Speed of Light

Discussion in 'Politics' started by ShoeshineBoy, Aug 9, 2003.

  1. nitro


    It would not appear as if anything unusual is happening. In your frame of reference, the light beam would look like if you were standind still and turned on the lights.

    That is the whole point of Special Relativity, this exact "thought experiement" that led Einstein to slowing clocks, Lorentzian transforms, and the shrinking of space...

    #21     Aug 11, 2003

  2. Who knows this shit?? NOBODY...not even Einstien.....nobody has ever gone the speed of light nor been able to measure it...it;s all approximations and guesses....Im always amazed at the certainty with which Sience will say somehting and then 20 years later say OOps!...
    #22     Aug 12, 2003
  3. To me that's not the point. Einstein said, "The most beautiful thing we can experience is the mysterious. It is the source of all true art and science." I absolutely agree with him. The remarkable thing about our universe is that our intermediate levels of understanding always prove to yield incredible insight and perspective as well. And if you're coming from a theistic perspective, here's a Proverb: "It is the glory of God to conceal a matter; it is the glory of men to uncover it." I don't buy into the idea that the only worthwhile endeavors are those where we have complete understanding - I wouldn't trade if I followed that philosophy...
    #23     Aug 12, 2003

  4. I agree.
    We don’t and can’t have a COMPLETE understanding of anything – it’s a proven mathematical truism:
    Gödel's Theorem and Information

    Uncertainty is the only certainty – this fact makes fundamentalists squirm like worms in protest.
    #24     Aug 12, 2003
  5. Actually, I think it says that there will always be an element of faith in all paradigms...
    #25     Aug 12, 2003
  6. nitro


    That is false.

    I suggest you start by reading about the Michelson-Morely experiment. Since that experiment, these types of calculations about the accuracy of Einsteins equations have been performed to 20 decimal digits of accuracy in the form of Quantum Electro Dynamics. It is possible that some of the axioms are off - in fact, it is believed that Einstein's theory cannot be the final say, as there is currently no way to reconcile Relativity with Quantum Field Theory. However, it will not make the theory "wrong" it will only say that at high energies the Theory of Relativity breaks down. This is similar to the way that Newton's theory breaks down at speed close to the speed of light, but are remarkably accurate in all other Physics. Newton's theory was an APPROXIMATION to the final truth, but not false.

    Science is not Perfect, but if there is a "perfect" science, it is Physics.

    #26     Aug 12, 2003

  7. You make it sound so complete and accurate... we know shit...physics on earth is assumed to be equal to physics across the universe...not necessarily...look up into the sky tonight ans each and with each and every star you see remember that those are solar systems and possibly a group of planters just like earth...we do a couple of math configurations that add up because we set the number sin place and now we know everything? we know shit...we take educated guesses....Think of this the same way you do these black box oscillator programs...anyone can plug numbers into the past 12 months of trading and show you an exact formula for why the naz went up or down......thats easy....now the hard part is predicting the next 8 hours.
    #27     Aug 12, 2003
  8. Physics defines the "universe." In that sense, proposing that different laws might govern events and processes elsewhere in this universe would be nonsensical. Alternative physical laws would equate with an alternative universe or universes.

    The above in no way implies a claim that physics is complete and perfect. No science makes that claim. You may call what we know "shit," and 10,000 years from now that may appear to be a reasonable description, but we also know around 10,000 times as much as we knew a century ago:
    #28     Aug 12, 2003
  9. August 12, 2003

    A Whole Other Cosmos
    With better tools and collaboration, scientists are discovering a more violent and vibrant universe than could be observed just years ago.
    By K.C. Cole, Times Staff Writer

    There's nothing like quietly contemplating the sky on a clear, moonless night to make us feel we can touch the cosmos in its entirety — the bright canopy of stars, the ever-shifting play of planets, the vast, cold silence of infinite space.

    How little we know.

    All this glory is but the barest glimpse of what's actually out there. Tales of extreme violence and profound mystery stream at us from every corner of the cosmos, and yet we're constrained to peering through the tiniest keyhole, seeing only the thin band that beams in visible light. Until very recently, even astronomers, who see nearly the entire electromagnetic spectrum, from radio to gamma rays, have been able to tune in to only the barest trickle from the flood of news.

    In the last few years, however, new instruments have begun painting a far more vibrant image of the universe. The celestial story now unfolding has as much in common with the picture of decades past as a Technicolor, Dolby Digital surround-sound production has with a grainy silent film.

    Consider: In the last year alone, a satellite tuned to faint microwaves still glowing from the Big Bang took a picture of the quantum mechanical quivers in the newborn universe that pulled matter into what eventually became galaxies, stars, and ultimately, us. The picture pinned down the age of the universe precisely — 13.7 billion years — and confirmed its exact mix of ingredients. The same astonishing image suggested that the fires of the first stars electrified the skies 200 million years after the Big Bang — much earlier than most astronomers predicted.

    Meanwhile, X-ray telescopes have been finding black holes — objects of such concentrated energy and warped space that they trap even light — virtually everywhere they've looked. One satellite alone found 1,500 supersized holes feeding on surrounding gas and stars in just a small patch of sky. Other telescopes found a whole new species of midsized models previously unknown to exist.

    "Far more black holes are lurking out there than anyone thought," said Sonoma State University astrophysicist Lynn Cominsky. "If you look at the universe in visible light, it's pretty calm. But in X-rays and gamma rays, it's very violent."

