Questions tagged [machs-principle]
Use this tag for Mach's principle. DO NOT USE THIS TAG for the Mach number!
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Would Doubly Special Relativity or Mach's Principle allow faster-than-light travel to occur without violating causality?
Doubly Special Relativity posits that the Planck length is the same in all reference frames. Mach's Principle posits inertia is produced by the combined mass of the universe.
From my limited ...
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1answer
50 views
Machs Principle Thought Experiment [closed]
Set-up:
Imagine a universe that only contains a few items:
A large planet - A Dyson ring around it -
and some people with baseballs.
This is to say there are no other stars, galaxies, or matter ...
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1answer
54 views
Does General Relativity actually satisfy the General Principle of Relativity?
The “General Principle of Relativity” being “All systems of reference are equivalent with respect to the formulation of the fundamental laws of physics”. To my knowledge, this is related historically ...
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2answers
63 views
How does an isolated observer know if they're accelerating?
I'm aware of this question and read its answers, but I'm not sure if it specifically addresses what I want to ask, and also it'd be nice to have a more accessible answer since I don't know GR.
I'm ...
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1answer
142 views
How does an isolated electron in deep space 'know' it is spinning? [duplicate]
This is a question about Mach's principle. Why is Mach's principle still an open question? In particular, if inertia arises from distant matter, Mach's principle raises the question would a particle ...
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2answers
66 views
Would an astronaut, alone in space with no reference point, get dizzy? [duplicate]
I’m not quite sure of the biology behind it, but for my question let’s assume that spinning of any kind would cause dizziness as a more dense object would sink to the outside of the body showing that ...
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3answers
569 views
Is all motion relative in general relativity?
I was reading up on Mach’s principle and the historical relation it had with the development of General Relativity. As I understand it, one formulation of Mach’s principle states that for all motion ...
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1answer
60 views
Understanding Mach Principle
I cannot get the essence of Mach's Principle.
In my undestanding, it states that the cause of the so-called "fictitious forces" which arise in non-uniform motion has to be found in the relative ...
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0answers
38 views
Grasping (Inertial) Frames of Reference [duplicate]
I am new to studying Special Relativity and have some trouble truly understanding what the phrase (Frame of Reference) tries to imply.
So I understand that an inertial frame of reference, for example,...
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6answers
3k views
How can we tell if the Earth is spinning without any external references? [duplicate]
The rotation of the Earth about its axis makes it bulge at the equator and contract at the poles due to the centrifugal forces. How do we know, without any external references, that the Earth is ...
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1answer
65 views
Questions about an inertial frame
Can someone explain to me what I put in bold?
Inertial frame definition:
When the coordinate axes are stationary with respect to the mean position of the "fixed" stars or if they move with uniform ...
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1answer
76 views
Mach's principle and centrifugal force
How does Mach's principle explain the centrifugal force as a result of the relative circular motion of the distant stars? Why does this, in the light of Mach's principle, make a net force although the ...
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2answers
159 views
Newton's First Law and things that are very old [closed]
Recently I've been revisiting physics text books, and books by Feynman, and others.
A curious thought has arisen, while I was reading about Mach's principle, and it seems to gnaw on my mind. I hope ...
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0answers
55 views
Black Hole and Mach Principle
In the derivation of the spin–orbit interaction, we transform to a frame that is fixed on the electron. I have several questions about this:
Will I see any radiation if I orbit around a static charge?...
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3answers
2k views
Do I have to know the General Relativity theory to understand the concept of inertial frame?
I have read answers on this site as well as the Wikipedia article, but they all add to the confusion. Some people suggest that a freely falling frame is an inertial frame. I learnt in classical ...
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1answer
259 views
Is MTW's argument in favor of Mach's principle valid?
Looking at older books, I was surprised to see that the general relativity "bible" by Misner, Thorne, and Wheeler is very strongly in favor of Mach's principle, which is treated in section 21.12.
...
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1answer
86 views
What was Newton's idea of absolute space and time?
