Questions tagged [relativity-theory]
For questions regarding either the special or general theories of relativity.
70
questions
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1answer
125 views
What is a spacetime continuum?
A very common expression I see in pop science is "the spacetime continuum". This expression isn't commonly used in modern discussions of general relativity, but looking at some older papers on the ...
2
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0answers
208 views
First paper introducing the concept of four-vectors
I'm trying to find the first paper in which the concept of four-vectors was introduced. I read "Principle of Relativity" by H. Minkowski but he only presents the notion of metric and invariant space-...
0
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0answers
27 views
Were Christoffel symbols used by Riemann?
The answer to the question would appear to be "no" looking at the transcription of Riemann's 1854 Ueber die Hypothesen, welche der Geometrie zu Grunde liegen lecture. However, Bernhard Riemann (1826-...
6
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1answer
86 views
What was the original reason physicists first believed that light must follow a geodesic?
Context: One of the key reasons Einstein first suspected space is curved by mass is due to the falling elevator thought experiment. This experiment implies that mass must curve the path of a light ray....
3
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1answer
115 views
Einstein praising Sophus Lie
p. 153 of
Raúl M. Falcón Ganfornina and Juan Núñez Valdés, “Mathematical Foundations of Santilli Isotopies,” trans. Alan Aversa, Algebras, Groups, and Geometries 32 (2015): 135–308.
quotes (but does ...
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1answer
75 views
What was the chain of theories that led to relativity? [closed]
Can you briefly sketch the sequence of math theories that were necessary for Einstein to figure out a convincing background for relativity?
17
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2answers
3k views
What was the relationship between Einstein and Minkowski?
I read many Einstein's Biographies, but Minkowski was never mentioned, though his discovery of the union of space and time created the basis for GR.
Minkowski was Einstein's teacher of mathematics ...
2
votes
1answer
147 views
Is it true Einstein doubted relativity near the end of his life?
Heard he wrote a bunch of rambling thoughts near the end of his life and doubted his own theory of relativity...it was in Einstein: His Life and Universe by Walter Isaacson
1
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2answers
84 views
Bainbridge's test of mass-energy equivalence
Kenneth Bainbridge was an early pioneer of mass spectroscopy. The Wikipedia article about him says:
He used this instrument to verify Albert Einstein's mass-energy equivalence, E = mc2
with a ...
3
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1answer
244 views
How did Maxwell fall short of Einstein?
This source (I believe it's in Ukrainian) claims that Maxwell came very close to creating the relativity theory, however, it was the fact that he was adhering to the traditional scientific frame of ...
5
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2answers
214 views
Did Einstein want to reduce general relativity to elementary mathematics?
In this recent article, the authors write
Consequently, it is a desideratum to teach general relativity in a way
that is based on elementary mathematics only. This objective, already
stated by ...
3
votes
1answer
96 views
Did Galileo state the principle of equivalence in full generality?
The weak equivalence principle (WEP) is often attributed to Galileo. Did Galileo ever state the WEP precisely? For instance as given here?
The original principle, usually attributed to Galileo, ...
4
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1answer
86 views
General Relativity, General Covariance and Equivalence Principle
Einstein realized that uniform acceleration is indistinguishable from a homogeneous gravitational field (the principle of equivalence) through the Einstein Elevator thought experiment.
From the ...
2
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0answers
46 views
First discussion of radial/volume excess in General Relativity
A well-known (but usually only cursorily discussed) feature of General Relativity is the so-called radial (or volume) excess due to the curvature of spacetime in the presence of mass/energy (or more ...
6
votes
1answer
153 views
When, and by whom was the Schwarzschild metric first taken to be valid for all radii greater than zero?
The metric was originally defined to be valid only from the surface of a black hole outward but somewhere along the line it was extended inward to include the region under the event horizon.
This ...
1
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0answers
59 views
Who first noticed that the radiation pressure formula $p=U/c$ agreed with $E=pc$ from special relativity?
Does anyone know behind stories? As it seems that $p=U/c$ was known before the advent of special theory of relativity, (Halliday, Resnick, Walker says that Maxwell derived this.) when $E=pc$ was first ...
