AI will soon takeover and do the voting for us.
Which will come first, discovering what gravity is, WW3 or the AI wars?
Answer: not discovering which particles mediate gravity, even after CERN has spent $100B (the quoted $70B ia bound to be exceeded by at least 50% by 2045)
Which will come first, discovering what gravity is, WW3 or the AI wars?
Answer: not discovering which particles mediate gravity, even after CERN has spent $100B (the quoted $70B ia bound to be exceeded by at least 50% by 2045)
No, I seem to recall somewhere in the back of my [small] mind that 1eV was the energy of an electron accelerated from 0 to 1 meter in 1 second. Anyway, I have been corrected!
You've got to careful when dealing with particle energies!
Imagine an electron accelerated across a potential difference of 1 MV (one million volts).
If we were to calculate the electron's final velocity v from 1/2 m v^2 = q V we would get an answer of 5.9 x 10^8 m/s.
(m = mass of electron = 9.109 x 10^-31 kg; q = charge on electron = 1.602 x 10^-19 C; V = potential difference = 10^6 V)
Redeem yourself @Bonsai and tell us why that answer can not possibly be correct!
Imagine an electron accelerated across a potential difference of 1 MV (one million volts).
If we were to calculate the electron's final velocity v from 1/2 m v^2 = q V we would get an answer of 5.9 x 10^8 m/s.
(m = mass of electron = 9.109 x 10^-31 kg; q = charge on electron = 1.602 x 10^-19 C; V = potential difference = 10^6 V)
Redeem yourself @Bonsai and tell us why that answer can not possibly be correct!
Well spotted! Explanation below:
Non-relativistic kinetic energy:
Relativistic kinetic energy:
Lorentz factor:
So, instead of using 1/2 m v^2 = q V we must use (ɣ - 1) m c^2 = q V.
Incorporating the term for relativistic kinetic energy gives a final velocity v of 2.82 x 10^8 m/s.
Non-relativistic kinetic energy:
Relativistic kinetic energy:
Lorentz factor:
So, instead of using 1/2 m v^2 = q V we must use (ɣ - 1) m c^2 = q V.
Incorporating the term for relativistic kinetic energy gives a final velocity v of 2.82 x 10^8 m/s.
You didn't follow up on what you meant by "actual" energy.
I've been looking further into the measured masses of subatomic particles.
What particle physicists call mass is actually 'invariant mass" or 'rest mass'.
Invariant mass doesn't change with speed.
So Higgs particles have a mass of 125 GeV/c^2 no matter how fast they are moving.
There's an interesting conversation on "the two definitions of mass" here:
https://profmattstrassler.com/artic...o-definitions-of-mass-and-why-i-use-only-one/
I'm still trying to get my head round the energies reported in particle physics.
I was wondering how a 125 GeV Higgs boson can decay into a pair of Z bosons when the Z boson weighs in at 90 MeV.
The Higgs peak, shown above in blue, is at 125 GeV. The decay into a pair of Z bosons is shown by the red peak at around 90 GeV, a quantity that corresponds to the mass of a Z boson as predicted by the Standard Model.
So 125 GeV becomes 90 Gev during the decay? What is going on here? Where is the contribution of the second Z boson?
It turns out that the second Z boson is actually a Z* boson - a 'virtual' particle which is only there as a 'calculational tool'! 😵
To balance the figures, I will assume the difference between the 125 GeV mass of the Higgs boson and the 90 GeV mass of the 'real' Z boson appears as kinetic energy of the latter.
I was wondering how a 125 GeV Higgs boson can decay into a pair of Z bosons when the Z boson weighs in at 90 MeV.
The Higgs peak, shown above in blue, is at 125 GeV. The decay into a pair of Z bosons is shown by the red peak at around 90 GeV, a quantity that corresponds to the mass of a Z boson as predicted by the Standard Model.
So 125 GeV becomes 90 Gev during the decay? What is going on here? Where is the contribution of the second Z boson?
