Much of the work of the natural sciences is to classify what is studied. So naturally different fields would have different classes for the same rock, depending on what the investigation addressed. Like other subtleties, Jarrah seems incapable of understanding them. All I can say to that is "Only a Sith deals in absolutes." Just sayin'!
For those who wish to maintain an illusion, ignorance is the best source of knowledge.
Well Jarrah did say in the Binall of America interview that his new website will have a link where people can request an interview with him for whatever reason.
Request an interview with him? Who does he think is? Oprah? Can you provide a link to that video, as I'd like to hear him say it. I'm not ploughing through a radio interview with Jarrah. For the record, I formally request an interview with him, over a phone line. He can come here and arrange it with me.
He mentions his new website from 6:30-7:00 in this video.
Whatever new theory scientists come up with, it also needs to explain the 99.99% that general relativity currently accounts for.
This is a very important point continually missed by many pseudo-scientists (e.g., those trying to build "free energy" machines, as well as those claiming evolution is a "theory in crisis").
Does this stop engineers from building GPS satellites using the principles of gravitation and kinematic time dilation.
I thought about mentioning relativity and GPS but I left it out because GPS is arguably not actually an application of relativity. It's just a navigation and timing system that uses satellites carrying highly accurate clocks. It measures locations (and times) relative to benchmarks (and reference clocks) on the earth's surface. The navigation messages give the numbers needed to locate the satellites with respect to those benchmarks and to convert clock observations to the GPS time scale.
Those navigation messages are generated from control station observations, thus closing a loop and correcting for any number of errors in the system - including the relativistic effects among others.
Yes, GPS most definitely demonstrates the validity of relativity. It's probably the very first operational system in which relativity is an engineering reality. But GPS doesn't actually rely on it for its operation. The satellite clocks are slightly biased low before launch merely as an optimization. Without that bias (which compensates for the gravitational "blue shift" predicted by general relativity) GPS would still be just as accurate but the clock frequency error term in the broadcast ephemeris would have a static offset and take more bits to encode.
Such a view shows he has little understanding of how real scientists work, and how he should interpret data and scientific writings. He and his friends call it skepticism. I call it ignorance and idiocy.
[GPS is] probably the very first operational system in which relativity is an engineering reality.
Not counting the view that what we call "magnetism" doesn't actually exist, but is actually just a manifestation of special relativity and the electrostatic force...
Anyone who understands science knows that when observations conflict with an existing theory, that theory must be modified to accommodate them. And if it can't be modified, then it must be discarded and replaced.
But one might also replace a perfectly good theory with a simpler or more general one. Maxwell's equations still work just fine, but there's a lot to be said for a theory that explains even more with fewer forces.
I can think of only one currently operating real-world system that actually applies relativity to an engineering problem: storage rings attached to particle accelerators. Particles accelerated to nearly the speed of light encounter a relativistic time dilation that makes time in the particle's reference frame seem to pass very slowly in ours. Thus subatomic particles that would otherwise live only a short time will seem to last much longer in storage.
Of course, most particle accelerators are themselves scientific research instruments, though some have found practical applications like cancer therapy and food sterilization.
I thought about mentioning relativity and GPS but I left it out because GPS is arguably not actually an application of relativity. It's just a navigation and timing system that uses satellites carrying highly accurate clocks.
That's a good point, and a subtle distinction between the application of a theory and validation. While not a direct application of a theory, my understanding is that the clocks (or measured times at least) used in the GPS system are adjusted to account for relativity. I ask this question. Had it not been for the Einsteinian revolution, there would be constant 'error' manifested in the outputs of the GPS clocks, and we would not be able to explain it. How would you, as an engineer, deal with an unexplained drift.
'In the poor actors moon books of lies, many say the moon smelled like spent gunpowder. How does an aroma fill the air in a vacuum?' - NASAHOAX
'All truths are easy to understand once they are discovered; the point is to discover them.' - Galileo Galilei
'It's fundamentally dishonest to use that man's authority without also his expertise.' - Jay Windley
While not a direct application of a theory, my understanding is that the clocks (or measured times at least) used in the GPS system are adjusted to account for relativity.
Right, but again it is not necessary to make GPS actually work. It's simply a convenient optimization. The ephemeris transmitted by each satellite gives all the coefficients (parameters to a model) you need to 1) compute the satellite's position and velocity in an earth-centered Cartesian coordinate system as a function of GPS time and 2) determine GPS time from that satellite's clock.
