The conversation revolves around a deep dive into how nuclear submarines work, specifically focusing on sonar systems. The host, Destin, interviews Chief Luth, the Sonar Division Lead and Chief Petty Officer on the USS Toledo. The discussion covers various aspects of sonar technology, including active and passive sonar, and the challenges faced by submariners in interpreting the data.
The host learns about the complexities of sonar, including the use of multiple frequencies to determine the shape of different objects, and the use of bearing rate graphs to track the movement of contacts. The conversation also touches on the challenges of multipath, where sound can take multiple paths to reach the submarine and on the return path, leading to multiple returns at the hydrophones.
The host also learns about the effects of the speed of sound in water on sonar waves, and how this can lead to convergence zones around the submarine, making it difficult to detect contacts at certain ranges and depths. The conversation also delves into the concept of the shadow zone, where the sound waves curve up and down, making the submarine virtually invisible to surface ships using sonar.
The host is also introduced to the concept of the best depth, a spot where a submarine could be placed that would be undetectable by surface ships using sonar. However, the host learns that even with perfect knowledge of everything about the ocean water around the submarine, it would still be impossible to find this spot without additional technology.
The conversation ends with the host expressing amazement at the complexity of sonar technology and the challenges faced by submariners in interpreting the data. The host also expresses a desire to learn more about the classified aspects of sonar technology, but Chief Luth advises against it, citing the need to protect classified information.
1. The speaker is discussing the process of sonar systems on a nuclear submarine, highlighting the fine line between unclassified and classified information.
2. The speaker mentions that the information is processed and distributed on monitors throughout the boat.
3. The speaker is on the USS Toledo and is about to talk to a very important person, Chief Luth.
4. The speaker had to hand over physically the cards and all his data to the Navy.
5. The speaker is discussing the concept of SONAR (sound navigation and ranging) and how it works.
6. The speaker explains that active sonar works by pinging and listening for an echo, and the amount of time it takes for that echo to return to you gives an idea of how far away and how big the object is.
7. The speaker introduces the concept of passive sonar, where the submarine is just listening to see what's up in the water.
8. The speaker explains that the Navy uses multiple frequencies in order to see shapes of different things.
9. The speaker discusses how the Navy uses a tool called a bearing rate graph to see the world.
10. The speaker explains that the bearing rate means a measure of angle over time.
11. The speaker discusses the concept of multipath, where there are multiple ways that a sound can return to the vessel.
12. The speaker mentions that the speed of sound in water changes with temperature, pressure, and even salt content, which can bend sound.
13. The speaker explains that the Navy uses a device called an expendable bathythermograph to measure the sound velocity profile.
14. The speaker discusses the concept of convergence zones around a boat, which can create difficulties in detecting contacts.