Methane For The Restless

More data on \(n\) for Methane \(CH_4\) (from http://www.ddbst.com/en/EED/PCP/DEN_C1051.php),

Temp (K)	Density     (kg/m3)	v boom (m/s)	T boom (K)	n
383.15	425.0	146.00	39.372	9.73
384.81	404.0	138.79	35.577	10.82
398.15	402.3	138.21	35.278	11.29
428.15	347.8	119.48	26.367	16.24
452.50	280.1	96.23	17.101	26.46
453.15	276.4	94.95	16.653	27.21
455.86	265.0	91.04	15.307	29.78
457.88	254.1	87.29	14.074	32.53
461.52	226.8	77.91	11.212	41.16
462.65	212.2	72.90	9.815	47.14
463.59	190.0	65.27	7.869	58.91
463.77	177.1	60.84	6.837	67.84
463.79	172.6	59.30	6.494	71.42
463.81	164.2	56.41	5.877	78.92

And the graph of "exponential" increase in \(n\) with temperature is,

We are not getting anywhere, restlessly so.