This furnishes me with an opportunity to publish my Feynman diagram tutorial on this thread!
Feynman diagrams represent the interactions between elementary particles.
1. The diagrams are made up of arrowed lines which represent matter particles, and wiggly lines which represent virtual particles (force exchange particles).
2. The point where the lines join, the vertex, represents an interaction between particles.
3. Matter particles are indicated by arrows which point from left to right and antimatter particles are indicated by arrows which point from right to left.
Above, the right pointing arrow is an electron and the left pointing arrow is a positron. The wiggly line (the gamma) is a virtual photon - a force exchange particle.
4. Feynman diagrams are read from left to right.
In the first diagram an incoming electron and positron annihilate each other, producing a virtual photon which then produces an outgoing electron-positron pair. In the second diagram, an incoming electron interacts with an incoming positron via a virtual photon, without ever touching the positron.
Feynman diagrams represent the interactions between elementary particles.
1. The diagrams are made up of arrowed lines which represent matter particles, and wiggly lines which represent virtual particles (force exchange particles).
2. The point where the lines join, the vertex, represents an interaction between particles.
3. Matter particles are indicated by arrows which point from left to right and antimatter particles are indicated by arrows which point from right to left.
Above, the right pointing arrow is an electron and the left pointing arrow is a positron. The wiggly line (the gamma) is a virtual photon - a force exchange particle.
4. Feynman diagrams are read from left to right.
In the first diagram an incoming electron and positron annihilate each other, producing a virtual photon which then produces an outgoing electron-positron pair. In the second diagram, an incoming electron interacts with an incoming positron via a virtual photon, without ever touching the positron.
Looks like 3D games of the 70s to me. Very easy programming, very little computing power required.
Could run on a Atari 520 STF with a monochrome CRT screen.
3D Nowdays is zillion light years from this.
Could run on a Atari 520 STF with a monochrome CRT screen.
3D Nowdays is zillion light years from this.
We have discussed Quantum Computers before (wasn't it that IBM simulator that you could access online?), and I thought that even a dozen Qubits was the current limit of technology even in simulation on a PC, so have no idea what the Quandoom simulator is about.
I have been mulling over more on neutrinos in Negative Beta decay, where Neutrons decay into Protons.
We have this regular sort of free Neutron decay yielding 11.3 MeV:
With a pleasant symmetry there is also the similar looking decay of Hydrogen 3 (Tritium) into Helium 3 yielding a mere 18.6 keV with a 12 year half-life:
This decay is of great interest to Neutrino people because of its relatively low energy, and to fusion people because these nucleons get involved in stars.
I suppose the low energy yield is because you are losing energy pushing two charged protons together.
I have got a bit confused with the chemist's bizarre unit of Carbon 12 Daltons in these things.
A single Neutron must be about 1.009 on this scale, being 11.3 MeV/c^2 more massive than a proton, but information varies.
Where I got muddled is with the familiar binding energy per nucleon in Nuclear Energy:
Why is 3H above 3He if higher means more stable? What is going on? It makes no sense that Tritium decays to Helium 3.
This bit I understood in Fusion:
And I suppose the Neutron can decay further with 11.3 MeV, though most of the energy disappears as a fast Neutrino.
At least it adds up... 🙂
I have been mulling over more on neutrinos in Negative Beta decay, where Neutrons decay into Protons.
We have this regular sort of free Neutron decay yielding 11.3 MeV:
With a pleasant symmetry there is also the similar looking decay of Hydrogen 3 (Tritium) into Helium 3 yielding a mere 18.6 keV with a 12 year half-life:
This decay is of great interest to Neutrino people because of its relatively low energy, and to fusion people because these nucleons get involved in stars.
I suppose the low energy yield is because you are losing energy pushing two charged protons together.
I have got a bit confused with the chemist's bizarre unit of Carbon 12 Daltons in these things.
A single Neutron must be about 1.009 on this scale, being 11.3 MeV/c^2 more massive than a proton, but information varies.
Where I got muddled is with the familiar binding energy per nucleon in Nuclear Energy:
Why is 3H above 3He if higher means more stable? What is going on? It makes no sense that Tritium decays to Helium 3.
This bit I understood in Fusion:
And I suppose the Neutron can decay further with 11.3 MeV, though most of the energy disappears as a fast Neutrino.
At least it adds up... 🙂
Four or five years back, I mentioned Google's Quantum Computer who's superconducting Sycamore chip contains 53 entangled qubits.
In performing a very particular task, the quantum computer performed 1.5 trillion times faster than a classical computer would.
