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Pandaren
2009-08-28, 07:53 PM
Everybody's heard about it


Toss one of the pair in, the other will, most likely, shoot out a geyser of water at....very, very high speeds.

Anybody actually wanna do the math?

quick_comment
2009-08-28, 07:57 PM
Yes. Magic doesnt conserve momentum, so the water comes out at whatever speed the DM wants.

Pandaren
2009-08-28, 08:08 PM
That would kind of suck,

pull of it for first time to try to kill a boss..

..trickle of water drips out.

Randel
2009-08-28, 08:23 PM
Or instead it works on Looney Toons physics so that instead of launching a high-pressure stream of water towards the enemy it acts like a rocket and launches the ring backwards at high speed into your chest and just leaves a little line of water to splash onto the ground.

Oh, and when it hits the wall of the dungeon it pushes a big hole in it so that a several hundred yard long plug of rock gets launched out of the ground on a rocket-like geyser of water and then crashes right into your home base (at which point the ring breaks).

Or it turns out some mer-people found the ring and rolled a large rock over it to keep it from making a big whirlpool in their backyard.

Korivan
2009-08-28, 08:23 PM
I guess you could argue that the farther down you go the more presssure is being exerted and thus water would pour out faster the farther down you manage to get the ring down. Though its probably a good way to get your toys taken away.

Lysander
2009-08-28, 08:52 PM
However that very pressure would also push the ring up from the bottom of the ocean. So it would have to be held down by something or it would probably shoot around wildly at a medium depth.

Korivan
2009-08-28, 10:12 PM
Depends on the density of the material of the ring gates. Could always weigh it down with extra weights.

Iku Rex
2009-08-28, 10:36 PM
Ring Gates

These always come in pairs—two iron rings, each about 18 inches in diameter. The rings must be on the same plane of existence and within 100 miles of each other to function. Whatever is put through one ring comes out the other, and up to 100 pounds of material can be transferred each day. (Objects only partially pushed through and then retracted do not count.) This useful device allows for instantaneous transport of items or messages, and even attacks. A character can reach through to grab things near the other ring, or even stab a weapon through if so desired. Alternatively, a character could stick his head through to look around. A spellcaster could even cast a spell through a ring gate. A Small character can make a DC 13 Escape Artist check to slip through. Creatures of Tiny, Diminutive, or Fine size can pass through easily. Each ring has a "entry side" and an "exit side," both marked with appropriate symbols.

Strong conjuration; CL 17th; Craft Wondrous Item, gate; Price 40,000 gp; Weight 1 lb. each


http://www.d20srd.org/srd/magicItems/wondrousItems.htm#ringGates

Admiral Squish
2009-08-28, 10:42 PM
Assuming the ring gate sinks, you have about a 35-40% chance that it will work as a gyser. 50% of the time, the gate lands face down and you just paw through wet sand and maybe a very confused crab. the other 10-15% is the probabability of somthing else happening. Like, ring get snagged on a passing fish. Merfolk decide it makes a pretty necklace. Silt buries it. there's a underwater mountain you didn't notice.

a notable issue with the gyser is, water pressure must equalize for the flow to stop. so suddenly, you have half an ocean where it's not supposed to be. Can you say, catastrophic environment change? Massive flooding? Deaths in the thousands? Ocean levels are half what they were before. rotting fish and seaweed exposed would render most of what was left putrid. Plant life would wither and die, even as nearby as the old shoreline. I don't even wnat to think of the really long-term effects.

However, This could actually be a really intersting idea: wizardly water features? Some wizard school has a waterfall that comes out of one gate, runs down a bunch of rocks and a small river chennel, then flows into the next gate.

Dark Herald
2009-08-28, 10:58 PM
wouldn't you just flood the dungeon and create a new river? Albeit a physics defying free energy creating river.

Tokiko Mima
2009-08-29, 06:26 AM
If you put the exit side of the ring inside a reinforced pressurized bottle with a valve attached, then drop the entrance side ring into a a few thousand leagues of water, you've just created a squirt gun that will cut steel.

Could also be fun as underwater jet propulsion. :smallsmile:

Curmudgeon
2009-08-29, 09:44 AM
You get 100 pounds per day. That's just 12 gallons of water, or what a 6th level Cleric can do with an orison (Create Water).

