I was recommended enthusiastically the book "Essential Relativity" by Wolfgang Rindler. It seems quite complete and original in its exposition, although it avoids very advanced topics like the Kerr solution. Has anyone read it? #physics #generalrelativity

Unifying general relativity and the electromagnetic force? (I presume this also includes the weak nuclear force at sufficiently high energies, but this summary doesn't say)

https://phys.org/news/2025-04-einstein-field-theory.html

I'm pretty much at the limit of my understanding of field theories and such just in this summary article, I don't think I'll even try their full journal article.

@cenobyte - Does Professor Skye or her research assistant have any comment on the matter?

#relativity #GeneralRelativity #electromagnetic #force #field #TOE #GUT

Fresh from the @j824h_arXiv_astro_ph : calculating (numerically) the impact of a wave hitting a spherical overdensity in the cosmos, the wave suffers from a Shapiro delay and thus shows interference patterns. So do we really need fuzzy dark matter to observe interference?! https://arxiv.org/abs/2504.08286

#astronomy #GeneralRelativity #DarkMatter #Cosmology #Gravity

[2504.01675] Einstein's elevator and the principle of equivalence https://arxiv.org/abs/2504.01675

#ITeachPhysics #GeneralRelativity

#totp if you're in the right frame of reference (it would be a non-inertial one), then the sun does indeed go around the moon #GeneralRelativity

Whooooaaaa! The new #JWST image is so good! So much physics going on — physics Einstein himself thought about!

This is called an Einstein Ring. When a massive foreground galaxy (in this case, an elliptical galaxy) warps the space-time around it, light from behind it bends in our direction.

The JWST caught this fantastic example, where the background spiral galaxy is getting warped into our view. It appears as a ring, but we can see its structures like its spiral arms, gas features and star clusters.

Incredible science happening here!

📸 ESA/Webb/NASA/CSA/G. Mahler

I added the annotations in the second image.

#astronomy #astrophysics #generalrelativity #galaxies #science #gravitationallens #Astrodon

Here we observe Einstein’s theories in action. Time dilation occurs in the faster iPhone due to its accelerated CPU.

#BadPhysics #GeneralRelativity

110 years ago today science and how we understand the universe was changed for ever.

https://youtu.be/eNhJY-R3Gwg

#Einstein #GeneralRelativity #theory #published

Entangled Whispers: Sensing Gravity's Quantum Dance

Unlocking the Secrets of the Universe, One Quantum Step at a Time.

https://open.substack.com/pub/influencer1986/p/entangled-whispers-sensing-gravitys?r=37m0cf&utm_campaign=post&utm_medium=web&showWelcomeOnShare=false

#QuantumEntanglement, #Gravity, #QuantumGravity, #Spacetime, #Physics, #QuantumMechanics, #GeneralRelativity, #HolographicPrinciple, #QuantumSensing, #BlackHoles, #Cosmology, #TheoreticalPhysics, #QuantumPhysics, #Science, #Universe, #Entanglement, #QuantumDance, #GravityWaves, #QuantumTechnology, #CosmicMysteries

Today I learned that the person that proved the equations of general relativity (for empty space) always have well defined solutions was a french lady who died about three weeks ago.

Dr Yvonne Choquet-Bruhat proved this via results published in 1952 and 1969: https://en.wikipedia.org/wiki/Yvonne_Choquet-Bruhat #historyofscience #generalrelativity

`In general relativity, a white hole is a hypothetical region of spacetime and singularity that cannot be entered from the outside, although energy-matter, light and information can escape from it. In this sense, it is the reverse of a black hole, from which energy-matter, light and information cannot escape. `

https://en.wikipedia.org/wiki/White_hole

#physics #relativity #Einstein #generalRelativity #gravity #spacetime #blackhole #whitehole

https://phys.org/news/2025-03-gravity-entropy-radical-approach-quantum.html

…quantifies the difference between the metric of #spacetime and the metric induced by #matter fields.

…modified Einstein equations that, in the low coupling regime, i.e., low energies and small curvature, reduce to the classical equations of #generalrelativity…predicting the emergence of a small, positive cosmological constant—a value that aligns with experimental observations of the universe's accelerated expansion…

#quantumgravity #quantuminformation

🌌 Confused by Relativity? We’re Here to Help!
🚀 Don’t Let Relativity Confuse You – Get Expert Relativity Homework Help and Excel in Physics!

✅WhatsApp:- +91-9878492406
📩Email:-help@tutorintellect.com
🌐Visit:- https://tutorintellect.com/relativity-assignment-help/

#tutorintellect #generalrelativity #relativityassignmenthelp #specialrelativity #gravityrelativity #theoryofrelativity #relativityhomeworkhelp #relativitytutoringhelp

Here are some very sad news on an already sad day! 💔
https://www.ihes.fr/en/yvonne-choquet-bruhat-eng/
Yvonne Choquet-Bruhat died yesterday at the age of 101. May she be united with Einstein again and the two can complete the GR-work that they had!
For everyone who wants to enjoy one of her works, have a look at this introduction to General Relativity: https://library.oapen.org/handle/20.500.12657/85657

#YvonneChoquet-Bruhat #GeneralRelativity #PioneersOfScience #History #science

#Euclid #telescope captures #EinsteinRing revealing #warping of #space | #EuropeanSpaceAgency | The Guardian

https://www.theguardian.com/science/2025/feb/10/euclid-telescope-captures-einstein-ring-revealing-warping-of-space

#Science #Astronomy #Relativity #GeneralRelativity #ESA

#DavidLynch consistent with his other worldly oddness par excellence , the last strip above contains one of the few examples I know of of a #GeneralRelativity joke.

