Pretty unbelieveable...

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Skipjack
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Post by Skipjack »

Well, the question is whether they would be sooo common, after all they would probably be pulverized by even the smallest piece of spacedust long before they come even close to the earth.

AcesHigh
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Post by AcesHigh »

Skipjack wrote:Well, the question is whether they would be sooo common, after all they would probably be pulverized by even the smallest piece of spacedust long before they come even close to the earth.
with good (and big) electromagnetic shields, I think you can avoid the ship being destructed by space dust.

again, can anyone calculate how much energy is released by a 1000 tons ship impact at 0.99% c?

djolds1
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Post by djolds1 »

Skipjack wrote:That is exactly why the possibilities are getting me so excited.
If and that is a big if it works. The thing is that this is one of those "high risk, large potential gain" investments. If someone was to invest into it.
Yup. The stuff of our childhood dreams.
Skipjack wrote:
Woodward claims that artificial gravity fields should be achievable in the medium term - that means acceleration compensators.
Ok, so there wont be any acceleration forces after all? Because that was my initial question.
No idea on the limits, practical or theoretical. Paul March should speak to that. It appears an artificial 1g field at minimum is envisioned, which would allow comfortable accelerations of 2Gs. 10Gs compensated is the stuff of dreams, 100Gs+ is Orgasmatron territory.
Skipjack wrote:I am confused now. This is unrelated to the Mach effect thruster? Or is that a derived development?
Related. Woodward and March refer to both as "Gravinertial effects."

See slide #60 for the projected range of possibilities.
Skipjack wrote:As I would understand it a "gravity compensation" in one direction would result in acceleration in the other direction. So it basically is Munchhausen pulling himself out of the swamp by his hair.


Slide 2 of this powerpoint is the only source I've yet found.
Vae Victis

pfrit
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Post by pfrit »

AcesHigh wrote: with good (and big) electromagnetic shields, I think you can avoid the ship being destructed by space dust.
Actually, I believe you will find that shields will fail long before you get a measuarble tau factor. Indeed, in a system that could be practically built, it would fail before you got past .1c. There are a number of factors that move against you. You have to give the particles a charge before you can deflect them. As you go faster, you have less time to charge them and give your shield time to deflect. Very quickly, the field generators become a majority of your mass. Additionally, the faster you go, the more radiation you recieve as your speed is in effect bumping up the energy of the incoming radiation. As for the interstellar hydrogen, long before you got up to .99c, its energy levels would get bumped up to it being essentially antimatter. Another problem with any active shielding system is that any transient failure is lethal. Remember Dr B's ramjet? Top speed ~.4 c? That is because the magnetic field has been flattened by your ship's speed and cannot collect enough anymore to increase the speed of the ship. Your shield will have the same problem but much worse as it must do a whole lot more. And it ignores the issue of a grain of sand that has an exactly matching negative vector. You can't deflect that one. You must stop it and then move it out of the way. And what happens when you run into that rare pebble?

Really, .1c is increadibly fast. Everyone gets so jazzed about approaching the immovable barrier of c that they become blinded to the fact that the ultimate speed limit is way past any practical speed that we could achieve. If you have an unlimited fuel supply/reactionless engine, and you want to go really fast, what you need is to make your ship out of something that will block the radiation and sand and gas. Like a planetoid. If I remember right, it amounts to blocking the high energy cosmic rays and being able to withstand repeated nuclear bombardment. Like bigger than Phobos if you want to exceed .8c.
What is the difference between ignorance and apathy? I don't know and I don't care.

AcesHigh
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Post by AcesHigh »

gee, thats quite the pleasure ruiner...

I wonder about the warp drive... (alcubierre)... the ship isnt trully moving... so what would happen with space dust, planets, etc? Would the distortion of the space-time avoid such objects?

djolds1
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Post by djolds1 »

AcesHigh wrote:Im quite scared of ships travelling at lightspeed... specially if they have the potential (with this technology) to be so common.

I mean... think of a 9/11, but with a terrorist hitting Earth with a 1000 tons spaceship, at 0.99999% c.

