Leverage

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thinkandmull

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Peace,

Descartes (according to the Britannica Encyclopedia) thought that walking involved simply force and leverage. Newton on the other hand wrote that for every action there is an equal reaction. Are these opposed, and what arguments can be applied in this regard
 
You have described two views of walking, neither of which is incorrect, though each is incomplete, and which are not opposed. I don’t know if philosophical arguments can be applied in this regard, but a mechanical analysis (accounting for all forces upon and within the body, and the resulting acceleration and momentum) would tell almost everything.

Other important aspects of walking are outside the scope of mechanical force analysis, such as control, stability, and energy efficiency. Some part of the brain controls the basic mechanics of walking, usually without our being consciously aware of it. It takes in sensory information and controls the forces applied by muscles in order to maintain stability, that is, to remain upright (to not topple or buckle), to move at the intended speed and in the intended direction, and to compensate for unexpected forces as might be encountered from uneven terrain, a gust of wind, or bumping into someone.

Walking is anything but simple, and it is amazing.
 
is there also inertia involved. Yer trying to roll the planet beneath your feet but 'cause it has so much mass you move more than it does. without inertia you’d be going nowhere really fast.
 
Both are involved.

There is no doubt that our human limbs (both arms and legs) and even the neck, to an extent, exert leverage. This leverage is multiplied by the muscular force available.

At the same time, our bodies move forward because our feet push back on the ground (reaction).

However, at the moment of pushing back, the ankle acts as a lever in pushing the toes down and back.

ICXC NIKA
 
thinkandmull said:
Peace,

Descartes (according to the Britannica Encyclopedia) thought that walking involved simply force and leverage. Newton on the other hand wrote that for every action there is an equal reaction. Are these opposed, and what arguments can be applied in this regard
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Hi Thinkandmull!

I think those were just simply two different ways to describe a common experience, and at that initial level it would not be possible to say if they are opposed or not. We would need to see how each one of these thinkers further developed their basic notions. For example, I understand that Descartes did not develop a notion of “vector” (which implies that for him, “force” was not yet a vectorial quantity, while for Newton it was), which simplifies the study of movement, and without it his followers faced certain difficulties to sustain the cartesian idea that the “amount of movement” in the universe is a constant.

What does the Britannica Encyclopedia say about how Descartes understood the notion of “force”?
 
I am confused on what inertia and vector mean in these contextes.

A youtube video of Bertrand Russell (talking about Descartes) said that Descartes believed in something similar to what I think you mean by vector at the location of the sun. In an early edition of Newton’s book a writer;s introduction said that Newton’s view needed a God while Descartes does not. I would like to know how Newton’s view needed an intelligence behind it, and also how he came up with the idea that “for every action there is a equal reaction”. I think walking does required this reaction from the earth.
 
Does anyone know where I can get some of the latter works of Descartes for not too much money?

The Britannica Encyclopedia says that Descartes did not believe in gravity because it wasn’t mechanistic enough. Instead there were round particles called “second matter” by Descartes that propelled things to earth through the ether, working like a clock. Even walking for him was like a clock, just pushing, pulling, and leverage. That’s all. He likewise did not believe in a vacuum with regard to water pumps. They worked “by the weight of the water which counterbalances that of the air” (Descartes). He could have gone further into mechanistic thought but didn’t however. Light was a propagation of pressure thru the fluid he called ether. Pressure was like a wave for him, and light could become heat and vice versa, predating modern physics on this.
 
thinkandmull said:
Does anyone know where I can get some of the latter works of Descartes for not too much money?

The Britannica Encyclopedia says that Descartes did not believe in gravity because it wasn’t mechanistic enough. Instead there were round particles called “second matter” by Descartes that propelled things to earth through the ether, working like a clock. Even walking for him was like a clock, just pushing, pulling, and leverage. That’s all. He likewise did not believe in a vacuum with regard to water pumps. They worked “by the weight of the water which counterbalances that of the air” (Descartes). He could have gone further into mechanistic thought but didn’t however. Light was a propagation of pressure thru the fluid he called ether. Pressure was like a wave for him, and light could become heat and vice versa, predating modern physics on this.
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You can look here:

http://www.earlymoderntexts.com/authors/descartes
 
Descartes and Newton offered differing accounts of mechanics and also of space. I think matter, too, if I recall. So I assume their explantains of walking are not compatible.
 
thinkandmull said:
I am confused on what inertia and vector mean in these contextes.

