MigL

Frustrated Alex Trebek: "Mr. Connery, WHO is Craven Morehead ?" Sean Connery: "Looksh like you are, lad !"

My use of Methyl Di-Isocyanate was limited to liquids John. There was no aerosols or blowing involved, and MDI is not particularly volatile. Routes of entry were by skin exposure, not vapor inhalation. I assure you no joking was meant. ( although my jokes are usually poor )

Still miss James Bond. What do I have to do ? Start a petition for you to bring him back ?

Haven't worked with Isocyanates for over 25 yrs. And it was MDI, not TDI which is more dangerous. All I remember from the MSDS is that it has a built in warning mechanism. In the case of low exposures, it is a sensitizer; so if you start breaking out in reddish splotches, get rid of any PU foam mattresses and avoid them in the future. If you don't break out in splotches, there is no appreciable exposure.

What I've understood so far from Raider's comments, is that he's under the impression that 'flat', in reference to the universe, implies that it is planar. That we only see galaxies along the plane, and since the plane has limited thickness, we see none in the third direction. I, and others, have been trying, unsuccessfully it seems, to convince him that is not the case, and that 'flat', in 3D, is NOT planar or a surface.

Maybe you didn't notice... The three pictures you posted of positive, negative, and no curvature ( flat ) are all 2D surfaces, as they only have two co-ordinates. They are reduced dimensionality analogues of 3D space, because you cannot show these curvatures in 3d. Or would you like to try and draw a positively curved 3D volume ? Stop confusing the model ( 2D representation ) with the reality ( 3D volume )

That's funny, I could have sworn there ARE galaxies in every direction. Can you imagine curvature in every direction ? It can be done mathematically, but you cannot 'picture' it in your head. So we reduce the problem to two dimensions for tractability. That does not mean galaxies lie in a plane !!! The observable universe is, by all measurements, very nearly flat, so the larger universe is even more so. So it would take more than 100 bill yrs ( grater than the extent of the observable universe ) for the two light beams to converge. I suspect you problem lies with your understanding ( or lack of ) of geometry. Nothing that a little studying won't fix. Try a book called Flatland ( I believe Gutenberg has it available as a free download ) for an example of how 2D reduction can give insights into 3D geometry.

We use a 2D analogy because we cannot picture curvature in 3D space, let alone 4D space-time. Imagine a beach ball. If you look at any point on its surface, you see curvature, because you are looking at it from a third dimension. If, on the other hand, you were an ant on the surface of the beach ball, you might not see the curvature as you only see the 'locally' flat area you are standing on, and an Ant Einstein would need to come along and notice that the metric has a slight curvature, and you live in fact on a spherical surface. Now imagine that beach ball has been expanding, so that all points on it are becoming increasingly separated. We attempt to measure the curvature of the beach ball, and find that even after 14 bill yrs, it is almost perfectly flat. And this is puzzling until an Ant Guth comes along with an idea, that shortly after T=0, a universal false energy level caused an exponential inflation which violently expanded the universe by many orders of magnitude. This had the effect of 'smoothing' it out, and neatly solved many other observational problems.

I think Stephen Hawking has become addicted to popularity.

Lesson learned. Don't argue with Janus about SR. Don't argue with Swansont about clocks. By the way, I gotta know... You being a former James Bond, and me being a watch collector, Swansont. Is it Rolex or Omega ?

The way I interpret things... ( as if any one cares ) Macroscopic objects do rotate classically, and have an associated energy due to this rotation. Molecules is where the transition starts between classical and quantum. A molecule can have a rotational degree of freedom, like vibrational ( stretching ) and translational and an associated energy. But even so, for some tightly coupled molecules it is impossible to treat this spin as classical. When we get down to the level of atoms, nuclei or particles, we are strictly speaking in the quantum domain. Classical spin has to be discarded and is nonsensical.

