HN user
https://1notes1.online/index.html
I read all the comments in the times post and no one mentions that this is due to the motion of the Artemis II. On the moon there is no "earthrise" or "earthset", only a yearly wobble. On the earth the moon rises and sets because of the earth's rotation. I guess the editors of the NYT knew this so that they put the "earthset" in quotes.
I was able to open it in archive
I use nano a lot but this page is not opening for me. Is someone else having the same problem?
A beautiful book by Michel Pastoureau, Blue: The History of a Color (2001), the same content as the article in book form.
https://www.amazon.com/Blue-History-Color-Michel-Pastoureau/...
More detailed video of Plimpton 322 from the authors of the paper https://youtu.be/L24GzTaOll0?si=sNdwKiM7uYXbzVfL
I tried but his pages do not have links to a home page or other posts
It looks like they chose to use the "universal gravitational constant" "k" instead of Newton^s constant, "G": p.23, "k^2 = universal gravitational constant, 1.32452139x10^20, m^3/(sec^2)(sun mass units)"
I think "k" was also known as "Gaussian gravitational constant" https://en.wikipedia.org/wiki/Gaussian_gravitational_constan...
But the value and unit of "k" given in the Wikipedia page is different. Do you know what NASA document means by "universal gravitational constant" in modern sense?
Mathematician Norman Wildberger has been criticizing the embrace of infinitiy by modern mathematicians for decades: https://www.youtube.com/@njwildberger/search?query=infinity
"What's irrefutably proven is that if you take this particular set of axioms, then these conclusions hold."
This is what I tried to say in my comment. It's the author who talks about the truth of the axioms. I'm objecting to his claim that we end up with "something we can know for sure". No. Your truth depends on your assumptions.
"If the axioms are true, and the subsequent reasoning is sound, then the conclusion is irrefutable. What we now have is a proof: something we can know for sure."
... if the axioms are true. We still don't know for sure absolutely.
"The idea of self-evident truths goes all the way back to Euclid’s “Elements” (ca. 300 B.C.), which depends on a handful of axioms—things that must be granted true at the outset, such as that one can draw a straight line between any two points on a plane."
Strictly speaking, Euclid does not state axioms. He starts with 23 Definitions, 5 Postulates and 5 Common Notions. Drawing a straight line from any point to any point is stated as Postulate 1.
I realize this is a newspaper article.
“the greatest scientist of all time is undoubtedly Sir Isaac Newton”
Newton routinely explained natural phenomena with supernatural causes, like God. In fact he overruled his mathematics with his supernatural explanations. A well-known example is his rationalization of chaotic behavior in his calculations of orbital motions with “the hand of God.” For this reason alone I would downgrade Newton’s scientific status and say that he was a prominent researcher in the 17th century but definitely not “undoubtably the greatest scientist of all time”. Today, we would not call someone who explains natural phenomena with supernatural causes a scientist.
"It concerns the size of the largest sum-free set [0]. Take a (finite) set of integers, A. What is the largest subset of A such that no two entries sum to a third."
Yes, it seems to me we are focusing mainly about sets, not addition. Addition is secondary. Mainly I'm debating the title. The word "set" ought to be in the title too. I guess not a big deal.
Is the main subject here addition or sets?
No, it was a serious question. Does anything that rotates create a magnetic field even if it is not an electrical material?
Why does the earth have a magnetic field?
"“Before we run out of operations, we will rotate it to replicate lunar gravity on the payload portion..."
As far as I can tell, this is the only reference to how they will create artificial gravity. Do you know any other sources with more technical details? Has this been done before?
I like the animation of the orbits. Earth and Mars (and even the satellite) look on circular but eccentric orbits.
Your comment is helpful, thanks. I also discussed this with chatgpt and he said similar things: “Strassler’s term "indivisible waves" seems to be his unique phrasing to make these ideas more intuitive for a lay audience. Physicists usually use more formal language, such as ‘quantized excitations of a field’ or ‘wave-particle duality.’
But my problem is different.
Below I use the word “particle” to mean “a three dimensional indivisible unit,” and nothing else. A particle is not a mathematical point as Strassler suggests when he describes a particle as a “dot.” And a particle is not a wave. If Strassler decides to call waves “particles”, waves do not magically become particles. Ever since the scientific revolution we have not explained natural phenomena by magic.
I read Strassler quote again:
“In a quantum world such as ours, the field’s waves are made from indivisible tiny waves, which for historical reasons we call “particles.” Despite their name, these objects aren’t little dots...”
My interpretation of this quote is like this:
In a quantum world such as ours the field’s waves are made from indivisible tiny waves...
This means that the world is made of quantum fields and fields are waves and not particles [particle are indivisible units, Strassler calls them “little dots”].
This is a clear statement. Strassler is saying that our world is quantum and it is made of fields. Fields are not particles. The unit of study of physics is now fields, not particles. There are no particles in this world because the field is made of waves. These waves are not particles. But they differ from the classical waves because they can only be scaled down to a certain length.
...which for historical reasons we call “particles”. Despite their name these objects aren’t little dots [they are not indivisible units with extension].
Strassler’s quote makes it clear that the building blocks of the world are waves, not particles. In this world of ours there are no particles in the sense of indivisible units. It is only that Strassler chooses to call these waves “particles.” This is just a naming convention.
If someone decides to call “monkey” the animal we know and love as a “donkey”, obviously the long eared cute animal will not become a monkey just because someone decided to call it “monkey”. This play on words can only make a monkey out of logic and create confusion. If we are calling an animal with the name of another animal we are only exposing ourself as a sophist.
This is exactly what Strassler is doing. He is intentionally trying to corrupt the meanings of well established words by loading them with new meanings. He is playing naming games. Calling a wave particle does not make the wave a particle. Then why call a wave particle? No sane person would call a wave “particle” unless he has something to hide and wants to deceive us or even deceive himself.
To me, if true, the fact that the building blocks of the world are waves is a huge and fundamental discovery because it proves that the world is not atomic and matterful as Newton assumed. There are no forces acting between particles because particles do not exist.
This is where the problem lies for physicists. Atomic materialism is their professional dogma and they need to save it despite the experiments contradicting it. But this dogma cannot be saved by using sophistry and calling waves particles.
I copied the quote you couldn’t find from his figure 8: “Figure 8: There’s no perfect intuition for quantum physics. But it’s not helpful to imagine photons and electrons as particles (top right), meaning a “tiny speck”. Nor is it helpful to imagine them as both wave (top left) and particle (top right).”
But he is not talking about wave particle duality. He explicitly states that it is not helpful "to imagine them as both wave and particle." He calls waves with very small amplitude "particles" (for historical reasons). So, according to this picture the building blocks of the universe are waves. It makes no difference if physicists choose to call a wave "particle". Calling a wave particle does not make the wave a particle.
"In a quantum world such as ours, the field’s waves are made from indivisible tiny waves, which for historical reasons we call “particles.” Despite their name, these objects aren’t little dots; see Fig. 8."
Does anyone know when physicists realized that the world is not made of indivisible units called "particles" but waves? Is there a specific experiment or are we talking about the results of many experiments?
"For the subtleties of different meanings of “mass”, see chapters 5-8 of my book.]"
Isn't this called "equivocation" in logic?
What a wonderful book
This is called Kepler's Third Law, right? Radius^1.5 :: Period
Why the date in the title? It's just from a few days ago. It's not like from 2014 or from years ago.
"And the problem was that people ignored what they were supposed to think, and carried on celebrating the new year on 1 January anyway, as they had done since time immemorial."
"Time immemorial" is an exaggeration, right, as many commenters here gave contrary examples.
“ 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?