Jump to content

Leaderboard

Popular Content

Showing content with the highest reputation on 12/27/22 in all areas

  1. I'd invert your logic, for better effect: Every religion should respect everybody.
    2 points
  2. It isn't the 'ultimate theory, but it is the one best supported by observational evidence. Do I need to go through the 100 years of evidence accumulated in support of GR ? Theories don't explain why, they explain how. And IIRC, your 'theory' did neither, other than conjecture, and had no supporting observational evidence.
    1 point
  3. I think you may be misunderstanding my context in using "objective." I am referring to facts about how a certain moral valuation would impact the viability of a species or society. No one is suggesting that those valuations have objective existence, rather that a certain moral rule could have a measurable consequence in terms of survival. For example, "eating your children is bad," is subjective, but the result of widespread adoption of the principle could conceivably have a measurable outcome which could be objectively stated. ("Tribes B, K, and X, which forbade infantiphagia, grew and prospered, while tribes A and M, which served them up with fava beans and a nice Chianti, died out...") IOW do our standards for the rightness or wrongness of actions have some grounding in external measurable facts about the human condition? So "objectivity" here only referred to an external state of affairs, not some numinous inner goodness. Does that help clarify?
    1 point
  4. lol its how I test myself for improvement. If I can help others also learn then bonus. One thing about any physics theory you never know enough
    1 point
  5. Why did you pick this particular situation?
    1 point
  6. If this is occurring just after sunset, could it not be a shadow cast by that island from below your horizon. This should cut out the red end of the spectrum leaving just a blue backfill from Rayleigh scattering.
    1 point
  7. If the analogy holds into the 2nd Law I get the result: (a/aref)^[3(k-1)] >= Tref/T where k is the isentropic constant, T is the bulk temperature of the universe and the ref subscript indicates values at some arbitrary reference time. This is the sort of thing I was thinking about as the 2nd Law setting constraints on the rate of expansion. I've uploaded my working as an attachment if anyone's interested. Univ. Expansion.docx
    1 point
  8. Agreed. I'm interested in fusion energy, but I've never seen any explanation how a laser/pellet inertial confinement system could ever be developed that could run economically. There's no substitute for the laser, that can kick in once fusion starts. Even the explosive event of one pellet can't kick off fusion in the next one, so as far as I can see, you would need to have the lasers constantly firing, in a continuously operating system, so you will never get more electrical energy out, than you put in. Unless someone invents a laser machine that lasts for decades, and converts about 50% of electrical energy to the final heat energy absorbed by the pellet. Maybe 10% would be enough, eventually, but there is no sign of that ever happening. Ideas come and go. There was a proposal to 'invent' a system that would work with smaller lasers, giving the same performance as current ones, and costing one tenth to build. It had a huge number of unknowns ahead of it, and it ground to a halt about ten years ago. They called it HiPer in Europe and Firex in Japan, wikipedia has a page : https://en.wikipedia.org/wiki/HiPER I don't think the concept has been abandoned, but nothing's happened in the last five years.
    1 point
  9. I can google this question as well as anybody else. So here is some commentary on an extract from a good reply article. Not that it is not only a question of initiating the fusion, but sustaining that fusion for long enough for it to produce enough energy for it to become self sustaining. Simple Fusion is more common than you think, simply firing a neutron or alpha or other particle into a nucleus can produce fusion. But that is only for one atom at a time. Nature takes a statistical approach in the stars since if you have a container of gas and either wait long enough or large enough or some combination of the two, two particles will eventually collide fast enough to provide the kinetic energy for initiation. In the laser approach you have to keep supplying the initiation energy since the process is a continual series of match strikes, rather than a continuous flame. This avoids the containment problem, but much of the energy is then needed to keep the matches striking. So the problem is a trade off between initiation, containment and sustainability.
    1 point
