Page 153 of 247

Re: Official "Discuss the latest page" thread

Posted: Mon Oct 17, 2011 8:58 pm
by robinmdh
CygnusX1 wrote:
Relativistic railgun shots look more like nukes detonating at the impact point( 0.1 gram at 0.99C for example, would have nearly as much energy as the nuke detonated at hiroshima).
Only if all energy is dissipated into the target.
If your 0.1 gram pellet enters at 0.99C and exists at 0.989C then only 0.1% of its energy is actually transferred into blowing things away. Rest is pretty must wasted...
so you design your bullets to fly apart and/or bounce around inside the armor of the target ship etc just like a whole bunch of normal bullets are designed to do.
or did you think the exit hole of a sniper rifle bullet is just as big as the entry hole?
or
allikat wrote:Another point: Projectiles designed to fragment are massively more efficient at transferring their kinetic energy to the target, a fine thing in space combat. A small projectile at near light speed may well punch through a corridor's worth of rooms and out the other side, but if it shatters on impact, it could very well take out several decks.

Re: Official "Discuss the latest page" thread

Posted: Mon Oct 17, 2011 9:17 pm
by David
skythorn wrote:Are you sure that you can't fire a railgun into the US visa requirements. David only managed to get his visa with 4 days remaining. Sounds a bit shirty to me.
There was a delay because the US law firm handling my application needed convincing that a 3-year Bachelor's degree in Australia is as good as a 4-year Bachelor's degree in the US. I'd argue an aussie degree is actually better, because we handle all the general subjects in Years 11 & 12 and dive straight into specialised study (a "Major") in our first year of University.

As for all the railgun discussion...

...NERDS!!!!

(don't stop)

Re: Official "Discuss the latest page" thread

Posted: Tue Oct 18, 2011 2:44 am
by CygnusX1
There was a delay because the US law firm handling my application needed convincing that a 3-year Bachelor's degree in Australia is as good as a 4-year Bachelor's degree in the US.
Heh, that's always the problem when you move from one country to another to somehow continue or base on the education you took earlier.
I was moving within Europe, and although we have somewhat unified educational system, there is still a lot of convincing on the way...

Re: Official "Discuss the latest page" thread

Posted: Tue Oct 18, 2011 9:01 pm
by skythorn
in the mid 1990's I flew from Hong Kong to Vancouver, via Los Angeles. The agency I bought the tickets from had no idea that a transit visa was required to get from plane A to plane B which took us through customs. I had no travel visa. I was ignorant. So were the 14 accompanying students. 50% of that contingent were given cavity searches before a temporary transit visa was given to us, for a 5 minute walk from one gantry to another. My experience with American Customs is most unpleasant.

I wish you luck David.

Re: Official "Discuss the latest page" thread

Posted: Wed Oct 19, 2011 9:26 am
by SoulWager
CygnusX1 wrote:
Relativistic railgun shots look more like nukes detonating at the impact point( 0.1 gram at 0.99C for example, would have nearly as much energy as the nuke detonated at hiroshima).
Only if all energy is dissipated into the target.
If your 0.1 gram pellet enters at 0.99C and exists at 0.989C then only 0.1% of its energy is actually transferred into blowing things away. Rest is pretty must wasted...
you don't understand, at impact the pellet will cease to be a pellet. Even if it hit a piece of tissue paper it would explode into a cone of radioactive plasma. When it hits the hull of a spacecraft the same thing happens, only that radioactive plasma further interacts with the mass of the spacecraft, depositing the heat of a small nuke near the point of impact.

And a less relevant but still important point, 1% of it's speed is NOT 1% of it's energy. At Newtonian velocities, energy increases with the square of velocity, but at relativistic velocities, energy approaches infinity as velocity approaches C, so if your projectile is going 5 9s of C, and you knock 1% of it's speed off, you'll be dumping the overwhelming majority of it's energy.

Re: Official "Discuss the latest page" thread

Posted: Thu Oct 20, 2011 3:12 pm
by Dhraakellian
SoulWager wrote:but at relativistic velocities, energy approaches infinity as velocity approaches C, so if your projectile is going 5 9s of C, and you knock 1% of it's speed off, you'll be dumping the overwhelming majority of it's energy.
The corollary to this, of course, is that accelerating the projectile to 5 9s of c also requires an overwhelming amount of energy.
I have no idea how the following ended up in my post. Someone else wrote:I don't want to imagine how much energy and how effecient the transfer of it to the velocity would have to be to get a projectile going that fast.

