# How could I scientifically explain Entropy Reversal?

Ah entropy, whether you hate it or love it, it's here to stay (at least until someone responds to this question).

What I mean by Entropy Reversal: Let's say you drop a cup containing coffee, now. In normal circumstances you would just have to accept the fact that your cup is broken... HOWEVER, since you have an Entropy Reverser™ you can restore you "broken" cup to it's prior form.

My question: How can I scientifically explain Entropy Reversal (within a 2 foot circular radius of the device)

I am well aware that Entropy can be slowed down. But what about reversing it? (or bringing it to a halt? I'll go with either).

• Science has proven that this is not possible: physics.stackexchange.com/questions/41943/…
– Aify
Feb 2, 2017 at 22:23
• You might find this question interesting, along with the story it refers to in which things happen as you describe. Feb 2, 2017 at 22:57
• that's not entropy reversal, that is closer to time reversal.
– John
Feb 3, 2017 at 4:24
• @John. My almost exact thought when I read the question. I think it is time reversal masquerading as entropy reversal. Feb 3, 2017 at 5:01
• Feb 3, 2017 at 11:04

## If you're plugging it in to use it, you're not actually reversing entropy, just shuffling it around. "Entropy Reverser" is just a catchy marketing slogan.

Specifically, you're shuffling the entropy off to the nearest power plant.

We reassemble things all the time already, after all; the trick here isn't violating the laws of thermodynamics so much as figuring out what the matter in the vicinity of your device is supposed to become.

Your device, in particular, attempts to reconfigure the matter in question into some previous state it had. At a guess, you probably don't want to "reassemble" your computer's motherboard into sand, but something closer to the reverse. This means - assuming you don't want to get into time travel shenanigans - your device is effectively solving a jigsaw puzzle with a ridiculously large number of pieces, presumably with handwavium forcefield generators and an internet connection/supercomputer to handle fitting the myriad pieces back together and figuring out which pieces fit where, respectively.

Along the lines of Stephen's answer, life actually reverse entropy locally all the time. It's not too hard. The thing that is forbidden is to reverse entropy globally. If you apply enough power to a system, you can return it to any state you please. The hardest part, of course, would be deciding what state to return it to. Perhaps it can read minds and, rather than converting the object back to what it was, it converts it to what people thought it was, letting people supply the extra information.

As already pointed out, you can't reverse entropy so you certainly won't find a scientific explanation.

## Scan objects and remember their states, then recreate exact replicas from this data

Your machine, however, could work by continually scanning the area within a 2ft radius of itself and remembering the position and state of each object within this area. This would require a lot of precise scanners to determine all this information. Think of it like an auto back-up of your pc. Then you knock your mug over and, instead of cleaning it up. You activate your machine and get out of that 2ft area before it sucks up the offending material (the object in a different state) and creates an exact replica of what the object was like at the time you want it restored to.

It would be easier if particular objects could be put into a machine to be scanned. You buy a new laptop and instead of insuring it you just plonk it in your Entropy Reverser™ which scans it for you. Then if it breaks you just have to get it to make you a new one (by providing the bits of the old one perhaps).

This is, by no means, actually reversing entropy. You would need to put a lot of energy in to do this and provide the raw materials (by giving it the object which broke or buying additional materials).

This isn't a scientific explanation but not beyond belief. We already have 3D printers which, given a 3D scan, can print out most objects and we have the scanning technology. Still need a bit of a jump to recreate absolutely anything though, plastic is easy to manipulate but 3D printing a mug requires ceramics and once the clay has been fired it cannot be returned to clay so fresh clay is needed.

It depends how far in the future and how much hand-waving you want your world to be.

• That is, you resist and/or repair. That’s the concensus answer it seems, from his companion question of freezing entropy. This A would fit that Q just as well. Feb 3, 2017 at 10:09

This is time reversal pure and simple. Your device is basically a form of time machine that can cause time flow backwards. [1]

Broken coffee cups! No worries. Just bring your handy time reversal system to within two feet of the broken coffee cup. Activate it to reverse time to before the cup was broken. No more broken coffee cups. Every home should have one.

[1] Of the three types of time machines this one fits the class of "clock-in-a-box" time machines. Time machines which can control time to go backwards or forwards inside a defined volume of space. Imagine if there was a clock inside a box or any sized container. Manipulating time will make the clock seem to go backwards or forwards and at any rate the operator determines.