Does speed of writing data on an optical disk affect the speed of reading data? Does speed of writing data on an optical disk ( like DVD ) affect the speed of reading data from that disk ? even a little?
 A: Only insofar that the maximum writing speed is limited by the need to unambiguously encode the disk's surface. If you tried to raise the speed of writing, the bit error rate increases: theoretically as a continuous, monotonic function of writing speed but practically a point is reached where the BER increases abruptly, so the BER as a function of speed tends to look like a step function. The writing data corresponds physically to changing the optical properties of the disk so this takes a nonzero time, and the more time one spends doing it, the more well formed the symbols are. As the BER increases, the error correction procedures, namely the computing of the nearest valid codeword to a corrupted one in coding space and, more importantly, repeat reads if error correction fails, use up more time, so the read gets markedly slower for a disk with a few errors, then fails altogether.
This phenomenon is very like the practical example where it gets harder and harder to read someone's hadnwriting as the writer gets more and more hurried and thus shapes their letters more and more ambiguously.