When one says that Newton believed in the concept of "absolute space" and "absolute time" does it simply mean that the length interval between two points in space and time interval between two events ...
5
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2answers
206 views
Ernst Mach vs. Einstein
In the Ernst Mach wikipedia page, Einstein seems to be influenced by Ernst Mach. But it says
In 1930, [Einstein] stated that "it is justified to consider Mach as the precursor of the general theory ...
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4answers
345 views
Is rotation absolute? [duplicate]
I was reading an article that rotation instead of linear motion is absolute. Can anyone explain why? Shouldn't an observer (A) moving in a circle around a point in an object that rotates (with respect ...
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0answers
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How come everything in the universe except the universe itself are spinning? [duplicate]
The planets and stars are spinning, galaxies and clusters are spinning so shouldnt the universe also spin? I think objects spin is to preserve angular momentum but it must also implied that in the ...
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0answers
49 views
How does physics know something is spinning or rotating? [duplicate]
From a purely mathematical point of view, as far as I'm aware, there is no difference between rotating a singular point by a phase phi, using its own location as the centre, or rotating all but the ...
9
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3answers
942 views
Can we determine an absolute frame of reference taking into account general relativity?
Given that acceleration induces measurable physical effects, would it be correct to say that there should be an absolute inertial frame of reference? I know that one cannot distinguish a priori ...
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9answers
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How does an isolated body in deep space 'know' it's rotating? [duplicate]
We can imagine an object floating in the known universe, maximally distant from any other large mass. Maybe it has been there since coalescing after the big bang.
What physical phenomena tell it ...
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1answer
177 views
Differentiating linear and non-linear motion
If there is a Person sitting in a vehicle which is moving, how could he find out whether it's in motion and if he figures that out, how does he find out whether it's accelerated or non-accelerated?
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1answer
90 views
Super luminal speed paradox? [duplicate]
Chosing a reference frame in which the Earth is at rest and doesn't rotate is related, but different. Here I'm asking if there is a paradox and if my attempt at resolution has merit, and if not ...
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4answers
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Would there be centrifugal force if I were alone in the universe? [duplicate]
When I'm rotating, I feel centrifugal force.
But if I were the only one in the universe and rotating, wouldn't I just kinda be still (since I'm not rotating with respect to anything) or would there ...
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3answers
169 views
Earth's rotation in an empty universe
I have read these questions:
Is rotational motion relative to space?
Rotation in an 'empty' universe
None of these talk about whether we can and how we can determine rotation of Earth ...
4
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1answer
288 views
Newton's Bucket, Artificial Gravity, Absolute Rotation, and Mach's Principle
I have been trying to understand how we can talk about absolute rotation in general relativity. I get that it is an area of active debate with some adherents of Mach's Principle and others believing ...
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0answers
74 views
To what extent is rotation relative (in GR and other theories)?
In Newtonian physics, rotary motion is absolute even though linear motion is not. More recently, there has been a hope that rotation can also be shown to be relative.
Two definitions of relative
A ...
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1answer
100 views
Mach's principle and infinite speed of distant stars
If rotation was relative, we could say that the Universe is revolving around the earth. But how could this be true, since at some distant point the speed of a star would be greater than the speed of ...
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0answers
76 views
Why is angular motion special?
I'm a biochemist, and not a physicist so bear with me if I say something stupid. I do like to read about physics, though and this is one thing I can't wrap my head around.
I was recently reading ...
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1answer
178 views
How can I interpret or mathematically formalize Maxwellian, Leibnizian, and Machian space-times?
I've been reading the book, World Enough and Space-Time, and I came across a rough list of classical space-times with varying structural significance.
Here is the same list, minus Machian Space-time,...
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2answers
317 views
Do absolute space and time exist? [duplicate]
Einstein's theory proved that most properties of a body are relative to something and are not absolute. I am still wondering if physicists still think that there is a way that Newton's absolute space ...
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1answer
70 views
Atom interferometry,gravity and inertia: What can it measure that light interferometry can't? [closed]
What previously unexplored effects in gravity and inertia can be examined with atom interferometry in ways that hasn't already been done through light interferometry?
