What would happen if this FTL drive type concept were used in an atmosphere?

Question

So I was working on this concept for a sci-fi story and in this universe it uses a "warp" drive.

The Genesis Field is a supra-dimensional field that causes spacetime to be created or destroyed (explaining dark energy), based on the pole of the field. This field used in an interstellar drive works much like the "Warp" Drive but it would not be called a warp drive. Basically it destroys space in front of it and creates space in back of it. Matter is not destroyed though. Matter that is in the space that is destroyed moves probabilistically to the space that was in front of or behind the space that was destroyed. If the matter is in the space being "grown" the matter moves in much the same way.

Here's my question. In space, the density of matter is low enough to not cause a problem because any matter that gets into the field would not be enough to collect (at least I don't think so) and cause a problem either exiting the field at a rate equal or greater than the amount of matter that would enter. However, in an atmosphere this field would have all that air in it already and entering it from when it's traveling...

What you have then is the field is moving forward at or above light speed with all the matter that was in it coming with it, creating an empty space where it was while simultaneously you have some of the air from where it moved to is moved to inside the field, assuming it's half in/half and half the volume of the field is filled with the ship, then the density of the air doubles... while, again, simultaneously half the air from that volume it just pushed into is being moved forward possibly with a seeming velocity of c and this is all done at the speed of light. And then this is done continuously for whatever length of time the ship is in atmosphere or using this drive.

What would the effect of this happening be? Since the air displaced by the field is not getting energy from this "move" I'm of the thought that any air that gets brought into the field would get just sorta start gathering in the front of the field.

So to clarify, there are sorta 3 parts...

1. What is happening to the empty space left behind? Would air be rushing in? Would something like that be dangerous to Earth?

2. What would the effect of the air density in the front of the field increasing so fast be?

3. Similarly what would the effect of all that increase density air being pushed forward, but not having "energy" imparted into it be?

When I first realize the consequences of this idea in an atmosphere my guess is that it would possibly cause the air to ignite, but I have no idea.

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Edit: There seems to be misunderstand from the 2 answer received. When the Space in front of the field is destroyed, the matter isn't so there needs to be someplace that it goes. This being the case it moves in any direction from where space was to where it is, to the closest it can reach. The result is not that half the matter moves to the other side of the ship's field, but rather goes inside the field, to the bubble volume that the ship is in.

Answer 1

It actually works out much better than you would think.

Let's work through what happens little bit by little bit by looking with our infinity-frames-per-second camera (it's made from unobtanium and the film is handwavium, shush). We're going to cheat with the units a bit though - we're working with a small prototype, so it's only got a surface area of one square foot. Also, the normal density of air has been tautologically redefined to be measured in units of normal density of air (one per cubit foot) (by density, here I mean the number of of particles per volume, not the standard definition).

We start at time zero. The ship is there, the field is there, the air density is the same (one per cubit foot) at all places around the field. No space has been created or destroyed. All is normal. Time to skip ahead by a fraction of a nanosecond.

Time one. The ship and field have moved forward by one foot. A cubic foot of space has been destroyed and recreated at the back. Statistically speaking, half of the air in the destroyed cubic foot stays in front of the ship (therefore the air in front of the ship has density 1.5) and half is moved to the created cubic foot (which then has density 0.5).

Time two. The ship and field move forward by one foot. A cubit foot of air is destroyed and recreated at the back. You get the idea. Again, half the air moves forward and half moves to the back. The back cubic foot has density 0.75, and the front cubic foot has density 1.75.

Time three. Same deal. The back cubic foot has density 0.8.75, and the front cubic foot has density 1.875.

Skip ahead, time eight. The back cubic foot has density 0.996, the front has density 1.996.

At time ten we're at 0.999 and 1.999 respectively, and I'm just going to stop there.

See, what you have here is the magic of limits. Since your Genesis Field basically works by continuously halving whatever matter is in front of you, you're never going to get a major buildup that gets out of control. The amount in front never reaches above double the standard air density -- which makes sense, if you think about it. You're halving whatever you have in front and adding one, so as long as the amount you're adding is less than one, you're never going to reach two.

