Does this explain what generates gravity?
- Thread starter edbarx
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As a man who rarely accepts explanations at face-value, having seen the lowest depths of human nature, I have to wonder if she FELL, or if she was PUSHED?
Who placed the offending Butt where ANYONE could trip over it, doubtless onto an unyielding brick path? 😕
Surely she can only have suffered Vertigo upon being led to the top of a lonely and precipitous Pembrokeshire cliff by person or persons unknown?
I am pleased to hear this lady is not travelling to Scotland soon. as It is my understanding it is home to countless Serial Killers:
The fact her husband seems to have an unhealthy interest in visiting Crime Scenes only disturbs one further.
There is a reason the Cops always check out family members first in such unsavoury matters... 🙁
Now I really think we need to get back on-topic now, lest this thread goes the way of "The Other Thread".
What were we talking about? I have quite forgotten. 🤣
Who placed the offending Butt where ANYONE could trip over it, doubtless onto an unyielding brick path? 😕
Surely she can only have suffered Vertigo upon being led to the top of a lonely and precipitous Pembrokeshire cliff by person or persons unknown?
I am pleased to hear this lady is not travelling to Scotland soon. as It is my understanding it is home to countless Serial Killers:
The fact her husband seems to have an unhealthy interest in visiting Crime Scenes only disturbs one further.
There is a reason the Cops always check out family members first in such unsavoury matters... 🙁
Now I really think we need to get back on-topic now, lest this thread goes the way of "The Other Thread".
What were we talking about? I have quite forgotten. 🤣
I have learned something interesting about folks from Norfolk from Toffish James Blunt's VV Funny new book:
Apparently folks from Norfolk are so inbred that it is quite normal to only have two grandparents. This must save money on Christmas cards. 🤣
"Goodbye My Lover" is apparently the most played Funeral Song in the UK. This is unsurprising since "You're Beautiful" bored most of them to death.
Carlo Rovelli (Unsurprisingly a Loopy Quantum Physicist...) spent most of his worthless book rambling not about Werner Heisenberg, but about Marx, Lenin and Stalin and Bogdanov.
Honestly, if I wanted that stuff, I would have bought "The Socialist Worker" newspaper, and as you know my robust politics, you will find that unlikely to the highest degree. 🙄
Evidently y'all have forgotten what we were talking about too... it is THE DIRAC EQUATION.
Since Ladybird have yet to tackle this fierce subject in one of their children's books, I have been looking for clarification on SU(2) spinors and unit Quaternions elsewhere:
Now I can tolerate a bit of Autistic Spectrum Disorder as well as the next chap, but listening to the flat monotone of "eigenchris" is like being stuck in the Lord Palmy with my friend Mike when he launches into one of his 10 minute Conspiracy Theory rambles.
Last time it was that Type 1 Diabetes doesn't exist and is cured with Broccoli if I followed. It is all on Youtube. Since our lovely barmaid Katie was present, and her son has this affliction, I was having to restrain her from punching him in the face.
I usually shut him up by deflecting him onto the subject of a wager on the horses, which he too enjoys. Like "Attila The Honey", which, I notice is running in the 15.45 Fillies Handicap at Newmarket tomorrow, and due a win. You heard it here first. 🙂
Apparently folks from Norfolk are so inbred that it is quite normal to only have two grandparents. This must save money on Christmas cards. 🤣
"Goodbye My Lover" is apparently the most played Funeral Song in the UK. This is unsurprising since "You're Beautiful" bored most of them to death.
Carlo Rovelli (Unsurprisingly a Loopy Quantum Physicist...) spent most of his worthless book rambling not about Werner Heisenberg, but about Marx, Lenin and Stalin and Bogdanov.
Honestly, if I wanted that stuff, I would have bought "The Socialist Worker" newspaper, and as you know my robust politics, you will find that unlikely to the highest degree. 🙄
Evidently y'all have forgotten what we were talking about too... it is THE DIRAC EQUATION.
Since Ladybird have yet to tackle this fierce subject in one of their children's books, I have been looking for clarification on SU(2) spinors and unit Quaternions elsewhere:
Now I can tolerate a bit of Autistic Spectrum Disorder as well as the next chap, but listening to the flat monotone of "eigenchris" is like being stuck in the Lord Palmy with my friend Mike when he launches into one of his 10 minute Conspiracy Theory rambles.
