Use this tag for Mach's principle. DO NOT USE THIS TAG for the Mach number!
Use this tag for Mach's principle. DO NOT USE THIS TAG for the Mach number!
Questions tagged [machs-principle]
143 questions
45
votes
12 answers
Is Mach's Principle Wrong?
This question was prompted by another question about a paper by Woodward (not mine). IMO Mach's principle
is very problematic (?wrong) thinking. Mach was obviously influenced by Leibniz. Empty space solutions in GR would result in a Minkowski metric…
Gordon
- 4,413
43
votes
10 answers
How does a spinning object "know" that it is spinning?
I am constructing a thought experiment about a spinning object that is floating in intergalactic space. I assume that this object is about the size of a planet so that it will have enough gravity so that a Foucault pendulum will work, although I'm…
user1928764
- 551
- 4
- 5
38
votes
9 answers
How does an isolated body in deep space 'know' it's rotating?
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 whether it is rotating relative to the rest of the…
chasly - supports Monica
- 3,026
38
votes
8 answers
What determines which frames are inertial frames?
I understand that you can (in principle) measure whether "free particles" (no forces) experience accelerations in order to tell whether a frame is inertial. But fundamentally, what determines which frames are inertial (i.e. what principle selects in…
Joss L
33
votes
10 answers
What is the Earth truly rotating about/revolving around?
Earth rotates on its axis and revolves around the sun, the sun revolves around the galaxy, the galaxy is also moving. So Earth's net rotation as observed from a fixed inertial frame consists of all these contributions (and is rather complex).
Now a…
Man
- 1,398
28
votes
4 answers
Would there be centrifugal force if I were alone in the universe?
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 just be a force pulling me out?
What if there were…
Jake B.
- 379
28
votes
8 answers
Is rotational motion relative to space?
Let's assume that there is nothing in the universe except Earth. If the Earth rotates on its axis as it does, then would we experience the effects of rotational motion like centrifugal force and Coriolis force?
The meaning of my question is: is…
S L
- 1,591
25
votes
7 answers
Why does rotation simulate gravity if motion is relative?
In Einstein's theory of relativity, if motion is truly relative, then why would somebody in a rotating space station experience (artificial) gravity? I mean, I get why they experience gravity IF the space station is rotating, but what I do not get…
Jeremy Olson
- 261
22
votes
5 answers
What is the origin of the inertia?
Is there any explanation why it is harder to move an object with more mass than an object with lesser mass? What kind of force is opposing our force? Is it finalized currently and well known what the origin of inertia is, or not yet 100%? I read…
MSH
- 367
20
votes
5 answers
Newton's Bucket
Newton's Bucket
This thought experiment is originally due to Sir Isaac Newton. We have a sphere of water floating freely in an opaque box in intergalactic space, held together by surface tension and not rotating with respect to the distant galaxies.…
Nigel Seel
- 3,394
19
votes
3 answers
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 mechanics that the frame attached to the surface of…
Black balloon
- 333
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- 8
17
votes
3 answers
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 absolute time, existing independently from anything…
Meep
- 4,167
17
votes
5 answers
How does one determine an inertial frame?
How does one determine whether one is in an inertial frame?
An inertial frame is one on which a particle with no force on it travels in a straight line.
But how does one determine that no forces are acting on it? After all, one might declare a force…
Mozibur Ullah
- 14,713
13
votes
5 answers
If there is no absolute reference frame, why do fictitious forces exist?
According to relativity (both Galilean and Special) no reference frame is fixed, but if that were the case, why do we feel fictitious forces when being in a car that's accelerating with respect to a road?
And why is that force proportional to the…
AhmedSahraoui
- 439
13
votes
1 answer
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 like the magnetic field produced by the circulation…
David Santo Pietro
- 1,361