Engine/Propulsion

[Jeremy Buloch]

Blake,

Thanks Blake that is some interesting information.
The wormhole (Black hole/White hole) be created if there is "Exoticite" to be invented. It sounds good and I agree with it.

Targon,

I am not misguided on phase/group light velocities. I am merely stating what a Theoretical Physicist has said. If you dont believe what he has said then take it up with Dr. Kaku not I.

-J.B.-

[Jeremy Buloch]

Here is a little bit of info on Wormholes to help everyone to understand it more fully:

"THE EINSTEIN-ROSEN BRIDGE

But this also revives an ongoing controversy surrounding black holes. The best description of a spinning black hole was given in 1963 by the New Zealand mathematician Roy Kerr, using Einstein's equations of gravity. But there is a quirky feature to his solution. It predicts that if one fell into a black hole, one might be sucked down a tunnel (called the "Einstein-Rosen bridge") and shot out a "white hole" in a parallel universe! Kerr showed that a spinning black hole would collapse not into a point, but to a "ring of fire." Because the ring was spinning rapidly, centrifugal forces would keep it from collapsing. Remarkably, a space probe fired directly through the ring would not be crushed into oblivion, but might actually emerge unscratched on the other side of the Einstein-Rosen bridge, in a parallel universe. This "wormhole" may connect two parallel universes, or even distant parts of the same universe. (See diagram.)

THROUGH THE LOOKING GLASS

The simplest way to visualize a Kerr wormhole is to think of Alice's Looking Glass. Anyone walking through the Looking Glass would be transported instantly into Wonderland, a world where animals talked in riddles and common sense wasn't so common.

The rim of the Looking Glass corresponds to the Kerr ring. Anyone walking through the Kerr ring might be transported to the other side of the universe or even the past. Like two Siamese twins joined at the hip, we now have two universes joined via the Looking Glass. Some physicists have wondered whether black holes or worm- holes might someday be used as shortcuts to another sector of our universe, or even as a time machine to the distant past (making possible the swashbuckling exploits in Star Wars). However, we caution that there are skeptics. The critics concede that hundreds of wormhole solutions have now been found to Einstein's equations, and hence they cannot be lightly dismissed as the ravings of crack pots. But they point out that wormholes might be unstable, or that intense radiation and sub-atomic forces surrounding the entrance to the wormhole would kill anyone who dared to enter. Spirited debates have erupted between physicists concerning these wormholes. Unfortunately, this controversy cannot be re- solved, because Einstein's equations break down at the center of black holes or wormholes, where radiation and sub-atomic forces might be ferocious enough to collapse the entrance. The problem is Einstein's theory only works for gravity, not the quantum forces which govern radiation and sub-atomic particles. What is needed is a theory which embraces both the quantum theory of radiation and gravity simultaneously. In a word, to solve the problem of quantum black holes, we need a "theory of everything!"

A THEORY OF EVERYTHING?

One of the crowning achievements of 20th century science is that all the laws of physics, at a fundamental level, can be summarized by just two formalisms: (1) Einstein's theory of gravity, which gives us a cosmic description of the very large, i.e. galaxies, black holes and the Big Bang, and (2) the quantum theory, which gives us a microscopic description of the very small, i.e. the microcosm of sub-atomic particles and radiation. But the supreme irony, and surely one of Nature's cosmic jokes, is that they look bewilderingly different; even the world's greatest physicists, including Einstein and Heisenberg, have failed to unify these into one. The two theories use different mathematics and different physical principles to describe the universe in their respective domains, the cosmic and the microscopic. Fortunately, we now have a candidate for this theory. (In fact, it is the only candidate. Scores of rival proposals have all been shown to be inconsistent.) It's called "superstring theory," and almost effortlessly unites gravity with a theory of radiation, which is required to solve the problem of quantum wormholes. The superstring theory can explain the mysterious quantum laws of sub-atomic physics by postulating that sub-atomic particles are really just resonances or vibrations of a tiny string. The vibrations of a violin string correspond to musical notes; likewise the vibrations of a superstring correspond to the particles found in nature. The universe is then a symphony of vibrating strings. An added bonus is that, as a string moves in time, it warps the fabric of space around it, producing black holes, wormholes, and other exotic solutions of Einstein's equations. Thus, in one stroke, the superstring theory unites both the theory of Einstein and quantum physics into one coherent, compelling picture.