Can atom interferometry be used ...
2
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0answers
99 views
Massless Electrons and Effect on Graphene Mass
I've read that electrons in graphene can travel masslessly, due to the effect of the graphene crystal around them. I'd also read that the application of an electric field can change this behavior and ...
12
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1answer
435 views
Is Weinberg wrong in this account of how Mach's principle is incorporated in general relativity?
In his book "Dreams of a final theory" pg.144 Steven Weinberg says
"the circulation of the matter of the universe around the zenith seen by observers on a merry-go-round produces a field somewhat ...
3
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1answer
142 views
Can empty space rotate without frame dragging?
A recent question Rotation of our Galaxy's inertial frame is about an observational evidence of the space rotation. My question is if such a rotation is conceptually possible in GR. Can we assume ...
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1answer
103 views
Rotation of our Galaxy's inertial frame
Suppose in the universe, there are inertial frames in the vicinity of galaxies. Suppose also that these frames rotate slightly with respect to each other - that the universe is not quite a 'mill pond'....
2
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1answer
73 views
Why there is a preference between different reference-bodies?
I know a classical mechanics law points out the following (Newton's first law): material particles with constant velocity will continue to move uniformly in straight line. If material particles are in ...
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2answers
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How can Newton's idea of absolute space be reconciled with Galilean relativity?
I wasn't sure if this might be better suited to History of Science and Mathematics SE, but I suppose it is a bit more 'science-y' than historical.
Apparently Newton believed in absolute space and ...
4
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2answers
277 views
Why is Brans-Dicke Theory considered as a failed attempt to incorporate Mach’s principle in a relativistic theory of gravity?
In Generalized Brans-Dicke theory: A dynamical systems analysis by Nandan Roy and Narayan Banerjee, Brans-Dicke theory is described as a failed attempt to incorporate Mach’s principle in a ...
4
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1answer
641 views
How can you tell if a given reference frame is inertial? [duplicate]
An inertial reference frame is one in which a particle has constant velocity if and only if has a zero net force acting on it.
How can one determine if a given reference frame is inertial? For ...
0
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2answers
168 views
Are laws of physics (mechanics) symmetric under uniform rotation?
I'm just starting to learn about symmetry. I understand that physical laws are symmetric under translation and consequently (is it not a consequence?) under uniform velocity in a straight line.
I see ...
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1answer
80 views
Rotation inside a black hole
As far as I can see most of the questions about rotation of a black hole refer to the appearance of a hole to an outside observer.
What about the region within the Schwarzschild radius?
According ...
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2answers
449 views
What is the solution to Newton's bucket problem? [duplicate]
What is the solution to Newton's bucket problem?
The Wikipedia page does not give me any finality.
After reading, I felt as if the problem implied either one of these two things
There is a special ...
1
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2answers
122 views
Question concerning the cause of the rise of water in a spinning bucket in empty space according to Mach
According to Mach we can attribute the fact that in a spinning bucket with water the water rises to the edges of the bucket just as well to the whole Universe rotating around the bucket, as to the ...
3
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2answers
111 views
Two masses in empty space
Consider two equal point masses which are rotating circular arround each other in empty space for ever (radiation effects are ignored).
Let an observer be at the center of mass of the system. Then, ...
3
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2answers
672 views
Is the pressure higher in the corners?
I was watching the video The Ingenious Design of the Aluminum Beverage Can. At 20'', the author says
[..] a spherical can [..] has no corner, so no weak points because the pressure in the can ...
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1answer
109 views
Would the Earth stop spinning in the absence of stars?
Please explain this in layman's terms.
A cosmos without stars would have no spacetime structure relative to which the earth could spin. For there to be gravitational (or inertial) fields capable of ...
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3answers
981 views
What is “a general covariant formulation of newtonian mechanics”?
I am a little confused: I read that there are general covariant formulations of Newtonian mechanics (e.g. here). I always thought:
1) A theory is covariant with respect to a group of transformations ...
