Who writes the test? As the Aesop fable of the mice and the cat illustrates, it is easy to propose impossible solutions.

Wrong. Mars lost it's atmosphere because it's gravity and non-existent magnetic field were insufficient to retain it against the solar wind. Venus has a very weak magnetic field either for its size (why is a mystery), and as a result the atmosphere it has is what remains after the lighter elements (water, hydrogen and oxygen) have been eroded off by the solar wind.

Low density? Density doesn't enter into the equation here - gravity is a function of mass, not density. Here, look at this

• Planet - Density
• Mercury - 5.427 g/cm
• Venus - 5.204 g/cm
• Earth - 5.515 g/cm
• Mars - 3.9335 g/cm
• Jupiter - 1.326 g/cm
• Saturn - 0.687 g/cm
• Uranus - 1.27 g/cm
• Neptune - 1.638 g/cm

Note, the inner rocky planets are WAY more dense than the gas giants - hell Saturn would float if you could find a bathtub big enough to throw it in. Saturn and Jupiter have no problem holding onto H2.

This planet is 6.5 the mass of earth. Uranus, the smallest gas giant in our own system is 14 times the mass of earth and has half the density of this planet.

This isn't surprising. This planet seems to occupy a transition zone between rocky planet and gas giant. Uranus & Neptune are primarily Methane.

I wonder if it turns out that most planets of a certain mass range are mostly water - earth being on the one end and this new planet on the other side of the curve. After a point the gases in the planet transition to methane for some reason, then finally to just diatomic hydrogen in the case of the largest gas giants, and finally stars.

We already know that Jupiter is about as large as a planet can get by volume - any larger and the density starts increasing again, until fusion occurs and you get a star somewhere around 50 Jupiter masses. (Some astronomer please correct me on that).

Statute of Limitations, in all cases, is a limit on how long you can wait to file a complaint. It is not a limit on how long the courts can take to decide the merits of the case.

"The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized."

How is the TSA screening [i]not[/i] in violation of this. Being forced to go through machines that essentially strip you naked is well outside the bounds of 'reasonable' by the definition of anyone but a politician it seems.

Missiles are a bit larger and more expensive than a 5 kg slug of metal and don't travel at 2,500 m/s (More like 500 to 900 m/s). The carrier's other roles won't go away with the appearance of the rail gun, but the roles that will remain for it are better served by amphibious landing carriers like the USS Wasp. Rather than be the core of the fleet it will return to a support role eventually.

Thing is, the carrier may not be feasible now in a equal fight with another superpower. It really hasn't been tested against a foe capable of throwing effective shore to ship or ship to ship missiles at it. But it is very effective at intimidating and controlling tinpot dictators.

After all, the uselessness of battleships in sea control against a carrier wasn't proven conclusively until midway through WWII.

If you'd read the article, you'd note the British and French fleets stopped all wooden warship production within a month of the battle. Within 20 years everyone had transitioned over to ironclads like the Merrimac or purely iron vessels like the Monitor.

A is indeed acceleration. An object travelling at a velocity of 2,500 m/s velocity that strikes an object at rest will impart an acceleration to that object. But working out the exact translation is beyond my skillset - what I wrote above is intended as an approxmation for getting an idea of the scales of the forces involved, not their precise measurement.

Also, Newtons as a unit of force require the acceleration and mass to be measured in specific units. There are other force measurements, such as joules. Since I'm not sure of the units involved I didn't name off the force unit because I know of two and don't know which is appropriate.

That definitely falls under the heading of "complication" - but I don't believe it would be an insurmountable challenge. They won't know until they try.

Radar detecting a mortar round, which is fired indirectly and falls onto the target at the speed of gravity (about 9.8 m/s/s) is a far cry from intercepting a shot travelling at 2,500 m/s by several orders of magnitude. Also, the impact energy at those speeds will not just punch a hole in the ship - it will explode. Kinetic Energy is not to be underestimated.

820 m/s is the muzzle velocity for the guns on the USS Iowa class battleships. That's pretty much as fast as a shell can be thrown with chemical propellant. They fire a 1,200 kg shell. That works out to an impact force of 984,000 (exactly what these units are I don't know offhand. I just know the formula is F = MA).

