Years ago I read a very small article in SciAm about a physicist who was trying to work out the pressure exerted by the constant creation and destruction of virtual particle pairs. The article explained that the numbers he was getting were familiar to him: they were exactly the same values as those for inertia.
He speculated that it may be more than a coincidence, and that this may, in fact, be the source of inertia. He further speculated that if it became possible to insulate an object from this pressure, that the object would then be inertialess. He maundered about the possible applications for lifting heavy objects on construction sites(!).
It seems to me that the applications of inertialess matter are rather larger than lifting I-beams. It also occured to me that there may be some rather serious dangers associated with this, if it is indeed possible.
If an object has no inertia, then – correct me if I’m wrong – any movement in any direction will cause it to accelerate indefinitely, right? In which case it will reach lightspeed and attain infinite mass, collapsing the Universe. Is this right? If not, how would inertialess matter behave?
Yes, if something was completely inertia-less, it seems to follow that any force would accelerate it infinitely, instantly.
That might mean one of several things, including:
-The good professor is simply mistaken.
-That insulation against the pressure cannot be perfect without the expenditure of infinite energy to make it so. (so the energy required to turn off 50% of the inertia, then accelerate an object to, say .01c ,would perhaps be equivalent to the effort required to not turn off the inertia, and accelerate the object to .01c)
Odds are that no matter could survive ‘infinite’ acceleration – if by nothing else, the Unruh effect will start heating things up considerably for accelerations greater than about 10[sup]24[/sup] m/s[sup]2[/sup]. (Actually, I’m just really impressed at google’s calculational abilities right now – it even does units!)
In what sense can inertia be said to have a pressure? All inertia is is the statement that a body at rest tends to remain at rest, along with the recognition that all non-accelerating reference frames are equivalent.
I just spent a bit searching for the article I read and I can’t find it, but I think I might have found an article in from another publication about it. From the article:
*But sometimes, virtual becomes real. Stephen Hawking worked out that the powerful gravity of a black hole distorts this quantum sea so much that when a virtual photon appears, it can break free and escape into space, becoming real and visible just like an ordinary photon. And a fundamental principle of Einstein’s theory of general relativity is that gravity is indistinguishable from acceleration.
So if gravity can release photons from the vacuum, why shouldn’t acceleration do the same? In the mid-1970s, Paul Davies at the University of Newcastle upon Tyne and Bill Unruh at the University of British Columbia in Vancouver realised that an observer accelerated through the quantum vacuum should be bathed in electromagnetic radiation. The quantum vacuum becomes a real and detectable thing.
This idea hit Haisch in February 1991, when Alfonso Rueda of California State University gave a talk about the Davies-Unruh effect at Lockheed Martin’s Solar and Astrophysics Laboratory in Palo Alto. If an accelerated body sees radiation coming at it from the front, Haisch thought, that radiation might apply a retarding force. “I’m an astrophysicist,” he says. “So I am used to the idea that radiation – for instance, sunlight - can exert a pressure on bodies such as comet particles.”
Rueda said he would do some calculations. Some months later, he left a message on Haisch’s answering machine in the middle of the night. When Haisch played it back the next morning he heard an excited Rueda saying, “I think I can derive Newton’s second law.” *
You’d still have to supply energy to lift an object against gravity. But even if an inertia-remover didn’t give you something for nothing, if you had to expend the same amount of energy it would take to accellerate a mass, it could still allow vast economies when trying to propel a starship. It would help enormously if you could give a spaceship a reduced inertia, especially if the effect could be applied with something close to direct conversion, rather than the enormous exponential mass requirements of rockets.