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geordief

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Everything posted by geordief

  1. What does it mean to say the Gravity Field is static? Is it not changing all the time ? Also ,when there is even the most minor of displacements of distribution of mass-energy in a system does that also cause Gravitational waves in exactly the same way as was detected with the recent Binary Black Hole Merger? Is is simply that the magnitude of Gravitational waves caused by such small redistributions of mass-energy in a system are entirely impossible to detect ? Is it correct to say that the universe is awash with small Gravitational waves so that the local and global Gravity Fields are actually in continuous change on a vanishingly small scale? They are in continuous "vibration" almost ? Are the Gravitational waves that have been detected merely the ones that are large enough to have been physically detected?
  2. i understand that the Gravity Field is static and not to be confused with Gravitational Waves which are dynamic. Gravitational waves are created when there is a change in mass-energy distribution and propagate at light speed (correct?). Do they have any effect on the static Gravity Field? Does the energy in these Gravitational waves get distributed throughout the Gravity Field it propagates through and so do these Gravitational waves get "converted" into a new Gravity Field?
  3. Does the concept of flatness vs curvedness apply inside or near to Black Holes ? Is the Black Hole circumstance similar to what pertained at times near (whatever "near" means) to the Big Bang? Does it make any sense to contemplate that journey where you end up where you came from? Do you not just (as a thought experiment) keep creating "new universe" if the universe is flat at large distances? Is it not the (non existent) curvature that would cause you to return to the starting point? I realise my understanding and imagination are probably critically lacking in this area.
  4. Do we get different curved geometries in all Spaces that have different forces(= fields?) present ? I have never heard of space time curvature being applied to other areas like magnetism but are there also geodesics in magnetic fields, as an example and is it right to also talk about a spacetime curvature in that context as well? If one needs to calculate the path of an incoming object that was subject to the Earth's magnetic field is it possible to do so (ignoring gravity) in terms of it following a "magnetic geodesic" ? Does such an object ,in a magnetic field undergo acceleration ? If it does, does that say it is not following a geodesic?
  5. That is exactly what it told me. The first thing in fact. I accepted it naively but it seems to be a debate that I was unaware of. http://philgons.com/2009/04/the-passive-voice-should-be-avoided-right/
  6. If an expanding wave of light is viewed as a sphere which increases in size and propagates away from the source, is it fair to say that a portion of the wave actually moves at 2c with respect to a corresponding portion of the wave expanding in the opposite direction? Is that true and does anything follow from that observation? Or is it not true and is this an example of how relativistic speeds do not add linearly ? Or is it perhaps an example of ,as I have heard the idea that you cannot use light as a frame of reference?
  7. I have just found this resource. It shows up " spelling errors, style suggestions , or grammar suggestions " in your text. http://www.grammarcheck.net/editor/ .
  8. Spot the ball? Here ,have this one on me
  9. The interviewer says; (at around 9 minutes in) "I think true contact between 2 particles ,say 2 electrons is the point at which the space occupied by the electron could have no Planck lengths between it and the space occupied by another electron..... " The professor says that that way of looking at the situation simply does not apply in quantum mechanics . He goes on to say that things cannot occupy the same space and that the interviewer is trying to define "contact" as the time when the two footballs "overlap" (become one football -which never happens). He finds the interviewer's suggested definition for contact "extreme" (he means "impossible" ) He also says (the Prof) that "you cannot define an electron like a particle like that"
  10. I don't think "logical" adds anything to what are supposed to be scientific observations. If a scientist( which I am not) allows him or herself by what seems "logical" it may be the equivalent of him "resting on his laurels". If something appears "illogical" ,however it must be a sign that something is amiss ,either with the observation or the interpretation of the observation. That it appears "logical" though may add nothing to what we already (think we)know.
  11. Get it fixed ,man (no pun included).
  12. Another one got through,imatfaal
  13. On the other hand ,when I heard the usage "amn't I ....?" I put it down to a similar kind of grammatical snobbery. It turned out ,years later that I learned it was simply part of "Irish English" https://stancarey.wordpress.com/2014/03/04/amnt-i-glad-we-use-amnt-in-ireland/
  14. It is a correct policy. The worst thing we can do is to talk past each other.
  15. Fine by me . I have lots to learn.
  16. bm?
  17. You don't think "was" is more definite than "were" ? Does "was" imply specific cases and "were" has more of a general sense? In Google "were" outnumbers "was " by 10 to 1 for the phrase "if it was/were to be done" . In my mind "was" is therefore used and cannot be wrong if it has that uptake. But does it have a different sense?
  18. Penny in the poor box it is 'posters' ' was right, though.(plural) EDIT: maybe "was" was good too(better?)
  19. Yes ,I also thought it was a bad idea. It smacks of picking on people. If it was to be done it should be with posters' consent. I would be happy to give mine though (and I see so does dimreepr) since I am all for clarity of thought and expression-and good communication. . Clarity is next to godliness ,or words to that effect.
  20. Indeed,although there are caveats that this is a speculative area. However ,from what I have read on this or other forums like it ,the underlined part of the following sentence is just wrong and shows up in the BBC article http://www.bbc.com/news/science-environment-21150047 "What makes more sense is the quantum effect of entanglement. Under quantum rules, no matter how far apart an "entangled" pair of particles gets, each seems to "know" what the other is up to - they can even seem to pass information to one another faster than the speed of light.." Am I right ; is that kind of a sentence a no-no?
  21. "contact" is also a word. I am not qualified to say whether the balance of forces he is describing is actually the case but ,until I hear otherwise it will be my working model. If he wants to call it "contact" then fine but I hope it is a definition that is widely accepted ( a convention). It is best that we all use the same language so far as possible. He makes the point the things never completely occupy the same space. I like that idea but ,who knows perhaps there are exceptions I do not know about......
  22. He explains what is going on. It doesn't matter what words are used to describe it so long as they are understandable and he is describing the same thing as you are trying to understand. It is good to be clear with language but sometimes it doesn't matter so long as you understand what is happening. Words are also tools.
  23. I knew the Cold War wasn't over. https://en.wikipedia.org/wiki/Spy_vs._Spy
  24. Here is a link I found http://www.sciencealert.com/how-graphene-could-help-solar-panels-produce-energy-when-it-s-raining
  25. Can it be tested as to whether the theory of GR still applies in the extreme situation where two bodies (not particles) interact at such a remove from sources of mass-energy that we can ,for all intents and purposes regard them as constituting the entire universe? If we consider only the mass-energy bound up in the two bodies in question is it known/expected that they will curve spacetime in the same way as they do when they are just a part of the overall system of macro objects? It is not possible is it that GR will lose its applicability (or need to be tweaked) as such an extreme situation is approached?
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