The ultimate weapon
- Thread starter Carlobrand
- Start date
My guess is it would be a purpose built craft. A buffered asteroid hull with a high M drive, an auto pilot, and large fuel tank would work. But at Near C you would not need that big a mass to cause devastating damage. And this is a case where some of the rules break down in that Traveller uses volume rather than mass to calculate acceleration. A 1000 dTon asteroid would mass several times a ship of the same displacement, yet accelerate at the same rate given the same drive.
Delurking.
So, what about Neutrino Detectors? It seems to me those will see your little ship/missile as soon as you exit Jump. Plus there is the Jump Flash itself to worry about.
All this near-C missile stuff might work as long as you shoot it years before the planned impact from way, way out of the target system, thus eliminating the Jump Flash. Still have to deal with the neutrinos though.
Honestly, considering what we are doing here on Terra to catch rocks before they catch us, I would think such a problem is pretty small potatoes in TUs. They have much more advanced sensors that our crappy TL-8 stuff, if they feel a system needs defending, I suspect they can lay out a sensor web that covers most, maybe all the system with out too much problem. Possibly for as little as 1 RU.
So, what about Neutrino Detectors? It seems to me those will see your little ship/missile as soon as you exit Jump. Plus there is the Jump Flash itself to worry about.
All this near-C missile stuff might work as long as you shoot it years before the planned impact from way, way out of the target system, thus eliminating the Jump Flash. Still have to deal with the neutrinos though.
Honestly, considering what we are doing here on Terra to catch rocks before they catch us, I would think such a problem is pretty small potatoes in TUs. They have much more advanced sensors that our crappy TL-8 stuff, if they feel a system needs defending, I suspect they can lay out a sensor web that covers most, maybe all the system with out too much problem. Possibly for as little as 1 RU.
What fittings do you need, really?
Densitometer to map its mass distribution, your computer should be able to calculate its CG, then burn a depression into one end so that a ship parked there is pointed at the CG.
Then you just accelerate....
A 1 km rock moving at ~.95c will hit with impact energy on the order of 100,000,000 teratons of TNT. A 500 megaton nuke going off would be a dead spot in the explosion.
If the rock gets destroyed far from the target, the 500 MT bomb harms nothing, since nothing is nearby.
If the rock gets destroyed within a light-second or so of atmosphere, well, you get 100,000,000 teratons spread evenly over the entire hemisphere toward the rock. In which case, the 500 MT is still a deadspot (you're already getting 500 MT of energy deposited on every 6 km^2 of the planet's surface (assuming Earth as the target)....
There really isn't much you can do to make a relativistic rock more deadly. Other than just make it bigger. Nor is there much you can do to wreck one unless you can spot it a LOOOOOOOOONG way out.
Blow it up as it's passing Luna, and it has less than 1.4 seconds to disperse (which means it'll still hit a 100 km diameter circle).
Blow it up out around Mars orbit? That'll probably mean that a little bit of it will miss the planet, but mostly it still hits as what amounts to a honking huge fusion gun blast (call it 50,000,000 teratons equivalent).
Note, for reference, that at 0.95c, to wreck it out beyond Mars, assuming:
1) your fleet can be underway an hour after detection,
2) your fleet can accurately hit an object 1km in diameter moving a near lightspeed,
You'd then have to detect it at 2333 AU (for reference, Pluto is 40 AU out)
Under those conditions, you get ONE shot. After that, your fleet is past it and won't ever be in position to try again.
For every ~20,000 AU farther out you detect it, you get an extra shot, to the limit of the number of ships you have, so if the first ship/group misses, there's another ship/group an hour behind it to try again.
Or only ~7000 AU extra distance if you want 20 minutes (one space combat turn, MT rules) between shots.
Good luck with that....
If all they're out there for is to refuel and move on, you'll detect them, but only after they've already finished refueling and jumped again.
Pluto is ~six light hours out. The Oort Cloud is...farther. Mostly way farther. You won't detect anything till many hours after it arrives, even if you have perfect sensors....
DangerousThing
SOC-13
When did they decide that gravity propagates super-luminally? As far as I know, changes in gravity and gravity waves both follow the speed limit (in real life).
Is this something in Traveller? Or have they discovered something new in the last decade in the real world?
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Jay
Yeah, that's what my father told me 40 years ago.
In post #126 of this thread, Wil posted a reference to an article that claimed that recent evidence pointed towards gravity being FLT. Somehow "evidence for" has become "proof of".
Hans
O
Omnivore
Guest
It appears that at least a few scientists disagree with special relativity in favor of lorentzian relativity. Lorentzian relativity supports gravity as propagating faster than light (by a factor of at least 10^20). This doesn't seem to be a mainstream belief. That doesn't mean it is incorrect more of a fringe science until conclusively established experimentally. That's if I understand it - which being that it is above my pay grade is likewise inconclusive.
DangerousThing
SOC-13
OK, at least there is *some* basis in the real world. I realize that we're playing around with FTL and other non-real world stuff, but there are a few theories that agree that FTL and gravitics could be real (Extended Heim Theory).
I'll check out the reference.
On IMTU:
I will admit that IMTU I allow M-Drives and J/H-Drives to be detected FTL *if* they change value (i.e., as long as you run a constant acceleration, there is no signal to detect, but if you shut your M-Drive off, that can be detected effectively instantaneously with the right set of sensors). This effect dampens quickly and the best sensors we have can't detect even a huge ship over an AU away.
