No, it'd vaporize and release its energy as soon as it hit the hull. At best, it'd start releasing energy as it struck the hull and continue doing so as it through and if there was any of it left then it might hit more stuff inside, but there's no way that it could just pass through the ship intact without vapourizing.
New drive type - the D-drive
- Thread starter dalthor
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No, it'd vaporize and release its energy as soon as it hit the hull. At best, it'd start releasing energy as it struck the hull and continue doing so as it through and if there was any of it left then it might hit more stuff inside, but there's no way that it could just pass through the ship intact without vapourizing.
Nope. If anything they vaporize instantly and each strike will be like a little particle beams going through the ship (assuming they do go through the hull) as the little fireball forms and starts to expand before hitting something in the ship.
http://www.astronomycafe.net/qadir/q2720.html
Not to mention that a hole going all the way through the ship will damage drives, cables, equipment, people, etc. And there'd be a lot of holes since there'd be a lot of dust strikes - that's generally why most realistic interstellar designs have a huge thick shield in the front to stop them from doing that.
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good link, thanks.
this fails to account for coupling. it doesn't matter what the dust grain's kinetic energy is, it has very little cross-sectional area to couple that energy to any target structure. the individual atoms transmit ke to impacted atoms, at these speeds breaking any ionic and covalent bonds in the impacted mass with almost no energy transmitted to the non-impacted atoms. the dust grain at .5c and 100-lb person at 13mi/sec may have equal ke, but the person will do far more damage because of the larger coupling area.
see this dynamic where I work all the time.
there will be little "explosions" sure, but they'll be way behind the ship by the time they're observable. radiation, however, may be an issue. don't know about that.
this fails to account for coupling. it doesn't matter what the dust grain's kinetic energy is, it has very little cross-sectional area to couple that energy to any target structure. the individual atoms transmit ke to impacted atoms, at these speeds breaking any ionic and covalent bonds in the impacted mass with almost no energy transmitted to the non-impacted atoms. the dust grain at .5c and 100-lb person at 13mi/sec may have equal ke, but the person will do far more damage because of the larger coupling area.
see this dynamic where I work all the time.
there will be little "explosions" sure, but they'll be way behind the ship by the time they're observable. radiation, however, may be an issue. don't know about that.
Even if that were the case, none of this avoids the fact that the ship would have has lots of tiny holes in it.
A 10m long shuttle travels its length in 0.000000067 seconds at 0.5 c. Radiation - including light - emitted at the speed of light (1.0 c) from the impact site would travel twice that distance in that time, so it'd affect the entirety of the ship.
It's definitely going to vaporize on impact because the grain is so much smaller than the hull thickness. The energy released will be sufficient to vaporize the hull at the impact site too. the energy (and molten hull) would travel through the ship in a tiny fraction of a second essentially blasting a hole in everything until it hits stuff dense enough to absorb it or goes straight through.
Whatever the mechanism, it's bad news for the ship and all within it.
o:
QM and "wavefunction collapse" don't come into it at all here. It's a macroscopic object hitting another (we're not even talking about relativistic speeds here), it works the exact same way as any small object hitting a larger one at high speed would - i.e. it vaporizes.
QM and "wavefunction collapse" don't come into it at all here. It's a macroscopic object hitting another (we're not even talking about relativistic speeds here), it works the exact same way as any small object hitting a larger one at high speed would - i.e. it vaporizes.
Actually, QM applies at all times - it's just that the waveform collapse of so many items at one point becomes a probability of "once per multiple lifetimes of the universe"...
Most of the interplanetary and interstellar medium is monoatomic ions of hydrogen, deuterium, tritium, and Helium with 2-4 AMU.
Right. So it's irrelevant to what's being discussed here (dust grains).
Which are covered in the article I linked (it'll turn into radiation at the hull), and we're talking about dust anyway.
IMTU I limit the speed of a dark matter (DM hereafter) drive to TL x 3 miles per second before the drive can no longer balance thrust versus mass. It would overload at that point, and no longer accelerate the object. Going back to the jet ski analogy, you simply can't force enough DM thru the pipe.