Chrono22
2009-08-29, 09:51 AM
If there was a way to negate the gravity surrounding the ocean-side ring gate, wouldn't that mean you could transfer unlimited quantities of water? The water pressure in the null field would still push water through the gate, since the surrounding waters would still be subject to the crushing force of gravity, but the water itself would be weightless until it exited the other side.

daggaz
2009-08-29, 09:52 AM
Yeah, but if you constrict it thru a pinhole sized arpeture, 12 gallons will go quite a long ways, and yeah, it will cut thru flesh like a hot knife thru butter, at least at very close range. Still, its rather anti-catgirl, as a DM I would be inclined to figure out more than a few ways to handwave its effectiveness out the window.

Ubergeek
2009-08-29, 10:00 AM
If you rule that matter, but not momentum, is carried through the ring, wouldn't the water just fall to the floor, instead of shooting out?

Chrono22
2009-08-29, 10:02 AM
Well, it would fall out, but explosively. The water coming through is under extreme pressure.
Magic is weird.

daggaz
2009-08-29, 10:11 AM
Assuming momentum is conserved (which it would kinda have to be, or it would do REALLY wierd things just sticking your head thru to look around), then the idea would work.

Except for one thing, which I had to look up to be sure, tho honestly this is silly point since we are mixing magic with real world physics (like i said, all the more reason for a DM to reach for the ban-bat). Each ring has an entry and an exit side, clearly marked. This means the ring only works in one direction. This means that you wont get any explosive jet of water, because the forces involved are static, or perfectly balanced. Since the water is being crushed in both directions thru the ring simultaneously and equally, the water which could be teleported wont be, as the water which is pushing up against it from the other side is still there, and is still pushing up against it, cancelling the force. You need a ring that lets the water in from both sides.

And really, for something that costs 40,000 gp, theres a whole lot more effective ways to build some sort of cannon. And a lot more effective uses for your rings.

Grumman
2009-08-29, 10:19 AM
If you rule that matter, but not momentum, is carried through the ring, wouldn't the water just fall to the floor, instead of shooting out?
No.

It makes almost no difference whether momentum is conserved or not. The idea is not powered by momentum transferred through the gate (because the water is initially almost motionless and thus without significant momentum), it is powered by the other water being pushed through the gate behind it.
Although it is less clear-cut than a suggestion on the Wizards forums that Ring Gates did not transfer force, such a ruling would have significant effects on how they were used. As it is possible to attack through a Ring Gate without the penalties that you would expect from attacking through what is effectively a viscous liquid, I would see this as evidence that momentum was retained.

ETA:

Each ring has an entry and an exit side, clearly marked. This means the ring only works in one direction. This means that you wont get any explosive jet of water, because the forces involved are static, or perfectly balanced. Since the water is being crushed in both directions thru the ring simultaneously and equally, the water which could be teleported wont be, as the water which is pushing up against it from the other side is still there, and is still pushing up against it, cancelling the force. You need a ring that lets the water in from both sides.
This is completely and utterly wrong. The idea only needs the rings to work in one direction, and it is the movement of water into the entry side of the water gate and out of the exit side of the cannon gate is what propels the water.

If you were correct in how the Ring Gates worked, this would also render them utterly incapable of transmitting solids from the transmitting end, as trying to push something through the gate would be blocked by the bit slightly ahead that had already passed through the gate.

Curmudgeon
2009-08-29, 10:28 AM
OK, so let's say you get a geyser from ocean pressure. But it's limited to 12 gallons a day. So at midnight you get a brief spurt of water, then nothing until the next midnight.

Is this really worth discussion?

shadzar
2009-08-29, 10:38 AM
Magic, the only thing that can compress water.

Erinyes
2009-08-29, 12:53 PM
OK, so let's say you get a geyser from ocean pressure. But it's limited to 12 gallons a day. So at midnight you get a brief spurt of water, then nothing until the next midnight.

Is this really worth discussion?

Or, 12 gallons of water blasting someones skin from their bones, once a day, whenver you want it.



