#relativity — Public Fediverse posts

@setebos Small #note for #future #posts:

Would be good to know why it's the #best #writing for you (before trying the link).

It is a bit clearer and more chance if it's #relative to me, rather than "I'm not sure why".

Just saying as I wouldn't usually want to click unless it's your stuff more directly and before trying other people's or without knowing why you recommend it.
Thanks

#mutual #relativity

@setebos Small #note for #future #posts:

Would be good to know why it's the #best #writing for you (before trying the link).

It is a bit clearer and more chance if it's #relative to me, rather than "I'm not sure why".

Just saying as I wouldn't usually want to click unless it's your stuff more directly and before trying other people's or without knowing why you recommend it.
Thanks

#mutual #relativity

The #paperOfTheDay is "Foundations of the new field theory" from 1934. This new field theory today goes by the name of "Born-Infeld theory", it is an alternative version of classical electrodynamics.
Recall that in 1934, #quantum mechanics had recently been developed, but there was not yet any consistent #quantumFieldTheory , let alone a fundamental theory of elementary particles. In particular, classical (Maxwell) electrodynamics predicts an infinite self-energy if one assumes the electron to be point-like, and people discussed different ways to unify the picture of microscopic #physics .
Born-Infeld theory represents one possible scenario, modeled after Einstein's general theory of #relativity . Namely, a theory of electromagnetism based on general coordinate invariance, and the assumption that there is an universal maximum electrical field strength that no system can exceed. This gives rise to a Lagrangian that is structurally similar to the Einstein-Hilbert one. The field equations are then non-linear, but reduce to the Maxwell theory for weak enough fields in flat space.
Close to the center of an electron, the field strength is large, and the new theory is substantially different from classical electrodynamics: The potential is not singular at the origin, but always stays finite.

Later, however, many of the old mysteries got resolved with the quantization of Maxwell electrodynamics. On the other hand, Born-Infeld theory (much like general relativity) is strongly non-linear and hard to quantize with existing methods.
https://royalsocietypublishing.org/rspa/article/144/852/425/3579/Foundations-of-the-new-field-theory

Why Does E=mc2?: (And Why Should We Care?) "In science, there are no universal truths, just views of the world that have yet to be shown to be false" Sale: $18.99 to $1.99 by Brian Cox Rating: 4.4/5 (2,118 Reviews) #physics #science #relativity #booksky #books #einstein #education #reading

Why Does E=mc2?: (And Why Shou...

Darkness Can Move Faster Than Light Without Breaking the Laws of Physics

Artistic depiction of the darkness measurement. Image not to scale. Physicists have experimentally confirmed a strange prediction: the…
#NewsBeep #News #Physics #CA #Canada #darkness #generalrelativity #relativity #Science #speedoflight
https://www.newsbeep.com/ca/649634/

Darkness Can Move Faster Than Light Without Breaking the Laws of Physics

Artistic depiction of the darkness measurement. Image not to scale. Physicists have experimentally confirmed a strange prediction: the…
#NewsBeep #News #US #USA #UnitedStates #UnitedStatesOfAmerica #Physics #darkness #GeneralRelativity #Relativity #Science #speedoflight
https://www.newsbeep.com/us/625064/

Darkness Can Move Faster Than Light Without Breaking the Laws of Physics

Artistic depiction of the darkness measurement. Image not to scale. Physicists have experimentally confirmed a strange prediction: the…
#NewsBeep #News #US #USA #UnitedStates #UnitedStatesOfAmerica #Physics #darkness #GeneralRelativity #Relativity #Science #speedoflight
https://www.newsbeep.com/us/625064/

https://www.europesays.com/ie/469668/ Darkness Can Move Faster Than Light Without Breaking the Laws of Physics #DARKNESS #Éire #GeneralRelativity #IE #Ireland #Physics #relativity #Science #SpeedOfLight

https://www.europesays.com/uk/939311/ Darkness Can Move Faster Than Light Without Breaking the Laws of Physics #darkness #GeneralRelativity #Physics #Relativity #Science #SpeedOfLight #UK #UnitedKingdom

Master Index

A guided map across physics, biology, engineering, and AI—built around a simple idea

Persistence is not generated, but permitted.

Systems don’t fail because they “break.”

