Moon-based lasers could uncover exotic physics
Posted on 06/26/2007 5:59:25 AM PDT by BGHater
The 'Pioneer anomaly' – the mystifying observation that NASA's two Pioneer spacecraft have drifted far off their expected paths – cannot be explained by tinkering with the law of gravity, a new study concludes.
The study's author suggests an unknown, but conventional, force is instead acting on the spacecraft. But others say even more radical changes to the laws of physics could explain the phenomenon.
Launched in the early 1970s, NASA's Pioneer 10 and 11 spacecraft are drifting out of the solar system in opposite directions, gradually slowing down as the Sun's gravity pulls back on them.
But they are slowing down slightly more than expected and no one knows why. Some physicists say the law of gravity itself needs revising, so that gravity retains more strength in the outer solar system. But there has been disagreement about whether such modifications would accurately predict the orbits of the outer planets.
Now, Kjell Tangen, a physicist at the firm DNV in Hovik, Norway, says tweaking the law of gravity in a variety of ways cannot explain the anomaly – while also getting the orbits of the outer planets right. After modifying gravity in ways that would match the Pioneer anomaly, he inevitably got wrong answers for the motion of Uranus and Pluto.
Conventional explanation
(Excerpt) Read more at space.newscientist.com ...
Newfound Data Could Solve NASA's Great Gravity Mystery (#10)I sent the ping message without the ping. Still, you're glad to know I'm on the job...
Has the spacetime curvature of the entire solar system as a unit been factored in? ... Where’s Dick Feynman when they need him. [Mumble, mumble ... CalTech Physics Lecture series, etc.]
The ether really does exist!
Ugh...spherical geometery I get and understand, hyperbolic, not so much.
What you need to understand is that physics and mathematics and all of the natural sciences are intertwined. I consider pure math as much of a science as physics or chemistry. Without math there would be no physics and without physics, well we’d still probably have math. But you can’t solve a physics problem without math, end of story.
What the other sciences DO is create a set of constraints with which to develop a mathematical model. The mathematical model usually mimics a “perfect” world, because there are so many variables in the real world that for engineering “close enough” is actually all that matters.
A mathematician, a physicist, and an engineer were asked to review this mathematical problem. In a high school gym, all the girls in the class were lined up against one wall, and all the boys against the opposite wall. Then, every ten seconds, they walked toward each other until they were half the previous distance apart. The mathematician, physicist, and engineer were asked, “ When will the girls and boys meet?”
The mathematician said, “ Never.”
The physicist said, “ In an infinite amount of time.”
The engineer said, “ Well... in about two minutes, they’ll be close enough for all practical purposes.”
Naturally-occurring wormhole. Got to be.
Heh, thanks for that one! I am committing it to memory now.
Yes, it has. Something else is going on, and it might not be dark matter but something even more unknown.
All of science, even physics, is heuristic but being refined constantly as measurements get more significant digits. One thing physicists might do to improve their position in the philosophy of science is to cease grabbing terms that are laying about and pasting them onto their theories. They could make up new words instead of calling one variable time and another mass, etc. They don’t know what time and mass are and shouldn’t use the terms as names for their Bridgman measurement procedures since they can’t know what they are measuring.
Well, yeah...Newton as modified by Einstein...but yeah.
And also:
Physical laws describe nature, and it’s up to us to discover them - you can’t do it just by thinking about it, like you can with math.
I'm trying to get at the core of what you mean to say here. Let's say I point out to you that you have ten fingers, in two sets of five...one set on each hand. Therefore two hands times five fingers per hand equals ten fingers in all, or 2x5=10.
Now, does my conclusion reflect a valid observation about our physical universe, or was it just made up?
I will agree that at some point math can (and does) branch off into the theoretical. However, prior to that point it is as concrete (and as reflective of physical reality) as the hashmarks on a yardstick.
If math is just made up there ought to be more variability from one to the next mathematician. Physics, though, does not describe nature but tries to explain phenomena by mathematical analogy. Since analogy is not proof, that leaves physics not proving anything. If you want to describe nature you might start by saying what nature is, if possible.
There is a lot of variability between flat, spherical, and hyperbolic geometry results! They can't even agree on how many lines, if any, are parallel to a given line, that pass through a point not on the line!
What doesn't change is the use of logic, but what does change are the axioms on which each mathematical structure is based. In contrast, the axioms of physics are not for us to alter; they are what they are, and it is up to us to attempt to identify them. We can't even be sure that we've correctly identified any of them, e.g. that the speed of light cannot be exceeded by a material object, in any inertial frame. The most we can do is assert that no known facts or observations contradict what we believe to be true, but even this allows that some other conditions might exist, that we have never observed or conceived of, in which what we believe to be true would not be.
>>It is based on the discovery of a phenomenon (roughly) that twin pairs of particles always spin in a direction with respect to each other, no matter how far they are physically apart.<<
Einstein’s “spukhafte Fernwirkung”. How about first using it for Earth-based FTL (”faster-than-light”) communication?
Sorry... it doesn’t work that way.
While mathematics might be based on axioms, and ultimately cannot be proved within itself, so it is something but we’re not sure what and is internally consistent and discoverable, physics is based on math. The idea that there are laws of nature and we can discover them is certainly ancient, but there is no reason mathematical explanations are the true form of those laws. Physics is no more than explanation by analogy. Analogy is not proof and is not discovery of natural law.
Maybe star trek was on to something with their subspace communication networks?
In principle, a person can sit inside a room, with no windowns, and come up with numbers, counting, adding, multiplcation, functions, calculus, topology, geometry, and so forth, until he has deduced every mathematical thing that there is. But he cannot - just by thinking - come up with the periodic table, with Maxwell’s equations and the charge on an electron, with relativity and the speed of light, time dilation, etc., because they are based on things that are outside of the room, and not just in someone’s head.
Now, it’s true that people are part of the natural world, and the person is indeed inside the room, so a bit of natural world will be discoverable by this person, since he’s not just a spark of pure intellegence and nothing else. That he has 10 fingers is indeed part of nature, but it isn’t a natural law like gravitation is; indeed, there are some people with 12 fingers, and some unfortunate ones with zero, but there aren’t any planets without gravity, at least that I know of. So the law of gravitation is more fundamental, more important if you will, than the law of 10 fingers.
I’m reminded of Feynman’s ‘excess radius’ ...
My favorite Feynman story was the frog eye light cells that detect dark rather than light. Also, the light sensors that face to the back of the eye socket rather than toward the lens. They say he was somewhat out of control most of the time but highly productive of a variety of ideas. I have his book, the one in three volumes.
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