"Pushes from both sides" doesn't work, that's just stupid. It would mean that nothing could teleport, it would get stuck teleporting back and forth.

shadow_archmagi
2009-08-29, 01:02 PM
Note: It's not a "Pinhole sized aperture" it's a circle a foot and a half wide.

Adumbration
2009-08-29, 01:36 PM
Guys, guys. You're looking at these completely wrong. Why use Ring gates and ocean, when you can use Planar Ring Gates and the Elemental Plane of Water?

10 000 pounds of water should be quite sufficient.

Curmudgeon
2009-08-29, 01:38 PM
Or, 12 gallons of water blasting someones skin from their bones, once a day, whenver you want it.
No, it's just once a day. "Whenever you want it" isn't in the item description.

Fax Celestis
2009-08-29, 01:42 PM
Guys, guys. You're looking at these completely wrong. Why use Ring gates and ocean, when you can use Planar Ring Gates and the Elemental Plane of Water?

10 000 pounds of water should be quite sufficient.

I used a variation on this: small gate to the Elemental Plane of Fire + decanter of endless water = steam engine.

kentma57
2009-08-29, 02:35 PM
I used a variation on this: small gate to the Elemental Plane of Fire + decanter of endless water = steam engine.

ok, I need to remember that one.

HamsterOfTheGod
2009-08-29, 03:03 PM
Now why would water, the medium that surrounds the ring gates, go in one ring gate and out another and not say something like air? Air, if we assume Earth like density, has a pressure of 15 pounds per square inch at the surface. If the ring gate surface simply took whatever medium pressed against and shot it out the other side, the ring gates would simply suck in air on one side and push it out the other at some ill defined speed. Now I haven't done the math, but I'm pretty sure after some time, say an hour, the gates would have transported 100 pounds of air and would not be usable for the rest of the day.

Why would you make such an item? You wouldn't. Real world physics should not be applied to D&D magic. D&D magic items are "smart" items. They only do what they are supposed to do. Ring gates do not transport the medium pressing upon them but only do as the spell description says
Whatever is put through one ring comes out the other, and up to 100 pounds of material can be transferred each day. (Objects only partially pushed through and then retracted do not count.) This useful device allows for instantaneous transport of items or messages, and even attacks. A character can reach through to grab things near the other ring, or even stab a weapon through if so desired. Alternatively, a character could stick his head through to look around. A spellcaster could even cast a spell through a ring gate. A Small character can make a DC 13 Escape Artist check to slip through. Creatures of Tiny, Diminutive, or Fine size can pass through easily.

Mad Wizard
2009-08-29, 03:10 PM
One of my friends pulled a trick similar to this in my game: he opened a Gate to the infinite ocean of holy water said to exist on one of the upper planes, creating what amounted to a huge geyser of holy water, utterly disintegrating a rather powerful evil outsider.

Edit: Anyone have any idea how much damage this kind of thing would do?

Foryn Gilnith
2009-08-29, 03:37 PM
I'd guesstimate about as much as full immersion in acid. Maybe substitute each 1d6 with 2d4, if you want, but that's unnecessary.

Curmudgeon
2009-08-29, 05:58 PM
Air, if we assume Earth like density, has a pressure of 15 pounds per square inch at the surface. If the ring gate surface simply took whatever medium pressed against and shot it out the other side, the ring gates would simply suck in air on one side and push it out the other at some ill defined speed. Now I haven't done the math, but I'm pretty sure after some time, say an hour, the gates would have transported 100 pounds of air and would not be usable for the rest of the day.
100 pounds of air is only 37.75 cubic meters at standard temperature and pressure. If you're assuming no back-pressure, that 0.2286 meter radius ring is going to pump through 67 cubic meters per second, so it'll be done for the day in just over half a second. With actual air in the way, a pressure surplus of 1 atmosphere would still just take a few seconds to move 100 pounds through.

Yora
2009-08-29, 07:20 PM
To get something through a portal, it has to be pushed into the magical event horizon (or how they call it in Stargate) to get through. So I usually hold it, that gasses or liquires get from one side to the other side, until the preasure is the same on both sides. Air or water currents would probably also do, but that would usually not make such a great difference.

There is a massive bubble of water on the astral plane in planescape, which is steadily growing. As preassure has no meaning in the astral plane, it would not be possible using this mechanism.