They fail because their boundaries were misclassified.

Core structure
state → constraint → resolution → persistence

From: - Titanic / Vasa / Challenger
– biological regulation
– AI hallucination & drift
– institutional collapse

Same pattern
only admissible states persist

This is the interface.
Start anywhere. Follow the path that fits.

#HybridMind42 #BoundaryDynamics #BoundaryArchitecture #BFPF #HQP
#Admissibility #ConstraintResolution #StateTransition #Persistence
#ComplexSystems #SystemsThinking #StructuralAnalysis #FailureAnalysis
#Physics #QuantumMechanics #Relativity #Lindblad #CPTP #Decoherence
#Biology #Physiology #Adaptation #Homeostasis
#ArtificialIntelligence #AI #LLM #AIAlignment #AIGovernance
#InstitutionalFailure #DecisionMaking
#Emergence #ScientificClarity

https://substack.com/@hybridmind42/note/c-252017333?r=75c2ac

i am the greatest #fortran programmer of all time. i wrote a program that does length contraction more accurately than my calculator. I am well chuffed with this considering how bad of a programmer i am.

#physics #relativity #math #programming

The Biggest Ideas in the Universe: Space, Time, and Motion "The most trusted explainer of the most mind-boggling concepts pulls back the veil of mystery " Sale: $19 to $2.99 by Sean M. Carroll Rating: 4.5/5 (1,271 Reviews) #Physics #Cosmology #Relativity #SpaceTime #Science #Books #STEM #BookSky

The Biggest Ideas in the Unive...

Einstein’s Relativity May Explain the Scarcity of Planets Orbiting Binary Star Systems

📰 Original title: Why two-sun planets keep disappearing scientists blame Einstein

🤖 IA: It's not clickbait ✅
👥 Usuarios: It's not clickbait ✅

View full AI summary: https://killbait.com/en/einsteins-relativity-may-explain-the-scarcity-of-planets-orbiting-binary-star-systems/?redirpost=b7abd2b2-f02e-475b-aba9-61edecc9ca39

#astronomy #exoplanets #relativity #binarystars

Einstein’s Relativity May Explain the Scarcity of Planets Orbiting Binary Star Systems

📰 Original title: Why two-sun planets keep disappearing scientists blame Einstein

🤖 IA: It's not clickbait ✅
👥 Usuarios: It's not clickbait ✅

View full AI summary: https://killbait.com/en/einsteins-relativity-may-explain-the-scarcity-of-planets-orbiting-binary-star-systems/?redirpost=b7abd2b2-f02e-475b-aba9-61edecc9ca39

#astronomy #exoplanets #relativity #binarystars

Einstein’s Relativity May Explain the Scarcity of Planets Orbiting Binary Star Systems

📰 Original title: Why two-sun planets keep disappearing scientists blame Einstein

🤖 IA: It's not clickbait ✅
👥 Usuarios: It's not clickbait ✅

View full AI summary: https://killbait.com/en/einsteins-relativity-may-explain-the-scarcity-of-planets-orbiting-binary-star-systems/?redirpost=b7abd2b2-f02e-475b-aba9-61edecc9ca39

#astronomy #exoplanets #relativity #binarystars

Einstein’s Relativity May Explain the Scarcity of Planets Orbiting Binary Star Systems

📰 Original title: Why two-sun planets keep disappearing scientists blame Einstein

🤖 IA: It's not clickbait ✅
👥 Usuarios: It's not clickbait ✅

View full AI summary: https://killbait.com/en/einsteins-relativity-may-explain-the-scarcity-of-planets-orbiting-binary-star-systems/?redirpost=b7abd2b2-f02e-475b-aba9-61edecc9ca39

