Polymerase chain reaction (PCR) is a laboratory technique used to amplify DNA sequences. The method involves using short DNA sequences called primers to select the portion of the genome to be amplified.olymerase chain reaction (PCR) is a laboratory technique used to amplify DNA sequences. The method involves using short DNA sequences called primers to select the portion of the genome to be amplified.
The smallest possible size for anything in the universe is the Planck Length, which is 1.6 x10-35 m across.
The nearest star is some 4.2 light years away, and that distance was known to within an accuracy of better than 0.1 light year. For a star measured as 20 light years away, the distance estimate is accurate to within a light year or so. For stars 50 light years away, the margin of error is perhaps 5 to 10 light years. Beyond 100 light years, the parallax is so tiny it cannot be measured accurately, and astronomers resort to more indirect methods to find the distances to the stars.