Last time it was that Type 1 Diabetes doesn't exist and is cured with Broccoli if I followed. It is all on Youtube. Since our lovely barmaid Katie was present, and her son has this affliction, I was having to restrain her from punching him in the face.
I usually shut him up by deflecting him onto the subject of a wager on the horses, which he too enjoys. Like "Attila The Honey", which, I notice is running in the 15.45 Fillies Handicap at Newmarket tomorrow, and due a win. You heard it here first. 🙂
The Dirac equation describes the intrinsic 'spin' of fermions and that's why its solutions are often called spinors.
What else would any budding astrophotographer require to know?
Apart from perhaps:
The Dirac equation is written as G - mΨ = 0, where G is the Dirac operator, m is the mass of the fermion, and Ψ is is a complex-valued 4-vector called the wave function, or spinor.
I shall proceed no further with the mathematics as, for me at least:
Paul Dirac was a trained draughtsman and expert in projective geometry (Which Felix Klein was rather good at too.), so I think he was doing the geometry of SpaceTime at heart,
Clearly there are things in 4 dimensions that are not our everyday 3D experience. No chance of a book about Linear Algebra outside the University Library, but I did pick up an interesting overview of the Cosmos by Dr. Jillian Scudder at Southsea Library, who's parents clearly couldn't spell:
It's really very interesting if non-technical. Our Galaxy is about 100,000 LY across but only 400 LY thick for the most part. Which makes it like a credit card if you want a sense of scale.
This means, I think, that if you look away from the Milky Way due Galactic North (Coma Berenices) or Galactic South (Sculptor), you shouldn't see many bright but distant stars. I think this is true.
This is for most of us the dull patch between Arcturus in Bootes and Denebola in Leo. Which happens to house Galaxy NGC 4565 almost edge on:
You can see all the dust which absorbs blue light, but that the JWST can see through in the infra-red. And the typical central bulge.
10Bn years ago there were 10X more short-lived bright blue stars, but the loose gas is running down now.
Still awaiting the new battery, but when it arrives I shall be off to Southsea Castle, which seems to have good and well-designed downlighters that I can work with:
Best, Steve.
Clearly there are things in 4 dimensions that are not our everyday 3D experience. No chance of a book about Linear Algebra outside the University Library, but I did pick up an interesting overview of the Cosmos by Dr. Jillian Scudder at Southsea Library, who's parents clearly couldn't spell:
It's really very interesting if non-technical. Our Galaxy is about 100,000 LY across but only 400 LY thick for the most part. Which makes it like a credit card if you want a sense of scale.
This means, I think, that if you look away from the Milky Way due Galactic North (Coma Berenices) or Galactic South (Sculptor), you shouldn't see many bright but distant stars. I think this is true.
This is for most of us the dull patch between Arcturus in Bootes and Denebola in Leo. Which happens to house Galaxy NGC 4565 almost edge on:
You can see all the dust which absorbs blue light, but that the JWST can see through in the infra-red. And the typical central bulge.
10Bn years ago there were 10X more short-lived bright blue stars, but the loose gas is running down now.
Still awaiting the new battery, but when it arrives I shall be off to Southsea Castle, which seems to have good and well-designed downlighters that I can work with:
Best, Steve.
Errata: I just reread what Jillian Scudder said about the general thickness and size of our Milky Way Galaxy. She really explained it badly. The correct figure is 4000 LY thick, and 100,000 LY wide.
Good. That ties in with the photo and alleviates my concerns, and doubtless yours too. 😎
Good. That ties in with the photo and alleviates my concerns, and doubtless yours too. 😎
Indeed, the Dirac equation is used to study the properties and behaviour of particles in curved spacetime.
Apparently, the Dirac matrices depend on the underlying metric of four-dimensional Minkowski spacetime.
That vaguely makes sense to me! 😀
Erratum: My previous (plural) Errata should have read (singular) Erratum. Schoolboy mistake in Latin. Sorry. 😡
You can imagine I have now been checking Dr. Jillian's statements for Mathematical or Chemical precision.
