If all EM waves are particles (aka photons), then how can a radio wave Particle (aka radio photon) be MILES long ?

[nick c]

As crawler stated GPS does not need relativity. The relativistic correction is a matter of 3 or 4 inches and GPS is only accurate to about 15 feet. Military GPS may, in some cases, be more accurate, but its accuracy is still measured in multiple feet.

Any relativistic correction is meaningless as it is a small fraction of the margin of error for GPS.

https://www.physicsmyths.org.uk/gps.htm

Do you think this is so from your own experience?

About 15 years ago I repaired the corroded battery contacts in a friend's aviation specific Garmin device which was a few years old at the time and noticed it recognized the difference in location between my hands on outstretched arms, a distance of about 6 feet. I mentioned this to a pal who works for the railroad and he chuckled, responding with his smart phone recognized the difference between one railroad track tie and another, a distance of about 18 inches.

From the link to Prof Smid's analysis of GPS and relativity:
https://www.physicsmyths.org.uk/gps.htm

The correction amounts to 0.8 cm (or less than 1/3 of an inch). Even if your measurements of GPS accuracy could be consistently maintained, the relativity correction is still enormously minute compared to the margin of error. Even with a 6 feet margin of error.... a third of an inch correction is completely irrelevant.

Now the quoted relativistic correction of 38 microseconds/day corresponds to ε=4.4.10-10. As the satellites are at a distance of around 20000 km (=2.109 cm), the positional error due to relativity should actually only be 4.4.10-10 . 2.109 cm = 0.8 cm!

[Maol]

As crawler stated GPS does not need relativity. The relativistic correction is a matter of 3 or 4 inches and GPS is only accurate to about 15 feet. Military GPS may, in some cases, be more accurate, but its accuracy is still measured in multiple feet.

Any relativistic correction is meaningless as it is a small fraction of the margin of error for GPS.

https://www.physicsmyths.org.uk/gps.htm

Do you think this is so from your own experience?

About 15 years ago I repaired the corroded battery contacts in a friend's aviation specific Garmin device which was a few years old at the time and noticed it recognized the difference in location between my hands on outstretched arms, a distance of about 6 feet. I mentioned this to a pal who works for the railroad and he chuckled, responding with his smart phone recognized the difference between one railroad track tie and another, a distance of about 18 inches.

From the link to Prof Smid's analysis of GPS and relativity:
https://www.physicsmyths.org.uk/gps.htm

The correction amounts to 0.8 cm (or less than 1/3 of an inch). Even if your measurements of GPS accuracy could be consistently maintained, the relativity correction is still enormously minute compared to the margin of error. Even with a 6 feet margin of error.... a third of an inch correction is completely irrelevant.

Now the quoted relativistic correction of 38 microseconds/day corresponds to ε=4.4.10-10. As the satellites are at a distance of around 20000 km (=2.109 cm), the positional error due to relativity should actually only be 4.4.10-10 . 2.109 cm = 0.8 cm!

In total agreement with the relativistic situation, however my contention is with your assertion GPS is only accurate to about 15 feet and merely relating personal experience.

If we can believe the internet, "high-end systems can reach precision within 2 centimeters."

[nick c]

In total agreement with the relativistic situation, however my contention is with your assertion GPS is only accurate to about 15 feet and merely relating personal experience.

If we can believe the internet, "high-end systems can reach precision within 2 centimeters."

I wrote that about 15 feet was for a typical GPS system used on your cell or from a commercially available Garmin or similar unit. You failed to mention that I did qualify that in the very next sentence stating that military applications would be much more accurate. As far as the 2 cm accuracy, no, I don't believe everything that I read on the Internet...do you?

Even if that were true.....IT STILL MEANS THAT A RELATIVITY CORRECTION IS STILL LESS THAN THE MARGIN OF ERROR!
As far as the 2 cm accuracy, I think forum member tharkun's assessment is accurate:

THe difference is likely one between precision and accuracy. Just because a small difference can register, it doesn't mean that either point is accurate. A standard digital caliper may be precise down to ±0.0005", but if it's zeroed incorrectly, your measurements will all be wrong.