7
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4answers
250 views
Textbook on the History of General Relativity
I have studied General Relativity from various textbooks already, and the subject fascinated me immensely. I was wandering if there is any textbook that deals with the chronological "steps" that ...
3
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1answer
175 views
Did Einstein get inspired by projective geometry?
I read somewhere that projective geometry was an inspiration to Einstein to build the theory of relativity. However, the keyword "projective geometry" isn't mentioned in history of general relativity ...
5
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1answer
218 views
What triggered the general relativity renaissance?
There is a period of general relativity history famous for its lack of activity, where during the 1950's, almost no general relativity was done. Looking through various bibliographies, there were very ...
3
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1answer
95 views
First appearance of causality issues
The oldest appearances of causality troubles in modern theories are of course the Kurt Gödel paper (1949), Reichenbach's philosophy of time and space (1927), Weyl's "Space, time and matter" (1922) and ...
8
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2answers
202 views
Could scientists of Newton's time have explored the limits of his laws of motion?
As noted on this Wikipedia page Newton's laws of motion and of gravity were "verified by experiment and observation for over 200 years" and found to be a "good approximation for macroscopic objects ...
3
votes
2answers
309 views
Math development and under-appreciation of Maxwell's Equations
Freeman Dyson expresses the opinion in his 1972 essay titled "Missed Opportunities" that Maxwell's equations could have played a much bigger role, one that is comparable to classical mechanics, in ...
2
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1answer
94 views
First descriptions of ultrastatic spacetimes?
What's the first appearance of ultrastatic spacetimes (that is, spacetimes with a metric of the form $ds^2 = -dt^2 + h$, with $h$ a Riemannian metric)? The oldest reference I can find on the topic is ...
3
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2answers
268 views
When Was Kaluza-Klein Theory Appreciated?
As far as I understand, the Kaluza-Klein theory, despite its unprecedentedly profound and beautiful character, had a modest following in its early days. I guess that two of the many reasons might be ...
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1answer
87 views
Can a straight line be produced in nature? [closed]
I understand that space is curved, but if one accounted for this curvature and warped the vector accordingly, could a straight line be produced?
When and how was it first proved that this can or ...
0
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3answers
169 views
Absolute space and time before Newton
Why is so much emphasis put on the concepts of absolute space and time as the grand foundations of Newtonian mechanics, and not as foundations also of previous theories, as for example Kepler's laws ...
1
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1answer
231 views
Why is time represented on the vertical axis in space-time diagrams?
One thing that bugs me when learning and explaining special relativity concepts is that the time axis on space-time charts always on the vertical axis. While almost everywhere else time is going on ...
10
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2answers
3k views
Why didn't Einstein win a second Nobel Prize, for relativity?
Einstein's failure to win a Nobel until 1921, and that prize's not being awarded for his work on relativity, is generally ascribed to these factors:
Lack of sufficient experimental proof for the ...
1
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0answers
93 views
Modification of Newtonian Gravity based on Maxwell's Theory
As is well-known, Maxwell's equations were already consistent with Special Theory of Relativity while the Newtonian law of Gravitation wasn't. It can be shown by solving the equations of Maxwell for a ...
1
vote
1answer
58 views
Was the pre-special relativity discussion a hot topic in the late nineteenth and early twentieth century?
We know that low-dimensional materials and topological materials are some of the current hot topics in Physics.
Did this happen with the pre-special relativity discussions in the late nineteenth and ...
3
votes
2answers
198 views
Was an expanding universe proposed before Edwin Hubble's observations?
General relativity (1915), as I've heard it explained, describes a universe that is either shrinking or expanding. By adding a cosmological constant it can describe a universe in eternal steady state, ...
1
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0answers
93 views
First appearance of the timelike cylinder spacetime
Spacetimes with causality violations go back a bit of a way (at least as far back as Herman Weyl's "Space, Time and Matter" in 1922, followed by the Gödel spacetime in 1949), but one of the simplest ...
2
votes
2answers
335 views
How Einstein got the first idea for special relativity?
I am reading Big Bang by Simon Singh. Here is the short story (as I understood it):
Einstein gets a contradiction by assuming that
1- The speed of light $c$ is constant with respect the ether.
2- ...
2
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0answers
82 views
What was Einstein's reasoning to conclude particles follows geodesics through spacetime?