Off IMTU
None of that was real world, nor is it from the OTU. It was strictly from my demented imagination.
far-trader
SOC-14 10K
Question:
For an instant (or nearly so) effect detection like the proposed FTL grav detection by whatever method... how does one determine distance or direction? Seems to me the only info you will get is "somebody (added/subtracted) gravity of Y-force" and in a universe of the supposed billions of switching gravity devices in use every hour of every day, hells, every microsecond even, you're really not going to have useful information. Your detector will be constantly flooded with signals.
For an instant (or nearly so) effect detection like the proposed FTL grav detection by whatever method... how does one determine distance or direction? Seems to me the only info you will get is "somebody (added/subtracted) gravity of Y-force" and in a universe of the supposed billions of switching gravity devices in use every hour of every day, hells, every microsecond even, you're really not going to have useful information. Your detector will be constantly flooded with signals.
O
Omnivore
Guest
Well, think of a gravimeter as a very sensitive mass-on-a-spring. When gravity changes, the position of the mass relative to its fixture changes slightly, in 3-D space.
If a sudden 0.1mm/s^2 acceleration to upward north hits, it will move ever so slightly up and left.
Traveller Gravitometers use gravitics to detect it rather than the sprung mass of primitive gravimeters (I don't know what current ones use, but I know 1970's ones used a sprung mass, just like any other accelerometer).
If a sudden 0.1mm/s^2 acceleration to upward north hits, it will move ever so slightly up and left.
Traveller Gravitometers use gravitics to detect it rather than the sprung mass of primitive gravimeters (I don't know what current ones use, but I know 1970's ones used a sprung mass, just like any other accelerometer).
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Apart from the K'kree... an article about an expedition to Tau Ceti (or something, a star far to trailing) stated (from the Zhodani Base) that the K'kree had nuclearly bombarded all the worlds between one and two sectors away from the Two Thousand Worlds during their war with the "G'naak Zone" (less than one sector is still K'kree client areas, more than two is too close to the Zone and the K'kree ships would be destroyed).
This is a steaming pile of...
If gravity propogated ftl, then there'd be a disconnect between the observed position of the planets and the effect of those planets' gravity on other planets/stars/etc.
There isn't.
Note, by the way, that what I'm describing HAS been established experimentally....
O
Omnivore
Guest
May well be. However Lorentzian Relativity, according to the proponents, and Special Relativity each stand up to the 11 experiments that are proof of Special Relativity and there has never been an experiment which proves one in favor of the other.
I don't find their arguments convincing personally, but as a layman I didn't note any glaring errors in them. Interesting reading but I'll leave it to the physicists to argue it out
DangerousThing
SOC-13
The abstract states that gravity itself is propogated ftl, but that gravity waves are limited to c.
The abstract has an I vs Them attitude, which is one sign of bad science.
Now, if somebody truly solves the n-body problem using this interpretation, I'll be more willing to believe.
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Jay
Jay, if you actually read it, he specifically notes that hes not the only one whose noticed; he's just an outlier in his field, and that the assertions of C-speed propagation are NOT astronomers, but mostly quantum physicists.
The issue of gravity not supporting C-Limited gravity is plenty enough for me, as I realized that implication back in the 1990s, the first time someone on the TML asserted Gravity propagates at C. And, truth be told, the Orbital mechanics math alone says to the Quantum Physicists, "Bovine Feces! Gravity propagates MUCH faster than C!"
But back then, I didn't have access to published papers supporting that with the math.
Gravity Waves are different than gravity. Axiomatic. But what is most interesting is that gravity is a very weak energy... a ship arriving will be a tiny drop in the bucket - a man next to the detector is likely a stronger gravitational force than a ship arriving at 1AU.
The issue of gravity not supporting C-Limited gravity is plenty enough for me, as I realized that implication back in the 1990s, the first time someone on the TML asserted Gravity propagates at C. And, truth be told, the Orbital mechanics math alone says to the Quantum Physicists, "Bovine Feces! Gravity propagates MUCH faster than C!"
But back then, I didn't have access to published papers supporting that with the math.
Gravity Waves are different than gravity. Axiomatic. But what is most interesting is that gravity is a very weak energy... a ship arriving will be a tiny drop in the bucket - a man next to the detector is likely a stronger gravitational force than a ship arriving at 1AU.
christopher.boote
SOC-12
That's the paper I was gong to quote
Changes in gravity CANNOT propagate at 'only' the speed of light, as simple gravitational lensing would then produce 'beats' (actually super-sub-positions of the light) as the difference in gravitation of multiple objects was observed at different times
As we do NOT observe beats, it can be inferred that gravity's effect on light is NOT 'travelling' at the same speed or slower than the light
Now, that doesn't mean that it's effect on other bodies that are not both waves and particles is observed faster than light, but it is strongly implied by that paper
Essentially, to test this, you get a super sensitive detector at one end of a long vacuum chamber, sensitive enough to detect the gravitational pull from a dense object at the far end
Then you add mass to the object at the far end, and see how long it takes your detector to register
the only people that I know have tried this are the LIGO folks in Australia, using a (I believe) 4km underground tube, mounted at a 7 degree angle to avoid being affected by the earth's curvature, and Osmium pits at the far end
They can detect changes of as small as 8 x 10^-4g with their rig
BUT the problem is that the detector trips enough as the new mass is brought close to the pit so as to render measurements imprecise -but for those 1/200 reading when a precise measurement is obtained, it SEEMS to show that the detector trips faster than the speed of light would allow
Final caveat. If (as is currently believed by some) gravity might be propgated in waves, the difference between the peak and trough of the wave may be enough to produce the variance that the LIGO folks are seeing
"If" ... "might" ... "may be" ... experimental physics at its finest
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