Question

8. What was the mechanism behind the nuclear test detection apparatus during the 1940s?

A. Seismic waves travel from the test site through the Earth to detectors.

B. The loud explosion sends noise through the atmosphere to microphones floating in the

sky

C. The brght flash of the explosion sets off cameras on satellites.

D. The nuclear explosion disperses radioactive isotopes into the atmosphere which are pickedup by sensors on planes nearby.

E. There was no such apparatus in the 1940s since the Partial Test Ban Treaty was not signed

until 1963

Answer 1

A. Seismic waves travel from the test site through the Earth to detectors.

The P- (primary or pressure) waves dominate the seismogram when nuclear test occurs. In the year of 1940, the Seismometer was well developed. Seismic waves travel from the test site through the Earth to detectors - this is a true statement.

B. The loud explosion sends noise through the atmosphere to microphones floating in the sky.

Loud explosion sends noise through sky - it is true. It is also true that in the year 1940, it is possible to hear the sound of the explosion via a microphone attached in a plane moving in the sky. But, this type of detection system is not able to detect nuclear explosion selectively as noise may come from other source too. Hence, this answer is not correct.

C. The bright flash of the explosion sets off cameras on satellites.

This is not possible as at that time there was no such satellite in Earth orbit. Hence, this answer is not correct.

D. The nuclear explosion disperses radioactive isotopes into the atmosphere which are picked up by sensors on planes nearby.

In the year 1940, we did not able to explore space even moon which is near to us. Hence, there was no possibility for installation of sensors on planet nearby. So, this answer is not correct.

E. There was no such apparatus in the 1940s since the Partial Test Ban Treaty was not signed until 1963

The Partial Test Ban Treaty (PTBT) (1963)forbids the nuclear Weapon Tests in the Atmosphere, Outer Space and Under Water, except for those conducted underground. In 1940, there was no technology to conduct the test in the atmosphere, outer space or in the water. Only possible option was underground test. Therefore, this answer is wrong.