nyc111

“ Evidence he and others have gathered over the past decade suggests something strange is happening in the outer solar system: distant subplanetary objects are being found on orbits that look sculpted, arranged by an unseen gravitational force.”

Does anyone know what they mean by “sculpted orbits”?

“A particle can have no mass when its energy is entirely derived from its motion, meaning it is essentially pure energy traveling at the speed of light.”

I never understood this. In this case, initially, it is assumed that mass is a property of matter of this moving body. Then we assume that mass disappears but matter or body keeps moving without mass. It looks like there is equivocation or some other kind of play on words here. Can anyone clarify without using the phrase “in Einstein’s special relativity. . .”?

"Sometime between 410 and 420 AD, Martianus Capella came out with a book saying Mercury and Venus orbit the Sun, while the other planets orbit the Earth!"

Was there ever serious considerations of Capella's model? How do we know it is wrong? For instance, Tycho's model was found to be wrong because, if I remember correctly, some orbits crossed each other and that ruined the theory. Is there such a contradiction with Capella's model?

You may want to watch this video to learn more about the project https://youtu.be/pIQ7CaQX8EI?si=mIsNJ-r1cfo3kokx

The authors define vacuum as absence of air. AFAIK in physics today there are several other definitions of vacuum.

I hope he'll recover. He really makes math fun and interesting.

How can this happen? Did they get hold of his email

This debate reminded me Matt Strassler's recent post that most of the data observed in the accelerators are thrown away [1]:

    So what’s to be done? There’s only one option: 
    throw most of that data away in the smartest way
    possible, and ensure that the data retained is 
    processed and stored efficiently.

I thought that was strange. It's like there is too much data and our technology is not up to it so let's throw away everything that we cannot process. Throwing data "in the smartest way possible" did not convince me.

[1] https://profmattstrassler.com/2024/10/21/innovations-in-data...

"...in any spacetime..."

This is just another proof that spacetime as a real entity does not exist. If there are infinitely many spacetimes, spacetime cannot be the fabric of the universe but it can only be fodder for academic careers. There is one universe but an infinite number of spacetimes. So which spacetime is the true one? None of them. You pick and choose one and write a paper on your chosen spacetime and collect your academic points. Another physicist chooses another popular spacetime and she writes a paper on that spacetime. The whole thing is a joke.

But physicists already made spacetime redundant by dividing it back to space and time. This was started by Dirac who restated general relativity with Hamilton formalism. The slicing of spacetime was completed in the sixties with ADM formulation. Also we know spacetime does not exist in practice because when we say "universe is expanding" we mean "space is expanding." It makes no sense to say spacetime is expanding.

I guess you guys found a way to accelerate human body to the speed of light without disintegrating. Why don't you prove your technique first with G-forces?

"'Close to the speed of light' means, like, 99% of the speed of light"

So, you are saying that it is possible to accelerate human body to 99% of speed of light without transforming the body into a massless particle?

"Any massless particle must move at the speed of light"

Does not change my argument. Human body is not a massless particle.

"This is the underlying reason why, when you move at speeds that approach the speed of light, you start to experience phenomena such as time dilation and length contraction:"

This is not even possible in pulp science fiction. In order to be able to move with the speed of light you need to transform yourself into a photon. Only a photon can move with the speed of light. Saying "close to the speed of light" changes nothing. You need to be light to move with the speed close to the speed of light. Macroscopic objects cannot move with speeds approaching light speed.

Org mode is great but for taking notes I started using howm https://github.com/kaorahi/howm?tab=readme-ov-file

I use org-mode export to HTML and then ftp that to the server. Is the OP doing the same without the org-mode?

"This video might help. https://youtu.be/UnURElCzGc0?si=MQa2JKT_CMmM-_JL"

Sagan's video proves that it's always helpful to investigate abstract concepts with an experiment.

But the video also raises an important question: Can we derive true conclusions from wrong assumptions?

Here the assumption that the "flatlanders" are really flat is wrong.

Sagan notices that too and he says that his objects are not really flat, but they have thickness.

  Now these little cutouts have some little height 
  but let’s ignore that, let’s imagine that these 
  are absolutely flat.

So the thickness of his objects are never zero. His flatlanders has a notion of third dimension because they have the third dimension. Their height is not zero.

This is the typical rhetorical sophistry widely used in physics. We may also call it equivocation on the word zero. Here, Sagan defined the word zero both as nothing and something and he wants us to go along with this equivocation.

You cannot have non-zero height and zero height at the same time. If you have zero height you do not exist. A door is either open or closed.

Instead of flatlanders, Sagan may have used shadowlanders. Shadow is closer to two dimensional objects but even shadow has thickness.

