Limbo

So I heckled "No, keep sinning, otherwise Jesus would have died in vain!"

They stumbled then continued, while turning up the megaphone a notch "Jesus died for your sins, ascended into Heaven and on the third day was resurrected..."

I interjected "So you're saying, He only gave up one weekend for our sins? That's a weak effort!"

The preacher spluttered, nonplussed, disturbed by my Atheist heckling.

I continued "Three days to get to heaven and back, even at the speed of light, would put Heaven somewhere in between the Kuiper Belt and the Oort cloud, quite close really and anyway we know he only went into Limbo for the three days. There's even a medieval painting of Him there, done by one of Heronymous Bosch's adepts.

"You are going straight to Hell!"

"No, I go to Limbo first and wait there until judgement day, don't you know your own doctrine?" Then I wandered off (to Limbo someday?).

All of which got me researching Limbo to find out more about the place.

Limbo comes from the Latin limbus, meaning 'the edge' (of Hell). Let's see how various religions perceive Limbo. . .

Medieval (catholic) theologians of western Europe described Hell as divided into four distinct parts: Hell of the Damned, Purgatory, Limbo of the Fathers or Patriarchs (who died in BC), and Limbo of the Infants (who died unchristened). Limbo is a sort of parking lot for those whose fate will not be decided until the day of judgement. Yet another imaginary figment of The One True Church^®'s imagination. Sort of like a black hole, if you go there, no information can possible get out ;-)

But the more modern 1992 Catechism of the Catholic Church does not actually use the word Limbo. Instead, Luke 16:22 called it "bosom of Abraham". Protestantism does not accept the concept of a limbo of infants. Jehovah's Witnesses, Christadelphians, and others have taught that the dead are unconscious until Judgement Day. As a neutral waiting place, the Zoroastrian hamistagan is like the Roman Catholic limbo. In the Hebrew Bible, She'ol is the equivalent of Limbo. Islam does not have a Limbo; their angels Nakir and Munkar interrogate a recently deceased soul, which then remains in its grave in a state of bliss or torment until Judgment Day. They call this Barzakh. In Classical Greek Mythology, the Fields of Asphodel were a realm in Hades much resembling Limbo. In Buddhism, bardo is a liminal state (aka parking lot) between death and rebirth. Aside : Do Buddhist medical records include a field for last cause of death?

In literature, Harry Potter is described by JKR as being in Limbo, after Voldemort attempts to kill him. Dante's Inferno depicted Limbo as the first circle of Hell. In The Matrix Revolutions, Neo gets trapped between the Matrix and the Machine in a train station named Mobil Avenue; if you hadn't noticed, Mobil is an anagram of Limbo.

I find it interesting that almost all religions find a need for this parking lot concept in order to resolve the dilemma caused by their various beliefs. We Atheists have it much easier, dead is dead, no need to invent a limbo, much less a god ;-) The preacher claimed I'd go to Hell directly , skipping Limbo, for saying that. So here's a photo upon arrival ;-)

Harping on with the Black Hole analogy, its event horizon is a 2D surface without the passage of time or any depth. So, without any depth, calling it an edge (lat: limbus) was a good idea, and any light quanta would be spread around in just 2D (Gravity's rainbow, perhaps?). And maybe those in Limbo (without the passage of time) are on an event horizon somewhere? So redemption happens by Hawking radiation perhaps? Is that a quantum of solace for the OTC? ;-)

Comments (5)
Cop Car wrote " Do you recall Bernard Wolfe's Limbo? It certainly caught my attention when I read it as a high-schooler. From https://www.depauw.edu/sfs/backissues/72/seed72.htm: "In 1952 there occurred in America the publication of one of the most unusual and original novels of the early postwar period. Bernard Wolfe's Limbo was the first novel of a Yale psychology graduate who had served for a time on Trotsky's staff in Mexico and then held a series of posts as editor or correspondent for a number of periodicals. Limbo has been routinely mentioned in histories of dystopias and more recently within the context of cybernetic fiction (Warrick 146-50; Gary K. Wolfe 211-24)."
Cop Car also sent me a scan of the cover, adding " As I recall, the front of the book had a logo comprising three legs (side-view as if running) radiating at 120-degree intervals from a common point at the top of the thighs. It foretold a main feature of the book wherein the protagonist " - finds to his amazement that facetious remarks he made in a wartime journal have been taken seriously and developed, in the wake of the war, into an international movement ("Immob," i.e. Immobilization) dedicated to the eradication of human aggression by voluntary amputations ("vol-amp") and their replacement by prosthesis." To which I replied : The Triskelion is the flag of the Isle of Man (and of Sicily). 'Quocunque Jesseris Stabit' is the Latin motto beneath it, which means 'whatever way you will have thrown [it] it will stand'. :-)
Petra (A) punned "CC, vol-amp sounds like Wolfe was punning on 'disarmament', but what about 'dislegament'?" Groan! That's going out on a limb, Petra ;-)
Liz wrote " What's that? Jesus said to the thief on the cross, today you will be with me in paradise. That'll do for me." You are referring to Luke 23:43, Liz; but on the Sunday of His resurrection He said that he had "not yet ascended to the Father" (according to John 20:17). So there may have been a translation error, the other version of Luke being "I say to you today, You will be with me in paradise", which doesn't say WHEN they'll be in Paradise. One of the many biblical contradictions. In the 3rd century AD, New Testament (NT) manuscripts (such as the oldest Luke we have) were written without separation between words and sentences and no punctuation was used to indicate how the text should be read. The comma, for example, was not introduced there until the ninth century. So, was it put in before or after the word for 'today'? Either way it was 800+ years too late.
Liz replied " Yes, I know. There are all sorts of contradictions in the bible. But you wrote: the other version of Luke being "I say to you today, You will be with me in paradise", But then you say the comma wasn't introduced until much later - so the original could well have been "today you will be with me in paradise." You know so much more about the bible than I do. " Exactly. We don't know what the author's intention was; since he did not punctuate his text, it could be either. So, going with the John 20:17 verse, I'd chose the second variant of Luke 23:43. YMMV :-)