Because the navigation message is only 50 bits/sec, it's obviously desirable to use those bits as efficiently as possible. The best way to do that is to use the best available models for the underlying physics leaving only the truly unpredictable "noise" to be encoded in the data. Why waste bits encoding physical phenomena such as relativity when you can predict exactly what they should be? There's no information (in a Shannon sense) in a message whose contents you know in advance.
The model for satellite position vs GPS time is a Keplerian orbital model with sine and cosine correction (fudge) factors. The model for the satellite clock is a simple polynomial with the parameters giving the static offset from GPS time and the rate (frequency) error. Since the net effect of special and general relativity is to make the clock appear to run faster in orbit than it did on the ground, the clock was set slightly slow before launch so that it would appear to run on time. Now only the unmodeled error in the clock itself has to be transmitted in the navigation message, and that takes fewer bits than if the error included the relatively large (heh) relativity correction.
But even if the clocks hadn't been biased before launch, GPS would still be just as accurate provided the clock frequency errors didn't exceed the range allocated to it in the nav message.
I ask this question. Had it not been for the Einsteinian revolution, there would be constant 'error' manifested in the outputs of the GPS clocks, and we would not be able to explain it. How would you, as an engineer, deal with an unexplained drift.
Correct -- there would be an unexplained drift, just as there was an unexplained (or incompletely explained) drift in the perihelion of Mercury's orbit. An incurious engineer would simply shrug and say "So what? If you really feel strongly about it, in version 2.0 we can work an empirical fudge factor into the clock frequency correction so we can bit-bum the nav message. But as to why, who cares? The system works fine so why are you complaining?"
I should point out that the orbit model used in GPS does not fully model all the physical forces that significantly affect the position of the satellite. It starts with a 2-body Keplerian model that ignores all perturbations, some of which are quite significant. Then it adds two corrections for the long-term effects of the earth's equatorial bulge: a steady precession of the orbital plane in right ascension plus the steady rotation of the major axis within the orbital plane.
Those perturbations are actually more complex than this, plus there are perturbations from the sun and moon. But rather than model them all individually, the official GPS model simply throws in a couple of "fudge factors" -- sine and cosine correction terms with no physical meaning that are empirically chosen to minimize the error in the predicted position.
You could do much better with a full-blown numerical integration of the equations of motion that takes into account all the various forces acting on the satellite, but you have to remember two things. First, GPS was designed in the 1970s when any kind of mobile computing was a really big deal. And second, the broadcast ephemeris is updated every two hours from ground tracking observations so it's not like you really need great long term accuracy anyway. Sometimes the simple, empirical (i.e., "hack") engineering approach is the better way to go...
Post by lukepemberton on Jun 24, 2011 6:54:15 GMT -4
I see the point you are making ka9q. It's interesting to see the difference between an engineers viewpoint and a physicists viewpoint. I think that both scientific branches strive for perfection, but their concepts of perfection and how they achieve it are very different.
This is why I have to laugh when I see Jarrah's treatment of natural science. At the moment, is entire argument seems to be:
Earth rocks have similar properties to moon rocks, therefore moon rocks were faked.
There are some difference between Earth rocks and moon rocks, but these difference can be faked too.
If I bring back rocks from the Moon and get result A, and send a probe forty years later I expect to get result A.
The last point is important to the previous discussion as it shows his black and white thinking, and how he clearly has no grasp of how grey science can actually be.
I would say how grey life can actually be. Science is actually much more likely to repeat result A after experiment A than, say, the arts.
True to a degree. If you are examining chaotic systems, then no, that would not happen. However, after examing the same chaotic system 1000 times (say), one might be able to say if we start the system with parameters between A and B, then we get an output between C and D. Not all science is absolute.
Also, when one interprets results, understanding the experimental parameters, control variables and technique are all important. These are central to the scientific method, for which Jarrah White has no clue. For instance, you can probe the first few layers of a material with low energy electrons. You can probe deeper into the material by ramping up the electron energy, and will probably get a different result pertaining to the properties of the material under investigation. Our antipodean friend quotes from various published articles, and because he does not get result A all the time, he seems to think foul play is at work. He simply does not understand that when he reads material he will get result A plus some delta, and that is because of the nature of scientific measurement and the systems that he is dealing with.