#Relativity

[spaceexp]

Relativity and Grand Theories

From the book DK Ultimate Science Knowledge Encyclopedia

[prokopetz]

Kerbal Space Program was once afflicted by a bug the fans dubbed the "Deep Space Kraken", whereby if you travelled far enough from the origin of the game's coordinate system, floating point rounding errors would cause your spacecraft's components to become misaligned and/or clip into each other, resulting in the craft falling apart or exploding for no obvious reason.

The bug was later fixed by defining the active spacecraft itself as the origin of the game's coordinate system. In effect, the spacecraft no longer moves; instead, the spacecraft remains stationary and the entire universe moves around it. Owing to how relativity works, to the player this is indistinguishable from the spacecraft moving about within a fixed coordinate system, and it ensures that the body of the craft and its components will always be modelled with maximal precision.

While elegant, this solution introduced a new problem: it was now possible, by doing certain stupid tricks with relativistic velocities, to introduce floating point rounding errors to everything except the active spacecraft. In extreme cases, this could result in the destruction of the entire observable universe.

Some might call this one of those situations where the solution proves to be worse than the problem. I call it a perfect expression of what Kerbal Space Program is truly about.

[todays-xkcd]

It says to cut the onions into 1/4" slices, but I'd better correct for length contraction.

Recipe Relativity [Explained]

[toastydumpster]

time loop shenanigans

1 - 2 for the @malevolentbigbang !

Death of The Arthur by @tallangrycockatiel was a delight to read !!!

I had the honor to pair up with @aktrashpanda and @whynotlol9 so please check out their pieces as well!!

ID (thank you Jack) under read more :>

[ID: A recreation of "Relativity" by by M.C. Escher. It includes multiple iterations of Arthur and John in a room made of seemingly nonsensical corridors, rooms and stairs. They're alternatively walking, sitting, and waiting. /End ID]

[noosphe-re]

Gravitation by Charles W. Misner, Kip S. Thorne, John Archibald Wheeler

[facts-i-just-made-up]

What does E = mc^2 actually mean?

Let's start at the very beginning, A very good place to start. When you read, you begin with A-B-C. In science, you begin with E and MC:

E, a quantitative property.

M, the mass of something there.

C, a speed as fast as light.

2, that stands for something squared.

So, if mass and light combined-

Square, and equal energy,

Then, in relative spacetime-

That will bring us back to E equals MC (squared).

That's all in a musical by Rodgers and Einstein of course.

[agent-troi]

big mood sam

[digitalfossils]

[secondwheel]

TIME- from different perspectives

[thedifferentialequationsboy]

black holes aren't black (with caveats)

The name is such a misnomer! In fact black holes in our universe tend to be some of the brightest things there are!

Why? because the immense gravity of a black hole tends to pull matter towards it, in tight orbits, and once close enough, into a whirlpool of sorts that enters into the black hole. Matter including things like stars! so a black hole might not itself produce light but it is surrounded by a bunch of things there are. Saying a black hole is a "light ring with a black inside" would actually be more physically accurate.

In addition, that matter, as it accretes around the black hole, it gets super hot and actually glows. This forms quasars, which are (I'm pretty sure) the most energy-efficient way to turn matter into energy in the universe, and hopefully one day we can control this process artificially with mirrors to extract this energy for human use. Here is what quasars look like:

By ESO/M. Kornmesser - http://www.eso.org/public/images/eso1122a/, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=15700804

So black holes aren't black. Yes, anything within the event horizon (Schwarzschild radius) is black but black holes in general look more like Gargantua in Interstellar than pure black regions of space.

EDIT: Something I forgot to mention but even if black holes don't have gas clouds/matter in their immediate vicinity, you would still definitely "see" them. This is because of gravitational lensing; the gravity of a black hole means that photons travelling from the rest of the universe follow curved paths around them, resulting in a lens-like effect. See here (I didn't make this but it's super cool!) for a very nice visualization. And yes, technically neutron stars also cause gravitational lensing, all things with mass do, but it is the most visible with black holes.

[artbyzigzag]

Meep by ./\/\/\/

Follow me and support my photography.

[tokyoviee]

productivity day 20.

for a girl who can't finish her own syllabus, i do have a lot of audacity to take interest in complex physics topics and read books on them just to understand only 0.1% of what's happening.

so burnt out because I know i’m cooked when even toxic study motivation is not working on me. might shit on my test papers.

MY FEET HURTSSSSSSS. why is training to drive a car so fucking difficult. my brain can't process the hand and leg co-ordination. *sobs*

[nirvanas-xanadu]

[reidiot]

when neville goddard said "since creation is finished, it is impossible to force anything into being" and albert einstein said "imagination is more important than knowledge" . they know exactly what it feels like to be a hot girl tbh

[4gravitons]

Book Review: The Case Against Reality

Nima Arkani-Hamed shows up surprisingly rarely in popular science books. A major figure in my former field, Nima is extremely quotable (frequent examples include “spacetime is doomed” and “the universe is not a crappy metal”), but those quotes don’t seem to quite have reached the popular physics mainstream. He’s been interviewed in books by physicists, and has a major role in one popular physics…