A 10 DIMENSIONAL UNIVERSE

The curious feature of superstrings, however, is that they can only vibrate in 10 dimensions. This is, in fact, one of the reasons why it can unify the known forces of the universe: in 10 dimensions there is "more room" to accommodate both Einstein's theory of gravity as well as sub-atomic physics. In some sense, previous attempts at unifying the forces of nature failed because a standard four dimensional theory is "too small" to jam all the forces into one mathematical framework. To visualize higher dimensions, consider a Japanese tea garden, where carp spend their entire lives swimming on the bottom of a shallow pond. The carp are only vaguely aware of a world beyond the surface. To a carp "scientist," the universe only consists of two dimensions, length and width. There is no such thing as "height." In fact, they are incapable of imagining a third dimension beyond the pond. The word "up" has no meaning for them. (Imagine their distress if we were to suddenly lift them out of their two dimensional universe into "hyperspace," i.e. our world!) However, if it rains, then the surface of their pond becomes rippled. Although the third dimension is beyond their comprehension, they can clearly see the waves traveling on the pond's surface. Likewise, although we earthlings cannot "see" these higher dimensions, we can see their ripples when they vibrate. According to this theory, "light" is nothing but vibrations rippling along the 5th dimension. By adding higher dimensions, we can easily accommodate more and more forces, including the nuclear forces. In a nutshell: the more dimensions we have, the more forces we can accommodate.One persistent criticism of this theory, however, is that we do not see these higher dimensions in the laboratory. At present, every event in the universe, from the tiniest sub-atomic decay to exploding galaxies, can be described by 4 numbers (length, width, depth, and time), not 10 numbers. To answer this criticism, many physicists believe (but cannot yet prove) that the universe at the instant of the Big Bang was in fact fully 10 dimensional. Only after the instant of creation did 6 of the 10 dimensions "curled up" into a ball too tiny to observe. In a real sense, this theory is really a theory of creation, when the full power of 10 dimensional space-time was manifest.

21St CENTURY PHYSICS

Not surprisingly, the mathematics of the 10th dimensional superstring is breathtakingly beautiful as well as brutally complex, and has sent shock waves through the mathematics community. Entirely new areas of mathematics have been opened up by this theory. Unfortunately, at present no one is smart enough to solve the problem of a quantum black hole. As Edward Witten of the Institute for Advanced Study at Princeton has claimed, "String theory is 21st century physics that fell accidentally into the 20th century." However, 21st century mathematics necessary to solve quantum black holes has not yet been discovered! However, since the stakes are so high, that hasn't stopped teams of enterprising physicists from trying to solve superstring theory. Already, over 5,000 papers have been written on the subject. As Nobel laureate Steve Weinberg said, "how can anyone expect that many of the brightest young theorists would not work on it?" Progress has been slow but steady. Last year, a significant breakthrough was announced. Several groups of physicists independently announced that string theory can completely solve the problem of a quantum black hole. (However, the calculation was so fiendishly difficult it could only be performed in two, not 10, dimensions.) So that's where we stand today. Many physicists now feel that it's only a matter of time before some enterprising physicist completely cracks this ticklish problem. The equations, although difficult, are well-defined. So until then, it's still a bit premature to buy tickets to the nearest wormhole to visit the next galaxy or hunt dinosaurs!"

-J.B.-

[Kuciwalker]

No black holes. They add too many of those logical inconsistancies that you're trying to prevent.

[Jeremy Buloch]

I disagree, black holes dont give off I think any inconsistancies. If so then please state some. In the meantime use this because its the only working theory for Stargates.
-J.B.-

[Straybow]

There is ongoing study of GR solutions that don't include black holes. With some effort I could look for some names (try General Relativity without Black Holes in "The Alternate View" columns of John G. Cramer for a start).