She states that the density of air is measured in Kilograms per cubic meter, but interstellar Space is measured in atoms per cubic meter. 😕
Surely air weighs nothing? NO. It is denser than I thought.
This means the mass of air under a standard Wetherspoon's Pub table weighs about as much as a 1kg bag of sugar if you make your own lumpy custard.
TBH, it takes huge mathematical ability to convert 35g to a heaped tbsp, or is it a level tbsp? I really get confused. But I do know, because I tried it, there are 10 regular cupfuls in 4 pints or 2.2lL of milk.
Or a carton of Ambrosia custard if you are like my spoiled great nephews, who evidently live solely on this extravagant stuff mixed with pricey Gu chocolate puddings!
Actually lasts about 2+ minutes in my lovely but extravagant niece's household. About the same as Magnum ice-creams. 😛
This brings us onto how much a cubic meter of water weighs. It is a staggering Metric Tonne or Imperial Ton:
What I am getting at, is most of us have absolutely no idea about what quantities like a Light Year or Planck's Constant mean, unless expressed in Pints, Bags of Sugar and the length of double-decker London Buses.
This is what Jillian is addressing.
FWIW, Outer Space apparently contains lots of molecules of Ethyl alcohol (Rum) and Ethyl Formate (Raspberries). Strange but true. 😀
You can imagine I have now been checking Dr. Jillian's statements for Mathematical or Chemical precision.
She states that the density of air is measured in Kilograms per cubic meter, but interstellar Space is measured in atoms per cubic meter. 😕
Surely air weighs nothing? NO. It is denser than I thought.
This means the mass of air under a standard Wetherspoon's Pub table weighs about as much as a 1kg bag of sugar if you make your own lumpy custard.
TBH, it takes huge mathematical ability to convert 35g to a heaped tbsp, or is it a level tbsp? I really get confused. But I do know, because I tried it, there are 10 regular cupfuls in 4 pints or 2.2lL of milk.
Or a carton of Ambrosia custard if you are like my spoiled great nephews, who evidently live solely on this extravagant stuff mixed with pricey Gu chocolate puddings!
Actually lasts about 2+ minutes in my lovely but extravagant niece's household. About the same as Magnum ice-creams. 😛
This brings us onto how much a cubic meter of water weighs. It is a staggering Metric Tonne or Imperial Ton:
What I am getting at, is most of us have absolutely no idea about what quantities like a Light Year or Planck's Constant mean, unless expressed in Pints, Bags of Sugar and the length of double-decker London Buses.
This is what Jillian is addressing.
FWIW, Outer Space apparently contains lots of molecules of Ethyl alcohol (Rum) and Ethyl Formate (Raspberries). Strange but true. 😀
3 to 10 hydrogen atoms (depends on the source) per cubic metre in the intergalactic voids is what I’ve read. These atoms are the detritus left over from the BB that weren’t sucked up into stars etc.
I think the more complex molecules are found in interstellar space and nebula rather than intergalactic voids. This is the case because the elements that go to form these compounds(other than hydrogen) are the result stellar nuclear synthesis which won’t be happening in the intergalactic voids.
I think the more complex molecules are found in interstellar space and nebula rather than intergalactic voids. This is the case because the elements that go to form these compounds(other than hydrogen) are the result stellar nuclear synthesis which won’t be happening in the intergalactic voids.
Earlier this year, I reported on the 2006 discovery of methanol filaments surrounding the stellar nursery W3(OH).
https://spacenews.com/upgraded-merlin-spies-cloud-of-alcohol-spanning-288-billion-miles/
These filaments are represented by the green contours in the image below.
W3 (OH) is part of a giant molecular cloud about 6200 light-years away in the Perseus Arm, one of the Milky Way galaxy’s main spiral arms.
Shown in the image above, W3 and nearby W3 (OH) contain the most recent high-mass star formation.
My old university text book, 'Heat' by R.G. Mitton gave some staggering facts about air which I've updated and will present in this thread.
There are approximately 30 million million million molecules in just 1 cubic centimetre of air at standard atmospheric pressure.
Now the diameter of an air molecule (O2/N2) is around 300 trillionths of a metre.