[crawler]

GPS is lucky that the aetherwind blows nearly south to north throo the solar system.
The aetherwind is 500 km/s, about c/600.
If it had a larger angle then that would make corrections for the tailwind/headwind effect(s) more drastic.

However, i reckon that the orientation of clocks drastically affects ticking.
And such ticking dilation is never mentioned.

[Maol]

Farmers have been using GPS for at least 30 years to steer tractors for planting and harvesting with accuracy within an inch. Check ads for GPS watches with similar accuracy used by hikers and hunters to keep track of location in back country expeditions, 21st Century trail of crumbs to find your way home. The "military grade" GPS has been available to the public for over 30 years for whoever will pay for the more elaborate systems.

The following link has a humorous description of the effect of the solar storm last May, causing tractors to become "demon possessed" and lose their way.

https://spaceweather.com/archive.php?vi ... &year=2024



https://www.popularmechanics.com/scienc ... -tractors/

“Our tractors acted like they were demon possessed,” Elaine Ramstad, an aurora chaser who’s family works a farm in northern Minnesota, told Spaceweather.com. “All my cousins called me during the May 10 storm to tell me that ‘my auroras’ were driving them crazy while they were planting.”

To reconcile this to the subject of this thread, "If all EM waves are particles (aka photons), then how can a radio wave Particle (aka radio photon) be MILES long ?", it is evident the distortion of EM radio waves by outside influence of charged particles is a phenomenon that is another way the EU is actually affecting our daily lives.

I found this GPS distortion effect on farmers' planting was (is) an interesting way to introduce the concept of solar system electrical and magnetic effects to a person who is not familiar with EU, because it provides visual evidence in relation to a concept anyone who ever planted straight rows in a garden can understand.

[Aardwolf]

Farmers have been using GPS for at least 30 years to steer tractors for planting and harvesting with accuracy within an inch.

Nonsense. Agricultural systems use Differential GPS which is regular GPS aided by ground reference stations. This gives approx. 1mtr accuracy which is more than enough for them and any industrial/military use. The best surveying systems use Real Time Kinetic GPS which again uses a dedicated ground station placed at a KNOWN POSITION. This is the only way to get 2-3cm precision.

Obviously neither of the systems above are really checking the accuracy of GPS which only gives a general position for the device which is refined by the ground systems. GPS used ALONE can never give accuracy better than 3 or 4 meters. As such the relativity "adjustment" is completely fatuous.

[mariuslvasile]

In Einstein's theory the photon has energy E=pc, where p is momentum. But p=mv=mc, and photon mass is 0. So his photon has 0 energy.

How does Einstein fix this ? He says momentum of photon is hf/c, cause E=hf=pc. But its measuring unit is still kg m/s, which is mass dependent. So his fix ain't working.

[mladen nb]

@mariuslvasile,

What if space itself is not an empty background, but has built-in properties, a.k.a. responses to:

1. energy density/distribution (that latter manifests as electric effects), and
2. inertial/rotational changes in motion (that latter manifests as magnetic effects)
P.S. By "latter" I mean with introduction, i.e., creation of mass and matter

If we agree that photons are finite-size particles or elementary energy packets, then:

3D space continuum with varying ε and μ → defines propagation

Energy packets (photons) → what propagates

Wave equations → describe collective dynamics

No object is both a particle and a wave.
Energy packets move; waves describe how motion unfolds in the medium.

[crawler]

@mariuslvasile,

What if space itself is not an empty background, but has built-in properties, a.k.a. responses to:

1. energy density/distribution (that latter manifests as electric effects), and
2. inertial/rotational changes in motion (that latter manifests as magnetic effects)
P.S. By "latter" I mean with introduction, i.e., creation of mass and matter

If we agree that photons are finite-size particles or elementary energy packets, then:

3D space continuum with varying ε and μ → defines propagation

Energy packets (photons) → what propagates

Wave equations → describe collective dynamics

No object is both a particle and a wave.
Energy packets move; waves describe how motion unfolds in the medium.

No particle is a wave. No object is a wave. Photons (quasi-particles) are not waves. Radio waves are not waves, they are pulses.
What we call waves (or pulses) are force waves (or force pulses).
And of course lots of particles & objects etc can make waves etc of many kinds which are of little interest to u or me (unless they are force waves/pulses).