Just to nit-pick... Did they also take rotational motion about the Sun into consideration ? And the galactic orbital motion of the Sun ? And the Milky Way about the local cluster ? Etc. Why not just fly North-South ( and with a correction for the inclination of the Earth ) and eliminate some extraneous factors ? ( or maybe I should look this stuff up )

Don't have a clue what Vmedvil is talking about... but anywhere inside an event horizon 'geometry' ( whether Euclidian or curved ) is impossible as there is only one direction. In any strongly curved space-time ( but outside an event horizon ), the local approximation is always flat, so, no doubt, these 'curvedlanders' would also come up with Euclidian geometry.

No suit involved; he is going out naked. Biggest factor would be the evaporation of all moisture from permeable membranes like your skin, eyes, etc. Your body cools by skin evaporation, and hospitals 'freeze' skin and layers below by spraying with low boiling organics. Water readily 'boils' in a vacuum, so yes, the body's outer layers would freeze and start 'cracking', leading to more moisture loss, until the whole body would freeze/dehydrate.

Eliminates a lot of the losses associated with Deuterium-Tritium reactions, but Boron plasma temps are about 10 times higher than the D-T reaction. So the 'engineering' and technological obstacles are even higher. Once those challenges are overcome , we can worry about squeezing efficiencies with optimized cycles. Nevertheless. a very interesting article.

The Wheeler-deWitt equation attempts to describe the quantum state of the universe as a whole. ( if that is what you mean ) It has a problem with time, though.

Should have known he had an agenda. He's going to explain to us how gravity REALLY works. Good night.

You should cry. ( about all the money you wasted on your education ) Buoyancy works by heavier things sinking, such that lighter things float to the top. The plasma doesn't so much rise, as get forced up by heavier air falling under it. Even in a microwave. There is NO anti-gravity. Gravity is simply determined by mass and separation, the same properties that ( somewhat ) describe density. That is the only relation, and at best, a correlation. A gas cloud as large as the Milky Way with a lower density than water could collapse into a Black Hole, but a ball Uranium with 20 times the density does not.

Mass is a property of the EVENT HORIZON, as we don't really know what's inside. ( we have GR theory that makes some predictions, but no observational evidence ) Since it has this property, it obviously has a gravitational field, and just like other massive object, can convert some of its mass to that other property, energy. The two merging BHs did exactly that. The merged event horizons did not increase linearly as the sum of the two original event horizons, but since three solar masses were converted to energy ( of the gravitational wave ), the combined event horizon was smaller than it would have otherwise been. This has nothing to do with anything inside the event horizon ( particles, quarks, quantum fluctuations or any other fancy names you can come up with.

White holes only appear in 'maximally extended' solutions to the field equations. That is, only where there are extended paths that particles can follow, without running into an 'edge' of space-time. To me, they seem to be an artifact of observer frame dependency, and not a physical event. And why would they be short-lived, in the order of hundreds of seconds; should they not last as long as BHs do since the event horizons are 'related' ? I would more likely assume your GRB was related to the final 'evaporation' of a small, primordial BH, rather than a white hole, BeeCee.

The mass, angular momentum, charge ( and entropy ) are encoded on the size/surface of the event horizon. Anything within the event horizon should be considered 'empty', at least until quantum gravity tells us otherwise.

I believe Scotty made a large transparent aluminum fish tank to hold two whales in a Klingon cruiser. This all happened in Star Trek iv : the Voyage Home, in which they travelled back in time to 1984. So it should be available already.

Hope is imaginary. So is love, and many other feelings and emotions. They are constructs of our brain with no physical evidence. Some of these constructs can give us comfort and well-being in times of need, while some, like despair or hate, can drive us to end our life or the lives of others. Religion, or more exactly religiosity, is exactly the same; the need to believe in a higher power ( that has a purpose for us we may not know ), gives religious people comfort and purpose in life. I don't have a grudge against them. Only those who seek to take advantage of them.

A boson is not necessarily an elementary particle. It is a particle ( or compound particle ) which obeys Bose-Einstein statistics. Similarily, a fermion obeys Fermi-Dirac statistics. ( hence the names )

Interesting paper Mordred. Very readable, even for a layman, as it has plenty of verbal explanations for any mathematics. It should be pinned ( if it could ) as it would rid a lot of the misconceptions about BH theory.