A youtube video of Bertrand Russell (talking about Descartes) said that Descartes believed in something similar to what I think you mean by vector at the location of the sun. In an early edition of Newton’s book a writer;s introduction said that Newton’s view needed a God while Descartes does not. I would like to know how Newton’s view needed an intelligence behind it, and also how he came up with the idea that “for every action there is a equal reaction”. I think walking does required this reaction from the earth.
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The notion of “vectors” is not something in which we believe or not. It is an intellectual instrument with which we can give relatively simple descriptions of motion.
 
Rhubarb said:
Descartes and Newton offered differing accounts of mechanics and also of space. I think matter, too, if I recall. So I assume their explantains of walking are not compatible.
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I think both descriptions of walking would not be compatible if they predicted different outputs; otherwise they would be simply different.

Another thing is to say that if you use the Cartesian concept of space in combination with the Newtonian concept of force you get contradictory statements. If that is the case, then those concepts would be incompatible.

I remember that there was a difference between the Cartesian and the Newtonian concepts of space, but I don’t remember exactly what it was. Do you?
 
Descartes didn’t believe in space, things didn’t occupy another but instead merely had relations to each other. Newton knew about the vacuum and thus could explain a water pump correctly
 
thinkandmull said:
How do Newton’s vector and inertia work together?
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Inertia is just the resistance to change in motion. The law of inertia simply states that a body at rest stays at rest, and a body in motion stays in motion, unless a force is applied.

In the case of our bodies, the force is applied by our muscles (or by friction to stop motion).

A vector is simply a set of numbers that describes the direction and magnitude of force or motion. Vectors are often represented graphically by arrows in 2 or 3 D.
 
thinkandmull said:
Descartes didn’t believe in space, things didn’t occupy another but instead merely had relations to each other. Newton knew about the vacuum and thus could explain a water pump correctly
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No Thinkandmull: one of the most basic Cartesian distinctions was the one between the “res cogitans” and the “res extensa”; and the res extensa implies space to be understood. Besides, as you say, Descartes did not accept the possibility of vacuum. So, everything around us was res extensa for him. The relationistic notion of space that you are mentioning reminds me of the Leibnizian idea, not of the Cartesian one. Are you sure that Descartes had that idea?

As for the functioning of a water pump, do you mean the one that was used to pump water from the mines? That one which required to fill a reservoir with steam and afterwards condense it by cooling its walls?
 
Leibniz and Descartes had the same view of space. Later Cartesians went the way of Newton
 
Passing over to time, Kant says that “Leibniz and his followers think of time as something real, abstracted from the succession of internal states.” Sounds like Einstein’s fourth dimension, no?
 
thinkandmull said:
Passing over to time, Kant says that “Leibniz and his followers think of time as something real, abstracted from the succession of internal states.” Sounds like Einstein’s fourth dimension, no?
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Not at all. But anyway Thinkandmull, don’t you think you go too fast tasting everything, but without getting enough nutrition? Besides understanding vectors, you would need to understand tensors to be able to catch something about Einstein’s theory.

Good luck!
 
thinkandmull said:
Descartes didn’t believe in space, things didn’t occupy another but instead merely had relations to each other. Newton knew about the vacuum and thus could explain a water pump correctly
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Right, Descartes’ conception of space was relational, whereas Newton’s was substantival.
 
Rhubarb said:
Right, Descartes’ conception of space was relational, whereas Newton’s was substantival.
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Newton thought that besides bodies there was space, and things were located in the space. But according to Descartes, extension -that is to say, space- constituted bodies. In which sense was space relational for Descartes , Rhubarb?
 
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