contested
  • Technical explanation
  • Conceptual clarification

Main Points Raised

  • Some participants argue that while Rice University correctly identifies Newton's Third Law, the accompanying text misrepresents how it works, drawing parallels to a historical error by the New York Times regarding Robert Goddard.
  • One participant expresses frustration that the diagram fails to depict the ground, questioning how it can apply forces if it is not represented.
  • Another participant raises concerns about the explanations of Newton's First and Second Laws, suggesting that the phrasing used could lead to misunderstandings, particularly regarding the concept of motion in curved space.
  • There is a discussion about the expression of motion in a straight line versus the same direction, with some participants noting that the latter could be misleading in the context of curved space.
  • One participant asserts that it is spacetime that follows Riemann geometry, not space itself, which adds complexity to the discussion of motion and direction.

Areas of Agreement / Disagreement

Participants express disagreement regarding the accuracy of Rice University's explanations and illustrations of Newton's laws. There is no consensus on the correctness of the interpretations or the implications of the wording used in the explanations.

Contextual Notes

Participants highlight potential limitations in the explanations provided by Rice University, including missing assumptions and the implications of using specific terminology related to motion and space.

bland
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I couldn't remember which number was which in Newton's laws of motion, and so I clicked the first link I found, but to my amazement it seems that while Rice University got the number right, they got the facts of how it works wrong. Ironically it seems they have made the same mistake as that famous article by the New York Times ridiculing Robert Goddard. Unless it is me who has made the error.The rocket's action is to push down on the ground with the force of its powerful engines, and the reaction is that the ground pushes the rocket upwards with an equal force.

http://teachertech.rice.edu/Participants/louviere/Newton/law3.html
 
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bland said:
I couldn't remember which number was which in Newton's laws of motion, and so I clicked the first link I found, but to my amazement it seems that while Rice University got the number right, they got the facts of how it works wrong. Ironically it seems they have made the same mistake as that famous article by the New York Times ridiculing Robert Goddard. Unless it is me who has made the error.The rocket's action is to push down on the ground with the force of its powerful engines, and the reaction is that the ground pushes the rocket upwards with an equal force.

http://teachertech.rice.edu/Participants/louviere/Newton/law3.html
You are correct. They got it right in the illustration but the text is nonsense and is in fact exactly the same POV as in that infamously stupid statement that you mentioned from the NY times.
 
If they are going to explain it wrong, the least they can do is be consistent and show it wrong in the diagram too! The ground isn't even drawn in the diagram, so how can it be applying any forces on anything? That's wrong-squared in my book.
 
What do you think of their explanations of the other two:

http://teachertech.rice.edu/Participants/louviere/Newton/law1.html

http://teachertech.rice.edu/Participants/louviere/Newton/law2.html?
 
zoobyshoe said:
What do you think of their explanations of the other two:

http://teachertech.rice.edu/Participants/louviere/Newton/law1.html

http://teachertech.rice.edu/Participants/louviere/Newton/law2.html?

Well they say this...
An object in motion continues in motion with the same speed and in the same direction

Usually it is expressed as 'in a straight line', which I think is more correct because it does move in a straight line but in curved space, if you say 'same direction' then that could technically be incorrect because the direction might be in a straight line but space may curve. For example the famous Eddington measurement of the position of a star near the sun. Not sure about this though.
 
bland said:
Well they say this...
An object in motion continues in motion with the same speed and in the same direction

Usually it is expressed as 'in a straight line', which I think is more correct because it does move in a straight line but in curved space, if you say 'same direction' then that could technically be incorrect because the direction might be in a straight line but space may curve. For example the famous Eddington measurement of the position of a star near the sun. Not sure about this though.
Space is not curved. It is spacetime that follows Riemann geometry (and therefor appears "curved" when viewed from the POV of Euclidean geometry).
 

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