Can any astrophysicist here tell me whether the blue ring in Webb's image of quasar RX J1131-1231 is also coming from the quasar, or whether it's coming from the lensing galaxy in the centre? I'm reading contradictory information about this on the ESA site

https://esawebb.org/images/potm2406a/

#astrophysics #quasar #gravitationallen #webb #generalrelativity

Newton’s Opticks and a Query about the Bending of Light

The story of the famous 1919 expeditions to measure the bending of light by the Sun as a test of general relativity has featured many times on this blog (e.g. here). I ahve also written elsewhere about it, e.g. here. One way this is often presented is whether the measurements preferred the “Einstein” prediction or one consistent with “Newton”, there being a famous factor of two between the two.

In fact the earliest published calculation of the deflection of light by the Sun was not by Isaac Newton but by Johann Georg von Soldner (Uber die Ablenkung eines Lichstrals von seiner geradlinigen Bewegung, durch die Attraktion eines Weltk¨orpers, and welchem er nahe vorbei geht. Berliner Astronomisches Jahrbuch, 1801: 161-172). This calculation does use Newtonian theory, but as far as I know there is no record tof any calculation of this sort by Newton himself.

There is, however, something very tantalizing in Newton’s 1704 book Opticks, published almost 20 years after his Principia outlined the laws of mechanics and of universal gravitation. Opticks which (unlike the Principia) was written in English, ends with a series of rhetorical questions called “Queries” which present speculative ideas about light and its interactions with matter. The first of these reads:

Query 1. Do not Bodies act upon Light at a distance, and by their action bend its Rays; and is not this action (caeteris paribus) strongest at the least distance?

This looks very much like a speculation about the bending of light by gravitation. But if that’s what it is, he could have done exactly what Soldner did about a century later. Why then did he never publish the result and why was it never found among his unpublished papers?

I’ve spoken to several people about this and there are three main ideas. One is that Newton actual did the Soldner calculation, and that the manuscript was accidentally destroyed in a fire caused by his dog, Diamond. The other is that he just never got round to it, which seems unlikely because it’s not a difficult calculation and Newton lived over 20 years after the publication of the Opticks. The third possibility is that Query 1 wasn’t about gravity at all. If it had been, wouldn’t he have used the word and wouldn’t he have mentioned the inverse-square law specifically? Perhaps what he had in mind was some kind of refraction. This interpretation is consistent with other Queries where he talks about the “aetherial Medium” through which he supposed light to propagate being distorted by the presence of massive bodies and thus causing refraction. For example, from Query 21,

Is not this Medium much rarer within the dense Bodies of the Sun, Stars, Planets and Comets, than in the empty celestial Spaces between them?

I suppose we’ll never know what Newton had in mind. I am split between the first and third explanations above.

It’s worth mentioning that some of the other Queries are very prescient. Take Query 5, for example:

Do not Bodies and Light act mutually upon one another; that is to say, Bodies upon Light in emitting, reflecting, refracting and inflecting it, and Light upon Bodies for heating them, and putting their parts into a vibrating motion wherein heat consists?

Clever chap, Newton!

#1919EclipseExpeditions #AlbertEinstein #generalRelativity #IsaacNewton #JohannGeorgVonSoldner

📣 Tiburtius Prize 2024 for Gustav Uhre Jakobsen 🏆

Recognition award for visiting postdoc at AEI Potsdam

Gustav Uhre Jakobsen, a postdoc at the Humboldt University of Berlin and in the Astrophysical and Cosmological Relativity Department at the @mpi_grav in the Potsdam Science Park, will be awarded a “Tirburtius Prize – Prize of the Berlin Universities” for his dissertation.

The reviewer praises not only the impressive wealth of topics in Jakobsen's doctoral thesis titled “Gravitational Scattering of Compact Bodies from Worldline Quantum Field Theory” and the quality of the research results, but also the impact it has had in the research community.

➡️ https://www.aei.mpg.de/1202051/tiburtius-prize-2024-for-gustav-uhre-jakobsen

#ResearchAward #Berlin #PhDThesis #PhDLife #QuantumFieldTheory #GeneralRelativity

@ec_euclid

Reminder: in a spacetime A satisfying #GeneralRelativity, light in a vacuum travels in straight lines, no matter how much mass is nearby. There's *no* bending of light paths.

Instead, spacetime is curved by mass. If you project from A to a Euclidean 3-space B, with a mapping f:A->B, then the *projected* paths of light are bent in B. Like the flight paths of planes flying in straight lines are bent when projected onto flat maps of the Earth.

#LiesToChildren

https://en.wikipedia.org/wiki/Lie-to-children