Phase Shift question.

[OrionsGambit]

Can PS actually stop a railgun/cannon round? (not linear round, a real railgun)

In the stats it says "all projectile rounds" but railcannons affect them in the show.

[Mwulf]

Keep in mind that "in the show" Rey morphs into Rau, the SF morphs into the Freddom, the Strike R morphs into the Strike and vice versa, and the battle between Kira and Rey was mostly identical to Kira's fight with Rau.

In short... like a lot of the weird stuff in Seed-D... I'd have to say it's an animation error.

[Wingnut]

PS can indeed stop shots from a rail gun. The Forbidden did ecactly that at least once when fighting the Freedom.

[OrionsGambit]

I don't remember that *needs to rewatch Seed*

1. How could it possibly stop a round going 300m/s

2. Why would they keep arming mobile suits with railguns when there;s better option out there?

[Wingnut]

I don't remember that *needs to rewatch Seed*

It was the first time the two suits fought each other

1. How could it possibly stop a round going 300m/s

Magic. It is the one thing that is constant about CE tech is that PS can stop any projectile round. The only instance of PS failing to stop a solid attack is when Shinn stabbed the Freedom in episode 34 of Destiny.

2. Why would they keep arming mobile suits with railguns when there;s better option out there?

I would guess that it takes less battery power to fire a railgun than it does to fire a beam rifle. Seeing as all but a few MS in the CE use batteries, a weapon that uses less power to operate would be the preferred weapon of choice.

[Genocide]

Don't forget Destiny taking a point blank shot from SF's railguns. I think when going up against something like Phase Shift, mass is more important than velocity... I know that doesn't make sense...

Also, keep in mind that only a select few MS in CE have Phase Shift, and therefore, railguns aren't as useless as they might seem.

[Homeless]

The only instance of PS failing to stop a solid attack is when Shinn stabbed the Freedom in episode 34 of Destiny.

Raider's hammer is stated to damage Phase Shift, and Nero Blitz's claw smashes through Phase Shift with sheer brute force.

[Wingnut]

The only instance of PS failing to stop a solid attack is when Shinn stabbed the Freedom in episode 34 of Destiny.

Raider's hammer is stated to damage Phase Shift, and Nero Blitz's claw smashes through Phase Shift with sheer brute force.

I personally don't completely buy that line, even if it official, as the Freedom's head was already damaged when the Raider's hammer knocked it off.

[Xess]

1. How could it possibly stop a round going 300m/s

300 m/s is subsonic, pistol round velocity. A lot of crap can stop that. You may have meant 3000 m/s.

mass is more important than velocity... I know that doesn't make sense...

Not at all, momentum is a big deal. A large mass will carry a lot more momentum than a smaller one. Phase shift might stop penetration but that won't magic away the momentum of the round, which can still smash things up on the inside and cause things like spalling.

It is the one thing that is constant about CE tech is that PS can stop any projectile round.

Which is an obvious No Limits Fallacy, a projectile round of sufficient momentum and energy will defeat Phase Shift armor. In SEED such rounds are either impossible to make or simply require to much energy to be useful. It is extremely unlikely that mobile suit grade Phase Shift could stop capital ship scale rail-cannon rounds.

The only instance of PS failing to stop a solid attack is when Shinn stabbed the Freedom in episode 34 of Destiny.

Which gives us a good idea of the upper limit of Phase Shift protection. In this case the penetrating capability of the sword were enhanced by the Impulse's own mass and velocity. If we had an estimate of the Impulse's velocity we could calculate the impact force of the sword on Freedom getting a figure of MS grade Phase shift strength.

[Homeless]

Hmm; there's also Delta's sword destroying the Noir striker, which according to the model booklets has Phase Shift IIRC.

[Deus EpS Machina]

Well, i dont see why it wouldnt be possible to destroy a PSAed MS without the use of beams...as Homeless says, brute force ftw...which is what i equate Impulse and Freedom to. Its entirely possible, as just cuz you need 72 hits for it to lose power and PSA, doesnt mean you couldnt get 73 in one hit.

