This is a crock of shit. It's based on '[a]' having tech that doesn't even exist.

Alternate reality? That would mean that there are INFINITE numbers of realitys. For every single action there are an ENOURMOUSLY large amout of possible outcomes. In one reality you can move your arm 2 inches, in another, 1.999999999999999999999 inches. ETc Etc. At this moment the two realities break apart. They are no longer identical. To see into another reality and see the planet exploding is just one POSSIBLE outcome. Not THE outcome. You'd have to go see millions of others to make even a somewhat educated guess, and even then the odds are that you are wrong. All you could do is warn them that this COULD happen. But try explaining to them that you saw into another reality timeline.... they'll institutionalize you.