Unfortunately, this feat is not particularly useful outside of the world of quantum mechanics and, in addition, entangled qubits become untangled after short periods and are susceptible to noise and errors.
The field of quantum computing is still in its infancy and practical quantum computers remain far on the horizon.
https://www.nature.com/articles/s41586-019-1666-5
If a Quantum Computer is the solution, what's the problem?
Apparently to generate pseudo-random numbers.... 🙄
Surely any handicap horse-race that I have bet on is similarly random! The darned bookies design them that way. 🙁
Northern lights excitement in the media today, though the "alledged conspiracy-theory weather control, wake up sheeples" was not a bit like this in my neck of the woods.:
https://www.bbc.co.uk/news/articles/c0lwerxge8ro
I see the Plough and its end pointing to the North Star here.
Looks like Perseus top left, Triangulum and Aries top right, and the Pleiades and Taurus bottom left. I would have got Jupiter in the shot if I had been there.
And surely adding a Supermoon over the Pyramids too wouldn't have been hard? 😀
I have solved the mass defect plot problem. I think it should distinguish proton and neutron number in such plots, then H3 (Tritium) and He3 (Helium 3) mass defect would make more sense.
Might end up 3D, but whatever. Physicists outrank Chemists IMO. And Mathematicians outrule them all, as all sensible people agree. 😎
Apparently to generate pseudo-random numbers.... 🙄
Surely any handicap horse-race that I have bet on is similarly random! The darned bookies design them that way. 🙁
Northern lights excitement in the media today, though the "alledged conspiracy-theory weather control, wake up sheeples" was not a bit like this in my neck of the woods.:
https://www.bbc.co.uk/news/articles/c0lwerxge8ro
I see the Plough and its end pointing to the North Star here.
Looks like Perseus top left, Triangulum and Aries top right, and the Pleiades and Taurus bottom left. I would have got Jupiter in the shot if I had been there.
And surely adding a Supermoon over the Pyramids too wouldn't have been hard? 😀
I have solved the mass defect plot problem. I think it should distinguish proton and neutron number in such plots, then H3 (Tritium) and He3 (Helium 3) mass defect would make more sense.
Might end up 3D, but whatever. Physicists outrank Chemists IMO. And Mathematicians outrule them all, as all sensible people agree. 😎
Regarding tritium (3H) decaying into helium-3 (3He) and a beta particle, I found a discussion here:
https://www.physicsforums.com/threads/why-does-tritium-beta-decay-to-helium-3.863339/
I have no idea if that is helpful to you. I can only hope it might help you sleep peacefully at night!
P.S. If I'd felt up to it last night (I had a tiring day) I could have motored out of the village to escape the street lights and witnessed what was, as evidenced by the many photographs taken by locals, a brilliant auroral display.
Peeps within 100 miles of me are posting aurora pic, but I'm too close to Atlanta to see anything.
https://imgs.xkcd.com/comics/purity.png
I remember that one.
https://imgs.xkcd.com/comics/purity.png
I think these Aurora pictures are wildly enhanced by modern iPhone cameras. My experience is I couldn't see a damn thing with my eyes in Leicestershire six months back, while my niece got a good phone snap from a nearby dark lane.
For the Real McCoy I think you need to go up to Norway!
Thanks @Galu for help here on mass defect an' all that. Seems binding energy is defined as the energy to break a nucleus into its constituent parts.
In the case of Tritium decaying to Helium 3, the parts are different, containing an extra Neutron instead of a Proton.
Binding Energy of Tritium or H3 = 8.482 MeV or about 2.8 MeV/nucleon.
Binding Energy of Helium 3 = 7.718 MeV or about 2.55 MeV/nucleon. As in this diagram.
But we know a Neutron (939.565 MeV) is heavier than a proton (938.272 MeV) by 1.292 MeV.
So 8.482 - 1.292 = 7.190 MeV. Also add the Beta decay electron at 0.511 MeV = 7.701 MeV.
7.718 - 7.701 = 17 keV. Which, allowing for decimal point inaccuracy, is near enough the exact 18.6 keV neutrino measured in the Tritium decay.
Sorry that was bit boring, but I enjoyed it. These sort of things keep me awake at night. 🙂
For the Real McCoy I think you need to go up to Norway!
Thanks @Galu for help here on mass defect an' all that. Seems binding energy is defined as the energy to break a nucleus into its constituent parts.
In the case of Tritium decaying to Helium 3, the parts are different, containing an extra Neutron instead of a Proton.
Binding Energy of Tritium or H3 = 8.482 MeV or about 2.8 MeV/nucleon.
Binding Energy of Helium 3 = 7.718 MeV or about 2.55 MeV/nucleon. As in this diagram.