If we could do the impossible and stack all the molecules in 1cc of air on top of each other, then the resulting line would stretch for around 9 thousand million metres.
That's around 11 times to the Moon and back! 😵
What makes it doubly more difficult to comprehend is that the 30 million million million molecules which occupy that single cubic centimetre of air are, on average, 10 times their own diameter apart. This means most of that tiny volume is empty space!
The World's Greatest Astrophotographer (Haua...) spotted an Orange Blue SuperMoon on Saturday. Through the clouds, if you follow.
Weird thing was my snap wasn't orange, so no-one will believe me... 😡
Silly Steve had left the camera set to Black and White for some reason! Oh well... 🙁
Now we are up to speed on the density of air and water, I have gleaned something weird and interesting about the Quasar APM 08279+5255 from Dr. Jillian's excellent AND funny and entertaining book:
https://en.wikipedia.org/wiki/APM_08279+5255
I won't try and explain how this distant and ancient elliptical Galaxy woks exactly.
But having a humungous Black Hole, lots of excitation and lots of gas and especially water vapour, it is a natural H2O Maser which happens to point and lens our way.
In fact the brightest thing in the known Universe.
How much water? Well this is the Earth's stock:
There is about 100 Trillion times more around the Black Hole. I have just done the maths, and I think this water would make a liquid blob the size of Mercury's orbit.
This is 25,000 times the mass of our Sun, and 4,000 times the mass of H2O in our entire Milky Way galaxy.
I really haven't done any more maths on it, but I understand a humungous Black Hole can be the size of Neptune's orbit, but strangely only the density of air.
TBH, the effect of cubic volume laws is a bit beyond me. Inverse square is weird enough sometimes.
Weird thing was my snap wasn't orange, so no-one will believe me... 😡
Silly Steve had left the camera set to Black and White for some reason! Oh well... 🙁
Now we are up to speed on the density of air and water, I have gleaned something weird and interesting about the Quasar APM 08279+5255 from Dr. Jillian's excellent AND funny and entertaining book:
https://en.wikipedia.org/wiki/APM_08279+5255
I won't try and explain how this distant and ancient elliptical Galaxy woks exactly.
But having a humungous Black Hole, lots of excitation and lots of gas and especially water vapour, it is a natural H2O Maser which happens to point and lens our way.
In fact the brightest thing in the known Universe.
How much water? Well this is the Earth's stock:
There is about 100 Trillion times more around the Black Hole. I have just done the maths, and I think this water would make a liquid blob the size of Mercury's orbit.
This is 25,000 times the mass of our Sun, and 4,000 times the mass of H2O in our entire Milky Way galaxy.
I really haven't done any more maths on it, but I understand a humungous Black Hole can be the size of Neptune's orbit, but strangely only the density of air.
TBH, the effect of cubic volume laws is a bit beyond me. Inverse square is weird enough sometimes.
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I read only the other day about how surprisingly little water the Earth has in relative volume terms.
Thankfully, we are blessed with more than 1.3 billion cubic kilometres of H2O, much of which may have been brought here by asteroids and comets.
The mathematics shows that the event horizon grows linearly with the mass. In other words, if the black hole’s mass doubles, the event horizon radius doubles as well.
A billion solar mass black hole would have an event horizon 3 billion km in radius, roughly the distance of Neptune to the Sun.
The resulting density would be roughly 1/1000 of a gram per cc - and that’s the density of air!
EDIT: I see that we looked at the mathematics back on page 47, post #922.
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That is indeed an interesting object, as I have been finding out: https://www.jpl.nasa.gov/news/astronomers-find-largest-most-distant-reservoir-of-water
The quasar is gravitationally lensed by an intervening galaxy and appears as two bright images.
Hubble spectroscopic analysis shows a rare, third faint image between the two brighter images.
The water Steve mentioned, equivalent to 140 trillion times all the water in the world's ocean, is in the form of water vapour which is distributed around the black hole in a gaseous region spanning hundreds of light-years in size.
This water vapour is unusually warm and dense by astronomical standards with a temperature of -53 degrees C.
There's water vapour in the Milky Way, although the total amount is 4,000 times less than in the quasar, because most of the Milky Way's water is frozen in ice.
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