Welp, I completely broke KSP.
If for whatever reason, you can't watch the video, I was trying to see what the highest velocity possible was in KSP 1.1.3. I went about this using the Boost in Hyperedit. (I slowly put the boost factor higher.) Eventually, I reached this speed: 111,039,787,973,867 meters per second. Doing some math, that is 370,388.86 Times the speed of light. Then, I set the boost factor to some insanely high number, and immediately, my height bar went blank and my speed said NaNm. Immediately, I was confused. Then I realized that NaNm was likely a placeholder if the game could not possibly list your velocity. Meaning, theoretically, I had reached ∞ m/s. Also, this bit scientifically explains the blank screen and non-existent height bar,
Overall, very interesting.