You turn on the loudspeaker, and after almost 80 years of having those gadgets, the sound just kind of goes where it wants.

To me, the most mind bending example of the interconnectedness of the ocean comes from an acoustic experiment where oceanographers took a ship to the southern Indian Ocean, deployed an underwater loudspeaker and played back a sound.

It should be clear to Kim by now that his parade of provocations is not benefiting his country. His bellicose behavior in 2013, for example, worsened his relationships with China, South Korea, and the United States simultaneously and in the recent crisis, all he earned was a halt to mocking loudspeaker broadcasts.

The idea is that when you have a riot or a protest and the police comes towards you, you're wearing this thing it's like a big heart and it has a loudspeaker over your heart so your heartbeat is amplified and the police is reminded it's like having a flower in front of the rifle.

SEOUL Last month, North and South Korea narrowly avoided a catastrophic military confrontation. After 40 hours of strenuous negotiations, the South agreed to stop loudspeaker broadcasts into the demilitarized zone between the two countries, in exchange for the North expressing regret for the South Korean soldiers killed by a landmine blast in the DMZ three weeks earlier.