If you account for the mass-energy density of gravity in the GR space-time curve black holes don't exist. Most physicists don't like the idea, calling it "double accounting." However, the fact is it works mathematically, and it is intrinsically a cleaner solution.

Intgrspin (a physicist no longer registered here) once explained on the Apolyton OT forum that in GR dimensions can be time-like or space-like. The "black hole" phenomenon comes about because at very small distances from very high densities a space-like dimension gets "twisted" into a time-like dimension. Therefore, light doesn't get trapped because the gravity bends it, but because the light can't move "forward" against the inwardly directed time-like dimension.

I agree with the minority of physicists looking into alternate solutions. That quirk in the std GR mathematics implies that the model isn't complete. The elegance of the grav-energy density solution is highly attractive, in terms of Occam's razor. (That's what I mean about being a cleaner solution.)

The model still allows collapsed matter states, including a true mass-energy singularity at gravitational pressures exceeding the limits of neutron integrity. There will still be "grey holes" from which only photons travelling close to a perfect radial direction can escape, otherwise being bent back into the mass.

So let's not chain ourselves to a mode of physics that may be a "fad" in any case. A space-travel game without FTL pretty much sucks.

[targon]

Black holes are such a neat thing for any theorist, so they gone almost excited with that stuff. The only wrong thing with theorists is that they tend to view their partial solutions as things really existing in the nature. This is inheritaly wrong, as math has nothing to do with actual nature. You see, math can't solve movement of 3 or more bodies under Newtonian gravity forces. How sad, the Nature solves limitless movements of bodies under plenty of acting forces, all 3D, all real-time, the only solution...

Returining to these toys, black holes, they in fact aren't "black" or even "holes". Singularity state exists as theoretical limit for infinite future for collapsing star. BTW, any travel even to the event horizon will take infinite time for outsiders...
About rotating holes, these beasts twist space/time continuum so any descending body will be accelerated and (virtualy) will "reach" speed of light at the ergosphere. Of course, ergosphere intersect event horizon near poles, so you can try here. Good luck.
Even if black holes exists (!), capable for space travel (!!) for limited time (!!!), lead to somewhere more than Universe trash can a simple quastion arises: we need really big hole in order to (a) survive tide forced and (b) survive black hole self radiation (any black hole radiate particles saved from virtual pairs) and radiation of accretion disk. So it must be really big thing.
But such a big holes aren't usual, they can't crowd like mad even in most sinister parts of the universe (in fact, black holes are very solitary creatures), so what practical benifit we may create from the wormholes?

[targon]

Concerning space/time "switch" below event horizon, it's simply the next theoretical toy. Of course, space or time meaning of the "generic coordinate" is determinited by the sign of the so-callded "metric tensor". For normal space/time, this thing is written as (1 1 1 -1) (or (-1 -1 -1 1), sign is arbitary, just multiply equations by -1). Nowdays theories try to describe black holes via plenty of various diagrams in bizzare coordinates. If you're interested, I suggest you read "White dwarfs, neutrons stars and black holes", this book is in English, I think. Some of that diagrams may "allow" solutions for particles moving thru event horizon. But all these stuff simply denotes inablility to solve GR equations for black hole inside. Sadly, but GR was't designed for such a exotic (and not existing for any finite time) areas. I even think that black holes have nothing inside, their mass is residual surface property and theorist try to solve equations for non-existing region of space.
The rare thing GR is sertain about is energy/momentum conservation law for the black hole. Energy ("matter") can't be created inside black hole, it must traverse event horizon (but it will take infinite time).

[Kuciwalker]

The inconsistancy I'm talking about is: "Hey, if I can manipulate gravity at will to create a black hole, even a small one, why can't I just put it in a star or planet and collapse it, or at LEAST cause considerable damage (assuming that it evaporates faster than it sucks in relatively dense matter)?"