#astronomy #exoplanets #relativity #binarystars

As is well known, the Einstein-Hilbert action of general #relativity, i.e. Einstein #Gravity, can not be "simply" turned into a #quantumFieldTheory in the usual perturbative way. Over the decades, this has given rise to dozens of proposed solutions, either by modifying the Einstein-Hilbert action (e.g. introducing a fourth derivative term), or by modifying quantum field theory (e.g. replace it by #stringTheory ), or by examining the possibility for fully non-perturbative quantum field theory (e.g. #asymptoticSafety studies via functional renormalization).
One of the approaches that somehow combines the first and second viewpoint is #causalSetTheory . There, one assumes that spacetime is fundamentally discrete, not like a lattice, but more like a random #graph and the edges in this graph represent causal relations (i.e. being in the future or past light cone). Viewed from afar, this might look like a 4-dimensional spacetime, but looked closely, there is only discrete structure. The edges (causal connections) do not only join nearest neighbours, but can reach far along the lightcone, this gives rise to non-trivial effects, and it makes it surprisingly hard to simulate such a causal set (I've tried that once, but without much success).
The causal sets community has produced a 1 hour video to explain these concepts to a general audience interested in #physics
https://www.youtube.com/watch?v=5EoZE1rOHAo

Very interesting and insightful. 👍

Why the Speed of Light Is NOT a Speed - Leonard Susskind
https://www.youtube.com/watch?v=QqcLRZdVBIg (~21 min.)

#Physics #SpeedOfLight #Einstein #Relativity #Spacetime #Science #QuantumPhysics #Universe #Mind #Reality

Often we seek to "cheat" relativity, but if we instead follow time dilation to its logical conclusion, the picture is unexpectedly...divine?

Read more at my #blog: https://www.adamasnemesis.com/2026/04/01/by-the-light-of-genesis/

This post's featured image is Witold Pruszkowski's "Falling Star".

#relativity #science #physics #spaceflight #worldbuilding #sciencefiction #scifi #timedilation #technology #futurism #futurology #future

#paperOfTheDay "On the identification of gravitation with a massless spin 2 field" from 1986. This article deals with the general theory of #relativity . Namely, if one starts from a generic field theory of a spin-2 particle, the resulting theory has a symmetry that suggests to identify it with general relativity. However, if one stays as closely as possible analogous to #electrodynamics and the conventional assumptions of field theory (fields decay at infinity), then the only possibility seems to be that the universe is asymptotically flat an has no holes or any other topological features, and the cosmological constant must be zero.
I am not sufficiently familiar with general relativity to assess if this is in fact the only possible conclusion. In any case, the paper is a nice exposition of field theory with spin 2, a topic which is not usually covered in introductory physics lectures.
https://link.springer.com/article/10.1007/BF03053785

@cenobyte

I've spent the last hour-plus going through more of the "stuff" he links from the overview, and (a) I still have no way to tell if it makes sense or if it's just LLM-generated physics drivel, and (b) I get more and more concerned that "one self-educated non-physicist overturns all of modern physics and solves all outstanding problems", while hypothetically tenable, strains credulity.

I mean, a long history of cranks "disproving" Einstein (dunno why they all hated relativity so much) and Dirac and everything else just screams "This guy is a nutter". The alarm bells are ringing. I really want people who actually understand this stuff to read it and tell me whether I can write this guy off as such a crank.

But weirder things have happened. Einstein was just a clerk in a patent office who no one had heard of when he demonstrated the then-new and completely unsupported-by-evidence quantum theory, which had only been proposed to solve the (ultra)violet catastrophe, could actually explain the completely unrelated and then-unexplained photoelectric effect. He won the Nobel in physics for that - not relativity - and cemented quantum theory in place, even if he never liked it. A nobody who single-handedly stamped the dividing line between classical physics and modern physics.

<brain-exploding>

#crank #cranks #relativity #nutter

Also my favorite diagram so far, illustrating what happens when you jump out of the John Hancock Tower (i.e., the version we built out of accelerating ships that has fake gravity):

#physics #ftl #relativity #scienceed

Part 6
https://wrog.dreamwidth.org/72287.html

in which, having established what (little) math we actually need, we get to the truly fun part:

How constant acceleration works
a.k.a.
What you need to know re
Faking Gravity in Special Relativity.

It is **a** **lot** weirder than you would expect.

Light shining up or down gets Doppler-shifted.

Gravity increases as you go downstairs, but you'll live longer.

There are event horizons.

And one year downstairs is the Infinite-Gravity Horror Show where time comes to a complete stop... or something...

#physics #relativity #ftl #scienceed

https://mastodon.murkworks.net/@wrog/116054745477223253

Part 5:
https://wrog.dreamwidth.org/71989.html
about how to transform between Moving and Stationary People coordinates (Lorentz transformations) and what velocity angles are (they're like rotation angles, but different)

(trying to make this accessible to folks who haven't seen a whole lot of linear algebra [though, as I recall, I *did* know about matrices in 6th grade;... thought they were cool..)

