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IM Egdall

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Posts posted by IM Egdall

  1. And, therefore if there is no such thing as a constant space or time, then by definition, there can be no constant speeds (light). The more hoops people jump through to protect light's status as a constant, the more it disproves itself.


    You can't have a constant measurement of two things that are, each, unconstant (change in position in space over a period of time).

    Huh? The fact that the speed of light is absolute, that it is unaffected by the speed of its source or the observer, is what leads to the relativity of time and space. Google "relativity light clock" and you'll find lots of explanations of this.


    To your last sentence: Relative (uniform) motion reduces both distance and time by the same factor, the Lorentz factor. This factor cancels out when you divide distance by time to get speed.


  2. In his book, A Universe from Nothing, Krauss says there is only one kind of universe where its "total energy is precisely zero." This is a closed universe (one with overall positive spacetime curvature.) A closed universe can "appear spontaneously with impunity, carrying no net energy."


    Krauss says he assumes here Richard Feynman's sum-of-all-paths method applies to quantum gravity. Since no prediction of any quantum gravity theory has been unequivocally confirmed by measurement, his ideas are speculation.


    See http://www.decodedscience.com/a-universe-from-nothing-lawrence-krauss-theories-explained/11450

  3. Ok, my understanding was that time was distorted by speeds close to the speed of light not the actual distance...

    There is no "actual distance." All distances are relative. The distance you measure, as Swansont said, depends on your frame of reference. And distance is affected by any speed. Its just that the amount of length contraction is extremely small at relative speeds which are small compared to the speed of light.


    The same is true for time.

  4. In quantum mechanics, all particles are derived from fields, not just the Higgs. And particles which interact with the Higgs field only do so when they try to change speed ro direction, i.e. accelerate.

  5. Our current best scientific understanding says the universe began with the big bang. This theory is supported by a number of independent observations of the cosmos, including the Cosmic Microwave Background, expansion of the universe, amount of hydrogen, helium, lithium, and beryllium in the universe, etc.


    This in turn is based on general relativity and quantum mechanics. But these two established theories -- validated in numerous observations and tests -- tell us nothing about what happened at time zero of the big bang. They break down and give us infinities for answers.


    So no one knows what happened at the big bang, what caused the big bang, or what, if anything, happened before the big bang. There are lots of new theories, but none have been substantiated by empirical evidence. So, although they are fun to contemplate, at this point they are all mere speculation.

  6. I think it goes like this:


    The distances between galaxy clusters is continually increasing over time. This is the so-called expansion of space. But gravity (spacetime curvature) within clusters offsets the expansion force, so there is no expansion within clusters.


    But there is still motion independent of expansion. For example, within our galaxy cluster the Milky Way and Andromeda galaxies are moving towards each other and will eventually collide. And my fingers are moving to type these words, which has nothing to do with the expansion of space.

  7. I think this thread maybe should be in Speculation. But here's my opinion anyway. I've tried till my head hurts to come up with something, anything which connects a "higher power" to the science of the beginning of the universe, some essence which goes beyond our minds, beyond one's personal religious beliefs, beyond opinion, beyond all subjectivity. The only thing I can come up with is this:


    Our universe is inherently logical.


    I know, I sound like Spock. But it seems to me to be true. Stripped of everything else, what is left is a logical universe. That is why humans can come up with mathematical equations to describe the behavior of physical phenomena. No matter what working scientific theory we look at-- including Hawking's -- at its foundations is the fact of logic.


    So here's my question. Who or what made the universe logical?

  8. I offer one possible explanation. Cometary impact. Four billions years worth. That would be wholly consisten with current theory.


    Right on. The finding of water on Mercury gives even more credence to this theory. It also says the water here on Earth most likely came from ice-containing comets. And that these comets have hit other planets and moons, which increases the probability of finding some form of life as we know it on them.

  9. You are right that the neutron and proton are not simply made of three quarks and some gluons. Really the nucleons are a "boiling pot" of particles coming in and out of existence; this is what quantum field theory tells us.


    Overall we have what looks like three quarks bound together.


    Anyway, you should not think of the particles that emerge from collider experiments as already being present in the initial particles. What is present is the energy to create such particles.


    Is this "boiling pot" of particles coming in and out of existence in neutrons and protons the so-called virtual particles that come in and out of existence in the vacuum of empty space?