[targon]

IMHO, any damage inflicted by "hand-made" black hole may be divided into 3 distinct categories:
1) Matter collapsed
2) Radiation from collapsing matter
3) Black hole self radiation

1. Amount of the matter taken under event horizon depends enterely on the black hole radius and speed. Black hole radius ("gravity radius") is given as follows:
Rg = (2 * G * M) / c^2,
there G is gravity constant (~6.7*10^-11 SI), M is black hole mass, c is speed of light.
In fact, black hole will suck matter from somewhat broader area due to tide forces, but not especialy huge, so for estimates we may consider:
Sg ~ pi * Rg^2
or even
Sg ~ (G * M)^2 / c^4
this radius is't especialy big, you see. For example, if you spend entire Earth mass, ~6 * 10^24 kg, you will have somethng around a cm (~8.9 mm, in fact). Hence, Sg ~ 2.5 cm^2.
For average Earth density rho~5 g/cm^3 that means that full run thru the Earth will gain ~ rho * 2 * R * Sg. Taking R ~ 6.3 * 10^8 cm we'll have total mass sucked ~8 * 10^6 kg, or around 10^-18 of the Earth mass.
2. I can't easily estimate amount of radiation from the collapsing matter. Stop, wait a minute: if we say it's simply like X-ray stopping radiation, we may estimate total amount of hard X-rays around 1-3% of the matter energy equivalent. This may look like an overkill (mass equivalent of 1Mt warhead is ~50 g) unless you compare it with black hole mass.
3. Of course, you can't imagine creating of black holes of Earth mass as warhead substitute. I think that escess energy "waste" created during its creation is much more dangerous than its sucking effect. But black holes may be used more like as warheads. Every black hole radiate "hot" particles like "black body" with temperature T ~ 10^26/M if M is in grams. So imaginable small holes must feature really high temperatures. Being such a hot means fast energy spending, leading to loss of mass and more intense radiation. This process may be delayed, as usual, by accelerating the black hole to near c velocity (How?!).

All the above shows that creating of black holes as weapon system aren't especialy useful, as enormous amounts of energy requared for the process may be spent by more useful way.

[Jeremy Buloch]

Yes the energy would be spent a more beneficial way and would not be wasted in constructing a weapon.
-J.B.-

[Straybow]

Yeah, targon, I've tried telling some myopic science-worshipper types that math isn't reality. Somehow it never really sunk in to any of them (to the best of my knowledge).

Given your formulae everyone should see that a low mass black hole won't do much damage and can't "suck in" a whole planet or spaceship. The size of the event horizon is so small it acts like a restriction nozzle.

If you had a small nozzle connected to the turbine feed penstock of a hydroelectric plant it would take forever to drain the whole lake because only so much water can squirt through. Just so, a nanometer scale singularity would not be capable of "sucking" matter in, it would simply absorb particles it came into contact with (which itself would be a rare event).

A somewhat larger singularity could release a substantial amount of gamma rays, as you describe. However, unlike fission/fusion warheads there would be little matter converted into high temperature plasma, because the gamma rays are released from matter being captured by the black hole. In other words, no mushroom cloud.

Remember that gravity is exceedingly weak, something like 10^27 weaker than EM forces. Gravitation near the event horizon of a million ton singularity (as massive as a 1 km long Star Destroyer from Star Wars) would scarcely be able to overcome typical molecular bonding forces. That means materials would get nice, neat holes punched but little structural damage.

[Kuciwalker]

Wait. Wouldn't a, say, earth-sized black hole stuck inside a star quickly gain mass and collapse the star? Even if it took a month, that would be a potent weapon.

[Jeremy Buloch]

Even if it would, it would be stupid to create such a weapon using up precious resources. I think it would go against common sense.
-J.B.-

[DeathByTheSword]

if you cant beat them with normal weapons......blow up there starsystem.......lol

[Jeremy Buloch]

Or infect them with a plague. Which would provide you later with a habitable system. Destroying the system would make it unstable to travel around the vicinity. Plague that would harm only Humans is good.
-J.B.-

[targon]

Originally posted by skywalker
Wait. Wouldn't a, say, earth-sized black hole stuck inside a star quickly gain mass and collapse the star? Even if it took a month, that would be a potent weapon.

Return to my previous post and calculate how massive earth-sized black hole would be. Hint: black hole with sun mass has radius ~3 km.