#physics #relativity #ftl #scienceed

I of course goofed and left out the explanation of Lorentz Contraction from the obvious place in Part 3 where I should have talked about it.

So I've slotted it in here:
https://wrog.dreamwidth.org/71271.html#hrel3_lorentz
along with a new diagram to make super-clear what's happening.

Or if you want to get the flow/parallelism there's now this link https://wrog.dreamwidth.org/71271.html#hrel3_timedil
to the earlier time dilation discussion (cleaned up a bit), since that's really the same issue but turned on its side 90°.

So maybe the Stargate SG-1 example will be clearer now. or maybe not
(the point of the blue arrows is this is the kind of shit you can do if you have stargates: A Completely Easy Time Machine they'd have built half-way thru season 2)

#relativity #physics #ftl #scienceed

Part 4:
https://wrog.dreamwidth.org/71432.html

#physics #relativity #ftl #scienceed

On the Storrow Drive Theorem

This is on how, having developed how one does spacetime for a 1-dimensional universe, how you put back the 2nd and 3rd spatial dimensions,

and the key question is what happens when you have college students attempting to measure the height of a bridge using rental trucks,

i.e., what differences are there in how the Moving People see it vs. how the Stationary People see it. Do the Moving People see a different height? Or see the truck slanted weirdly? Curiously, the answer to both of these turns out to be NO.

And we have this fun diagram

Part 3:
https://wrog.dreamwidth.org/71271.html

…introduce the _Interval_ between two events

= (Δz, spatial separation)² − (Δt, time lapse)²

and show that this number is an **invariant**, i.e., all slower-than-light observers get the same result calculating this in their own coordinates.

Magic diagram (with ALT text!) below proves this for Moving (upwards) vs. Anti-Moving (downwards, same speed) observers (i.e., using that Intermediate POV from before), and go from there.

Interval is either
(*) (proper distance)² > 0 [events are simultaneous for somebody],
(*) −(proper time)² < 0 [events are co-located for somebody], or
(*) zero [light-speed trajectory]

and then we do Twin Paradox and How FTL Violates Causality.
#physics #relativity #ftl #scienceed

I also really like how this diagram came out.

It's another spacetime-with-left-to-right-time grid from the stationary observer POV, showing trajectories of
(*) the stationary observer,
(*) the (velocity v) moving observer, and
(*) all possible in-between trajectories
+
how the two observers measure velocities
+
how the two observers will **not** agree on which trajectory is going v/2
+
how the One True Intermediate Trajectory
(i.e., the one that both see going the same speed) is between the v/2 trajectories **and** seen by both observers as going **faster** than v/2.

...this being the Big Red Flag that velocities don't add the way you'd think.

(also spelled out more fully in Part 2)

#physics #relativity #ftl #scienceed

Part 2:
https://wrog.dreamwidth.org/71156.html

In some ways, the following diagram is the whole ball of wax, essentially summarizing why the moving observer will *not* agree with stationary observer on simultaneity of events.

It's a spacetime diagram with time going left to right, depicting someone moving upwards (black line), bouncing a light ray off of a reflector above/below them (yellow lines).

If you get what's going on here, why the moving person''s '"snapshot" (blue line) of what's going on Right Now cannot be vertical (i.e., aligned with the stationary person's snapshots), you can derive everything else.

(see the full post for the actual argument)

#physics #relativity #ftl #scienceed

`The Lense-Thirring effect, a prediction of general relativity, implies that massive rotating objects like Earth can slightly "drag" spacetime, which could affect the pendulum's oscillation. This effect, though theoretically significant, is currently too small to measure with a Foucault pendulum.`

https://en.wikipedia.org/wiki/Foucault_pendulum#Absolute_reference_frame_for_pendulum

#physics #Foucault #pendulum #FoucaultPendulum #Earth #rotation #relativity #generalRelativity #Einstein

`The Lense-Thirring effect, a prediction of general relativity, implies that massive rotating objects like Earth can slightly "drag" spacetime, which could affect the pendulum's oscillation. This effect, though theoretically significant, is currently too small to measure with a Foucault pendulum.`

https://en.wikipedia.org/wiki/Foucault_pendulum#Absolute_reference_frame_for_pendulum