  10. The concept of Riemann curvature as it is used in ordinary GR applies in any dimension equal to or greater than 2. That means that yes, you can have “curved” 2D and 3D spacetimes as well. The big difference is the level of complexity - in 2D, the Riemann tensor has exactly one independent component, so it is simply a scalar; in 3D, it has 6 components, and can be shown to equal the tank-2 Ricci tensor. Hence these situation have a lot fewer degrees of freedom than we see in our 4D world. Geometrically speaking, in 2D you have only scalar curvature, so the only thing that can happen is that the area of a 2D surface differs as compared to the same situation in a flat spacetime. It is very simple. In 3D, you get a new kind of curvature which is Ricci curvature, which means that volumes may differ as compared to the same situation in flat spacetime. In 4D and above then you have, in addition to scalar and Ricci curvature, also Weyl curvature, which introduces (relative) tidal forces and shear between neighbouring geodesics, meaning it (roughly speaking) distorts shapes as compared to the flat spacetime situation. So yes, it is in fact possible and meaningful to talk about GR in three dimensions. However, since such as theory contains only scalar and Ricci curvature, but no Weyl curvature, the resulting phenomenology is very different from what we actually see in the real world - at a minimum there would be no gravitational radiation, no gravity at all in vacuum, and gravity in the interior of bodies would behave quite differently.
    1 point
  11. No. I’ll do what I want. Keep your childish fairy tales to yourself you deluded fool. lol. Too over the top?
    1 point
  12. No. Everybody should be skeptical toward their religion.
    1 point
  13. That's demonstrably false, but makes a snappy sound byte. Most religions place their deity at the top, and then rank all the pious in order of worthiness, with church leaders high on the totem pole, church patrons below them, regular church members below them, members of false religions are further down, atheists are down there too, and everyone else in the world they don't like somewhere below that. Why should anyone respect a hierarchy that judges them disrespectfully, that doesn't take their humanity into account but instead berates them for it, using humanity as a synonym for "flawed" and "weak" and "sinful"? Or lack thereof.
    1 point
  14. What is religion without people?
    1 point
  15. Especially the ones that kill people for showing disrespect.
    1 point
  16. Well obviously. It's other people's religions where the problems can start.
    1 point
  17. Respect has to be earned.
    1 point
  18. l wrote: and you can't deny that 😄 You are very attached to the current understanding/definition of time, the one used in GR, but you really think that this is the final/ultimate theory that we can have in order to explain gravity with all its aspects? There are already many complaints about it since dark "stuff" appeared. Some even say that dark matter is not real and is used to maintain GR valid (I don't agree but it is possible). There are MOND theories proposed. There are other attempts also, including my theory, based on dark matter. Moreover, if the GR definition/notion of time is "the one and only", please explain how is this particular definition (the notion of space-time) used in quantum physics. Also please explain why, and how exactly, gravity wells are formed around massive objects and why exactly is the speed of light invariant? If you don't have an explanation, how can you be so sure that GR is the ultimate theory? With my theory I explained them fairly easy. My opinion about time is that it is something we cannot see, touch, feel in any way. What we can see/observe is change. Because there is change, we can invent/define time as an useful notion/tool. We need it to compare changes (faster/slower), both in position (movement, speed, acceleration) and in structure (ageing, decay). We need it to make our theories, for our equations, for accurate predictions. And we also need it to write our history in chronological order. Last but not least we need it to function, to catch a train, to meet someone, to plan a trip, etc. So time is as real as density, or pressure, or temperature, but more important. Gravitational radiation? You mean gravitational waves? If so, what is the explanation for them? The space-time vibrates? How? You are absolutely sure that there is no other possibility to explain gravitational waves (outside GR)? How can you be? ( I have one, not the one I wrote here, that one was wrong).
    0 points
  19. Religion's do, it's people that don't.
    0 points
  20. Gravity does exist regardless on how we define or understand time. Good point. Once (in this sub-forum, in august 2018) I wrote that space-time is a like a 4-D map of a 3-D reality, not entirely different than a 2-D paper map we used when travelling. In this sub-forum, called "Speculations", we often see how people with not enough knowledge/information tend to make inadequate, poor, sometimes even stupid theories or assertions (it happened to me many times, so I know first hand 😃). Well, Einstein and the others, more than 100 years ago, did not know many, many things (dark matter, dark energy, etc.), compared to what we know today, so we should not be surprised that their theory may soon be proved inadequate and their understanding wrong. I have (and posted here) a new interpretation of the theory of relativity, based on dark matter, and although it agrees with Einstein's relativity predictions, it makes also predictions that differ, so one of the theory/understanding can be proved wrong ... When I'll have the time I'll come back, in my topic, with details. It's not big rush because my experimental tests imply atomic clocks on the Moon and/or beyond.
    -1 points
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.