What techniques can be used to mitigate obstruction impact during time-travel?

Question

In the future, when an object emerges in a different time, that moment is referred to as a crowning. An impacted crowning is when said object materializes within another object, fusing with it. An aerial crowning occurs when it is a certain level above solid ground. I suppose we can also have aquatic crownings, for that matter...

This brings up a number of questions:

1. Would materials simply fuse together, or would the forced merging of two materials set of some type of atomic explosion?

2. Air itself is matter - Then why does the "fusing" effect not take place with a solid material and air?

3. In order to mitigate the fusing phenomenon, all crowning events, by their nature, are preceded by what is known as "displacement." Meaning, that all existing matter is either vaporized, or simply "ceases to be" and is replaced by the emerging object. This either occurs by design (i.e. a pre-singularity is created in order to clear/swallow-up a certain area, so that it can be "made ready" for the object to have a clean entry, or it simply occurs via the laws of nature. Please explain the workings of either approach.

4. As the problem of undesirable terrain/conditions is inevitable when doing any type of time traveling, does it not become a necessity to send a probe to do a quick check regarding conditions prior to sending the actual payload? What are some considerations of the "scouting" aspect of time-travel? i.e. you don't want to travel in time, only to discover that you end up in a pool of lava, or if you follow the John Titor model, you don't want to end up on an Earth which has so far deviated from the Earth that you know, and the atmosphere on it is completely different to the one you're used to.

Answer 1

Save Points

The idea came from a4android's comment:

You create specific points in time and space which we prepare for time travel : perfect vacuum, and we save the exact coordinates (both in time and space) so that travellers can go there.

Time travel would then only be travel to these spots.

You would then have to manage the usage of such spots, several time travelers can't use them at the same time. I would imagine some kind of infrastructure that continuously welcomes time travelers, being able to take care of a certain amount of travels.

This is extremely restrictive but solves a lot of problems.

Answer 2

Pure information scouting

Concerning point 4: the "scouting" aspect of time-travel.

You couldn't send any physical kind of probe back in time to "scout" the destination because it would encounter the exact same problems you would have if you went there yourself (possibly fusion or explosion or displacement, whatever you choose).

To check the terrain before jumping in time, you would need a way to send and receive pure information. In Alex Scarrow's "Time Riders", they use Tachyons to communicate through time: a hypothetical particle that always moves faster than light.

I'm guessing this is the kind of thing you're looking for, some kind of sonar through time. The problem with this idea is that I have no idea how you get the information back. You send your signal to scan a certain time, but I don't see how you could get them to suddenly map out a physical instance and then come back to the time from which they left.

This also disregards the fact that you need to send a physical being afterwards. I'd argue that you'd try to "land/arrive" back in time but in space (where there is as little matter as possible) with a space ship to come back to earth. The scouting would be to check that you are going to space.

Answer 3

Ret-con

Clearly, if you can time travel, then you can "un-time-travel," in the event of an impacted or aerial crowning.

If an event goes awry, you build in safe-guards to retroactively move the event to a better location.

Over time, software learns how to better self-correct for this, with AIs that make these corrections fast enough that even outside observers wouldn't be aware of the events.

Probe

Another technique would be to send a tiny probe through first. If a drone-like object or a camera lens on a movable "stick" goes throw and scans the area ahead of your crown event, then it can determine with high precision whether anything in the subject area would represent a negative outcome. Then the transition can be moved to a safer location before larger objects (people) go through.

Answer 4

Swapperoo

The solution is for the matter which travels forward in time to switch places with an equal volume of matter that travels backwards in time. This also sidesteps the problem of leaving a vacuum at the site where I was when I leave my time.

It would make it easier to probe the destination time: send a block of ice and see what you get in return. A block of lava? A block of brontosaurus meat? A block of clove-scented island air?

Traveling with a bubble of air around me will also give me a chance to remedy some errors - I might materialize in a very dark, very small cave, with a small bubble shaped oval of stone appearing at my origin time. I can go back, or make another jump to a time when that boulder is not there, walk a few paces, and try again.

Answer 5

This answer could easily be 100 pages long explaining everything, but I will just name some points you should consider. I will pretend that nuclei have an actual position in space because I think it is a good approximation in this context. I will also only discuss the first two points because I think they are plenty already. How people do time travel in your world is in my opinion whatever you believe is best.

Assume you teleport one solid onto another:

1. Nuclei are very small compared to atoms. Very few nuclei will be teleported directly onto each other. Your main concern isn't some nuclear fusion / "atomic explosion" type of stuff.

2. The actual problem is a chemical one. Usually, a material is in what one would call an equilibrium structure. Now you introduce a lot of new nuclei in different positions, resulting in something that no longer is at equilibrium. Let's not worry about conservation of energy/momentum because time travel and a magical machine that does stuff and focus instead on what happens next. Your "former material" desires to be in equilibrium, therefor a violent chemical reaction occurs - I do not even know what to compare this to. The material will almost certainly violently expand (because too many particles occupy too little space currently), it will radiate a lot (because we are dealing with a vibrationally excited state here) and all kinds of weird stuff. I'm even afraid to call anything specific, I suspect some beta radiation ( emitted electrons) for example - this is highly exotic. One definition of temperature involves the amount of molecules in a certain excited state. Since every "molecule" would be in an excited state, you would have (minus(?)) infinite Kelvin for a short while. Of course not an actual infinity because temperature doesn't make sense at one point anymore, but there you go. Does that make sense to you? It doesn't to me. I might be wrong about specifics here, but I think it is clear that nothing would survive this "crowning" time jump. Please be aware that the ultimate result of course would depend on what exactly is crowned.

If you now teleport on something less dense, the same will happen but to a lesser degree of course.

Also, just to be clear, if you were to teleport nuclei onto each other, all would be much, much worse. My above scenario wouldn't destroy earth or anything, just your time machine and lab.

Answer 6

You're kind of trying to solve a problem that you're introducing yourself here. The type of thing that I would imagine that you could find in any Sci-Fi technology (and Magic to a lesser extent).

The point is, take any technology which exists in Sci-Fi - teleporters, faster than light space ships, light-sabres, universal translators, replicators, androids, and if you analyse it close enough, you can find lots wrong with the concept, lots of points similar to the one you just made, and the only "real" answer is, "Yeah but that's why they don't exist in real life".

And the in-universe version of that answer : The inventors have encountered that problem and found a way around it. (So don't worry about it)

Now, I know that doesn't answer your question, so what I can offer is as follows: If you're considering a problem at that low a level you must also describe the process at that low a level.

You have a time machine that teleports the subject through time á la Back To The Future. How is the data sent back in time? As in what are the mechanics/details of the transport? Is it through a worm-hole type thing or a sort of hyperspace/4th dimension concept? Is there a transmitter/receiver & data transfer? Do they travel back as a tachyon wave and somehow rematerialise at the right point in time? Once you fleshed that out, what happens during re-entry, or "crowning", will be a lot clearer.