Honestly I like to think plain and brutal. Build a huge, long cannon like the old style ship guns, get a nuke with a cannon ball on one end and shove it down the barrel, nuke first. Boom goes the nuke and woosh goes the cannon ball as fast as that nuke can blast it out that barrel... I wonder if a focused nuke blast alone would have much affect in space...

Probably need some insanely thick and strong barrel... Wouldn't like to know what the recoil would be like for the ship that fires it... maybe very small nukes rather than the full city or state wide killers.

Re: Official "Discuss the latest page" thread

Posted: Thu Oct 20, 2011 7:52 pm
by SoulWager
Dhraakellian wrote:
SoulWager wrote:but at relativistic velocities, energy approaches infinity as velocity approaches C, so if your projectile is going 5 9s of C, and you knock 1% of it's speed off, you'll be dumping the overwhelming majority of it's energy.
The corollary to this, of course, is that accelerating the projectile to 5 9s of c also requires an overwhelming amount of energy.

I don't want to imagine how much energy and how effecient the transfer of it to the velocity would have to be to get a projectile going that fast.

Honestly I like to think plain and brutal. Build a huge, long cannon like the old style ship guns, get a nuke with a cannon ball on one end and shove it down the barrel, nuke first. Boom goes the nuke and woosh goes the cannon ball as fast as that nuke can blast it out that barrel... I wonder if a focused nuke blast alone would have much affect in space...

Probably need some insanely thick and strong barrel... Wouldn't like to know what the recoil would be like for the ship that fires it... maybe very small nukes rather than the full city or state wide killers.
You're not going to get a projectile going that fast with a nuke. A big synchrotron will work on nuclei, but the only way I know to accelerate a projectile to those velocities without vaporizing it are extreme gravitational forces. (you either need a target deep in the gravity well of a black hole, or you need to invent new physics to allow the manipulation of gravity.)

Re: Official "Discuss the latest page" thread

Posted: Fri Oct 21, 2011 8:31 am
by Dhraakellian
Dhraakellian wrote:
I have no idea how the following ended up in my post. Someone else wrote:I don't want to imagine how much energy and how effecient the transfer of it to the velocity would have to be to get a projectile going that fast.

Honestly I like to think plain and brutal. Build a huge, long cannon like the old style ship guns, get a nuke with a cannon ball on one end and shove it down the barrel, nuke first. Boom goes the nuke and woosh goes the cannon ball as fast as that nuke can blast it out that barrel... I wonder if a focused nuke blast alone would have much affect in space...

Probably need some insanely thick and strong barrel... Wouldn't like to know what the recoil would be like for the ship that fires it... maybe very small nukes rather than the full city or state wide killers.
First, I have absolutely no memory of writing this and, thus the editing of it into quote tags.

Second, if I'm going to use nukes in my weapon systems, I think I'd rather use them directly in the warheads rather than projectile launchers. I somehow doubt that nuclear explosion-launched projectiles are the most efficient way of doing things, and I'd prefer to have that hard radiation be released as far away from me as possible.

Re: Official "Discuss the latest page" thread

Posted: Fri Oct 21, 2011 2:50 pm
by zeracore
the nuke idea has ben thought of in the past but not as a weapon system but as a propulsion systems

and gravity manipulation is theatrically possible according to current string theory sympathetic frequency oscillation

http://www.wired.com/science/discoverie ... _alphageek now if i can just find and articular about the British Physicist that did a similar experiment
if we can use sound waves mixed with radio and possibly light waves we may be a bull to make a gravity field ether stronger or a new one were there was not one before (at the moment highly theoretical)
current thought is if you have the technology to manipulate gravity you can make psp (Point Singularity Projector) and you wood not only have the best means of propulsion but the best means of both offense and defense

Re: Official "Discuss the latest page" thread

Posted: Fri Oct 21, 2011 3:31 pm
by Dhraakellian
zeracore wrote:the nuke idea has been thought of in the past but not as a weapon system but as a propulsion systems
Propulsion system, yes, with a shaped charge and a large reflector shield behind the ship. The use in question here was instead as a way to launch ordnance from shipboard launch tubes.

Aaaanyway, back to the Story, how long is this Epilogue likely to last? On one hand, I'd like to see the resolution. On the other hand, I don't want it to end!