So then in the back, you're going to have 0.5, 0.75, 0.875, .... 0.999, 0.9999,...... Almost, but not quite, reaching standard density. The less dense air at the back would be (relatively) slowly filled in by the surrounding pressure.

So all in all you'd be fine using this in an atmosphere. Yes, you're doubling the number of molecules in the air in the space in front of the field, which would double the pressure, but that's still less pressure than is in a bicycle tire (scroll down to the 100 kPa range).

TLDR, bicycle tires exist, therefore your warp drive won't blow up the atmosphere.

Answer 2

This is a bit tricky to through because some of the concepts are slippery to deal with.

Firstly, spacecraft in your story use a Genesis Field (GF) drive to 'move' at lightspeed and above. Space is destroyed in front and new space is created behind the vehicle. Somewhat like an Alcubierre metric drive, but instead of contracting space in front and expanding it behind GF ships create and destroy space (presumably in accordance with a conservation law applied to the nature of space). Secondly, matter caught in the forward lobe of the GF isn't destroyed along with the space it reappears half and half in both the forward and rear GF lobes respectively.

Note: a GF ship have any momentum or velocity with respect to its 'motion' due to the GF travel. It will retain whatever state of motion, momentum and velocity it possessed when the GF drive was activated. GF travel is more a matter of space rearranging itself, so a GF drive vessel is undergoing a continuous process of repositioning itself with respect to the rest of the universe.

Let's just do a little thought experiment. A GF ship is cruising through the solar system at twice lightspeed. Its course will take through the upper atmosphere of planet Earth. We will assume its passage through Earth's atmosphere is a chord three thousand kilometres long. At twice the speed of light the GF drive vessel will only take one-two-hundredth of a second to traverse its course through the Earth's atmosphere.

Half the matter in the air along that traverse will pile up in the front GF lobe of the ship. While the other half of the air will be distributed along the traverse through the atmosphere. This means a high pressure will form on the frontal area of the GF vessel in one-two-hundredth of a second, this will be more like a burst of pressure but this will dissipate into the vacuum of space. Depending on the pressure involved this might be like an explosion and there could be damage to the frontal area of the GF ship. Air pressure and density along the path of the GF vessel through the atmosphere will be halved. Also, half the mass of air along that traverse will be carried off into the space.

This is unprofessional conduct by the captain of the GF vessel. He or she should expect a severe reprimand and have to face a disciplinary tribunal. No self-respecting planet wants to have space vessels removing chunks of its atmosphere. The atmosphere won't blow up, but illegal depletion of planetary atmospheres should not be encouraged.

Most of the effects will depend the rapidity of the 'motion' or the pseudovelocity of the GF ship. It will be subject to the planet's gravity, so it won't want to linger. Mostly you expect possible damage to the ship from the sudden pressure increase and loss of atmosphere. Plus the repercussions from the owners for damaging their property (including costs of repairs) and planetary authorities who object to the loss of atmosphere.

Answer 3

You now have an explanation why spaceships do not enter planets atmosphere using their FTL.

Going off of John Robinson's wonderful answer the air pressure in front of your ship will approach (but not reach, unless the ship travels an infinite distance inside of a 1 Pressure atmosphere) 2 atmospheres of pressure. Which is problematic for cities, will shatter glass, etc.. This will create a shock which will be capable of destroying even extremely heavily reinforced concrete structures, produce a wind speed of close to 502 mph According to the CDC, and have fatalities approach 100% (the human body is surprisingly tough, the majority of deaths will not be due to overpressure, but due to collapsing buildings, and hurled debris). This is if the ship survives long enough traveling down the atmosphere to effect a city. Which depends on the effective speed of travel thru realspace, as if it is fast enough, it is possible that a ship could punch thru the middle of a star before the matter that is captured by the ship propagates thru the bubble of space sorounding the ship.

The space time bubble surrounding the ship (assuming the ship moves fast enough that the amount of air escaping from the bubble is negligible) will slowly increase until the ship is crushed by the pressure. As every ship length the vessel travels thru atmosphere the space bubble adds .5 atmospheres worth of air near the front of the ship.

Looking at this further, it might mean that ships are required to perform microleaps while traveling to prevent a dangerous buildup of a pressure front inside of the ships travel bubble.