So, Sagan's assumption that his objects have no height is definitely wrong. Can we arrive at a correct conclusion from this wrong assumption? I guess not.

Also it is clear that when we try to transform a 3-D object into a 4-D object, the object's morphology changes. A cube becomes something else. A cube does not cross the dimensions as a cube.

This also raises questions about physicists' claim that we are living in a 4 dimensional continuum called spacetime. If so, our current morphology in the 3-D world and 4-D world of spacetime cannot be the same.

Then the question is, is our present anatomy 3-D anatomy or 4-D anatomy?

I would really appreciate if people writing these types of articles first give rigorous and unique definitions of space and time.

"The third dimension won’t be orthogonal."

Are you sure? In a 3-D coordinate system all axes are orthogonal because they make 90 degrees angles with each other.

Edit: I see that you mean "cannot be drawn as orthogonal lines on paper." But, in reality they are orthogonal e.g., when I construct a 3-D model of a cube.

From Wikipedia: https://en.m.wikipedia.org/wiki/Hypercube "4 – If one moves the cube one unit length into the fourth dimension, it generates a 4-dimensional unit hypercube (a unit tesseract)."

How do we draw an orthogonal line to the three orthogonal linas that we have?

I don't understand what is meant here by "dimension." Is the definition of "dimension" consistent for 3-dimensional figures and n-dimensional figures? In other words, what is the importance of the orthogonality of the axes? The axes of dimensions beyond 3-d are not orthogonal, does this change the definition of "dimension".

I cannot conceive a geometrical image of higher dimensions. Algebraically, yes, but not geometrically.

"(as I’ve argued at length elsewhere)"

Everything he writes is "at length". This looks like an interesting read with good ideas but it is so long and has no structure that I gave up reading. It may help to give an abstract in the beginning of the article.

The problem with the treatment of time in physics is that we can only measure time intervals not the philosophical Time (with capital T). But physicists gladly conflate the two.

Mach said: Absolute time [the philosophical Time] cannot be measured by comparison with another motion, it has therefore neither a practical nor a scientific value.

Which means that all of the "t" terms standing for time in astronomical equations are for time intervals and tell us nothing about the philosophical Time.

I couldn’t agree with her more. They’ve turned physics into scholastic sophistry.

Requires subscription to Medium.

"For photons there is [] no inertial frame of reference where photon will [appear to] be stationary (relative or absolute means nothing actually)."

I added my comments to your sentence. Obviously, if photon appears to be stationary, this means relative to something else. So relative and absolute are not meaningless.

"In special relativity the important concept is the frame of reference."

I study motion not special relativity. Motion is a fundamental concept. We don't need to use Einsteinian lingo to study motion.

I was reading this article carefully. I noticed that he uses the word "stationary" to mean both "absolutely stationary" and "relatively at rest". The reasoning in this article is based on conflating and mixing the two meanings. So for instance when he writes "photons are always in motion" [1] he assumes that there are objects that are not always in motion, that is, they are in absolute rest. But he also writes "specifically its 'rest mass' m, which is the mass as measured by an observer who is stationary relative to the object." In this quote, he defines the word "stationary" as relative rest.

This rhetorical trick is so common in physics, that's why I wanted to mention it. The trick is to define the same word twice with its opposite meanings and use the word with both meanings sometimes even in the same sentence. I wonder what is the name of this trick in logic.

[1] This quote is from a different articla: https://profmattstrassler.com/waves-in-an-impossible-sea/wav...

Spacetime in physics has always been an imaginary mathematical construct. Spacetime is not something that exists in reality. Take the deflection of light equation used to compute the deflection of light in General Relativity:

alpha = (4GM)/c^2*r

This equation contains no terms for something called “spacetime”. This equation does not say that the light is bent by spacetime or that this observation is done in spacetime. But physicists write a fictional story over this equation and pretend that spacetime bends the light. The equation doesn’t say that, physicists do. And now physicists decided that spacetime does not really exist, it is emergent etc. Just a few years back people who said these things in forums would be dubbed crackpots by physicists.

Before VAR football was played in real time. The referee who was in the pitch had the sole authority to stop the game and assign the appropriate penalty according to the rule book. Now football is not played in real time. A committee of referees in front of screens watching replays make a decision and can overrule the referee in the pitch. I agree with this article. VAR system must be abolished. The only benefit of VAR is to the technology firms who sell these systems to football.

"This guy is popular with the CS crowd because of his views on infinity & constructivism"

I didn't know. I'll try to find his videos on infinity. I agree with his views on axiomatic set theory. To me the axioms of ZF read like hidden definitions. First they say "in ZF set is not defined" but then they define it with the Axiom of Extension.