It turns out that the second Z boson is actually a Z* boson - a 'virtual' particle which is only there as a 'calculational tool'! 😵
To balance the figures, I will assume the difference between the 125 GeV mass of the Higgs boson and the 90 GeV mass of the 'real' Z boson appears as kinetic energy of the latter.
The mass difference is radiated out perhaps as a particle we don’t know about yet? There are just too many ‘virtual’ particles and cosmos wide fields!
Yes, it's a virtual jungle out there!
I read that virtual particles may be real particles that are out of phase with our reality!
I asked Ethan if virtual particles actually exist: https://www.forbes.com/sites/startswithabang/2021/05/07/ask-ethan-do-virtual-particles-really-exist/
I had to labour all the way to the last sentence to find, "The effects of virtual particles are real, but the particles themselves are not!".
I read that virtual particles may be real particles that are out of phase with our reality!
I asked Ethan if virtual particles actually exist: https://www.forbes.com/sites/startswithabang/2021/05/07/ask-ethan-do-virtual-particles-really-exist/
I had to labour all the way to the last sentence to find, "The effects of virtual particles are real, but the particles themselves are not!".
I have grown weary of murder mystery novels... time for some Sci-Fi!
https://www.newscientist.com/articl...february-2024/?utm_source=pocket-newtab-en-gb
This looks good, if you can judge a book from its cover:
Space-Time, Space Chicks. What is not to like? Must get to the bookshop. 🙂
Putting serious hat on, can anyone confirm I have differentiated Gamma correctly with respect to v?
I make it -1/2 x -2v/c^2 x Gamma ^3.
= v/c^2 x Gamma ^3.
I need this step to evaluate the frequency and wavelength of matter waves at near light speed. De Broglie, an' all that.
Best, Steve.
https://www.newscientist.com/articl...february-2024/?utm_source=pocket-newtab-en-gb
This looks good, if you can judge a book from its cover:
Space-Time, Space Chicks. What is not to like? Must get to the bookshop. 🙂
Putting serious hat on, can anyone confirm I have differentiated Gamma correctly with respect to v?
I make it -1/2 x -2v/c^2 x Gamma ^3.
= v/c^2 x Gamma ^3.
I need this step to evaluate the frequency and wavelength of matter waves at near light speed. De Broglie, an' all that.
Best, Steve.
This is literally what virtual means.
In computer sciences we have virtual memory, there is no RAM, however programs run in this memory, they see no différence with real memory ( but a slower speed ).
One can have virtual disks, there is no HD, however they behave like, programs see no difference ( but a faster speed ).
I see that I have looked into the distinction between 'real' and 'virtual' particles before.
A particle has a particular mass associated with it, it's just that it doesn't always have to have that mass.
When a particle has the right mass it is said to be "real", or "on mass-shell". If not, it is said to be "virtual", or "off mass-shell".
These off mass-shell particles occur in the middle of Feynman diagrams and the associated calculations of how particles interact, and lead to observable effects - so despite being called virtual, they are important.
The Higgs discovery relied on measuring events in which off mass-shell Z bosons participated in the decay of the Higgs to four leptons (electrons or muons). The Feynman diagram of such an event is shown below.
References:
https://handwiki.org/wiki/Physics:On_shell_and_off_shell
https://www.theguardian.com/science...ythagoras-to-the-lhc-via-einstein-and-feynman
Talking about virtual, here is Sabina Hossenfelder talking about the latest string theory incarnation ’dark dimensions’.
To be honest, I am getting same feeling and sense of frustration with this physics stuff that I felt when I came back into audio 20 yrs ago after a 30 year hiatus.
‘Feedback is bad’, ‘oh, you must use Mundorf, everything else has a veiled sound’, ‘bipolars are no good, you must use FETs’, ‘only Beyerschlag resistors sound good’ etc. aAl of it absolute subjective claptrap.
I get the feeling a lot of physics is like this now. The physics community seems to be thrashing around in the dark, with each passing year bringing ever more outrageous claims and theories.