#physics #Foucault #pendulum #FoucaultPendulum #Earth #rotation #relativity #generalRelativity #Einstein

`The Lense-Thirring effect, a prediction of general relativity, implies that massive rotating objects like Earth can slightly "drag" spacetime, which could affect the pendulum's oscillation. This effect, though theoretically significant, is currently too small to measure with a Foucault pendulum.`

https://en.wikipedia.org/wiki/Foucault_pendulum#Absolute_reference_frame_for_pendulum

#physics #Foucault #pendulum #FoucaultPendulum #Earth #rotation #relativity #generalRelativity #Einstein

`The Lense-Thirring effect, a prediction of general relativity, implies that massive rotating objects like Earth can slightly "drag" spacetime, which could affect the pendulum's oscillation. This effect, though theoretically significant, is currently too small to measure with a Foucault pendulum.`

https://en.wikipedia.org/wiki/Foucault_pendulum#Absolute_reference_frame_for_pendulum

#physics #Foucault #pendulum #FoucaultPendulum #Earth #rotation #relativity #generalRelativity #Einstein

`The Lense-Thirring effect, a prediction of general relativity, implies that massive rotating objects like Earth can slightly "drag" spacetime, which could affect the pendulum's oscillation. This effect, though theoretically significant, is currently too small to measure with a Foucault pendulum.`

https://en.wikipedia.org/wiki/Foucault_pendulum#Absolute_reference_frame_for_pendulum

#physics #Foucault #pendulum #FoucaultPendulum #Earth #rotation #relativity #generalRelativity #Einstein

I decided it was time for another go at explaining Special Relativity.

I remain annoyed at how few people really get it, even amongst avid SF consumers, who have gotten entirely too accustomed to generations of SF writers papering over the FTL issues with technobabble, 'cause we need that galactic empire, don'tcha know.

The idea is to do this with basic geometry you knew or could have learned about in 6th grade plus a bit of algebra (up to Pythagorean Theorem, which I *definitely* remember our math classes teaching in 6th grade).

I think I can get by without using a single square-root sign.

Anyway, here's part 1:

https://wrog.dreamwidth.org/70909.html

#physics #relativity #ftl #scienceed

🎉 Ah, the profound musings of #Ryan Moulton: #time is relative, #kids have lots of it, #adults don't. Who knew? 🤯 Let's all think about #clocks 🕰️ and pretend we're doing something ground-breaking. 🌈
https://moultano.wordpress.com/2025/12/30/children-and-helical-time/ #Moulton #relativity #groundbreaking #HackerNews #ngated

🔭 Marvin Watches a Cube Break Common Sense

If a cube flew past at nearly the speed of light, it wouldn’t look squashed.
It would look… rotated.

Marvin pauses mid-sip of tea.
“That,” he notes, “is not what intuition promised.”

Terrell & Penrose showed (1959) that relativistic motion produces an optical twist, not a squash. Light from different parts of an object reaches the observer at different times, and the brain stitches time into shape.

A new lab experiment made this visible by slowing light with ultrafast lasers. Cubes and spheres appear rotated — exactly as predicted.

Marvin understands the problem immediately;
“You never see the thing,” he says. “You see the story light tells you.”

Nothing changes physically.

The boundary does.

🧠 In relativity, seeing is a space-time calculation.

#Relativity #Physics #ObserverEffect #SpaceTime
#HybridMind42 #BoundaryPhysics #ScienceExplained

Hackaday Links: December 14, 2025 https://hackaday.com/2025/12/14/hackaday-links-december-14-2025/ #HackadayColumns #ColonialMarine #Hackadaylinks #hackadaylinks #righttorepair #JeMeSouviens #timedilation #relativity #SpaceForce #airstream #bugbounty #einstein #GameOver #guardian #Montreal #Artemis #Slider #bounty #canada #brick #Canoo #DCMA #mars #nest #drm #ice #VCF #ev