Copyright ^© Ole Phat Stu on April 19, 2019 permalink Comments Email

Black Hole : first photo

Scientists today released the first photo of a black hole (the supermassive black hole in the galaxy Messier M87). As predicted by Einstein, this is a region of spacetime where gravity is so strong that matter is compressed to a point of infinite density known as the singularity. Further out is the event horizon - defined by the Schwarzschild radius - from inside which even light cannot escape the gravitational pull. But this is NOT what is shown on the photo. At 1.5 Schwarzschild radii it would theoretically be possible for photons (light) to have a stable circular orbit around the singularity. At 2.6 Schwarzschild radii particles of matter could orbit it (at the speed of light?). Outside of that we can see the accretion disc of matter being fed into the black hole. So we are actually seeing the shadow of the black hole against the accretion disc. There is a short (9½ min) but good explanatory video on YouTube of what we are seeing in the photo.

Galaxy M87 is so far away that sophisticated interferometry techniques were needed over a period of 6 months to get a baseline long enough to enable this photo of its supermassive black hole to be calculated. Photo attributed to the EHT, Event Horizon Telescope and just released an hour ago :-)

After the EHT press conference, I felt a need to celebrate with a donut ;-)

Comments (6)
Petra (A) asks "Why did you write that the photo was 'calculated'?" Because it is not an optical photo. It is an analog representation of the signal strength received by RADIO (λ=1.3mm) telescopes. Nobody on the (European) news/press conference mentioned that one small fact :-(
Schorsch (D) asks "The black hole emits no light. So what is illuminating the accretion disc?" Remember the picture is showing microwavelength radiation. What you are seeing is synchrotron emissions from charged particles orbiting the black hole. The brighter portions are moving towards us, the darker away. Afaik. BTW, the photo's colours are arbitrary.
SWMBO asked "How big is it?" M87 is about 54 million light-years away. The black shadow in the picture is about 4 times the size of our solar system, i.e. the radius is about the same distance as to Voyager 1 now. The black hole itself (event horizon) is about 40% of that and probably spherical. The invisible singularity is a point of course.
Peter (UK) wrote " York (UK) has a 'cycle the solar system' scaling ... and pubs to match :-) is it worth considering the distance to a radius from the sun maybe.. ;-)" Yes, Peter, like York's, most scaled solar systems I've seen put all the planets more or less in a straight line (a VERY rare occurence indeed!).
Cop Car wrote " Thanks for the great posting (and for the link to the video)! We have become so accustomed to false color and construction of astronomical images that sometimes we fail to tailor the language. Your language, contrarily, is precise." Blush :-) Credit is due elsewhere, I merely reported the work of others. E.g. Katie Bouman, who led a team that designed one of the algorithms that helped analyze data that led to the first image of a black hole. And Andrew Chael who wrote much of the code for data analysis. And the (as always, nameless) QA tester [it was Katie] ;-)
Ed (USA) suggests "That's where Trump's tax returns disappeared ;-)" I thought they died of windmill cancer :-("

Copyright ^© Ole Phat Stu on April 10, 2019 permalink Comments Email

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Thursday, April 4, 2019

Scarecrow maths right under one condition

Did you ever see "The Wizard of Oz"? There's a scene where the scarecrow says he has regained his brain after misquoting Pythagoras' theorem. He said "The sum of the square roots of any two sides of an isosceles triangle is equal to the square root of the remaining side."

Obviously, this is a parody. Also repeated by Homer of The Simpsons a couple of times. But let's ask ourselves if there any circumstances where the scarecrow's version might be true?

So the scarecrow is claiming √a + √a = √b where the equal sides are both a.

Squaring both sides of this equation we get a + 2√a√a + a = 4a = b,
so the isosceles triangle would not close! There can be no such plane triangle!

However, that was for a triangle on a plane. What happens if the triangle was on e.g. a sphere? Looking at the sphere/globe from the top/north-pole, we can see the equator shown in black, length b, and two meridians shown in red, each of length a. This is an isosceles triangle in spherical geometry. The condition 4a=b is only (just) satisfied when the two meridians overlap - the limiting case.

So the scarecrow's version of Pythagoras is only just possible for spherical geometry with both meridians merged into one and the angle between the isosceles arms being 360°, QED :-)

Which only goes to show that you shouldn't let math-geeks watch children's movies. We get distracted too easily ;-)

Comments (1)
Piet (B) grinned "Your mind certainly does wander! But thanks for that derivation, I shall pass it on." Spherical geometry is a load of balls ;-)

Copyright ^© Ole Phat Stu on April 4, 2019 permalink Comments Email

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