A dimensional cut

[Shinova]

If you, a 3-dimensional entity, get cut by a 2-d plane of infinite energy that is infinitely thin, do you get hurt?

[BloodAngel]

Depends on the cut...

If it's a flesh wound, then it'll probably hurt as much as a papercut.
If it happens to lob your arm off, I think you'll feel pain.

[Surlethe]

What is a "2-d plane of infinite energy"?

[Sriad]

What is a "2-d plane of infinite energy"?

I am also curious.

[Shinova]

It's like getting hit with a buzzsaw of infinite energy that is infinitely thin. Or a flat plane with infinite destructive energy that is also infinitely thin.

[Surlethe]

It's like getting hit with a buzzsaw of infinite energy that is infinitely thin. Or a flat plane with infinite destructive energy that is also infinitely thin.

Right, but what is "infinite energy"? How is it kept infinitely thin? Does it interact with three-dimensional objects?

My first instinct is to say that of course it would hurt as you fell apart and blood started spurting, but it's possible that, if it doesn't interact, you could just walk right through it.

[Sea Skimmer]

If you, a 3-dimensional entity, get cut by a 2-d plane of infinite energy that is infinitely thin, do you get hurt?

A 2-D plane would not be infinitely thin, that dimension would simply not exist, no value can be assigned to it.

[Shinova]

Right, but what is "infinite energy"? How is it kept infinitely thin? Does it interact with three-dimensional objects?

My first instinct is to say that of course it would hurt as you fell apart and blood started spurting, but it's possible that, if it doesn't interact, you could just walk right through it.

Well, the way I'm thinking it is that if it were a 3-dimensional volume of infinite energy, everything inside it would be subjected to infinite amount of energy, so all matter inside it would be destroyed, whether through thermal or kinetic or whatever energy, whether it gets vaporized, or just gets pelted with so much energy the molecules simply fall apart and disintegrate into subatomic quarks or something.

And it is infinitely thin in the way that in mathematical geometry, a point is a point in space that is infinitely small but you can measure and do calculations with it, or a geometrical line that is infinitely thin but you can draw it and make calculations with it. Basically a plane of energy that is infinitely thin, the thickness (or the lack of) of which cannot be measured by any conceivable physical or theoretical measuring instrument, but can be theoretically or conceivably shown or accepted to exist.

As for whether it interacts with 3-dimensional objects, that's my question. It's a solid 2-d plane of infinite energy so the first thought would be that it can cut or burn up solid 3-d objects, but in another sense it's infinitely thin so there's the question of whether it could even interact with 3-dimensional physical matter, and to interpret what Sea Skimmer might be trying to say, that because there is no 3-rd dimension to this plane of energy, this plane of energy cannot "move" "up" or "down" across, up, or through a 3-dimensional object since the concept of "up" or "down" does not exist to this 2-dimensional plane, only "sideways" and "forwards and backwards".

[Gil Hamilton]

I'm willing to bet that chances are if the plane was truly zeroth of a meter in thickness, you'd be able to walk right through it without noticing, because the odds of any atom in your body being intersected by it are extremely low.

[Surlethe]

The thing is, if it's really infinitely thin, it's still going to be thin relative to the atoms in your body and their constituent subatomic particles. If the subatomic particles are actually point particles, they might interact with the slice, but I don't know how it would do work on them. If they're not point particles, then I really have no idea what would happen, because you can't split them up further than they already are, and I have no idea how to approach quantum mechanics to describe this further.

[Guardsman Bass]

Since most of your body is, in fact, empty space (the space inside the electron shells of atoms), an infinitely thin 2-dimensional plane might pass right through your arm without even interacting with it, although it might depend on what exactly the plane is made of.

[rhoenix]

My physics isn't as well-versed as I'm sure others here are, and please correct any misunderstandings I may have, but couldn't you accomplish this with what is essentially a focused beam or plane of pure gravity, approximately 40-50G's, or more?

If one were to be hit by this, it would be basically a glorified sword stroke, but it would likely pull all matter within the directional arc along with the direction the beam was "swung."

[Shinova]

What I'm trying to work out is that what you depict would be a plane, but it would still be a plane in 3D because that plane could conceivably be moved up or down, but what would happen if a truly 2-D plane of energy hit you, is what I'm wondering.

[Surlethe]

My physics isn't as well-versed as I'm sure others here are, and please correct any misunderstandings I may have, but couldn't you accomplish this with what is essentially a focused beam or plane of pure gravity, approximately 40-50G's, or more?

If one were to be hit by this, it would be basically a glorified sword stroke, but it would likely pull all matter within the directional arc along with the direction the beam was "swung."

How would you get a focused beam or plane of pure gravity? Gravity's a field governed by a = α/|r|³ r; there's no way I can think of to create a plane or beam of pure gravity (by which I assume you mean a plane or beam of gravitational acceleration). Besides, wouldn't you want to use the electromagnetic force anyway, if you could make a focused field? It's dozens of orders of magnitude stronger.

[rhoenix]

How would you get a focused beam or plane of pure gravity? Gravity's a field governed by a = α/|r|³ r; there's no way I can think of to create a plane or beam of pure gravity (by which I assume you mean a plane or beam of gravitational acceleration).

That was my original idea, yes. I was sure of any details in how this might be accomplished - this is basic conjecture.

Besides, wouldn't you want to use the electromagnetic force anyway, if you could make a focused field? It's dozens of orders of magnitude stronger.

Aha, perfect! Thank you for that idea actually - that "gravatic arc" concept was something I was toying with using in a story, but your suggestion actually fits things far better.

