Opening a portal to the center of the Sun

[some bloke]

Whilst perusing a D&D forum, I stopped to answer a question someone put out which was "what would happen if we used the gate spell to open a portal to the middle of the sun?"

I replied (this was a while ago) and whilst I'm reviewing it, I am troubled by the fact that this uses such high forces & speeds that I need to start thinking about relativity, which I didn't take into account!

The reply I put up was:

Spoiler: My Reply

The suns core is 15,000,000°C, or thereabouts. It's not going to be pleasant.

Assuming you go for the smallest diameter, you've got a 5 foot diameter disc which is opening onto liquid hydrogen at 15,000,000°C and 265,000,000,000 Bar.

We can assume that the magical portal is going to have no resistance to go through it, and even if it did, at these pressures it's going to be negligible.

In 1 second, you will have channeled 4,182,768,456 litres of sun into your immediate vicinity. This will form a cylindrical "laser" of immensely high pressure, high temperature hydrogen, which will be 6,032,223,125 feet long. That's 1,142,466.5 miles, or 1,838,621.6km long. If you opened this portal pointing in the right direction, you will have hit the moon after a third of a second.

But then it gets worse.

Every litre of sun you've poured out in this one, monumental lapse in judgement weighs 150kg (330lb). Imagine a 2-litre bottle which weighs as much as a large motorbike. Yeah, you've got billions of them. Assuming that the portal is pointing upwards (to try and vent into space), and that the portal is magically anchored to the planet, then you've just accelerated a mass of 627,415,268,343kg away from earth an average distance of 3,016,111,562 feet. The recoil of this (every action has an equal and opposite reaction) is 576789634843671000000N of force, which is like suddenly dropping 58,796,089,000,000,000,000kg onto the planet, which would probably crack it in half.

But then it gets worse.

Those astute scientific folk out there will have noticed that I'm treating this like it's a solid. It is in fact a liquid, composed of hydrogen at a pressure 265,000,000,000 times greater than the atmosphere at sea level. It's going to expand. In fact, this much hydrogen will form a bubble at a pressure of 1 bar of 265,000,000,000 times larger than in it's compressed state. This makes a bubble which is 3.13x10^22 cubic feet, which is 1% of the volume of the earth, released in 1 second.

But then it gets worse.

Remember when I said that the temperature was 15,000,000°C? I do!

At this pressure and temperature, and suddenly released, it's going to all undergo nuclear fusion. At once. Fusing one kilogram of hydrogen into helium releases 630 trillion joules of energy, so fusing just half of what we've got will release 2x10^26 joules of energy. Hiroshima was 1.32x10^13 joules, so you've released 13,175,720,635,206 Hiroshima Bombs somewhere within 60ft. of yourself.

Now, in D&D terms, we can take bludgeoning damage as a baseline. Falling 10ft. deals 1d6, for an average 100kg person (assuming armour) that's about 3000 Joules of energy. So if we divide this by the energy you're releasing, we get an approximation of 6,500,000,000,000,000,000,000d6 damage, for an average of 250,000,000,000,000,000,000,000 damage, or half as much on a successful save.

Dex saves, please?

Now the issue here is that I've said that the plasma is ejected at 1.1 million miles per second, and the speed of light in a vacuum is 186,282 miles per second, so I am curious if someone who knows more about relativity (and presumably fission/fusion) can elaborate further!

So, what else did I need to take into account for this to be as "realistic" as possible (with the inevitable result of the end of the world, obviously)?

 

[DaveC426913]

This is cool.

<digression>
I have had a sci-fi story bumping around in my head for many years with almost this exact plot device.

The plucky mercs come across a portal being secretly tested by the big mean Empire.
While the Empire fleet is on coffee break, they steal the two halves of the portal. When the Empire fleet gives chase, they try to throw them off by dropping one half of the portal into the core of a local star.

But the Empire fleet is not fooled and overtakes them, cutting off their escape. So they point the other portal half out the back of their ship and open up the portal juuuuuuuust a smidge.

Go go Gadget Getaway!

</digression>

 

[DaveC426913]

A couple of technical notes:

1. I'm not sure how you calculated the velocity of the plume of plasma. Where did "1.1 million miles per second" come from? It can't be, of course, since as you note, that way exceeds c. You would use the formula for addition of relativistic velocities. But I think the first thing to resolve is how you derived the speed in the first place.
2. Not sure why it would undergo fusion upon release of pressure. The drop in pressure should stop any fusion that was occurring in the core of the sun.

 

[Algr]

you've just accelerated a mass of 627,415,268,343kg away from earth an average distance of 3,016,111,562 feet. The recoil of this

There is a well known issue with portholes that it isn't clear how recoil works. Does it apply to the porthole on the planet, or the one in the sun?
...Of course, either way, no one is going to survive to talk about it.

