On 29 June, four separate teams of scientists announced they had seen strong hints of very long gravitational waves warping our galaxy.
Until now the gravitational waves that have been detected have wavelengths of tens to hundreds of kilometres, but the latest evidence hints at ripples with wavelengths of 1 light year or longer.
The most likely sources of the newfound gravitational waves are merging supermassive black holes 100 million to 10 billion times the mass of the Sun.
This discovery is the culmination of a decades-long study involving a galaxy-sized detector made up of rapidly spinning pulsars.
I'm trying to access more information, but the National Geographic article to which I've linked is only available to subscribers:
https://www.nationalgeographic.com/...he-first-time#:~:text=The most likely sources
Until now the gravitational waves that have been detected have wavelengths of tens to hundreds of kilometres, but the latest evidence hints at ripples with wavelengths of 1 light year or longer.
The most likely sources of the newfound gravitational waves are merging supermassive black holes 100 million to 10 billion times the mass of the Sun.
This discovery is the culmination of a decades-long study involving a galaxy-sized detector made up of rapidly spinning pulsars.
I'm trying to access more information, but the National Geographic article to which I've linked is only available to subscribers:
https://www.nationalgeographic.com/...he-first-time#:~:text=The most likely sources
@brianco. I found your Artificial Hollow Moon Hypothesis surprisingly plausable as an engineering concept. 
As every gifted mathematician knows, the centre of gravity of a hemispherical shell of notional radius R is located at R/2, therefore it should work.
It would also have to subtend a solid angle larger than 2Pi Steradians to account for libration.
Perhaps I should more precisely have said that there exists a Full Moon in Portsmouth, of which at least one side is Orange.
Where it will "Fall Down" is that the Tidal Effect on Earth would be detectably less than expected due to its low mass, IMO. But doubtless good enough to fool the "Flat Earthers" who have no concept of how Gravity, or indeed Science, works.
Since @Galu mentions Cosmic mergers of Humungous Black Holes in the early, hotter and denser Universe, I want to mention Gold:
They say the best things in Life are free, but that don't mean a lot to me.
But where does GOLD come from? If you say a hole in the ground, you are being facile. If you say from a Supernova, and not many people know this, you will be PLAIN WRONG!
As every gifted mathematician knows, the centre of gravity of a hemispherical shell of notional radius R is located at R/2, therefore it should work.
It would also have to subtend a solid angle larger than 2Pi Steradians to account for libration.
Perhaps I should more precisely have said that there exists a Full Moon in Portsmouth, of which at least one side is Orange.
Where it will "Fall Down" is that the Tidal Effect on Earth would be detectably less than expected due to its low mass, IMO. But doubtless good enough to fool the "Flat Earthers" who have no concept of how Gravity, or indeed Science, works.
Since @Galu mentions Cosmic mergers of Humungous Black Holes in the early, hotter and denser Universe, I want to mention Gold:
They say the best things in Life are free, but that don't mean a lot to me.
But where does GOLD come from? If you say a hole in the ground, you are being facile. If you say from a Supernova, and not many people know this, you will be PLAIN WRONG!
"Gold" comes from True, Spandau Ballet's third album!
Seriously though: Gold has been seen to be created when a pair of city-sized neutron stars in a galaxy 130 million light years from Earth smashed into each other at one third the speed of light, forming a kilonova.
The spectrum of the kilonova contained the fingerprints of the heaviest elements in the universe, including platinum and gold.
These elements are formed by the r-process (rapid neutron-capture process) that is responsible for the creation of approximately half of the atomic nuclei heavier than iron.
I see that I described the r-process back on page 152, post #3,035 when discussing a neutron star merger and the resulting kilonova.
It's a process in which an atomic nucleus captures neutrons quickly enough to allow very heavy elements to be created.
The kilonova in the distant galaxy referred to in my previous post is estimated to have produced a whopping 10 Earth masses of gold!
If you are wearing some gold jewelry right now, then take a good look at it.
That gold would have been created in a similar kilonova that took place in our own galaxy billions of years ago!
It's a process in which an atomic nucleus captures neutrons quickly enough to allow very heavy elements to be created.
The kilonova in the distant galaxy referred to in my previous post is estimated to have produced a whopping 10 Earth masses of gold!
If you are wearing some gold jewelry right now, then take a good look at it.
That gold would have been created in a similar kilonova that took place in our own galaxy billions of years ago!