But we know a Neutron (939.565 MeV) is heavier than a proton (938.272 MeV) by 1.292 MeV.
So 8.482 - 1.292 = 7.190 MeV. Also add the Beta decay electron at 0.511 MeV = 7.701 MeV.
7.718 - 7.701 = 17 keV. Which, allowing for decimal point inaccuracy, is near enough the exact 18.6 keV neutrino measured in the Tritium decay.
Sorry that was bit boring, but I enjoyed it. These sort of things keep me awake at night. 🙂
The human eye is not as sensitive to the wavelengths produced when charged particles collide with the Earth's atmosphere as our cameras are.
Plus a long camera exposure setting allows more light to accumulate on the sensor, thus intensifying the colours.
Here's an article, dating from the May 2024 displays, which explains how the altitude and different gases involved determine the different colours seen in an aurora: https://www.itv.com/news/anglia/2024-05-13/why-did-the-aurora-borealis-look-better-through-a-camera
And then there's the little matter of 'scotopic vision': https://www.msn.com/en-us/news/tech...n-the-naked-eye/ar-AA1s3aMt?ocid=BingNewsSerp
I think the better "scotopic" colour rendering aspect of 'Phone cameras must be key here. I thought I was looking at white light pollution from the nearby "Cloud" quarry.
My niece (who is ex-nurse and expert on all things medical, so is the family go-to on aches and pains and medicines) surprised me with a detailed discussion of Oxygen and Nitrogen colours in her photos. She's got a good scientific brain when she gets interested in things.
I am honing up my camera skills for the Comet next week, as I hope you are too.
I was puzzling why TNT gets more stars than me. It is because he can use longer exposures pointing North, plus he can multiply by 3 because of his 11mm lens, as opposed to my 35mm one. So he gets away with over 20 seconds, when I prefer 4.
At 30 degrees from the Pole Star, the sky is moving half as fast as near the ecliptic. I lay awake working this out using 60 degree equilateral triangles within a circle, which avoids sines and cosines an' all that, as one does when sleepless with a good and important physics problem to solve... 🙄
Though light pollution, terrrible weather and telephone wires and even wobbly car rooves don't help my efforts.
TADA! The Constellation of Orion in the small hours, where the Nebula below the belt comes out much brighter than with you eyes:
And Castor, Pollux and Mars (Centre Field), which is to the left of Jupiter (and Uranus) in Taurus ATM and not very bright yet:
Hope you enjoyed that. 😛
My niece (who is ex-nurse and expert on all things medical, so is the family go-to on aches and pains and medicines) surprised me with a detailed discussion of Oxygen and Nitrogen colours in her photos. She's got a good scientific brain when she gets interested in things.
I am honing up my camera skills for the Comet next week, as I hope you are too.
I was puzzling why TNT gets more stars than me. It is because he can use longer exposures pointing North, plus he can multiply by 3 because of his 11mm lens, as opposed to my 35mm one. So he gets away with over 20 seconds, when I prefer 4.
At 30 degrees from the Pole Star, the sky is moving half as fast as near the ecliptic. I lay awake working this out using 60 degree equilateral triangles within a circle, which avoids sines and cosines an' all that, as one does when sleepless with a good and important physics problem to solve... 🙄
Though light pollution, terrrible weather and telephone wires and even wobbly car rooves don't help my efforts.
TADA! The Constellation of Orion in the small hours, where the Nebula below the belt comes out much brighter than with you eyes:
And Castor, Pollux and Mars (Centre Field), which is to the left of Jupiter (and Uranus) in Taurus ATM and not very bright yet:
Hope you enjoyed that. 😛
My biology knowledge is scanty, so I did some quick research:
Scotopic vision is the vision of the eye under low-light conditions.
The cone cells in the retina are responsible for colour vision, but they do not function well in low-light conditions.
Low-light vision relies on the rod cells which, being most sensitive in the blue-green wavelengths, have little to do with colour perception.
A reminder that comet A3 may be visible from now until October 30th.
The advice from the Royal Astronomical Society is to go out immediately after sunset with a pair of binoculars, head for higher ground and look west towards the horizon.
Unfortunately, the land looks mighty flat around Portsmouth!
Steve, it looks like you may have to head north. Make sure you wrap up warm and take a hot drink with you!
There is a hill above Portsmouth called Portsdown Hill which would be good. But I headed to Southsea Castle on the southern tip of the island an hour and a half after sunset.
Couple of other brave souls stmbling around with a Nikon D5000 camera on the bank with lights in front of it.
I headed to the waterfront which is nicely unilluminated and stepped, and the council is thoughtfully using black tape over parts of the downlighters.