[razgriz]

it all goes back i guess as to how phase shift actually negates the physical force delivered by a solid or semisolid projectile smashing into it at high speed. all that inertia has to end up going somewhere

[Homeless]

Hits from missiles and railguns do tend to rattle the pilots around, even if PSA prevents actual damage.

[razgriz]

i guess its a bullet proof vest principle, stops the bullet but not the bullet's force.

[NachtWeissritter]

1. How could it possibly stop a round going 300m/s

That's really slow for a vehicle mounted projectile weapon. The 120mm gun on an Abrams chucks metal downrange at about 5 or 6 times that velocity.

That said we've seen that Phase Shift can be overwhelmed with sufficient force on several occasions. What it does is make anything equipped with it very very RESISTANT to kinetic energy strikes.

As for how it works.. you may as well say 'a wizard did it' and it'll make as much sense as any other explanation.

[Lert]

Ammunition does damage because of it's kinetic energy.

Kinetic energy is velocity x mass. So a 5 pound round at 1000 m/s will have the same kinetic energy as a 1 pound mass at 5000 m/s.

What makes a railgun so powerful is the fact that it chucks a relatively tiny round at enormous, gargantuan velocities. Say, a half-a-pound round at 10000 m/s. That has the same kinetic energy as a 5 pound round flying at 1000 m/s. So regular armor should have the same amounts of defense against both rounds, right ?

Wrong.

The lighter round is smaller, and therefor has a smaller surface area contacting the armor, which makes for better penetration. In a real world example: I'd rather have a 1 pound brick falling on my hand than a 1 pound needle. The needle will have far greater penetration at the same weight / velocity ( = same kinetic energy )

This penetration (due to small impact area) is what makes a railgun so deadly against regular armor.

How this affects PS ? My theory is that PS uses some sort of magic - forcefield - type - thingy, that spreads all incoming kinetic energy over it's entire field, as long as the suit's generator / battery has the juice to power said field. Because of this, it wouldn't matter what kind of round hits the PS equipped mobile suit - given a certain amount of kinetic energy in the round.

A 5 pound 120mm shell traveling 1000 m/s will have the same effect on PS as a half-a-pound railgun round traveling at 10000 m/s. This is my theory, based solely on real-world physics.

Which, as we all know, have little basis in anime. >.>

Take this little bit of theory any way you like .. I'm not saying that what I wrote here is the absolute end-all-be-all of PS systems vs solid shot, but it sounds plausible to me ..

[NachtWeissritter]

Actually that concentration principle has been in use with bullets since.. well since proper rifle rounds became available. Modern tanks even use it with their sabot rounds, and the whole shaped charge concept is based on it as well so it's hardly something exclusive to railguns.

If you want to get into it the real benefit of railguns are:

1.) Reduced weight.. all the mass of the round is the projectile which lets you either carry more ammo or throw heavier rounds.

2.) There's an upper limit on the projectile velocities you can get from a chemical reaction due IIRC to expansion speeds. With a railgun you can surpass this and throw rounds faster.. provided you have the power generation to do it. In short there's a higher ceiling with railguns than with chem powered weapons.

[SNT1]

minor nitpick, but Kinetic Energy is (1/2) m * v^2.

m * v is momentum.

[Lert]

So it is. >.>

Well, it's been a good 12 years since I last had physics class. My ramblings remain, though ..

[Hyakushiki]

There's some question as to how Phase Shift Armor works.

Gundam Official says this.

The most distinctive feature of the prototype Gundams developed by the Atlantic Federation. While active, this special armor nullifies all attacks by physical weapons, including blades, projectiles, and conventional explosives. However, it has no effect against beam and laser weapons, so most of the Gundams also carry shields treated with anti-beam coating. And because PS Armor consumes large amounts of energy, it cannot be used for extended periods lest it drain the mobile suit's energy battery.