If you want to get a feeling for the scales involved, the average depth of the Earths oceans is 3700 metres while the diameter of the Earth is about 25 million metres. Consider the oceans like the skin of an apple. The habitable atmosphere's is about 2 apple skins thick. Life on Earth exists in a very, very confined space.The World's Greatest Astrophotographer (Haua...) spotted an Orange Blue SuperMoon on Saturday. Through the clouds, if you follow.
View attachment 1346786
Weird thing was my snap wasn't orange, so no-one will believe me...
View attachment 1346787
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:
View attachment 1346789
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:
View attachment 1346795
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.
The image below shows the Earth's atmosphere as seen from the International Space Station.
You've put your foot in it there, TNT!
https://avia2b.com/blog/why-feet-ar...on between pilots and air traffic controllers.
Feet, yes.
Feets, no.
https://avia2b.com/blog/why-feet-ar...on between pilots and air traffic controllers.
Feet, yes.
Feets, no.
I mean, really, why don't planes cruise at 26,666 cubits and travel at 1,344,000 furlongs per fortnight?
I suppose that keeping flight altitude at 40,000, 35,000 and 30,000 feet is easier than ~12,000, ~10,600 and ~9100 meters.
Besides, surely it upset the French and Germans.
They already came up with CAN and AFDX....
I suppose that keeping flight altitude at 40,000, 35,000 and 30,000 feet is easier than ~12,000, ~10,600 and ~9100 meters.
Besides, surely it upset the French and Germans.
They already came up with CAN and AFDX....
More pesky abbreviations!
I had to call for help: https://www.abbreviations.com/CAN
CAN: Common Area Network?
AFDX: Avionics Full Duplex Network?
Unfortunately those full forms still leave me none the wiser!
OK, here it goes.
This is the reason why so many German cars became so unreliable and expensive to maintain... eventually the technology matured and it started to get used in some avionics ( where the cost is not so important... I mean, 2000 bucks to fix a Bimmer's window that won't crank? ).
https://www.ni.com/en/shop/seamless...p614IZJ_-KjHDCMV5zPse7l9aFiTav9Ybl1l-TgJ36gXm
Here you have an example where the Euro's just couldn't leave well enough alone. They were worried about the non determinism of ethernet and decided to lavish it with ATM like extensions to make it deterministic.... when in reality the easiest thing was to do go to Gig E and not load the bus over 50%.... but nooo... the euros had to do it... ( OK, it was the Germans )...
https://www.ieee802.org/1/files/public/docs2015/TSN-Schneele-AFDX-0515-v01.pdf
Oh, yeah, ATM, it actually worked great for Telcos but then GigE ate its lunch... they might still be using over optical networks though.
https://www.ibm.com/docs/en/aix/7.1?topic=adapters-atm-technology
This is the reason why so many German cars became so unreliable and expensive to maintain... eventually the technology matured and it started to get used in some avionics ( where the cost is not so important... I mean, 2000 bucks to fix a Bimmer's window that won't crank? ).
https://www.ni.com/en/shop/seamless...p614IZJ_-KjHDCMV5zPse7l9aFiTav9Ybl1l-TgJ36gXm
Here you have an example where the Euro's just couldn't leave well enough alone. They were worried about the non determinism of ethernet and decided to lavish it with ATM like extensions to make it deterministic.... when in reality the easiest thing was to do go to Gig E and not load the bus over 50%.... but nooo... the euros had to do it... ( OK, it was the Germans )...
https://www.ieee802.org/1/files/public/docs2015/TSN-Schneele-AFDX-0515-v01.pdf
Oh, yeah, ATM, it actually worked great for Telcos but then GigE ate its lunch... they might still be using over optical networks though.
https://www.ibm.com/docs/en/aix/7.1?topic=adapters-atm-technology
Oh sorry.... I take those things for granted. My business.
Over the years there has been a push to decentralize control and to put the communications on busses so the old point to point analog wires, bundles in expensive and heavy harnesses has mostly gone away. That begat the CAN bus.
For intra aircraft avionics comms the issue is then two fold... in many real time applications you want determinism.. that is, you want to know EXACTLY how many resources you need and how many you have. Then, you NEVER run out of "pipeline" so to speak. Unfortunately, designing for a static bandwidth can be costly and often may not be needed except in the worst cases.
Stuff like Ethernet, OTOH, is non deterministic. You can design for a worst case by doing a statistical analysis and allowing for no more than 70% of the buss bandwidth to allow for contention ( to control the bus ).
