Two silver crystals touching is dangerous: how and why?

[Crescent Pulsar S]

Sounds like every creation story I've ever heard.

Besides, one variable could be zero, the other infinity.

You divided zero and got the UN?

An even greater force emerged, yes?

[Moridin]

supposedly two objects cannot occupy the same space at the same time. both objects would simply explode, the detonation probably dependent on their total energy.
Two objects that share the exact same atoms in the exact same configuration touching or being in the same space would be even worse, though the one native to that time might survive or absorb the other one.

on the other hand if two of the same object, like say Usagi Tsukino's soul, were in two different places at the same time they would try to merge back together. this effect increases due to proximity. if usagi is close to neo-queen usagi while the scouts are not close to their future/past versions then it would take longer for the scouts to fade.
There are a couple of episodes in stargate sg-1 where this happens, i cannot recall the exact episodes however. in season 1 Daniel Jackson finds the quantum mirror that takes him to another reality where he is already dead and so suffers no effect. a later episode a doctor samantha carter appears from the mirror and starts experiencing an effect where she is being drawn into the main reality's colonel carter. being the same person with the same soul (although having made different decisions) the native carter would absorb the non native one. that said they seemed to have forgotten this in a much later episode where they have about 20-30 SG-1 teams coming through a dimensional breach in a black hole.

why the silver crystal dosnt suffer this effect like usagi dose i have no clue. but as you asked they them touching is bad the first paragraph should help. it's also impossible to say if it would happen that way as not only can we not make two objects occupy the same space (as far as i know anyway) it would be rather stupid to test.

[Cheb]

if two of the same object, like say Usagi Tsukino's soul

It's more likely that soul is transcendental, so it exists in the entirety of space and time. Or that spatial and temporal coordinates have no physical meaning for it.
I rather liked the implications depicted in the Steins Gate anime That even if you erase all physical traces of some event by the means of time travel, all souls involved will still remember.

Back to the topic: the ASC (Almighty Silver Crystal) is areality warper device. Let's assume that it warps reality constantly in a static field. Then bringing it close to itself, this field could become distorted forming some really bad reality warping sideeffects. Imagine two immensely powerful magnets brought together.

Maybe the resulting forces are strong enough to break the crystal, resulting in a galaxy-shattering kaboom.

Or doubling the field pushes it over some threshold, resulting in a reality-warping singularity that initiates vacuum decay.

[Moridin]

given that the soul thing is all metaphysical nonsense anyway using it as a example was a bad idea. I see the soul as an object that exists at one point in space and time, like a body dose. (baring the whole time line thing where everything in the past is still leading to the present). so having two of the same soul at the same time in two different places would cause problems.

I have not seen the steins gate anime but Balefire in the wheel of time books is a good analogue for what you describe. where i can destroy something before it was destroyed and cancels the actions that person took in that time, yet everyone that was there remembers what had happened. at least that's the simple way of describing balefire without giving a whole lot of back ground info.

The silver crystal is a reality warping device? makes sense but magic in of itself warps reality. the crystal either has a lot of power or helps focus a lot of power into a pure state. after all Usagi beat Beryl by focusing her power through the crystal and enforcing her will on the power/magic/whatever she was using. The sword, mirror,glaive,key and orb probably also focus magic so when the outer's got them they became more powerful (least in the anime).

given the probable simalaritys between Usagi and chibi-usa's magic the two crystals probably got so close that they tried to focus and channel two different sources of will and magic at the same time, causing something bad to happen.