interesting physics

Presumably two gammas could collide in free space and create a particle pair. That complicates the "think of a photon as a wave until it encounters matter" idea.

I wonder if longwave, like visible, photon pairs create particles. It would have to be something light, like a neutrino.

Jan Panteltje snipped-for-privacy@yahoo.com wrote in news:sf2j0o$3up$ snipped-for-privacy@gioia.aioe.org:

That's not right... (Sam Rockwell inflection)

Reminds me of this:

Clive Arthur snipped-for-privacy@nowaytoday.co.uk> wrote in news:sf2q4k$q35$1@dont- email.me:

I guess it depends on what school of reasoning one chooses to follow.

Jeroen Belleman snipped-for-privacy@nospam.please wrote in news:sf2v3d$157h$1 @gioia.aioe.org:

The waves are made in an otherwise 'standing' energy field.

Hard to picture since there is no "perfectly still" space.

The FCC used to have fleets of cars with snoopers on them to go out looking for CB radio enthusiasts that got too zealous and fired up a linear RF amp, but now they likely only have one per state or such and the air is so flooded with waves it would be hard to track folks. That was when the density was so low they could come nail yer butt.

That is why cells phones are all addressible and the node you are logging into and your device's GPS chip allows you to be tracked and or data grabbed as timestamped evidence of a person's location. They do not need triangulation any more or direction finders.

The waves floating around are pretty dense... All across the spectrum too. Good thing they do not interact with flesh.

Unlike what those TrumpTarded conspiracy theory believing idiots who think that the coronavirus was created by 5G cell service towers. Even TrumpTarded Larkin can't fall for that bullshit.

As ironically stated by the John Doe snipped-for-privacy@message.header troll in message-id <sdhn7c$pkp$ snipped-for-privacy@dont-email.me who has posted yet another incorectly formatted USENET posting on Thu, 12 Aug 2021 16:45:13 -0000 (UTC) in message-id <sf3j6o$83o$ snipped-for-privacy@dont-email.me.

Pair production in gamma collision requires extremely high energy gamma rays in the vicinity of an atomic nucleus. Thus it cannot occur in a vacuum. See Wikipedia:

Pair production

Photon to electron and positron

For photons with high photon energy (MeV scale and higher), pair production is the dominant mode of photon interaction with matter. These interactions were first observed in Patrick Blackett's counter-controlled cloud chamber, leading to the 1948 Nobel Prize in Physics.[3]

If the photon is near an atomic nucleus, the energy of a photon can be converted into an electron–positron pair

The photon's energy is converted to particle mass in accordance with Einstein’s equation, E = m·c2; where E is energy, m is mass and c is the speed of light.

The photon must have higher energy than the sum of the rest mass energies of an electron and positron (2?·?511 keV = 1.022 MeV, resulting in a photon-wavelength of 1.2132 picometer) for the production to occur. (Thus, pair production does not occur in medical X-ray imaging because these X- rays only contain ~150 keV.)

The photon must be near a nucleus in order to satisfy conservation of momentum, as an electron–positron pair produced in free space cannot satisfy conservation of both energy and momentum.[4] Because of this, when pair production occurs, the atomic nucleus receives some recoil. The reverse of this process is electron positron annihilation.

No, it suffices to have a function solution formed like exp( j * (omega * t - k* x)) and once we find that (for instance) electrons diffract, the deBroglie and Davisson-Germer wavefunction ideas are established.

On a sunny day (Thu, 12 Aug 2021 17:07:20 +0200) it happened Jeroen Belleman snipped-for-privacy@nospam.please wrote in <sf3df8$1pd6$ snipped-for-privacy@gioia.aioe.org>:

Thank you. Just did read it, the math sort of overwhelmed me.. Just had a flashback to what's his name doctor ????? long ago in sci.physics he would write weird crap ... just to play with people there... One day he got it from some professor, never returned,

On a sunny day (Thu, 12 Aug 2021 16:30:09 -0000 (UTC)) it happened snipped-for-privacy@decadence.org wrote in <sf3iah$459$ snipped-for-privacy@gioia.aioe.org>:

In the early seventies when CB was illegal here, we went to some local meeting of CBers in Amsterdam, We had two of these small handsets. On the way back was talking to some guys, my friend driving and I with antenna stuck out of a window talking. We got stopped by police who thought we are robbing a bank or something like that, Taken to the police station, had to turn in the sets... Could id ourselves, we both worked at the state TV station :-) Month later we got a message we could collect the CB sets, power was too low to be illegal. A few years later the 27 MHz was made free up until 4W and FM only IIRC.

