Physicists use some basic terms when they look at motion. How fast an object moves, its speed or Velocity, can be influenced by forces. (Note: Even though the terms 'speed' and 'velocity' are often used at the same time, they actually have different meanings.) Acceleration is a twist on the idea of velocity.
Expungement is the legal process by which a court removes or erases all records of a criminal conviction, even if it is a felony conviction. Your conviction will not simply disappear on its own even if you wait 10 or 20 years - you have to take action (see how long does a felony stay on your record).
Getting a felony expunged is difficult, and each state has very specific rules about what can and cannot be expunged. So, How Long Does a Felony Stay On Your Record? Unfortunately a felony doesn't ever go away unless you go through a strict process to have it expunged. While many states have banned asking about felony convictions on applications, most employers will find past felonies by running a background check or asking candidates about their criminal past later on in the hiring process.