Final answer:
In the context of the Millikan oil drop experiment, if a scientist reports charges in different multiples or fractions, they are noting the quantization of charge. Millikan's original experiment determined the elementary charge to be -1.6 x 10^-19 C. In an alternate scenario with different measured values, the elementary charge can be deduced by identifying the greatest common divisor of the reported charges.
Step-by-step explanation:
When a scientist repeats the Millikan oil drop experiment and reports the charges in multiples of 2e, fractions of e, multiples of e, or fractions of 2e, they are referring to the quantization of electrical charge.
The smallest charge observed by Millikan was -1.6 × 10-19 C, known as the elementary charge, which is the charge of a single electron.
Thus, in the experiment done in an alternate universe where charges of 8 × 10-19 C, 12 × 10-19 C, and 20 × 10-19 C were observed, the elementary charge would be determined by finding the greatest common divisor of these measurements.
Observing the pattern, you can deduce that the elementary charge is 4 × 10-19 C, as each reported charge is an integer multiple of this value.