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[EH.INS.]

Arukamatel soovitaks lugeda Hawkingut
Mees ei olnud ainus mustade aukude uurija kuid tema panus oli erakordne just kvantfüüsika ja relatiivsusteooria ühendamisel
Originaalsus ja julged ideed (nt Hawkingi kiirgus) teevad temast ühe suurima...
Mh ühendas kvantmehaanika, relatiivsusteooria ja termodünaamika – suur panus kvantgravitatsiooni suunas...

[T25]

Louis Essen, aatomikell
Hawking- ?

[T25]

https://www.alternativephysics.org/book ... hology.htm

Tsitaat relativistlike effektide mõju kohta:

Ignoring all the above arguments for the moment, there is another important consideration that warrants attention. And that is the fact that such relativistic effects would render the entire navigation system unworkable, at least in its present configuration. According to the US-DOD [4] the satellites lose 7200 ns a day due to special relativity and gain 45900 ns a day due to general relativity. These effects combine to yield a net speeding up of 38600 ns a day (45900-7200=38600), relative to clocks on Earth. The clocks are then slowed by a suitable degree to negate this daily amount, and everything is fine for GPS receivers.

However since the Earth is rotating, the speed of a satellite relative to a GPS receiver will be different at different latitudes. Therefore the amount of dilation should also be different. That 7200 ns was calculated relative to a pole, where the Earth is not moving and only the satellite’s speed of 3870 m/s need be considered. If the calculation was done at the equator where the surface moves at 465 m/s and GPS satellites cross at 55 degrees, the SR time dilation works out to 6300 ns. That’s a 900 ns difference between pole and equator which presumably would yield an increasingly inaccurate position determination of 270 meters per day.

Next we have a problem with altitude because the 45900 ns figure was calculated for sea level. This figure will decrease as we move higher and experience less gravity. For example, at 1060 metres above sea level there will be a decrease of 10 ns per day. This presumably would lead to an inaccuracy of 3 metres per day, accumulating up to 1 km per year. Aeroplanes flying at 10km would be worse off; accumulating a 10 km error per year.

If it were necessary to accommodate for relativity at different latitudes and altitudes, the calculations would be very complex and would need to be done at the receiver. But they aren’t done there: only a fixed time adjustment is made at the satellites for all points on Earth. This fact alone demonstrates that Relativity is irrelevant to the GPS operation.

Kokkuvõttev tsitaat:

The presence of Special and General Relativity effects has no bearing on the accuracy of GPS operation. In summary, it wouldn’t matter whether clocks aboard GPS satellites ran faster or slower than Earth’s clocks or even changed their speed each day. Just so long as the satellites’ clocks remained synchronised with each other and the time-difference relative Earth’s clocks didn’t become too large, GPS receivers would continue to calculate their correct position.

The GPS is certainly an excellent navigational aid. But from an operational viewpoint at least, it doesn’t serve as a test for Relativity. Scientists should stop calling it that.

[EH.INS.]

Arukamatel soovitan lugeda nt MIT ja Harvardi teadlaste arvamusi...
alternativephysics peaks ka arukamatele midagi ütlema...

[T25]

GPS-süsteemiga seoses tsiteerin Claes Johnsonit (Claes Göran Johnson is a professor of applied mathematics at the Royal Institute of Technology in Stockholm, Sweden):

The famous physicist Stephen Hawking, the present holder of Newton’s chair in Cambridge, claims in his best-seller The History of Time that the GPS system (obviously) builds on both special and general relativity:
Hawking claims that without both special and general relativity, the GPS-coordinates
would be off by hundreds of kilometers or more and the GPS-system would be completely useless. Who would dare to question such a statement in a best-seller by the successor of Newton?

Let us anyway face the facts: The GPS system uses an absolute time common to all satellites orbiting the Earth all with different velocities, but there is no time dilation: All clocks run at the same rate and the synchronization does not have to be updated. According to special relativity there should be some time dilation because all satellites are moving with respect to each other, but there is none.