At TL-16 this is about 172,800 miles per hour, or about .00025c. This is about triple the speed of the average asteroid, based on what I recall and can find online.
In comparison, our (current) fastest spacecraft maxed out at about 157,000 mph, but that was gravity assisted.
This would still do significant damage at impact, but it also gives a pretty good chance of detection and destruction before it actually hit a world, for example, especially at TL-12+
Obviously, using gravity-assist you could theoretically boost your speed significantly, but most likely still not to any significant percentage of the speed of light.
Maneuver drives work on a different principle, and don't have this limitation, but outside of 1000D are essentially useless. The D-drive (or DM-drive if you prefer) isn't limited by location, but does have a speed limit.
I just set this up based on what worked for me at the time, and left it at that.
Maneuver drive is much more common IMTU, since most travel is within the 1000D limits of a system; the D-drive is useful outside that limit, and may get you there, but you better have the time and life support.
I haven't done any calculations to find out the max velocities involved on the travel time tables. Those probably involve MUCH higher speeds than I allow the d-drive. I wasn't too worried about it when I originally posited the drive, back in the late '90s.
At 9g acceleration, from a stars 1000D limit, just how fast COULD you go, moving in-system??? This is, of course, dependent on the star, but what if wen used Sol as an example? Anybody got the time and availability to check that? I don't know that I've ever seen that set of numbers.
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173000 mph is *slow* in interplanetary terms. It'd take 22 days to travel 1 AU at that velocity.
1000D from Sol is 9.28 AU. If a ship travelled inwards to 1 AU accelerating at 9g (90 m/s²), it could get there in 166132 seconds (1.92 days), from SQRT((8.28 AU in metres)* 2))/90).
So final velocity would be from (v = at) which is 90 * 166132 seconds - 14951923 metres/second, or 14951.9 km/s (about 0.05 c).
I think.
1000D from Sol is 9.28 AU. If a ship travelled inwards to 1 AU accelerating at 9g (90 m/s²), it could get there in 166132 seconds (1.92 days), from SQRT((8.28 AU in metres)* 2))/90).
So final velocity would be from (v = at) which is 90 * 166132 seconds - 14951923 metres/second, or 14951.9 km/s (about 0.05 c).
I think.
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Math looks about right .
Running it again
Spoiler:
I verify your numbers close enough.
Note that at that speed or faster, the interstellar medium itself effectively becomes low-energy alpha radiation unless moving with the solar wind.
Anything much past that, and material fatigue and abrasion is going to be a major issue, save for a straight radial trip out to the heliopause.
Why? because an alpha disturbs 450,000 electrons... and you're hitting about 14 million particles per second per square meter at peak velocity.
It's generating a milliamp for every square meter. It's slowly (because probably 99% of the displaced electrons return) ionizing the hull, and also kinetically volatilizing the hull's outer shell (literally, wearing away the paint).
Oh, and at that speed, a 0.1 mm sand grain at SG=5..
5.5740e+5 J, and 0.1 mm2... TNE damage value 49.7... That's enough to hurt a ship. The TL13 sample plasma gun only has a DV of 40...
You hit one such grain per hour (IIRC, that size is about 1 per cubic kilometer, and you're crossing 14 km2 per second...
OUCH! I'd expect deflectors/shields/pressors/armor probably wouldn't help much at those speeds, and the rad itself seems like it would become a serious issue.
Thanks to all that supplied math!
Oh, and one thing I forgot to mention, minimum drive size is one ton. IMTU this drive is primarily used for small ships, under 100 tons. Made smaller ships much more practical, but was balanced by practical distance limits - over large distances they became less efficient.
I also limited them to speed 9 in ATM, modified by hull shape.
Speaking of speed in ATM, the speed for smallcraft (gigs, for example) per T5.09 page 265 is maxed at 7, or about 186 mph.
Is that meant to be cruising speed?
Might have to do some research into the space shuttle for a better understanding. Unpowered reentry, speeds from initial atm penetration down to landing speed, and all that.
The problem with high sublight drives is the radiation and friction of the IPM & ISM... how one deals with that is a pretty definitive driver of the setting feel.
Including "ignore it and pretend the ISM and IPM are true vacuum."
