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Unfortunately cosmic string and string theory are different things.

https://en.m.wikipedia.org/wiki/Cosmic_string says

Not to be confused with String, the subject of String Theory.

Under the Bayesian way to do science, you start off with some beliefs (”priors”) about what your trying to understand. You then devise experiments that either confirm or deny those believes. You then update your priors based on the data you see from the experiment.

A normal person might start off with, say, 70% belief that the earth is flat. They then look at some data (take an airliner around the world, look at pictures of earth taken by satellites, do some of those curvature measurement experiments, …). Each time they update their priors, and soon enough it becomes a 99.99% belief that the earth is NOT flat.

A flat earther, for some reason, starts off with a 99.99999% belief that the earth is flat, along with a 99.99999% belief that the government is trying to hide the fact from them. You show them some experiments, they might update their priors to a 99.999%. To convince them the earth is not flat, you would need a LOT of data. You might tell them to look at previous experiments done on this, but due to the 99.99999% belief that the government is lying, they would only have a 0.00001% confidence in the data reported by scientists. So it takes a lot more to convince them that the earth is not flat.

Now why did they start off with such strange priors? They’re probably conspiracy nuts. You can criticize them for that. But don’t call them unscientific if they are still doing experiments and updating their priors.

I am saying flat earth believes attract a lot of conspiracy nuts, and a lot of conspiracy nuts also believe in anti-semitic conspiracy theories.

That doesn’t mean flat earth believes cause them to be anti-semitic.

Are you denying Bayesian statistics now? I’d argue that is even more “unscientific” than denying the earth is round.

Flat-earth belief likely has secondary unwanted effects, like how all conspiracy theories eventually funnel into anti-semitism.

Correlation is not causation

They have their theory. It’s compatible with their experiments. They’re not being “unscientific”. What they believe makes perfect sense given their very strong priors against the possibility that the earth is round.

If you want to criticize them, criticize they way they obtained those extremely strange priors. Do not call people “unscientific” for doing science based upon different prior believes then yours. If everyone have the same believes, there would be no scientific progress.

You can make the nipple pressure sensitive? How?

I am right handed but I always use the Thinkpad nipple with my left hand. I tried switching the click buttons to make it properly left handed, but that made it way harder to use because then the primary click button sits on the right and I have to reach my thumb over. With the right handed settings my thumb is right on the button.

Since when do they have those rules? A year ago I unlocked my Xiaomi phone. Outside China. Did not have a Chinese phone number. It took less than an hour.

even light can stop following null geodesics because the curvature can be too big compared to the wavelength

Very interesting! How do you study something like this? Is it classical E&M in a curved space time, or do you need to do QED in curved space time?

Also, are there phenomena where this effect is significant? I’m assuming something like lensing is already captured very well by treating light as point particles?

So if I have a spherically symmetric object in GR I can write the Schwarzschild metric that does not depend on the radial mass distribution. But once I add a second spherically symmetric object, the metric now depends on the mass distribution of both objects?

Your point about linearity is that if GR was linear, I could’ve instead add two Schwarzschild metrics together to get a new metric that depends only on each object’s position and total mass?

Anyway, assuming we are in a situation with only one source, will the shell theorem still work in GR? Say I put a infinitely light spherical shell close to a black hole. Would it follow the same trajectory as a point particle?

For the bowling ball, Newton’s shell theorem applies, right?

Earth is in this case not an inertial reference frame. If you want to apply Newton’s second law you must go to an inertial reference frame. The 9.81m/s/s is relative to that frame, not to earth.

That is one very impressive feather.

Restricting ourselves to feathers made by non-human animals

🤔🤔🤔

Newton’s second law works in inertial frames. The acceleration of both objects would be the same in the inertial frame. But in the inertial frame, the earth would accelerate faster toward the object if the object was a bowling ball than if it was a feather.

the original title was “your mom falls significantly faster than g”

You said the two objects accelerate at the same rate, but then in the PS you said the feather gets accelerated faster. What do you mean?

Are you saying the feather gets pulled on more because the mass of earth minus feather is greater than the mass of earth minus ball? You would be right. If you lift the feather, measure how long it takes to fall, then lift the ball and measure, you should get the same number. This meme was assuming you either let them fall side by side, or measure them separately but each time conjure the object out of thin air.

Re your first point: I was imagining doing the two experiments separately. But even if you do them at the same time, as long as you don’t put the two objects right on top of each other, the earth’s acceleration would still be slanted toward the ball, making the ball hit the ground very very slightly sooner.

Re your second point: The object would be accelerating in the direction of earth. The 9.81m/s/s is with respect to an inertial reference frame (say the center of mass frame). The earth is also accelerating in the direction of the object at some acceleration with respect to the inertial reference frame.

Nope. The argument only works if you conjured the bowling ball and feather out of thin air vacuum. https://lemmy.world/comment/13237315 discusses what happens when the objects were lifted off earth.