Hackaday Links: December 14, 2025 https://hackaday.com/2025/12/14/hackaday-links-december-14-2025/ #HackadayColumns #ColonialMarine #Hackadaylinks #hackadaylinks #righttorepair #JeMeSouviens #timedilation #relativity #SpaceForce #airstream #bugbounty #einstein #GameOver #guardian #Montreal #Artemis #Slider #bounty #canada #brick #Canoo #DCMA #mars #nest #drm #ice #VCF #ev

Hackaday Links: December 14, 2025 https://hackaday.com/2025/12/14/hackaday-links-december-14-2025/ #HackadayColumns #ColonialMarine #Hackadaylinks #hackadaylinks #righttorepair #JeMeSouviens #timedilation #relativity #SpaceForce #airstream #bugbounty #einstein #GameOver #guardian #Montreal #Artemis #Slider #bounty #canada #brick #Canoo #DCMA #mars #nest #drm #ice #VCF #ev

Hackaday Links: December 14, 2025 https://hackaday.com/2025/12/14/hackaday-links-december-14-2025/ #HackadayColumns #ColonialMarine #Hackadaylinks #hackadaylinks #righttorepair #JeMeSouviens #timedilation #relativity #SpaceForce #airstream #bugbounty #einstein #GameOver #guardian #Montreal #Artemis #Slider #bounty #canada #brick #Canoo #DCMA #mars #nest #drm #ice #VCF #ev

philosophically speaking, the coolest thing about relativity is that it explicitly states that time & space have to be jointly defined. space has no meaning without time, and time has no meaning without space.

#relativity #philosophy #physics #science #spacetime

I've been thinking about writing a piece on the Relative Intersubjectivity of Subjectivity, but I need to focus on indexing my Language Insufficiency Hypothesis.
👉 https://philosophics.blog/2025/11/29/the-relative-intersubjectivity-of-subjectivity/?utm_source=bluesky&utm_medium=social
Meantime, enjoy this #Midjourney clip.
#philosophy #ideas #subjectivity #relativity #aiart #amwriting #thinking #blog #ideation #marination #thoughts #art

I've been thinking about writing a piece on the Relative Intersubjectivity of Subjectivity, but I need to focus on indexing my Language Insufficiency Hypothesis.
👉 https://philosophics.blog/2025/11/29/the-relative-intersubjectivity-of-subjectivity/?utm_source=bluesky&utm_medium=social
Meantime, enjoy this #Midjourney clip.
#philosophy #ideas #subjectivity #relativity #aiart #amwriting #thinking #blog #ideation #marination #thoughts #art

I've been thinking about writing a piece on the Relative Intersubjectivity of Subjectivity, but I need to focus on indexing my Language Insufficiency Hypothesis.
👉 https://philosophics.blog/2025/11/29/the-relative-intersubjectivity-of-subjectivity/?utm_source=masto&utm_medium=social
Meantime, enjoy this #Midjourney clip.
#philosophy #ideas #subjectivity #relativity #aiart #amwriting #thinking #blog #ideation #marination #thoughts #art

I've been thinking about writing a piece on the Relative Intersubjectivity of Subjectivity, but I need to focus on indexing my Language Insufficiency Hypothesis.
👉 https://philosophics.blog/2025/11/29/the-relative-intersubjectivity-of-subjectivity/?utm_source=bluesky&utm_medium=social
Meantime, enjoy this #Midjourney clip.
#philosophy #ideas #subjectivity #relativity #aiart #amwriting #thinking #blog #ideation #marination #thoughts #art

I've been thinking about writing a piece on the Relative Intersubjectivity of Subjectivity, but I need to focus on indexing my Language Insufficiency Hypothesis.
👉 https://philosophics.blog/2025/11/29/the-relative-intersubjectivity-of-subjectivity/?utm_source=masto&utm_medium=social
Meantime, enjoy this #Midjourney clip.
#philosophy #ideas #subjectivity #relativity #aiart #amwriting #thinking #blog #ideation #marination #thoughts #art

An excellent 1964 pop sci video from the USSR, explaining special relativity in a very accessible way, newly subtitled in English:

https://youtube.com/watch?v=P_1DJhLEHEQ

#PopScience #PopSci #relativity #SpecialRelativity #einstein #AlbertEinstein #USSR

SES expands launch contract with Relativity Space

https://fed.brid.gy/r/https://spacenews.com/ses-expands-launch-contract-with-relativity-space/