  10. Again, the so-called "singularity" means we do not know. The equations of general relativity break down up at the singularity and give infinity for answers. So I don't think we should puzzle too much over whether a singularity contains space or whatever. We have to wait for some yet to be substantiated new physics to tell us what is going on.

  11. I guess I would say the atomic clock has a certain reading whether a human looks at it or not. Say we somehow connect the clock to a bomb so it goes off when the clock reaches a certain reading. The bomb will still explode at that time, even if there is no one to observe it.

  12. I think it is dangerous to attribute the necessity of humans to the notion of an observer. Take an electron for example. In quantum mechanics, the electron wave function collapses when it is "observed". I think it is better to say the "interaction" of the electron with the detector resulted in the collapse of the wave function. No human observer is necessary.


    In relativity, the "observer" is a particular frame of reference. If you place a measurement device like an atomic clock in a particular reference frame -- say on a rocket moving with respect to the Earth-- it will register the passage of time differently than an identical clock on the Earth. Again no human observers are necessary.


    The universe existed for some 13.7 billion years before humans first walked the Earth. So it seems to me humans are not needed for the laws of physics to play out.



  13. As others on this forum have pointed out, "singularity" means we don't know. The so-called big bang singularity is where the mathematics of general relativity blows up -- it gives us infinity for a solution at time zero. The singularity is not real. Current physics can't tell us what happened at time zero. Again, we just don't know.

  14. U.S. Air Force Captain Joseph Kittinger jumped from a helium balloon from an altitude of 102,800 feet on August 16, 1960. "Try anything" Joe was testing the ability to survive the rigors of space in a pressurized suit. Because his historic leap was nearly eight months before Russian cosmonaut Yuri Gargarin's pioneering space flight, Kittinger has been called the first human is space.


    See link: http://decodedscience.com/joe-kittinger-and-einsteins-equivalence-principle-the-first-human-in-space/10776



    Kittinger held the record for a high altitude jump for over 50 years, until Felix Baumgartner's leap the other day. Eighty-four-year-old Kittinger, an adviser to the Red Bull team, was the voice Baumgartner heard on his way down.






  15. There are several points that could be made here. Time in modern physics is generally considered a complicated concept yet what would be the meaning of time without matter or energy? Essentially time is an interval of change in matter or energy. According to the consensus version of the Big Bang model, all mass and energy in the universe began with the Big Bang. If this is so then what would be the meaning of time, concerning the idea "before the Big Bang."


    "When forced to summarize the general theory of relativity in one sentence: Time and space and gravitation have no separate existence from matter."

    (Albert Einstein)


    The meaning of this sentence, in the context of this discussion, is that there is no possibility of the existence of time or space before the existence of matter. It would follow that if matter began its existence at the time of the Big Bang, then neither time or space could have had existence before then.


    The existence of Time and Space, therefore, is a function of matter/energy.



    On an earlier forum thread, I made arguments similar to those above. However, I was told by those smarter than me (most everybody) that what Einstein said was that time and space have no separate existence from a gravitational field. So since matter/energy produces a gravitational field, I assumed this meant there is no time and space without matter/energy.


    I was corrected. If I remember it right, per general relativity, even a universe with no matter/energy has a gravitational field. So saying you need matter/energy to have space and time is not right.


    Also, the big bang theory tells us nothing about time zero when the universe began. The equations blow up at time zero, giving infinity for answers. This is the so-called singularity -- a name for "we don't know". So no one knows what if anything happened before the big bang.

  16. Um, we don't have anything to test where time stops after a certain region in space, unless there's some top secret government program you weren't suppose to just tell everyone. Based on our information, the object should at least get smeared throughout the surface of the black hole, not just stop, and how could the atoms be measured but be in both inside and outside the black hole?


    Sorry, I am not understanding you.


    What do you mean by time stops "after a certain region in space"? We know time slows down in a gravitational field. (This has been observed many times in all kinds of tests.) The idea for an event horizon is that gravity (spacetime curvature) is so great that time slows down to the point where it stops altogether, as seen from far away. You are correct that, I as far as I know, this stopping of time has not been observed (yet). But it is a prediction contained within the construct of general relativity, which has been tested extensively in nearly all its other predictions.


    And what do you mean "an object should at least get smeared throughout the surface of the black hole"?


    Plus I never said the atoms are measured both inside and outside the event horizon of a black hole. Please clarify.

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