To be honest, I am getting same feeling and sense of frustration with this physics stuff that I felt when I came back into audio 20 yrs ago after a 30 year hiatus.
‘Feedback is bad’, ‘oh, you must use Mundorf, everything else has a veiled sound’, ‘bipolars are no good, you must use FETs’, ‘only Beyerschlag resistors sound good’ etc. aAl of it absolute subjective claptrap.
I get the feeling a lot of physics is like this now. The physics community seems to be thrashing around in the dark, with each passing year bringing ever more outrageous claims and theories.
Sabine Hossenfelder has written a book entitled Lost in Math.
In the book she says that theoretical physicists waste a lot of time trying to solve problems that don’t exist. They do this because they are unhappy that the current theories are not beautiful enough to their taste. She regards this as bad scientific methodology which has to stop.
She thinks the public has been misinformed. We have been told that theories like supersymmetry and string theory and multiverses can be tested, even though it’s not true.
Sabine sums it up thus: "If it’s not testable, it’s not science. Why do we even have to discuss this?"
I want to argue we should be grateful to cern or any other Institute which are actively involved in finding stuff.
Inventions made this world lounge possible.
How much money do you think invention of transistor have made us so far. Might go in zillion if you ask me.
Your money is worth less without somebody selling the stuff you need.
Also research means finding the unknown. No point in searching what already know. And they there's no surety either.
Humans as a species is so stupid. Sometimes I feel who we actually managed so far.
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Here's Sabine Hossenfelder's opinion on the abundance of 'virtual' particles:
"You see, particle physicists think it is a great problem that theories which have been experimentally confirmed are not as beautiful as particle physicists think nature should be. They have therefore invented a lot of particles that you can add to the supposedly ugly theories to remedy the lack of beauty. If this sounds like a completely non-scientific method, that’s because it is. There is no reason this method should work, and it does as a matter of fact not work. But they have done this for decades and still have not learned that it does not work."
https://backreaction.blogspot.com/2020/10/particle-physicists-continue-to-make.html
In her blog, she is reacting to the "roadmap for the future" issued by The European Strategy for Particle Physics (ESPP) group in 2020 regarding the Future Circular Collider (FCC) which had not at that point been given that name: https://www.nature.com/articles/s41567-020-01054-6
I can see why doubt can arise in our minds when the roadmap tells us such vague things as:
@vishal raju Your argument matches that of that the ESPP when they say, "Investments in science are comparatively small on the macro-economic level, but their impact on the future of humanity is vast.", and I have a lot of sympathy for that argument.
"You see, particle physicists think it is a great problem that theories which have been experimentally confirmed are not as beautiful as particle physicists think nature should be. They have therefore invented a lot of particles that you can add to the supposedly ugly theories to remedy the lack of beauty. If this sounds like a completely non-scientific method, that’s because it is. There is no reason this method should work, and it does as a matter of fact not work. But they have done this for decades and still have not learned that it does not work."
https://backreaction.blogspot.com/2020/10/particle-physicists-continue-to-make.html
In her blog, she is reacting to the "roadmap for the future" issued by The European Strategy for Particle Physics (ESPP) group in 2020 regarding the Future Circular Collider (FCC) which had not at that point been given that name: https://www.nature.com/articles/s41567-020-01054-6
I can see why doubt can arise in our minds when the roadmap tells us such vague things as:
- Even if it is difficult to anticipate what these studies will reveal, we can be certain that this path of exploration will greatly expand our knowledge on many fronts.
- A good example of a guaranteed result is dark matter (my highlight).
- This will lead either to a sensational discovery or to an experimental exclusion that will profoundly influence both particle physics and astrophysics.
@vishal raju Your argument matches that of that the ESPP when they say, "Investments in science are comparatively small on the macro-economic level, but their impact on the future of humanity is vast.", and I have a lot of sympathy for that argument.
Even if we only understand 5% of the Universe, that's not bad considering its vastness and complexity. 🤓