And, it helped clarify my meaning much better. Thank you.

[rhoenix]

Pseudo-edit: "I was sure" should be "I was UNsure."

Yeah, I should preview more often.

[Winston Blake]

If we consider that this '2D plane' has to either be made of point particles or itself be one big 'plane particle', then you have to wonder how it's interacting with normal matter. If it has no fundamental force fields associated with it, then for all purposes it doesn't exist. If it has, say, electric charge, then it could fuck up the chemical bonds making up your body.

An ideal knife would be a plane one atom thick, with the force field interactions of the leading atoms doing the cutting. If you extend this idea to a rigid plane shape in which a certain density of electrons (i.e. point particles) are fixed, then you're essentially cutting a person's flesh with a knife of finite sharpness. The interactions involved in 'cutting' matter happen over some distance, so it wouldn't be infinitely sharp. If it was, then it wouldn't exist (see above).

Of course, it might interact with matter so weakly that there's practically no perturbation at all as it passes through. E.g. a low-density plane of neutrinos.

[Winston Blake]

My physics isn't as well-versed as I'm sure others here are, and please correct any misunderstandings I may have, but couldn't you accomplish this with what is essentially a focused beam or plane of pure gravity, approximately 40-50G's, or more?

If one were to be hit by this, it would be basically a glorified sword stroke, but it would likely pull all matter within the directional arc along with the direction the beam was "swung."

"A focused beam or plane of pure gravity, approximately 40-50G's, or more" doesn't really make sense in real physics. It sounds great, it'd be fine as a line in a story, but just saying 'focused pure gravity' isn't really saying much at all. Adding a range of figures to an undefined idea doesn't make it any more understandable.

I think what you mean would be a weapon that 'shoots' a thin planar region where any matter inside that region feels a great force away from the central plane. AFAIK this sort of complex arrangement could only be a fictional forcefield that's like gravity (in that it acts equally on uncharged matter). It wouldn't be anything like real gravity.

[rhoenix]

"A focused beam or plane of pure gravity, approximately 40-50G's, or more" doesn't really make sense in real physics. It sounds great, it'd be fine as a line in a story, but just saying 'focused pure gravity' isn't really saying much at all. Adding a range of figures to an undefined idea doesn't make it any more understandable.

Granted - as you probably guessed by the disclaimer I gave, I wasn't sure of how to present the idea. The main reason I posted a half-formed and ill-described idea was to see if that was possible, and if so, by what mechanism.

I think what you mean would be a weapon that 'shoots' a thin planar region where any matter inside that region feels a great force away from the central plane. AFAIK this sort of complex arrangement could only be a fictional forcefield that's like gravity (in that it acts equally on uncharged matter). It wouldn't be anything like real gravity.

Ah, thank you - that is a far more apt and accurate description than "gravity." Would you mind going into more specifics about how this fictional forcefield would be gravity-like, thus accomplishing the above stated? Or provide a link that you know of?

[Dooey Jo]

What I'm trying to work out is that what you depict would be a plane, but it would still be a plane in 3D because that plane could conceivably be moved up or down, but what would happen if a truly 2-D plane of energy hit you, is what I'm wondering.

Planes and such thing are mathematical models which work very well for macroscopic objects, but things aren't quite as simple on the atomic levels. It's impossible to tell really. All quantum mechanical interactions are between particles, but such a "plane of energy" would presumably not be made of particles. In fact, if it was, it would not be truly 2D, because of the uncertainty principle.

If you were to use this in a story you could probably say that it is a "planar field" or something that prevents charged particles from passing through, and that would work like an ideal knife of infinite sharpness. However, such a thing wouldn't make sense, physically.

Although, I think certain string theories describe "branes" which can have two dimensions (or zero or anything up to twenty-something). But they are probably very different from some kind of macroscopic "plane of energy"...

[Darth Wong]

This is a retarded question; pure energy exists in 3D space, not in 2D planes.

[Shinova]

If you were to use this in a story you could probably say that it is a "planar field" or something that prevents charged particles from passing through, and that would work like an ideal knife of infinite sharpness. However, such a thing wouldn't make sense, physically.

What I'm trying to see is the opposite. Whether, for example, a 3-dimensional blast of infinite energy (just thought experiment-wise) could do anything to a barrier or object that exists in 5 or more dimensions.

Or a 2-dimensional plane filled with infinite energy at infinite thinness could do any real damage to, say, a 3-dimensional person.

[Lord of the Abyss]

The closest semi-real world thing I know of to a "two-dimensional plane of infinite energy" is a theoretical spacetime defect called a "domain wall", a relative of the more famous cosmic strings ( neither of which have ever been seen, and neither of which has infinite mass ).

My guess is this; matter and energy are the same thing in different forms, so a plane of infinity energy would have infinite mass, and suck in the universe. If this was magically prevented from happening, the moment your arm breached the magic barrier it would be subject to infinite force, and the question would be if the magic infinite containment can stop the resulting infinite explosion.

Lesson : Infinity in the real world tends to lead to absurdities.

[Jawawithagun]

Does the plane disrupt interaction between both parts of your body? And for how long does it cut you?

[Junghalli]

Something of infinite thin-ness probably could not exist. AFAIK even singularities have dimensions. Likewise since IIRC energy exists as particles it's hard to see how you'd get an infinite density of them. So I'm pretty sure the phenomena you've described is totally impossible.

The closest thing I could think of that might occur or be technologically generated would be a wave of intense energy one particle thick, somehow held in place with some kind of forcefield. I'm not sure what that would do to you but seeing as it'll mostly pass through empty space it probably won't sever a limb. I think.