Knowledge Bank

The velocity of light has been measured by precision measurement of $B\prime \prime \mathrm{<mrow\; data-mjx-texclass="ORD">000</mrow>}$ obtained from the 004 and 103 bands of the rotation vibration system of HCN. The ratio of $B\prime \prime \mathrm{<mrow\; data-mjx-texclass="ORD">000</mrow>}$ microwave to $B\prime \prime \mathrm{<mrow\; data-mjx-texclass="ORD">000</mrow>}$ infrared is identically equal to the velocity of light. A description of the experiments and statistical methods of treating the data will be given. The result obtained by this method is $299,776\pm 7$ km/sec.