PS Armor changes color upon activation. The Gundams which use this technology thus sport brilliant colors while in their Active Mode, and turn a dull gray when they switch to Deactive Mode.

While Wiki has a more detailed explaination.

Phase Shift Armor

Phase Shift Armor is a technology designed to protect mobile suits from physical attack.

Phase Shift, or "PS" armor, is an armor system that uses electricity to reduce the damage from all forms of physical attacks although in most practicalities, PS armor makes a mobile suit virtually immune to solid body impact attacks. When PS armor powers up, a hissing sound can be heard and the grey surface of the mobile suit's armor is overlaid in color, which appears to be alterable by entering different values in the Armor Voltage section of the OS. Once powered up, the PS armor requires a steady flow of energy to maintain although power consumption spikes momentarily whenever the mobile suit is hit. ZAFT commander Andrew Waltfeld, after watching the Strike fight, estimated that the GAT-X105 Strike in standard use can take approximately 76 hits from the missiles of a TMF/A-802 BuCUE, before the energy usage drains the battery. This example illustrates that even solid ballistic weapons can eventually overpower Phase Shift Armor. Most beam weapons are able to overpower PS Armor faster than ballistic weapons. However, should a power failure occur, caused by either prolonged use or the use of high energy beam weapons, which will further drain the mobile suit's battery, the PS Armour will power down, leaving the mobile suit vulnerable to even the simplest physical attack.

Phase shift armour is also able to protect the unit from great heat and thus making the unit possible for atmospheric re-entry.

Phase Shift armor (PS) was developed by the Earth Alliance, and first rolled out in Cosmic Era 71. It remains in use as of CE 73. The first mobile suits to be equipped with PS Armor are the so-called "Gundams", GAT-X102 Duel, GAT-X103 Buster, GAT-X105 Strike, GAT-X207 Blitz and GAT-X303 Aegis. Later, both ZAFT and the Orb Union's Morgenroete, Inc. were able to study and duplicate the armor design.

The inverse of the Phase Shift armor concept is the Universal Century's I-field generator, which defends against beam weaponry but has no effect against physical attack. Phase Shift itself was once claimed by the mechanical designer to be referenced from a British army research program for ERA (Electric reactive armour).

w:ja:フェイズシフト装甲

[edit] Limitations

Because PS armor draws energy off of a mobile suit, the suits so equipped must have a means of replenishing that energy, or risk power depletion. During the war, the existence of N-Jammers limited mobile suits and mobile armors to operation on an energy battery (some mobile suits were equipped with various turbine engines to extend their operating time, but almost none had truly unlimited operational ability). Due to the the limited amount of energy within each battery only a certain amount of power is ever allocated to the PS armor system. This limitation prevents the armor from being able to nullify higher forms of energy such as beam weapons.

PS armor grants near-invulnerability to ballistic attacks such as projectiles, but it has virtually no effect on beam weapons, so most PS armored mobile suits carry a shield with an ablative anti-beam coating for defense against beams.

Nuclear power could give a PS armored mobile suit theoretically unlimited operating time. However, during the Bloody Valentine War, the widespread use of N-Jammers made this impossible without the use of N-Jammer Cancellers; afterward, the Treaty of Junius Seven outlawed nuclear-powered mobile suits. Only a few nuclear-powered mobile suits were made in any event, including the YMF-X000A Dreadnought, ZGMF-X09A Justice, ZGMF-X10A Freedom, ZGMF-X11A Regenerate,ZGMF-X12A Testament, ZGMF-X13A Providence, and the ZGMF-X999A ZAKU Trial Type. Each of these units incorporated an N-Jammer Canceller in their design, negating the effects of the N-Jammers in the field. With the tremendous amount of energy made available through the use of nuclear power, even greater amounts of energy could now be allocated to PS armor. GENESIS allocated so much power to its PS armor that it was able to nullify direct energy beam attacks from the Eternal and Kusanagi, including the Kusanagi's "Lohengrin" positron blaster cannons.

Hope that helps