    From the infrared end of the spectrum comes UCLA astronomer Andrea Ghez's discovery that the supermassive black hole in the middle of the Milky Way is flinging a star around at 3% of the speed of light as if it were a pebble from a slingshot.

    And the adventure has barely begun. On Aug. 23, NASA is set to launch the last of its four "great observatories," grand telescopes in the sky, each tuned to a particular swath of the electromagnetic spectrum. While Hubble, Chandra and the now defunct Compton telescopes looked at visible light, X-rays and gamma-rays, respectively, the new infrared telescope will allow astronomers to peer through the fog that shrouds the births of stars and planets.

    Following not far behind them are two more "Great Einstein" observatories. Both involve arrays of telescopes flying in formation like well-practiced flocks of birds, in one case effectively creating an observatory millions of kilometers across.

    Almost every month, new ground-based telescopes open their eyes, and new special-purpose explorers take off for the clearer skies of space. Some, like the Sloan Digital Sky Survey, are mapping much of the sky in great detail, pinning down the location of galaxies, stars and distant quasars to create a three-dimensional image of its large-scale structure. Others, like Hubble, often go deep and narrow, taking what amounts to a core sample of the universe.

    "It's amazing to think about how much this has developed since I was in graduate school," said Michael Jura, a 55-year-old astronomer at UCLA. The laws of physics haven't changed, "but the consequences are enormously greater than people imagined," he added.

    The vast expansion of the spectrum of the possible puts scientists on the brink of being able to answer some of the thorniest questions ever posed: How do solar systems form? How did matter come into being? Does space really crinkle, and time really stop, at the horizon of a black hole?

    As Einstein once put it, the most incomprehensible thing about the universe may well be that it's comprehensible at all. Certainly, the recent unveilings — and those to come — have been made possible not only by leaps in technology but also by a willingness to follow the often outlandish lead of theoretical predictions.

    In fact, one of the niftiest new tools astronomers use to see deep into space comes straight out of an outrageous suggestion by Einstein. His theory of general relativity implied that large concentrations of mass should bend light just as glass does, forming "gravity lenses."

    The first such lens was discovered in 1979, and more than 100 have been found since. Today, they are regularly put to use as natural "telescopes," enabling astronomers to find everything from previously unseen distant galaxies to concentrated globs of dark matter.

    At present, most of the eye-opening discoveries stem from improved techniques for tuning into the electromagnetic spectrum, which ranges from gamma rays smaller than atoms to radio waves bigger than mountains. (The rainbow of visible light our eyes detect is a narrow ribbon midway through the spectrum.)

    The universe broadcasts in all these bands, yet very little gets through. X-rays, for example, can easily see through Lois Lane's clothes but can no more penetrate our atmosphere than they could a sheet of lead. And violent objects like collapsing stars and black holes broadcast their presence almost exclusively in X-rays.

    Some infrared light does get through to Earth, but only in patches, with a lot of interference from sources like infrared telescopes themselves. Everything above absolute zero temperature radiates in infrared — including air and icebergs.

    Thus, even astronomers like Ghez who already observe in infrared from the ground are excited about NASA's Space Infrared Telescope Facility, or SIRTF, which will be chilled to close to absolute zero. That, plus state-of-the-art detectors, means that SIRTF will be a million times more sensitive than previous infrared missions.

    (In all respects, SIRTF is a very Southern California enterprise. The SIRTF Science Center, which evaluates proposals for observing time and processes data, is based at Caltech. Two of the original science team members — Jura and Ned Wright — are professors at UCLA.)

    Infrared astronomy is particularly effective at looking back at the earliest moments of time. In an expanding universe, light that began its multibillion-year journey as X-rays would have by now become almost entirely stretched into longer wavelength infrared. Infrared also slips through the thick, dark dust that clouds the birth of stars. Astronomers don't even know whether stars are typically born in splendid isolation, like our sun, or as twins, which seem to be far more common.

    And it's the only way to study the cool dust itself, critical to understanding how planetary systems form. (Planets are little more than clumps of dust left over from coalescing stars.)

    It would be misleading to credit space-based astronomy with all the big advances. At the Keck telescopes in Hawaii, Ghez, for example, keeps track of stars speed-racing around the Milky Way's center. Their vision was dramatically improved when they were fitted with "adaptive optics" that can clear up atmospheric blurring using mirrors that flex thousands of times per second, effectively taking the twinkle out of starlight.

    Another breakthrough is the increasing use of interferometry — the combining of waves from many different telescopes, often widely spaced, to produce a single, vastly magnified image. Long a staple of radio astronomy, it's exceedingly difficult with short-wavelength light. Still, most major observatories are working on it, and recently the twin Keck telescopes successfully combined infrared light to bring into focus a swirling disk of dust around a very young star.

    #29     Aug 12, 2003
  10. nitro


    We do not know much, I agree.

    However, we do know quite a bit about the physics of the ENTIRE Universe. For example, take a look at the COBE explorer that measured the background radiation coming from the ENTIRE VISIBLE UNIVERSE.

    It is possible that the laws of Physics are not constant throughout the Universe, either in space or time. However, that would not make our approximations in our "vicinity" wrong, just an approximation to the final truth as it is presented to us. If we find a fact that contradicts our theory, we would only be so happy, as that would allow us to get a glimpse deeper into the Russian doll.

    Science is not Perfect, but if there is a "perfect" science, it is Physics.


    #30     Aug 12, 2003