Brent, Here's another relativity question I'd like to get your explanation for if I may...
In Thorne's 'Black Holes and Time Warps' he gives the following example. Two observers A and B. A leaves earth orbit to travel to the center of the galaxy, 30,100 light year away, using a constant 1g acceleration to the midpoint and a constant 1g decelleration on the second half of the journey to arrive stationary at the galactic center, Thorne tells us that the 30,100 light year trip takes 30,102 years on B's clock back on earth but only 20 years on A's clock aboard the spaceship. Now my question is what causes the extreme slowing of A's clock? It can't be the acceleration as both A and B experience the exact same 1g acceleration for the duration of the trip. I can understand that during the trip B will observe A's clock to be greatly slowed due to the extreme relative motion, but since the motion IS relative wouldn't A also observe B's clock to be slowed by the same amount during the trip? And since the time dilation of relative motion is relative then how does it actually produce a real objective slowing of A's clock that both observers can agree upon? You had said yesterday that "geometry doesn't cause clocks to slow" but other than the trivial 1g acceleration isn't all the rest just geometry in this case? What's the proper way to analyze this to get Thorne's result? Thanks, Edgar On Tuesday, January 28, 2014 7:20:25 PM UTC-5, Brent wrote: > > On 1/28/2014 3:36 PM, Edgar L. Owen wrote: > > Brent, > > I did read the Wikipedia page, and frankly I don't buy your > interpretation that proves 1. and 2. below though I'm trying to keep an > open mind. > > > It proves that no mass is *needed* inside a BH, that the gravity alone, in > the absence of matter (you know what "vacuum" means?), forms a BH. If you > added matter to the Schwarzschild solution it would quickly disappear into > the singularity with a corresponding increase in the size of the BH. > > > And I'm not going to go by what 1 person, who I don't even know and who > is presumably your friend says via an email. > > > So you don't know who Sean Carroll is and you didn't even bother to look > him up!? > > I'm afraid you're hopeless Edgar. > > Brent > > Again I challenge you to provide me some authoritative online sources > who agree with you that > 1. Matter (mass) vanishes inside a black hole > 2. The intense gravitation of a black hole is not due to any mass inside > of it but to the trail of space curvature left behind outside the event > horizon by the matter entering the black hole. > > I haven't found a single source that claims that but I'm open to > correction if you can provide some authoritative ones..... > > And I disagree with your interpretation of the Schwartzchild solution > which clearly is based on the ACTUAL mass of a BH. So far as I know all, or > at least most physicists, agree with me that it is the mass INSIDE the > black hole that produces the event horizon. > > Again, authoritative sources to support your 1. and 2. above? Can you > produce any? If not I find your explanation unsupported.. > > Edgar > > > On Tuesday, January 28, 2014 5:19:27 PM UTC-5, Brent wrote: > > On 1/28/2014 12:45 PM, Edgar L. Owen wrote: > > Brent, > > > > Perhaps I'm missing something but I read the Wikipedia article and > several others (eg. > > http://casa.colorado.edu/~ajsh/schwp.html) and reread Chapter 13: > Inside Black Holes of > > 'Black Holes and Time Warps' by Kip Thorne and NONE of those sources say > what you are > > saying, namely that > > > > 1. Matter (mass) vanishes inside a black hole > > 2. The intense gravitation of a black hole is not due to any mass inside > of it but to > > the trail of space curvature left behind outside the event horizon by > the matter > > entering the black hole. > > > > I haven't found a single source that claims that but I'm open to > correction if you can > > provide an authoritative one..... > > You didn't read the Wikipedia page I referenced, which showed that the > Schwarzschild BH > solution is found by assuming a vacuum, T_u_v=0? > > > > > In fact the Schwarzchild solution specifically HAS a mass term in it on > the basis of > > which the radius of the event horizon is calculated. So my reading of > the Schwarzchild > > solution is that it specifically ASSUMES that the black hole is created > by the mass > > INSIDE IT. > > But that's the "equivalent" mass that would be necessary to produce the > same field outside > the event horizon. As I said, the BH is massive in that it warps space, > but it doesn't > follow that it has matter inside the event horizon which is trying to > "send out gravity". > > > > > So are 1. and 2. above YOUR own interpretation of what's inside a black > hole or do you > > have some authoritative source(S) that actually states that in plain > English you can > > provide? > > > > Now I certainly don't automatically discount the possibility that the > matter inside a > > black hole leaves through the singularity and pops up somewhere else, > > I doesn't pop up somewhere else. Remember mass and energy are the same > thing in GR. One > way to look at it is to say the mass in converted to gravitational energy, > i.e. is takes a > lot of energy/mass to warp space up into a singularity. Gravity in GR is > non-linear so it > "pulls on itself", that's why it makes a singularity (classically). > Hawking the radiation > is the conversion of this mass/energy back into particles. > > > but there is no convincing argument that that must be true. And if so > you must come up > > with a VERY convincing argument that explains why a BH still appears to > contain all the > > mass producing its gravitational field even though that mass isn't > actually there anymore. > > > > Just referencing an equation that doesn't have a mass term does none of > the above. > > No, but it shows that a BH doesn't have to be created from matter, and in > fact there is > speculation that black holes might have been created in big bang just from > fluctuations in > the metric. Of course we suppose that BH like the one at the center of > the Milky Way were > created, or at least grew large, by matter falling in. > > > > > Again is this your personal interpretation or can you give me an actual > authoritative > > reference that states your 1. and 2.? > > No, it's common knowledge. Here's Sean Carroll's email, > seanc...@gmail.com; ask him. > > > > > BTW where are you employed as a physicist? In academia or the corporate > world? > > I'm retired. I worked for the U.S. Navy. > > Brent > > -- > You received this message because you are subscribed to the Google Groups > "Everything List" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to <a class="moz-txt-link-abbreviated" href="mailto:e <javascript:> > > ... -- You received this message because you are subscribed to the Google Groups "Everything List" group. 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