mothythewso

How could you get a sick Sequoia into the ambulance?

I think most people would consider an anencephalic baby not to be human, something that will never achieve "personhood". So in that particular case I would say that life never began in the human sense. I have a nephew that is profoundly retarded; I think of him as a "it", I almost never refer to it by name. It looks human, it's certainly viable with support because it's 40 years old; it has a heart that beats, lungs that take in oxygen and remove CO2, kidneys, a liver, and even something that resembles a brain taking up space in its cranium. But, even tho it can react to its name, recognize its parents, etc., it can't look up at the universe and ponder its place in the grand scheme of things, because as far as I am concerned, it has no place. Its mother loves it, its brother and sister treat it well and have arguably become better persons because of their experience. But is it human? I would say "No". I wouldn't even consider the moral, ethical questions. I suppose if somebody harmed it, legal views would prevail. But when you ask "When does life begin?", in the human sense, would the dispassionate scientific, biological view be that in this case it never began?

Cool

Swansont said at 02:03 today Untested hypotheses are not mainstream, accepted physics. When I was a lowly undergrad, quarks weren't accepted physics. In 1800, Newtonian physics reigned supreme. And why do physicists refer to "string theory" when not only is it not tested, it's inherently untestable at this time. Shouldn't it be referred to at best as "string hypothesis" or "string conjecture"? Can or should string "theory" be open for discussion on this forum? Cronons? I admit I've indulged in speculation in this thread, and I apologize if it's not appropriate.

(But you actually said time and space are quantized. (no 'if'). So even if your other statements didn't imply that, do you have a citation for accepted physics that says that time and space are quantized?) I was a biology major, for god's sake. But: 1) "Introduction of a quantum of time(chronon) and its consequences for quantum mechanics", Roy A. H. Farias, Erasmo Recami, 27 Jun 1997, Cornell University Library 2) Entry in Wikipedia, Quantum Spacetime> "...the concept of 'quantum spacetime' is a generalization of the usual concept of spacetime..." 3) "Quantum Time", Mark Lawrence, July 13, 2011 Agreed, these are not "citations", I shouldn't have said space-time IS quantized, but some people a whole lot smarter than I seem to think so. Also, M-Theory, (which I do not accept), the cutting edge of physics (or metaphysics, take your choice), certainly deals with the quantization of space-time, tho I truly can't wrap my brain around strings and 26 dimensions.

I didn't say that the Planck length or Planck time "quantized" anything; I said they are the lowest values of those measurable physical attributes, and smaller values have no physical meaning, granted as we NOW understand physics. However, if time is quantized, I suppose the Planck time could be considered as the quantum of time. As I understand things, the photon is the quantum of electromagnetic radiation, radiation is emitted in discrete, quantized values. Isn't there a least value for a quantum of electromagnetic radiation? Some value below which there is no reality? After all, there is no "half" quantum, the quantum value doesn't approach 0 as lower limit.

>:DI have to ask. If gravity isn't truly a force as fundamental forces are understood, if it's an artifact, a result of the curvature of space-time, why does it have to obey the speed of light limit. Also, what I meant by saying "absolute lower limit" is that since space-time is quantized, smaller than 1 quantum of anything obeying QT is impossible.(Sorry for the wording). Finally, the Planck length and Planck time are absolute lower limits; a smaller value is essentially meaningless, in any theory we now have, at least in my understanding. It's sort of like speculating on the physics extant before the beginning of physics, the properties of the pre-universe, the quantum foam, say. It's fun, nobody can say you're wrong, but neither can anyone say you're right. Kind of like super-strings, imhp

I misspoke in my Jan 13 post when I said that dark matter particles pass by/thru each other with no effect. I think I should have said that they pass by each other with negligible effect. But what kind of dark matter are we talking about? I've seen references to cold DM, warm DM, hot DM, clumping DM, non-clumping DM(in reference to DM distribution in dwarf galaxies), etc. How boring our baryonic universe seems in comparison? Perhaps we're just some kind of impurity in the grand scheme of things. How humbling.

Strange ; Thanks for your info. I've gotten intellectually lazy, I should have researched this topic myself. Actually got a lot of good info. Thanks for helping me get my stuff back together. One thing I still can't wrap my 2 remaining brain cells around. Dark matter particles don't even react to each other, in fact they pass thru/by each other without any effect (according to what I've read). But they do interact with gravity, I guess through some type of boson, a graviton I suppose. Is it because they have such a vanishingly small mass that their individual gravity pulls are effectively 0,but their preponderance over normal matter in the universe is so large, that their cumulative effect is enough to shape the macro-structure of the universe? mothythewso

Strange: Can't figure out how to cut&paste your quote. I got D's in physics, on my second attempt. Go Figure! I think the point that dark matter does exist in diffuse clouds, that it doesn't clump, supports my premise. If you accept the existence of gravitons, can you conceptualize "dark gravitons", mediating a sort of dark repulsive force. And because the dark matter is diffuse, dark gravitation isn't necessarily less powerful, but the distance between individual particles tends to lessen its effect. I know that dark matter is theorized to constitute most of the mass of the universe, to affect the spin rate of observed galaxies, implying an attractive force between normal and dark matter. But I point out that most of the observable universe is empty space, clumps of galaxies clustered in a large scale web-like framework. So the overall effect of dark matter would be minimal. And the Universe IS expanding. Why? Sorry for the unscientific phrasing, I lack the formal education to properly express my thoughts. mothythewso

Normal gravity exerts an attractive force between masses of ordinary matter, or a bending of space-time resulting in the same effect. Just because dark matter and dark energy don't interact with ordinary matter or energy, this has nothing to say regarding how these phenomena interact amongst themselves. It defies common sense (at least mine) that they don't interact. Could there be "dark" analogues to the fundamental particles, fundamental forces that we encounter in our realm? And, if there is dark matter, does "dark gravity" logically follow? Would it exert a repulsive, rather than an attractive, force between whatever constitutes dark matter, a sort of bending outward of space-time? And, again positing the preponderance of dark matter over ordinary matter, if there is a "dark gravity", shouldn't it overwhelm the effects of normal gravity, and possibly be responsible for the observed expansion of our universe? Amazing the thoughts that a good glass of Malbec in the morning can elicit! mothythewso

Agreed about the Planck mass and Planck energy; mea culpa. mothythewso

I admit first-off I have absolutely no expertise in this area, this question may be utterly absurd, but: As I understand things, the 3 fundamental forces that conform to quantum theory have an absolute lower limit, based somehow on the Planck constants; nothing can have a lower energy than the Planck limit, no particle can have a dimension smaller than the Planck length, etc. But why does gravity have to have a lowest possible limit, a quantizeable value. Again, as I understand things, gravity acts by bending space-time, it's thought of as being as being a "geometrical" phenomenon. Does a geometrical function, a geometrical progression that has a limit of zero, ever actually reach zero. Of course not. So why does gravity have to be quantizeable lowest value? And another thought: If in a truly empty space (I know such a thing doesn't exist, virtual particles and all) 2 masses appear simultaneously 1 light year apart, how long will it take for gravity to interact with them? If the 2 masses are sufficiently small, can one reasonably treat the force between as zero? I would really appreciate a non-condescending, thoughtful reply, even if it proves that I'm totally out to lunch! mothythewso