New weapons in DARPA

Cool weapons. I just wish we had the appropriate wisdom about how to use them. (sigh)

And this is two years ago for what DARPA has for rail guns
https://www.youtube.com/watch?v=eC2hu9bildA

@swordedge:
Here is a railgun update for you, article link. Video from article below. Official Navy Article.

<iframe width="560" height="315" src="//www.youtube.com/embed/qJQfAcBs5vQ" frameborder="0" allowfullscreen></iframe>

It's also good to note that ground based version was unveiled a in 2013, article.

Hmmm ... So, the projectile is a fin-stabilized, discarding sabot -- kinda like a Sabot tank round -- 23 pounds and length over radius ratio (possibly depleted uranium), and fired at a muzzle velocity of more than 2300 meters per second (more than 5,000 MPH). All without explosives to drive it. Not only safer for the sailors, but a ship would be able to store a larger combat load of just the projectiles. Or, less space would need to be devoted to combat load storage.

Anyone remember old SF stories about rail drivers being used to launch space vehicles or shuttles into escape velocities or orbit?

And, not long ago, there was some experimentation on hand-held rail guns (needlers).

I think the future is slamming into our face. 😉

As I recall the DoD set some pretty high goals for rail gun deployment, as early as next year for some systems.

The really cool part about the rail guns is that in theory you can reach relativistic speeds. I wouldn't want to pay the electric bill to get a BB up to 50% light but I'd love to see what a BB would do at 1% light.

The question is, what is the speed of light? Does anybody really know? Or is it all speculation

@davidj: Interestingly enough, it would only take at least 500 megajoules to get a BB up to 0.01c.

@will91: The speed of light has been measured with a fair bit of accuracy. There are a number of simple experiments that can be done to measure the speed of light. Interestingly enough searching online for "simple experiments to measure the speed of light). Though the simplest ones seem to use a microwave to get the speed of light. I believe I measured the speed of light in a physics class I took years ago.

Hmmm … So, the projectile is a fin-stabilized, discarding sabot — kinda like a Sabot tank round — 23 pounds and length over radius ratio (possibly depleted uranium), and fired at a muzzle velocity of more than 2300 meters per second (more than 5,000 MPH). All without explosives to drive it. Not only safer for the sailors, but a ship would be able to store a larger combat load of just the projectiles. Or, less space would need to be devoted to combat load storage.

Anyone remember old SF stories about rail drivers being used to launch space vehicles or shuttles into escape velocities or orbit?

And, not long ago, there was some experimentation on hand-held rail guns (needlers).

I think the future is slamming into our face.

The reason I keep hearing for railgun development is safety. Having lots of high explosives and propellant on board a ship that is designed to be shot at is a good thing. See the USS Maine, and the HMS Hood for example. Wouldn't the batteries needed for railguns, with the huge amount of energy they have to store be almost as dangerous?

I don't think the batteries as such would be nearly as dangerous. Most likely it would us very large capacitors powered by turbines.

Here is a nice video about 16" guns.

https://www.youtube.com/embed/C2sYtq7hI74?autoplay=1

I don’t think the batteries as such would be nearly as dangerous. Most likely it would us very large capacitors powered by turbines.

Super caps. This is something we have now. They can hold their charge at up to 5000 volts. Normal usage is lower, 3500 volts. NASA has been using them since at least the 60's. A company called EEStore patented a system that stores 52.220 kWh of energy. That is roughly what the Tesla roadster has but you can't charge it quickly like you can this. Nor can batteries be instantly discharged like capacitors. An article on it is here http://www.olino.org/us/articles/2006/10/11/has-the-supercapacitor-been-invented Apparently, they are difficult to make today.

I did a quick calculation. If you discharged 52.22 kWh of energy in .1 seconds, that is 1.88 Gigawatts. That should make a projectile go fast. You'd probably have to replace the cap then too. What can handle 1.88 Gigawatts?

http://www.wolframalpha.com/input/?i=52.22+kWh+in+.1+second

http://www.youtube.com/watch?v=CWwm39Xx2YQ
another interesting darpa investment.
sumo