MigL

So a gravity wave is not simply a propagating step potential ? Your second link does, however, state that measurement of the speed of gravity may be possible by the detection of gravity waves from a super nova ( last paragraph ). I thought we were agreed that the implosion/explosion of a super nova produces a symmetric acceleration of mass resulting in a propagating step potential ?

Yes that DeWitt paper is the one I was looking for, but I could've sworn it came to the opposing conclusion ( it was quite a while ago that I looked at it ). From several searches, the general consensus seems to be that a falling charged particle CANNOT follow a geodesic since, as you previously pointed out, its EM field will interact to modify its path. True geodesic motion is an idealization ( like point particles, ideal gases, etc. ), and probably does not exist for real world particles and gravitating objects. I guess I'll have to concede defeat. ( For now, until I can find more literature on the subject ) Funny how when you think you understand a situation, you don't look for answers. It turns out even Wikipedia has an entry under " Paradox of a Charge in a Gravitational Field", which explains the reference frame dependence which I introduced and Elfmotat expanded and clarified.

Fairly certain ??? So a charged particle orbiting the earth, i.e. in free fall, has an acceleration due to gravity, and must by necessity, radiate. Now take that charged particle and put it at the laGrange point, so that it's not being kept in orbit by its motion, but by another force, and is now moving in sync with the cyclical earth-moon rotation. Is it still radiating ? And how is that differnt from the case where it is sitting on the surface of the earth, and rotating along with the earth. An accelerated,charged particle has a time dependant EM field. The particle is accelerated with respect to its global EM field, which is constrained by space-time. The effects must then be frame dependant. If you are standing on the ground watching the charged particle fall, you will see it radiate. Similarily, if you are in free fall watching a particle on the ground ( or at the laGrange point ).On the other hand, if you are in free fall along with the particle,or standing on the ground along with the particle, you will not see any radiation. See post #32. That is my understanding, and I'm not too confident with the reasoning ( then again, you don't seem to be either ) I will have to see about finding some material to back me up.

I'm not sure I can agree with you guys ( furiously turning pages in my copy of Gravitation ). Your explanation doesn't take into consideration that, globally, there is no co-ordinate in space-time absent of curvature. Flatness is only a local approximation. That means every charge would be radiating,no matter how many orders of magnitude smaller than detectable. This would be a cumulative, large scale effect. The only way to reconcile both, the lack of this universal effect, and the equivalence principle,is to consider the possibility that charge doesn't radiate in free fall.

Think I'll stick to English.

Let me make a further attempt at clarification... If the charge was radiating as it fell to earth, as Bluemoon suggests, but then stopped radiating when it came to rest upon the surface, we would have inconsistencies across different frames as the Earth ( and its surface ) is still 'falling' around the Sun. And in another frame, the Sun is still falling about the galaxy, which is still falling about the centre of mass of the local group, and so on, and so on... In effect, we only have a non-vanishing energy flux when the charge is accelerated with respect to its own 'distant' EM field. I believe I read about this in a paper by DeWitt, but it was quite a while ago and while I remember the concept, I don't recall specifics or the math.

If it's a separate fan, either below or beside the power supply, it can be replaced cheaply from any computer store. Just take your old non-working one with you to get the same connector ( and wire length ). If it's the power supply fan, I'm afraid it'll cost quite a bit more as I'd advise buying a new power supply. ( I have personally replaced power supply fans, but it sometimes involves soldering inside a high voltage switching power supply, and a soldering mistake can injure/kill you when you re-apply power )

I always thought they were 'molded' in that shape by the streamlines of the medium they are falling through. But if they're not 'teardrop' shape, I guess I'm wrong. ( Don't tell me actual teardrops aren't that shape either )

-Newton's law of gravity is not universal, but a very good approximation for areas where space-time is not too severely curved. -A free falling charged particle feels no force ( neither do you when you fall, only when you land ) so why would it accelerate ? It is following a geodesic. -In GR gravity is not a force ( action at a distance ) but a geometry of space-time. -And for the last point you bring up, maybe I should add that if the charge and observer are in the same frame, there is no radiation, i.e. both in free fall along geodesic, or both supported at 1g, either by the earth or the accelerating rocket. If the charge and the observer are in differing frames then there is an energy flux, since the EM field is non-local ( stretches to infinity ). That is my ( limited ) understanding of how an observed non-radiating charge in a shared frame is reconciled with the equivalence principle. Maybe Elfmotat or others familiar with GR can elaborate.

Somebody trying to re-invent the wheel here ? On the one hand we have a mechanism that works extremely well, but since Jeremy0922 can't see the 'logic' of something round going in a straight line, we should replace it. Replace it with what, we ask. Well, Jeremy0922 has got nothing. Yup, we'll start burning all Quantum Physics books right away ! ( Dripping sarcasm all over the place )

Ah, I see where the confusion comes from... You are applying the equivalence principle to the Newtonian concept of acceleration due to gravity, and Newton says absolutely nothing about inertial and gravitational mass. I sometimes get confused and do the same, but in reverse. In GR a free falling charged particle is not accelerating as there is no force acting on it. It is accelerating when it comes to rest on the surface of the gravitating body. It is there that the particle feels an upward force, which keeps it from further free fall, and so it 'accelerates' upward at 1g and radiates.