But in avionics they don't like that, they are very old fashioned, even if the typical traffic needs are low. So the Germans came up with a mixture of ATM (very deterministic) and Ethernet (not at all). They took the cheaper ethernet hardware and wrapped it around some logic from ATM to make it deterministic by losing the contention and going bidirectional.
Think of 1553... but much faster.
But bottom line, currently the most data intensive thing in an airplane is the cabin's In Flight Entertainment... and it uses ethernet and 801.11 (WiFi)... so, you figure out why they had to make it so complicated.
I think it comes down to a German engineering ethos which is to make thing far more complicated than they should be.
But, in the meantime, it pays my bills.
Over the years there has been a push to decentralize control and to put the communications on busses so the old point to point analog wires, bundles in expensive and heavy harnesses has mostly gone away. That begat the CAN bus.
For intra aircraft avionics comms the issue is then two fold... in many real time applications you want determinism.. that is, you want to know EXACTLY how many resources you need and how many you have. Then, you NEVER run out of "pipeline" so to speak. Unfortunately, designing for a static bandwidth can be costly and often may not be needed except in the worst cases.
Stuff like Ethernet, OTOH, is non deterministic. You can design for a worst case by doing a statistical analysis and allowing for no more than 70% of the buss bandwidth to allow for contention ( to control the bus ).
But in avionics they don't like that, they are very old fashioned, even if the typical traffic needs are low. So the Germans came up with a mixture of ATM (very deterministic) and Ethernet (not at all). They took the cheaper ethernet hardware and wrapped it around some logic from ATM to make it deterministic by losing the contention and going bidirectional.
Think of 1553... but much faster.
But bottom line, currently the most data intensive thing in an airplane is the cabin's In Flight Entertainment... and it uses ethernet and 801.11 (WiFi)... so, you figure out why they had to make it so complicated.
I think it comes down to a German engineering ethos which is to make thing far more complicated than they should be.
But, in the meantime, it pays my bills.
Your business resides far outside my frame of reference, Tony, but thanks for trying to edumacate me!
The thing I continue not to understand is what all that computer business has got to do with "feet"!
Unless:
"Gold" comes from True, Spandau Ballet's third album!
Seriously though: Gold has been seen to be created when a pair of city-sized neutron stars in a galaxy 130 million light years from Earth smashed into each other at one third the speed of light, forming a kilonova.
The spectrum of the kilonova contained the fingerprints of the heaviest elements in the universe, including platinum and gold.
These elements are formed by the r-process (rapid neutron-capture process) that is responsible for the creation of approximately half of the atomic nuclei heavier than iron.
I can scarcely say "Correct!" to @Galu on this occasion... but he is right that the LIGO discovery and the subsequent search by 80 major telescopes for the visible source were key.
130 Million Light Years is twice the distance of the hugely distant Virgo Cluster of Galaxies, thus hardly likely to explain the amount of GOLD on Earth.
No, the exact explanation is a merger of Neutron Stars at a distance of 1,000 LY or 300 Parsecs from us, 80 Million Years before the formation of the Solar System.
What does this MEAN? It means that whilst Gold is quite hard to dig up on Earth, and usually only found near the scene of large meteorite impacts, small asteroids and moons must just be teeming with the stuff near the surface!
Hence the current Space Race. Now you know. Follow the money, as ever.
Apropos UNITS, I find Furlongs the most useful one to make money at the Bookies, though we account for Pounds weight carried modifying the OR or Official Rating:
Not many people know that 5 Furlongs is a convenient 1006 metres, or just over a kilometre. The above legendary sprinter Battaash in 2020 with Jim Crowley looking very happy, could run this in an eye-watering 57 seconds, or under a minute!
I doubt that today's contenders in the Nunthorpe will get anywhere near that, but Asfoora, Big Evs and Bradsell must be fancied.
https://www.sportinglife.com/racing...horpe-stakes-group-1-british-champions-series
I say this as the man who had 4 tasty Winners at around 7-1 in seven races at York yesterday, and whose wallet weighed more going home than coming out. My secret? Sound Mathematics.
I wonder how long it would take Battaash to run to the nearest star? He would do it pretty damn quick, I reckon.
Reread my post and you will see I said that the gold in your jewelry "would have been created in a similar kilonova that took place in our own galaxy billions of years ago!"