Then again, light is a bit nonsensical itself, since it requires no medium like other waves -- hence the photon, and in turn the larger classification of boson, was theorized.
Could you quote some of Krauss' explaination?
OK. First, Krauss explains Maxwell's theory of electromagnetism and the following implication that electromagnetic waves exist. We of course know v = f * lambda with regards to wave velocity, and if it's a wave then that formula should be applicable to it. Using that formula on EM waves, Maxwell got a speed of c and pretty much ended the particle/wave debate. Then he moves to Einstein's realization that the only way all EM waves can travel at the speed of light is if the speed of light remains the same regardless of the observer, hence the name relativity. Here's the actual quote:
"By the same token, not just light but all massless radiation must travel at lightspeed. This means that the many types of beings of "pure energy" encountered by the Enterprise, and later by the Voyager, would have difficulty existing as shown. In the first place, they wouldn't be able to sit still. Light cannot be slowed down, let alone stopped in empty space. In the second place, any form of intelligent-energy being (such as the "photonic" energy beings in the Voyager series, the energy beings in the Beta Renna cloud in The Next Generation, the Zetarians in the original series, and the Dal'Rok in Deep Space Nine) which is constrained to travel at the speed of light, would have clocks that are infinitely slowed compared to our own. The entire history of the universe would pass by in a single instant. If energy beings could experience anything, they would experience everything at once. Needless to say, before they could actually interact with corporeal beings the corporeal beings would be long dead."
The first part proves that ghosts have to be made out of some other particle than light. Dark matter, perhaps? Its summoning and utilization is said to be a Shadow ability -- theoretically, introducing enough dark matter into a person or object will exert enough antigravitic force to tear it apart painfully, hence the attack's extreme damage. Enough antigravity emitted by an object could conceivably render an object invisible, or nearly so. However, it would take an extraordinary amount of antigravity to accomplish this, considering that according to Krauss the gravitic force at the surface of the sun is sufficient to bend light by a fraction of a degree so small I'm not willing to type out all the zeros to accommodate it.
The bit about experiencing everything at once also comprises the only factual basis for out-of-body experiences.
No, electromagnetic waves will pass through each other completely unchanged.
Every force is transmitted by force fields. The impact of a sword is the electromagnetic repulsion between the atoms of the sword and the target. The physical and chemical properties of the sword are determined by the electromagnetic forces acting between its atoms, and the strong and weak forces acting within the atomic nuclei. Atoms and subatomic particles, being point masses, do not come into direct contact.
Exactly -- however, no currently known particle can both do this normally and exhibit the properties we see in ghosts.
We know one thing now: ghosts aren't made of light or any wave claiming c as its velocity. The Lavos in the Tesseract, however, is presumably a spirit form of some sort. I'd guess that now we need a section on the physics of the Tesseract with regards to entities.
