system
Given the following post, respond as if you're commenting on Reddit:
human
[DC] what stops Superman and The Flash from having the atoms in their body convert into energy why they go at translight speeds.

From what I understand one of the obstacles with Faster Than Light travel is that the atoms in the object will have so much energy they will collide and fuse with other atoms causing a huge explosion. Basically accelerating an object to light speed just turns it into a nuclear bomb.
gpt
The Flash has the speedforce, which protects him from the deleterious effects of speed *if* he wants it to.

Superman has a powerful tactile-telekinetic field, which encircles things he touches and helps him lift them. It's why things don't crumble when he lifts them, and why he can fly. This same field, I'd reckon, holds his atoms together and apart, and grants them resistance to these effects.