----------------------------------------------------------------- X-ray 0 rad ----------------------------------------------------------------- Gamma ray 0 rad ----------------------------------------------------------------- Acoustic 0 dyne/cm² ----------------------------------------------------------------- Table III.—_Extreme Physical Environmental Factors_ ---------------------------------------------------------------------- Physical Maximum Organism Activity factors ---------------------------------------------------------------------- Temperature 104° C (1000 _Desulfovibrio Grows and reduces atm) desulfuricans_ sulfate ---------------------------------------------------------------------- Magnetism 167 000 _Neurospora_ 1 hr—no effect, gauss _Arbacia_ _Arbacia_ _Drosophila_ development delayed ---------------------------------------------------------------------- Gravity 400 000 g _Ascaris_ eggs 1 hr—eggs hatch, 40 110 000 g _Escherichia coli_ days’ growth ---------------------------------------------------------------------- Pressure 1400 atm Marine organisms Growth ---------------------------------------------------------------------- Microwave 2450 Mc/sec _Drosophila_ 68 hr, growth not 0.3 to 1 affected W/cm² ---------------------------------------------------------------------- Visible 50 000 ft-c _Chlorella_, Seconds, 17 000 ft-c higher plants recurrently continuous ---------------------------------------------------------------------- Ultraviolet 10⁸ erg/cm², Bean embryos Suppressed growth 2537 Å ---------------------------------------------------------------------- X-ray 2×10⁶ rad Bacteria Growth ---------------------------------------------------------------------- Gamma ray 2.45×10⁶ rad _Microcoleus_ Continued growth _Phormidium_ _Synechococcus_ ---------------------------------------------------------------------- Acoustic 140 db or Man Threshold of pain 6500 dyne/cm² at 0.02 to 4.8 kcs/sec ---------------------------------------------------------------------- Table IV.—_Extreme Low and High Temperature Effects Permitting Life Processes_