What to say? Well, first of all the assumptions of special reltivity are not fulfilled because the satellites don’t move rectilinearly, and secondly the effects of time dilation are anyway too small to be noticable.
All in all, GPScertainly confirms special relativity (which by the way does not need any
confirmation), right?

With a closer look we find that the GPS-satellites carry identical atomic clocks with the clock rate adjusted at launch to 10.22999999543 MHz from 10.23 MHz, corresponding to 38 nano-seconds a day. Physicists claim this results from a combination of a gravitational effect by general relativity making
the clocks tick 45 nano-seconds fast, and an effect in the opposite direction by special relativity of 7 nano-seconds with the net result of 38 = 45 − 7.
Voila! Both special and general relativity thus confirmed by GPS! But isn’t this a little bit too good to be true? Let’s dig deeper:

We recall that the current GPS configuration consists of a network of 24 satellites in orbits around the Earth at an altitude of about 20,000 km with an orbital speed of about 14,000 km/hour and orbital period of roughly 12hours (contrary to popular belief, GPS satellites are not in geosynchronous
or geostationary orbits). The satellite orbits are distributed so that at least 4 satellites are always visible from any point on the Earth at any given instant (with up to 12 visible at one time). A GPS receiver on ground or in an airplane receives signals from at least 4 satellites encoding the position
and clock-time of the satellite at the moment when the the signal was sent out. From this information the distances to the satellites can be computed including synchronization of the receiver clock with the satellite clocks, from which the position of the receiver can be computed to within 5 to 10 meters in only a few seconds. With differential techniques involving at least two nearby receivers, the precision can be improved to centimeters.

Evidently, GPS requires that the satellite clocks all run at the same rate and thus show the same time, and evidently they do since GPS works. The remarkable fact is now that GPS works without any individual adjustment of the clocks, although they are all in relative motion and thus by special relativity should suffer from time dilation and run at different rates. But they don’t, and thus GPS cannot be viewed to give any experimental support of special relativity. If anything, GPS shows that any effect by special relativity in GPS is neglible, according to R. Hatch chief engineer of the GPS-system
Who should we believe, Hawking or Hatch?
The satellite clocks are subject to different physical conditions, as compared to ground clocks, such as gravitation, temperature and pressure, all which potentially could affect the clock rate even in Newtonian mechanics.
Thus it is not clear that the required 38 nanosecond adjustment is an effect of general relativity, or is it?

Tõmbasin isikliku rõhuasetuse boldi.

[aero]

Gravitatsioonilained väidetavalt detekteeriti

were detected = detekteeriti ?!
https://et.wikipedia.org/wiki/Detekteerimine

[Küülaline]

were detected = detekteeriti ?!

No tegelikult on detektor ka eesti keeles samuti mingi kiirguse või osakeste avasaja:
https://arhiiv.eki.ee/dict/qs/index.cgi?Q=detektor&F=M

[EH.INS.]

Ma korraks viitaks veel:
Tasuks eristada "pupulaarteadust" ja akadeemilist teadust, sh refereeritud teadust

[suvaline]

EH.INS.
Keegi ei viitsi sõna pupulaarteaduslik välja hääldada, lihtsam ongi puputeadus. Pupu lühendi sisust saate ju aru.

[T25]

Pupulaarteaduslik aatomikell kõlbab aja mõõtmiseks küll. Hawkinsil, Einsteinil jpt pole aga eriti midagi ette näidata, peale "mõtteeksperimentide" ja sealt tulevate mustade aukude, singulaarsuste, paralleeluniversumite jppms, millega reaalses elus pole paraku midagi peale hakata. Holliwoody tarvis sealt muidugi materjali saab.

[EH.INS.]

Hawkinsil, Einsteinil jpt pole aga eriti midagi ette näidata...

Ainult sügavalt rumal, harimatu (IQ ilmselt tugevalt alla keskmise) jne inimene võib sellise asja peale tulla...