Actually they do Whole thing going on with radar here less than a mile away. Holding a cellphone next to your brain also has an effect on its function and cells, as does sleeping with your cellphone under your pillow (my experience, radiation from the GHz processor). But things need to sell...

That said, been exposed to strong RF so many times, now you see what happens!!

That is an other thing, it may however somehow decrease your resistance. I sure would not like a 5G transmitter next to my front door, I even switch off all wifi at night (it is off most of the time here anyways).

PS this also was drawn to my attention by somebody in sci.physics:

And for a radio view of the sky

Jan Panteltje snipped-for-privacy@yahoo.com wrote in news:sf59ua$1atu$1 @gioia.aioe.org:

I posted about slow light here over two years ago.

On a sunny day (Fri, 13 Aug 2021 13:54:57 -0000 (UTC)) it happened snipped-for-privacy@decadence.org wrote in <sf5tjh$3fs$ snipped-for-privacy@gioia.aioe.org>:

There is some logic in that, even in a Le Sage theory, Maybe after the big bang that was actually some sort of explosion and assuming there were many bangs like that (as professor Penrose claims to have shown evidence for), the Le Sage particles (or call it the light's aether) (and thus transferring gravity AND EM waves) were a result of particles released in those explosions and much faster. Question is then 'is light speed still getting less and less over the ages? Then with more bangs there should also be different light speeds.. at the same time some of those (much more rare from other bangs far away) mediums (aethers) allowing faster - and some slower transport of EM waves and gravity.

Would it be possible to test for a slowing light speed somehow? Something for NIST? Some interference or reflection setup versus the super accurate clock?

More:

Imagine a setup with a light source flashing and a detector at some given distance We measure the time it takes, !BUT! we find occasional the detector is late (once in a few thousand times and mysteriously we get a detector signal that is early. For sure good all CERN statistics say these strange effects can be ignored.

But what if it was not instrument noise, but a faster or slower carrier particle... (Le Sage particle or whatever). Most experimenters would dismiss those data points as Einstein is always right. Anyone detected this? I feel an urge to try :-)

Jan Panteltje snipped-for-privacy@yahoo.com wrote in news:sf5usg$mm2$ snipped-for-privacy@gioia.aioe.org:

If there are galaxies where things are faster than for us, then there would surely also be some that 'move' slower.

Does the "blue sky" have the same "blue look" to all of us?

Mediums slow light. Free space is one medium, and we now have mediums we have used to slow light quite measurably.

There is material dispersion and waveguide dispersion methods.

There already is a superaccurate clock and it is done by improving the ion trap of an existing design and that increased its accuracy beyond any resolution we would ever need to care about.

On a sunny day (Sat, 14 Aug 2021 10:28:55 -0000 (UTC)) it happened snipped-for-privacy@decadence.org wrote in <sf85t7$18ir$ snipped-for-privacy@gioia.aioe.org>:

Thanks, nice link!

So if a tree falls in the forest when there's nobody to hear, it doesn't make a sound?

I agree that a photon isn't a thing, as a boulder or even an electron is a thing. As an elementary excitation of another system, it's a property of that system.

Where we maybe differ is that I think that a perfect vacuum would qualify as such a system, whereas you apparently insist on nearby matter.

Cheers

Phil Hobbs

Interactions of light with matter are still super mysterious though--you can send an arbitrarily weak and arbitrarily short pulse of light at an efficient large detector, and you'll get one detection event per photon even though most pairs of points on the detector are separated by a spacelike interval, i.e. no mutual communication is possible between them during the pulse duration.

Cheers

Phil Hobbs

'Tain't so--see Michelson-Morley.

A solid body and a liquid surface are just examples of systems that support wave behaviour. Electromagnetic fields in free space are another, and GR gravitation is yet another.

So what?

Cheers

Phil Hobbs