I hope positron works out fine, last time I checked it was not yet usable.
Replacing Rstudio with something more reliable would be nice, because of some major design flaws Rstudio has.
A lot of the UI stuff runs also in R, so when the R kernel dies, quite often I cannot save unsaved files. So I need to copy the file content to a different text editor when that happens.
I also don't understand why the LLM-Chat window is running inside the R console, and then blocks running R code. That makes it completely unusable.
I fully agree! But at least this shot with the Seestar 50 motivates me to try to get a more sharp shot on the full moon with my telescope. Just to prove to myself that I can do that.
Yes, exactly. That is why we think the extra dimensions might be small, und the inverse square law is only violated at and below the size of the extra dimensions.
This is also why we are using the Yukawa Potential to constrain that possibility, because it has a length scale and a strength of a potential deviation from the inverse square law.
See also: https://en.wikipedia.org/wiki/Fifth_force
It could be a compact[0] dimension, i. e. of finite length. In the simplest case you might imagine it as a circle attached to every point in our 3-dimensional Euclidean space. The aforementioned length scale would be the circumference of that circle.
Trying to wrap my head around this explanation and I’m picturing a looping gif. You have your normal x and y dimensions and then time through the gif. If the loop length is very short then distance between any two pixels will mostly only depend on x and y. Is that right?
Interesting case if we are the “ants” and it is our 3 dims happen to be compact looping somewhere beyond our event horizon. Multitude of Universes in that garden hose in which gravity can be falling as cube or more while at small scale if our compact Universe we’ll see square, and only very precise measurements may notice a bit larger than square.
Another possibility is if our brane has a lot of folds coming close/touching - that would make gravity there stronger like say that dark matter idea inducing rotation speed curve of the disk stars.
> Interesting case if we are the “ants” and it is our 3 dims happen to be compact looping somewhere beyond our event horizon. Multitude of Universes […]
I think you're mixing up two different cases here: 1) Our established 3 dimensions are actually compact, i.e. loop around or hit a boundary somewhere. No multiverse here. 2) There are extra dimensions, meaning that for every point in that extra dimension there's another 3-dimensional universe as we know it.
The expansion of the space is the feature which prevents any physical process inside to distinguish between those options. Kind of a hack - make compact Universe, add expansion and it would inside look and feel indistinguishable from non-compact.
In the simplest case, yes. Though, once curvature (gravity) enters the picture, it could (in theory) become more complicated, as the additional dimension could get stretched or compressed.
Imagine if Flatland were a very long string in a big circle. In one direction you go around the big circle and it's a long distance. At a right angle to that, you go around a tiny little circle.
Because gravity will be observed to decay with distance cubed for distances on the scale of the extra dimension, and distance squared beyond that; and we have not found a scale where we see gravity decay faster than distance squared (but it gets harder and harder to measure at small scale, so the error bars grow).
IIRC experimental gravity data rules out any compactified dimension bigger than 50μm, but a question I keep coming back to is "surely the pictures of atomic bonds taken by electron microscopes rules compactified dimensions larger than 1Å?"
interesting question. my (somewhat naive) thought about it is that bonds are maintained by the EM force, which is so strong that it swamps out any contribution from gravity.
If a compactified spatial dimension exists in our universe, and was big enough to fit an atom, why couldn't we see two atoms that seem like they're in the same 3-dimensional coordinates?
Sometimes compactified dimensions are analogised to a straw: seen from a distance it seems one dimensional, up close (an ant's perspective) it's got one long dimension and one short dimension.
I don't know how far to take the analogy. It sounds like surely photons with wavelengths smaller than the compactified dimension would be likely to take a spiral path, looping around compact dimension n times for every m units of 3-space travelled, which would seem like they were mysteriously slow if you weren't expecting the compact dimension to exist.
I vaguely remember the idea of wavelength-dependent speed of light is a thing that's been ruled out by tests with supernova data, but not to what wavelength or sigma.
I think you're describing a completely different geometry than I'm describing.
An ℝ²-brane such as flatland existing in a ℝ³ bulk is different to an ℝ²⨯S¹.
If the S¹ part* is present in our universe to the degree that it can explain anything about gravity, it should also have an impact on everything else in the universe larger than the radius of the S¹ dimension's circumference.
* well, S^n ⨯ T^m, the version of string theory I hear most about has n+m = 6, but there are others, and this thread is a toy model where n=1, m=0
Edit: Apparently the U+1D54A character is stripped, so put a plain ASCII "S" back in.
Yes but you would sure as heck bump into it if it was big.
Like literally in the middle of your sitting room. Isn’t it a known meme horror thing - monster slices from another dimension splicing across into ours as they move through their planes .
Basically it doesn’t happen but the dimensions do exist so they must be small.
At a research institute I worked for, we had a proxy server that intercepted http. The antivirus software on the proxy made it impossible to download some security updates once in a while.
Fortunately it was possible to change the ubuntu URIs to https:// to use HTTPS and the broken antivirus sofwate did not intervene anymore.
In a closed physical system energy is conserved.
For example, if you have container that has Helium on one side and Oxygen on the other. Both gases will mix, i.e. maximize entropy.
Minimizing energy would mean, the gas would reach absolute zero.
Replacing Rstudio with something more reliable would be nice, because of some major design flaws Rstudio has. A lot of the UI stuff runs also in R, so when the R kernel dies, quite often I cannot save unsaved files. So I need to copy the file content to a different text editor when that happens. I also don't understand why the LLM-Chat window is running inside the R console, and then blocks running R code. That makes it completely unusable.