Motion/Rest: Definition & Explanation

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Discussion Overview

The discussion centers around the definitions and implications of motion and rest, particularly in the context of a single object in space. Participants explore the nature of motion, reference frames, and the relationship between energy and motion, as well as concepts like rest mass and acceleration.

Discussion Character

  • Exploratory
  • Debate/contested
  • Technical explanation

Main Points Raised

  • Some participants propose that motion is defined as a change in position relative to another object or reference frame, suggesting that without another object, one can only state that it is at rest with respect to itself.
  • Others argue that motion and rest are inherently comparative, requiring at least two objects, and that energy differences between them can influence perceptions of motion.
  • A participant raises the question of rotation, noting that an object could be considered to be moving relative to itself, while another suggests that it cannot determine its rotation without a reference frame.
  • There is a discussion about the speed of an object approaching the speed of light (c), with some claiming it can approach but never attain c, while others seek clarification on the concept of reference frames in this context.
  • Participants discuss the concept of rest mass and its relation to reference frames, with some asserting that rest mass is defined with respect to an object's own reference frame.
  • Questions are raised about maximum acceleration, with one participant suggesting a formula involving Planck time, while another challenges the notion of a strict upper limit on acceleration.
  • There are conflicting views on the nature of light and its reference frame, with some asserting that light does not have a reference frame, while others attempt to connect the concepts of mass, energy, and reference in relation to light.

Areas of Agreement / Disagreement

The discussion remains unresolved, with multiple competing views on the definitions and implications of motion, rest, reference frames, and related concepts. Participants express differing opinions on the nature of acceleration and the role of Planck time.

Contextual Notes

Participants express uncertainty regarding the implications of a single object in the universe and the limitations of defining motion and rest without comparative reference points. There are also unresolved questions about the nature of time and acceleration limits.

  • #31
Acceleration has a upper limit if there was no limit it would simply violate the maximum speed of information law.

In fact that stands for every variable x where

x = dy/dt (t is time and y is another variable)

=> x < ((3 x 10^8)[si unit of y])/sec
 
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  • #32
ManishR said:
Acceleration has a upper limit if there was no limit it would simply violate the maximum speed of information law.

In fact that stands for every variable x where

x = dy/dt (t is time and y is another variable)

=> x < ((3 x 10^8)[si unit of y])/sec

I don't understand this concept of light as propagation of information. EM radiation propagates energy. Information is patterns, no?
 
  • #33
when we say acceleration has no upper limit what we saying actually is change in speed will be reflected to observer instantaneously.

for example let's consider an observer observing position and speed of an object (with help of thread and pulley, say)

first let me explain u the upper limit of speed( which is c )

distance between observer can be either x1 or x2.
but since object cannot change x faster than c
so information cannot reach at observer faster than c

now acceleration

let the speed be s1 or s2
if there is no limit at how fast s should change (ds/dt = infinity)

by changing speed (s1 or s2) the object can pass information to observer with speed of infinity ( using s1 as 0 and s2 as 1 which can be taken as a representation of information)

the point here is by using a thread and pulley ( not light) we can observe change in speed and distance instantaneously.
 
  • #34
ManishR said:
by changing speed (s1 or s2) the object can pass information to observer with speed of infinity ( using s1 as 0 and s2 as 1 which can be taken as a representation of information)

the point here is by using a thread and pulley ( not light) we can observe change in speed and distance instantaneously.
how does the change in the thread move faster than the thread itself? Also, what are you saying is changing speed, exactly, since radiation can't?
Is this a serious post or a homework project for obfuscation 101?
 
  • #35
It is time we changed our concept of motion! Whether the motion has relevence or not, a body in motion should be regarded as a body in motion. Maybe, energy is the quality of matter and all bodies remain in motion irrespective of whether it is alone or a part of a system.

We can define a body as something which may or may not have an internal structure. Any large body has an internal structure and so is a system. If it is alone, it is an independent system. The question that arises is: at what level of integration would a system become independent? At the level of universe? Then, will the universe move? Or, will the motion remain restricted to its constituents?
 
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