Alas I couldn't see anything below orange Arcturus and its companions. And not even a Nova either! In the background is Gosport, Stokes Bay and the higher Isle of Wight, looking west:
I am seriously worried about the abysmal hazy/cloudy weather forecast this week as the comet fades towards Aquila. And even the half moon was spoiling things a lot. 🙁
Perhaps @TNT can save the day!
Couple of other brave souls stmbling around with a Nikon D5000 camera on the bank with lights in front of it.
I headed to the waterfront which is nicely unilluminated and stepped, and the council is thoughtfully using black tape over parts of the downlighters.
Alas I couldn't see anything below orange Arcturus and its companions. And not even a Nova either! In the background is Gosport, Stokes Bay and the higher Isle of Wight, looking west:
I am seriously worried about the abysmal hazy/cloudy weather forecast this week as the comet fades towards Aquila. And even the half moon was spoiling things a lot. 🙁
Perhaps @TNT can save the day!
No can do as I have been forced to temporarily over the weekend locate myself to the vicinity of the Nobel Museum and therefore I have too less camera and much light pollution. This will reverse for Monday night towards tuesday ;-) the forecast looks not too good but the night after I shall go on a comet hunt like Filifjonks in the Muminvalley.
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That's a shame. At least you can tell the Nobel people to think of a PROPER Physics subject to award a prize to next year. 🤣
It's the weather in Hampshire I am worried about this week. Last night had patches of clarity, but overall pretty hazy. And the Moon didn't help.
Looks like I missed the Comet by 20 minutes!
Sunset was about 6.15 BST, and this was taken 10 miles away in Southampton Water overlooking Fawley Oil Refinery at 7.30 PM:
https://www.bbc.co.uk/news/articles/cx25x4582elo
Who designs this terrible lighting? But blow me down, if it isn't the same cloud formation! 🙁
It's the weather in Hampshire I am worried about this week. Last night had patches of clarity, but overall pretty hazy. And the Moon didn't help.
Looks like I missed the Comet by 20 minutes!
Sunset was about 6.15 BST, and this was taken 10 miles away in Southampton Water overlooking Fawley Oil Refinery at 7.30 PM:
https://www.bbc.co.uk/news/articles/cx25x4582elo
Who designs this terrible lighting? But blow me down, if it isn't the same cloud formation! 🙁
Timing would appear to be crucial!
Martin Cohen said: "It was a very narrow window of time between it being dark enough to see (the comet) and it disappearing below the horizon!"
I once took a picture of (and I have to be careful what I say here) "Old Nick" himself parking his Black BMW car ( Registration number: SAT4N ) near Winchester Cathedral!
He was dressed in black and had a pony tail on his balding head. He was also, and this did not surprise me, using a disabled sticker to avoid paying for parking. 🙄
Alas Gremlins affected my camera, and the picture didn't come out... so no-one believes me. I mention this because Saturday's pictures have disappeared from my camera. I was wanting to see if I had captured Venus by accident.
The BBC have just published a view of the A3 Comet in time lapse from the splendid Subaru facility on Hawaii:
https://www.bbc.co.uk/news/videos/c4gl3xlwypjo
Seems the fun started an hour after sunset, and was all over 15 minutes later. You can see Corona Borealis, Arcturus, Venus and Scorpio here from Hawaii, which is about 20 degrees North of the equator.
Venus is almost impossible to see in the Autumn from Europe, because of a falling Ecliptic.
I failed the Subaru Quiz. Thought it was @TNT's Capella! See how you do:
https://subarutelescope.org/en/gallery/maunakea/
The weather is atrocious again. 😡
He was dressed in black and had a pony tail on his balding head. He was also, and this did not surprise me, using a disabled sticker to avoid paying for parking. 🙄
Alas Gremlins affected my camera, and the picture didn't come out... so no-one believes me. I mention this because Saturday's pictures have disappeared from my camera. I was wanting to see if I had captured Venus by accident.
The BBC have just published a view of the A3 Comet in time lapse from the splendid Subaru facility on Hawaii:
https://www.bbc.co.uk/news/videos/c4gl3xlwypjo
Seems the fun started an hour after sunset, and was all over 15 minutes later. You can see Corona Borealis, Arcturus, Venus and Scorpio here from Hawaii, which is about 20 degrees North of the equator.
Venus is almost impossible to see in the Autumn from Europe, because of a falling Ecliptic.
I failed the Subaru Quiz. Thought it was @TNT's Capella! See how you do:
https://subarutelescope.org/en/gallery/maunakea/
The weather is atrocious again. 😡