Can anyone calculate the power of such impact?
E= 0.5mv^2
1gm TNT equiv = 4184 Joules

Boom Table
R Bomb
Relativistic Kinetic Kill System
AcesHigh wrote:lets not forget that fuel for electricity generation FOR PROPULSION is just a small part of what is needed... travelling at such high speeds, I would guess that we would need another fusion reactor only to create very large electromagnetic shields, very distant from the ship, to prevent collision with minor particles at near c speeds.
Woodward predicts wormholes and Alcubierre warp drive effects w/in 40 years of development. Project Daedalus style front impact shields should be sufficient in the interim.
Vae Victis

ravingdave
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Post by ravingdave »

pfrit wrote:
AcesHigh wrote: with good (and big) electromagnetic shields, I think you can avoid the ship being destructed by space dust.
Actually, I believe you will find that shields will fail long before you get a measuarble tau factor. Indeed, in a system that could be practically built, it would fail before you got past .1c. There are a number of factors that move against you. You have to give the particles a charge before you can deflect them. As you go faster, you have less time to charge them and give your shield time to deflect. Very quickly, the field generators become a majority of your mass. Additionally, the faster you go, the more radiation you recieve as your speed is in effect bumping up the energy of the incoming radiation. As for the interstellar hydrogen, long before you got up to .99c, its energy levels would get bumped up to it being essentially antimatter. Another problem with any active shielding system is that any transient failure is lethal. Remember Dr B's ramjet? Top speed ~.4 c? That is because the magnetic field has been flattened by your ship's speed and cannot collect enough anymore to increase the speed of the ship. Your shield will have the same problem but much worse as it must do a whole lot more. And it ignores the issue of a grain of sand that has an exactly matching negative vector. You can't deflect that one. You must stop it and then move it out of the way. And what happens when you run into that rare pebble?

Really, .1c is increadibly fast. Everyone gets so jazzed about approaching the immovable barrier of c that they become blinded to the fact that the ultimate speed limit is way past any practical speed that we could achieve. If you have an unlimited fuel supply/reactionless engine, and you want to go really fast, what you need is to make your ship out of something that will block the radiation and sand and gas. Like a planetoid. If I remember right, it amounts to blocking the high energy cosmic rays and being able to withstand repeated nuclear bombardment. Like bigger than Phobos if you want to exceed .8c.



I've posted this before, and it took me awhile to find it, but it's relevant. The problem might not be as bad as people think it is. Apparently an object moving at significant percentages of light speed creates an automatic repulsion in front of it, so there is no need for shields.


Image
The field equation of Einstein's General Theory of Relativity has never before been solved to calculate the gravitational field of a mass moving close to the speed of light. Felber's research shows that any mass moving faster than 57.7 percent of the speed of light will gravitationally repel other masses lying within a narrow 'antigravity beam' in front of it. The closer a mass
gets to the speed of light, the stronger its 'antigravity beam' becomes.
http://www.spacedaily.com/reports/New_A ... Light.html



David

Betruger
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Post by Betruger »

Another Mach effect threshold.. What a coincidence that would be.

KitemanSA
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Post by KitemanSA »

AcesHigh wrote: again, can anyone calculate how much energy is released by a 1000 tons ship impact at 0.99% c?
Yes. :lol:

Not me, but I am pretty sure someone can!

93143
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Post by 93143 »

...so is this guy recommending accelerating a spaceship by throwing a star at it at three quarters of the speed of light?

On another note, if the Mach effect devices can produce artificial gravity, it's possible they could produce artificial antigravity (okay, that's hilarious; apparently Firefox doesn't recognize "antigravity" as a word), which brings to mind the image of the "navigational deflector" on a Star Trek ship... not to mention tractor beams...