If you want the event to be survivable, you could say that magic portholes have a limit to how much mass or energy can go through before they collapse. You'd still get one hell of a blast, but it would only last a microsecond. Or maybe you would get a plasma laser with a hair-thin beam.

 

[Office_Shredder]

The correct answer is that a deity may prevent a gate from opening inside their domain, and Pelor would never stand for this.

 

[snorkack]

I see that the gate spell has minimum radius of 5 feet. That´s dangerous when connecting with something as high pressure as Sun.
How about creating a smaller portal? You are effectively creating a high pressure flamethrower.
I found that a Japanese WWII flamethrower had a nozzle diametre of 6 mm. Which is about 28 square mm area.
One physical insight: If you feed a nozzle from a tank then at optimum, the fountain will rise as high as the surface of the tank. If you are using dimensional portals to avoid global energy conservation, you can still use the local energy conservation, just keep track of how you are tampering with it.
The potential energy of pressurized fluid at the centre of a sphere of uniform density is one half smaller than the potential energy on surface.
If you drilled a shaft from surface of Earth to centre and put a nozzle at the bottom (centre), molten iron should spray up with just the speed to reach ground. If you put the nozzle by portal on Earth surface or outer space, the speed at nozzle should be the same.
Put a 28 square mm nozzle in Earth centre, and my estimate is that there would be 10 kg/l molten iron spraying out at 10 km/s. That makes 280 l/s, which is 2800 kg/s. Since 10 km/s means about 50 MJ/kg, this means 140 GW heat as the jet is slowed down. Trying the same approach with Sun, I would get 150 kg/l and 600 km/s, making 17000 l/s, being 2500 t/s... and if your nozzle is 1500 mm rather than 6 mm, the power will increase with the nozzle area.

 

[hmmm27]

I'm trying to figure out how y'all get "laser" out of this. It isn't a stream of incompressible water. May want an adamantium or magical bell : particles are diverging from horizontal right at the portal.

 

[Rive]

I'm trying to figure out how y'all get "laser" out of this.

I guess it would require some length/depth for the portal to make a jet out of anything coming through
Given the distance bridged it's easy to suppose to have some length, but honestly, it's up to imagination.

 

[DaveC426913]

I guess it would require some length/depth for the portal to make a jet out of anything coming through
Given the distance bridged it's easy to suppose to have some length, but honestly, it's up to imagination.

I am pretty sure it would expand spherically the moment it cleared the portal.
Unlike a liquid, plasma is compressible.
The lateral pressure is going to cause expansion in all directions, not just forward.
So, boring as it may be, it will be indistinguishable from a nuclear bomb or asteroid strike.

 

[Rive]

The lateral pressure is going to cause expansion in all directions, not just forward.

Just think about rockets and gas leaks
You get a jet.

 

[DaveC426913]

Just think about rockets and gas leaks
You get a jet.

I don't know if it's analogous. Rockets have bells to direct the (otherwise spherical) expansion.

 

[Rive]

Rockets have bells

That's the length there I've mentioned in #8
And regarding gas leaks, you have the wall thickness
Length makes jets

 

[Vanadium 50]

what would happen if we used the gate spell to open a portal to the middle of the sun?"

Cant be done. It takes 8 minutes for the spell to reach the sun and another 8 minutes for the portal to establish on earth. So your magic user needs to concentrate, cdhant and gesture without error for 16 minutes lest he be cast into the Pit of Outer Darkness.

 

[some bloke]

Thanks all for the replies!

Annoyingly, this was a while ago so I cannot offhand remember the way I worked out the speed. I think I worked out the speed in m/s based on diameter and differential pressure, and then worked around 1 second. For obvious reasons, most "flow through a pipe" calculations don't account for relativity!

I had anticipated this going off like a nuclear bomb (several thousand of them, actually!).

So the portal opens, and the moment the matter flows through it expands in all directions, creating a hypersonic fireball of plasma which would probably do loads of damage to the world - how much? Does it disintegrate a section of the earth, throwing off its orbit? Does it displace or ignite the atmosphere? I'm really curious as to how bad bad is - when detonating something this powerful, what implications would it have for the opposite side of the world?

 

[DaveC426913]

So the portal opens, and the moment the matter flows through it expands in all directions, creating a hypersonic fireball of plasma which would probably do loads of damage to the world - how much? Does it disintegrate a section of the earth, throwing off its orbit? Does it displace or ignite the atmosphere? I'm really curious as to how bad bad is - when detonating something this powerful, what implications would it have for the opposite side of the world?

That comes back to whether a portal has recoil. I don't see why it would.

At least, not directly. The plasma fireball would vaporize anything it comes in contact with, including oceans and landmasses - and that secondary explosion would have recoil.