Just about all 15.4" widescreen displays are standardized, they have common screw holes ( along the side ), common connector on back and common resolution ( 1280x800 pixels ). Other sizes, not so much. Replacement is extremely easy. Open laptop. Remove covers over screws of display shell and separate. Remove screws from side of sealed ( there is no liquid to worry about ) panel. Unplug connector from back of panel. Replace panel with new ( or used ) reversing steps. Note:- About 4-5 yrs ago they went from fluorescent to LED illumination, the LED being thinner. If you get the wrong one, it may not fit properly in the display shell.

Well IIRC 'Doc' replaced the 2.1 GW Flux Capacitor of the deLorean with a burst of lightning... So during the next lightning storm, fly a kite with a metal or conductive string. You'll be flying in no time !!!

Why do you guys keep engaging him ? He's obviously not even considering your learned replies. He makes statements like... 'Photons spin. Wheels on cars spin. Can you imagine how fast we could drive on the sun ?' And by engaging him, the threads go on for several pages before they are invariably locked. He's managed to lock more threads in the last couple of days than anyone else in the last couple of years. By engaging him, you give legitimacy to his ignorant ( as in lacking knowledge ) ramblings, and may be doing more harm to new members wishing to learn some real science than if you ignore him, hope he goes away, and buys an elementary physical science textbook ( Gr. 10 level should do ). He's like a classic drug addict, there's nothing we can do, he has to want to help himself.

If you were blindfolded and orbiting around a star, or a neutron star, or a black hole, you couldn't tell the difference. Similarly, if you were ionized gas and being accelerated in the accretion disk of a strong gravitational source. There is no difference !!! I believe I've already explained the source of the energy. The NASA article explains that an 'active' pulsar has never been observed before, but many 'active' black holes have been ( every quasar observed ).

I think you misunderstood the NASA article. This pulsar may be smaller in mass than that required to collapse to a black hole, but it is a gravitational sink, just like a BH, and acts just like one. This means it has an accretion disc, just like an active BH, and will radiate as much energy in the X and gamma range as a BH. It is the accelerating, ionized gases spiraling into the neutron star which generate the energy along the axis of rotation ( which may be facing our direction ). I would assume once this neutron star 'eats' enough mass, it will undergo further collapse to a BH.

Pressurised flight suits only work for low sustained Gs, not for high instantaneous Gs such as impacts. They work by squeezing your body to keep your head supplied with blood. Lack of blood to the brain results in tunnel vision and, shortly after, unconsciousness. Not a good thing when maneuvering a high performance military jet. This is extremely common these days, as most military fighters are stressed and can maneuver to +9/-3 Gs; much more than a pilot can handle for any length of time. The first time I recall it happening was during demonstration of the Northrup F-20 ( neverwent into production ) in the 80s. The pilot was killed.

Yeah I watched ''Lucy" also. Started out good but quickly degenerated into rubbish. Thank goodness for Scarlett Johansen. Oh, and Morgan ( Shawshank ) Freeman also.

Play nice, boys. I don't want to seem like I'm taking sides, elfmotat, as I have a great respect for your knowledge and opinion. And while your suggestion would be great in a situation where everyone was as knowledgeable, unfortunately, sometimes wavefunctions, states and probabilities are above the level of new members, and even some of us others. An analogy is sometimes useful in grasping a concept in order to proceed to amore advanced understanding.

Why has no one commented on the fact that Sorcerer, in post #27, gave the wrong definition for non-commutation ? It should be... A*B==B*A commuting A*B=/=B*A non-commuting

I'd rather have Ripley than Tony. ( Not that there's anything wrong with wanting Tony ) Oh, that's not what we were talking about ?!?!

The gear 'chamber' still needs to have fluid pumped into it for lubrication, and AFAIK drain holes carry this back to the pan. Thickening of the fluid due to temp degradation, metal/friction particles from a failing tranny, or even just plain dirt can clog these drains and lead to foaming. That being said, foaming doesn't seem to be much of an issue these days, hi-temp degradation is. I've always owned GM, but my current transaxle on a V6 MDX doesn't even have a replaceable filter, and I've always done a couple of flush and fills with hi-quality synthetic fluid ( never mind what Honda/Acura says ). I use Amsoil fully synthetic ( no one else, not even Mobil 1, is fully synthetic anymore ) for both tranny and engine.

Since the body is an adaptive organism, its not always damage, but change. As an example, uv causes skin cancer, but, it also makes cells produce melanin, which is a good defense against skin cancer. The cancer, or damage if you will, only occurs when the body's adaptive processes ( or repair mechanism ) is overcome. I got all my vast knowledge about adaptation and evolution from the first ten minutes of 2001:A Space Odyssey.

If you try to visualize what the probability distribution would look like for non-trivial probabilities, it would probably be densest in a certain area and gradually diffuse out towards the edges, i.e. a 'cloud'. Is it any wonder that images show the same ?

Sorry studiot but what I was trying to do was, start from a false premise, and show that it leads to inconsistencies. And I would say, on second reading and as elfmotat pointed out in a previous post, made a 'dog's breakfast' out of it. JonG is also right in stating that it is language that fails us as it is open to interpretation. In the example I used, I was trying to define an object which exists simultaneously in the past ( 5 units ), present, and future ( 5 units ), but that is already inconsistent as simultaneously means 'at the same time'.