Granted the order of magnitude seems wrong; as noted previously, 0.1c is VERY fast...
AcesHigh wrote:again, can anyone calculate how much energy is released by a 1000 tons ship impact at 0.99% c?
About 130,000,000 Mt.

kurt9
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Post by kurt9 »

My thought on Woodward's theory on inertia is that it is very similar to Cramer's retro-causality theory of quantum mechanics in that they are both based on the concept of waveforms traveling both forward and backward in time. I know that John Cramer passed the plate around to do his retro-causality experiment. Has this experiment been performed? Successful demonstration of this effect would certainly provide theoretical support for Dr. Woodward. Confirmation of both Cramer's retro-causality and Woodward's mach effect would provide the missing link between GR and QM.

I've been pouring through the papers on Dr. Woodward's site. I definitely have to bone up on the fields and waves part of electrical engineering (this was the most difficult part of the EE program for me when I was in college, materials science and control system theory were the easiest). What was most interesting about Woodward's paper on inertia is that every theory of inertia he talks about should lead to a space drive. If Woodward's ideas prove wrong, then the other theories should be pursued.

If a 1.1g drive can be developed, regardless of technology, it seems to me that winged space planes would be an unnecessarily complicated space craft design. A more simple design would be a conical shaped craft (looking like Phillip Bono's SSTO design) that would ascend and descend vertically from the Earth's surface. An acceleration of 0.1g is quite slow, but would still get you into space in less than an hour. Once outside the Earth's gravity field, acceleration could then be increased to 1g, providing Earth normal gravity for the people in the space craft. Even if Mach's principle could make for artificial gravity generators (like SF movies), the "vertical" conical-shaped space craft design is still the simplest (and cheapest) design to go with. The structural design parameters of such a craft would be the same for both ascent and descent in Earth's atmosphere as well as 1g acceleration and deceleration in deep space. The craft is subject to 1g stress in both operating modes. So, no need for separate Earth to LEO and deep space craft.

This idea brings to mind the lighthuggers in Reynold's "Revelation Space" novels.

1 to 10 Newtons per Watt? This seems unbelievable. It would certainly make a good hybrid or electric car. Airplanes, too.

blaisepascal
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Post by blaisepascal »

93143 wrote:
AcesHigh wrote:again, can anyone calculate how much energy is released by a 1000 tons ship impact at 0.99% c?
About 130,000,000 Mt.
Hmm, I get about 955 Mt. for 99% c I do get around 120,000,000 Mt, but for 0.99% c I get 955 Mt.

Skipjack
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Post by Skipjack »

0.1 c is fast, but not fast enough. If you want to go to the nearest star it is still 42 years away. That is to much, especially since it is a dwarf star which means that there is nothing interesting to find there (most likely anyway). I am wondering how much shorter the tripp would seem for those on board though due to relativistic effects.

pfrit
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Post by pfrit »

blaisepascal wrote:
93143 wrote:
AcesHigh wrote:again, can anyone calculate how much energy is released by a 1000 tons ship impact at 0.99% c?
About 130,000,000 Mt.
Hmm, I get about 955 Mt. for 99% c I do get around 120,000,000 Mt, but for 0.99% c I get 955 Mt.
Would that include the tau factor? BTW, imagine the problem with calculating a tragetory that could hit the earth at that velocity! Your mass would be such that almost anything would deflect you (you would only need the tiniest bit of deflection to miss at that velocity and distance). And virtually no time to do any course corrections. And the delta V required to move the mass! Tough problem, but probably doable. A whole lot of three body solutions, though.
What is the difference between ignorance and apathy? I don't know and I don't care.

Skipjack
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Post by Skipjack »

Kurt9
I know, I too favor Bonos designs, basically the DC-X if you want it that way over winged designs. Gary C. Hudson has a really nice paper on the designs on spacefuture.com.
For a ship with this tech it would definitely be desireable.
One minor correction: If I understand it correctly, you never actually leave earths gravity field, you only get to a point where the gravity of other celestial bodies will compensate for earths gravity and will at some point zero it out (or be stronger). I think that the amount of acceleration possible with the Mach engine would only be limited by the energy source and the people on board. I think that 5 gs is about what the space shuttle launch does. So that should be fine.

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