"Punch a Hole" is what a 420 m/s 9mm parabellum round does. Such bullets weigh around 9 grams. Or 3.78 units.

An armor piercing battleship round FYI does NOT have explosives in it. It doesn't need them. 984,000 vs. 3.78.

Compare 2,500 m/s * 5kg still outputs 12,500. It's hitting with 1/100th the energy of the old battleship, but doing it at 10 times the range. That's still sufficient to do a lot more than merely "punch a hole."

Here's the thing folks... A ship is the size required to carry the weapon and no larger. This applies to all ships, even carriers. Supercarriers are as small as they can be while still being able to deploy jet aircraft. Battleships where as small as they could be while still providing an adequate platform for those 16" guns. Rail guns will not require carrier or even battleship sized ships. Being smaller and stealthier they will have a decided advantage.

Advancements in battery and magnetic technologies, particularly as they try to miniaturize these things to a soldier held weapon (though giving each infantryman ten times the firepower of an Abrams tank creates a whole new dimension of problems). But energy storage and release mechanisms will be improved by this research, just as interchangeable parts - originally developed by Eli Whitney ( cotton gin's inventor, remember him? ) - spread from guns to all manner of mass production through the industrial age.

The obsolescence threat to the carrier does not come in the form of a direct threat to the ship's survivability. That is part of it, but not the whole or even the largest of it, and you are ignoring that largest part. What is the carrier's role?

Projection of Force.

Carrier aircraft allow it to hit targets up 600 to 1000 km away, or more with refueling tankers. Rail guns however can also hit targets at these ranges, or even further, and even harder.

And don't kid yourself about being able to dodge the shot either. Not even 2 weeks ago another slashdot article was going on about a steerable bullet that could be fired from a sniper rifle. There is no reason to believe the shells of a rail gun might not also one day be likewise steerable. If we can build a steering system in a 30 gram bullet we can build one in a 5Kg shell. It doesn't take much steering to hit a moving carrier, which can only move 200 meters at most during the entire flight of your bullet.

And you don't need an explosive in the warhead at all if you have a 2,500 m/s velocity. The kinetic energy from a 5kg slug travelling at that velocity will punch through the hull of a carrier like butter and the impact will be quite explosive without any actual explosive chemicals. After all, F = MV. 2,500 m/s is a LOT of velocity, and you don't need much mass to impart a lot of force on a very small area of the armor to punch through. That's what makes hyper-velocity projectiles so appealing. Their threat is entirely from their velocity - not a dangerous explosive that might go off in storage.

Anyone who thinks the carrier can survive the appearance of the rail gun on the scene of naval warfare is still fighting the last war, not the next war. The carrier is a big relatively easy to hit target for guns. WWI Battleships can't get close enough to them to sink them because of the planes. A railgun equipped battleship however will be able to not only get in range of the carrier, but outrange the carrier. The shell makes the trip in 2 minutes. That's a long lag time, but nowhere near as much as the hour it takes to launch a plane out to and bomb the attacker. Even if the planes are in the air at the start its still 20 minutes before they can be on site. And yeah, you might shoot down or dodge a rail gun projectile, but what about one every minute? Every 15 seconds? A gun may only have a 1 / 15 minutes firing rate, but multiple ships with these can mass their fire on the large target.

Carriers are awesome, but so where battleships, so where Ships of the Line. Their days are numbered, and this gun is writing on the wall for them just as surely as the USS Monitor was the writing on the wall for the whole British fleet that fateful day 150 years ago next month at Hampton Roads.

I stand by what I said. Lawyers without any ground to stand on rattle their sabers all the time - and sometimes they even make the mistake of going to court with their pants down (Universal vs. Nintendo for example). And what I said is they do not likely have a case. But I'm not ruling out that they do. I am both not a lawyer nor did I stay at a Holiday Inn Express this morning, so frankly I don't know.

More likely than not, he's registered with BMI or ASCAP. You can purchase global rights through those agencies. I'm fairly certain Gingrinch's campaign has dotted that 'i' and crossed that 't'.

If he hasn't then by all means tear him up - I hate the guy myself. But his is likely a case of a composer wanting to distance themselves from the politician who likes their music. That's not exactly a new phenomena by any stretch of the imagination.

And -40 is the same on both scales... I'll never forget that day in Manitoba... Yeesh.