When formulating General Relatvity Einstein proposed that freely falling particles, that is those subject to no forces other than gravity, follows geodesics through spacetime. In other words, those ...
1
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1answer
144 views
Why did Einstein get a better hearing in Goettingen than Berlin?
Jeremy Gray in his 2008 book writes matter-of-factly that Albert Einstein "found he got a better hearing from Hilbert and Klein in Goettingen than he did from his colleagues in Berlin" (page 326). ...
3
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1answer
197 views
Einstein already used the idea of time orientation when formulating General Relativity?
The theory of General Relativity as usually presented currently defines the relativistic spacetime as a tuple $(M,g,\nabla, T)$ where $(M,g)$ is a four dimensional smooth lorentzian manifold, $\nabla$ ...
5
votes
1answer
187 views
Did Einstein ever refer to the coordinate speed/velocity of light?
In modern parlance we talk about two different speeds of light in general relativity. We distinguish between the local speed of light, which is always $c$, and the coordinate speed of light, which can ...
7
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1answer
190 views
How did Einstein arrive at his field equations without the Bianchi identities or variational formulation?
When we introduce the Einstein equations in courses on General Relativity we use either the Bianchi indentity or the the variational principle to motivate the appearance of the Einstein tensor
$$
G_{\...
19
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1answer
2k views
How was Einstein led to make a contact with Differential Geometry for his theory of General Relativity?
General Relativity was developed with Differential Geometry as the tool.
How was Einstein led to make a contact with Differential Geometry for his theory of General Relativity? Who suggested him to ...
7
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1answer
226 views
Debate between relationship of philosophy of mathematics and physics
Did there exist and does there still exist a debate over which school of mathematical thought (i.e. formalism, logicism, intuitionism, etc.) had the most affinity or application for physics? In ...
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0answers
132 views
Was Einstein original formula E =1/2 m c^2?
I read somewhere that, but unfortunately I cannot retrace where, can you help me find a reliable source?
Actually, they said a sad story, hardly believable: They stated that Einstein had circulated a ...
15
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2answers
1k views
What did Einstein contribute to Special Relativity that hadn't already been done by Lorentz in 1904 and Poincaré in 1905?
What did Einstein contribute to what is now called Special Relativity theory that hadn't already been done by
Lorentz in his 1904 "Electromagnetic Phenomena in a System Moving with any Velocity ...
10
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1answer
802 views
Max Planck's reaction to Einstein's 1905 STR Paper
It is quite well-known that Planck was one of the first people to realize the significance and importance of Einstein's theory of relativity. But I have heard a few times that when Einstein sent his ...
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5answers
1k views
Why didn't Einstein's Nobel Prize mention relativity theory?
It seems Einstein's most original contribution to physics was General Relativity Theory, as Lorentz and Poincaré already laid the foundations of Special Relativity. So, why didn't his 1921 Nobel Prize ...
2
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2answers
315 views
How did Lorentz transformations get their modern definition?
Historically, Special Relativity was motivated by apparent inconsistencies between Maxwell's Electrodynamics and Newtonian Mechanics. In Einstein's well known paper "On the electrodynamics of moving ...
4
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1answer
3k views
An English copy of One Hundred Authors Against Einstein?
I've been trying to find the famous article, "One hundred authors against Einstein" (100 Autoren gegen Einstein), of various objections to special relativity, which is quite often referenced, but ...
4
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2answers
290 views
What made Einstein believe (or know) that time was affected by speed and gravity?
How did he come up with this idea before there was any experimental data to prove this?
2
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1answer
93 views
Two articles of Poincaré
In Jammer's book Concepts of Simultaneity on page 108, there is a reference to two of Poincaré's papers:
"...his 1904 lecture on St. Louis..."
"...his contribution to the Lorentz Festschrift."
...
5
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1answer
239 views
What is the origin of the use of “g” for a Riemannian metric?
I am asking about the reason for the use of this letter, if known, as well as the initial occasion of its use. Ideas that have been suggested concerning the former include:
That it stands for ...
9
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4answers
258 views
What was the longest delay between prediction and confirmation of a theory?
The recent announcement of the detection of gravitational waves by LIGO comes almost exactly 100 years after Einstein predicted gravitational waves in 1916. Are there other examples (in the era of ...
