# How would stopped time look from the outside?

If there were a sphere or a cube where time is stopped, how would someone passing by perceive that? I have something in mind that stops everything, including air and light, not only solid matter.

My first thought was, if nothing comes out it must be pitch black. But that would lead to this region building up enormous amount of energy over time, absorbing all light. When the time starts moving again I think this would result in some kind of huge catastrophe eliminating everything inside the area (and probably outside too).

Not only when time stops there should be no change at all. So no energy build up. But also it would be inconvenient for the plot ;)

But if it can't be black, how should it look? Bonus points for how it would feel to touch it.

• Question is akin to "What happens if unstoppable force meets immovable object"? en.wikipedia.org/wiki/Irresistible_force_paradox As such it is unanswerable. Jun 19, 2016 at 12:11
• This question has no science based answer, because every law of physics we have is based on a continuous manifold of spacetime. If you create a discontinuity, all of our laws fall flat on their face. You have to make up what happens, or reduce the situation from perfectly stopping time to merely slowing it a great deal so that physics can have a say. There's are two discontinuities I know of in modern physics like this: one is the singularity inside a black hole (which is protected by an event horizon), and the other was the big bang itself. Jun 19, 2016 at 15:04
• Well that makes sense. I removed the tag. Jun 19, 2016 at 16:42
• Doesn't a black hole have the same effect? youtube.com/watch?v=vNaEBbFbvcY Jun 19, 2016 at 18:56
• Obligatory Atomic Rocket link
– Eth
Apr 18, 2019 at 15:52

If nothing, neither light nor matter, can interact with the region, I see three possibilities:

• total specular reflection

• The region acts as a perfect mirror at all wavelengths. It looks like a shiny silver sphere or cube.
• The surface feels warm to the touch, since you feel your own warmth reflected back at you
• The region feels perfectly smooth and rigid.
• Either it acts like an absolutely immobile object, anchored to some point in space; or you can move the whole region with enough force, but only as a block.
• If the region has sharp corners or edges, they will indeed be very sharp. Even the 90° angles of a cube could be dangerous.
• total diffuse reflection

• the region reflects light of all wavelengths, but the reflected direction is random. It looks like a white sphere or cube.
• the surface appears to be a perfect white. In the shadow it will appear darker; under a green light it will have a green tint, and so on.
• Interaction with matter will be similar to the specular reflection case
• invisible and intangible

• the region does not interact with light and matter at all, everything simply passes trough, or spacetime bends around it.
• not very interesting, for all intents and purposes the region has simply disappeared

Use in literature:

• Vernor Vinge uses regions of stopped time in his books "The Peace War" and "Marroned in Realtime", which I heartily recommend. Scientists invent a device which can create a "bobble", a spherical region in which time has stopped.

One interesting consequence he mentions is the buoyancy of such a bobble. A bobble that contains mostly air has almost the same density as air. If the region of stopped time is not anchored to anything, it may rise and sink in the atmosphere, as the surrounding air gets warmer or cooler.

• Larry Niven has a similar device in his "Known Space" series, the slaver stasis field. The region appears silver and smooth to the touch as well.

Some notes on the possible physical problems:

• A perfectly rigid object is not allowed in general relativity; it would allow faster-than-light communication: push one side, and the other side is immediately pushed by the same amount.
• an object anchored to some point in space is likewise problematic under relativity, since there is no absolute reference frame to decide where that point is. (This is not a problem if the region is not anchored to anything)

Some handwaving may be required to explain these contradictions.

• I like the version that behaves like a mirror. And thank you for pointing out that if the frozen time zone has not enough mass it would start to fly. Jun 19, 2016 at 16:47
• I like the mirror version as well. I wrote some fanfic (yet unpublished) for the universe created by Daniel Keys Moran, which includes a similar time bubble (from The Last Dancer). In my story, it's primarily a dark mirror (as if the mirroring element is black paint rather than silver). However the device creates an imperfect time stoppage, so there's some interaction with the outside world, which shows up as lightning bolting across the surface. YMMV, of course. Sep 22, 2016 at 22:52
• The invisible/intangible version solves the issue of being perfectly rigid, and probably the anchoring problem, although it's harder to deal with as being un-anchored who knows where it would reappear. Sep 25, 2019 at 16:40