Scientists have long known that Earth produces an eerie low-frequency hum that’s inaudible to humans but detectable with seismic instruments. But as for what’s causing this “microseismic” activity, scientists have never been sure.
A new study published online Feb. 10, 2015 in the journal Geophysical Research Letters indicates that the hum is largely due to ocean waves that cause our planet to vibrate subtly – or “ring”, as the researchers put it. 
Weird how we tend to look at everything material with so much detail and yet we fail to recognize the importance of non-material entities into our lives. We recognize how waves can result into a global “activity” and yet fail to recognize even the possibility of feelings or emotions resulting in any kind of “activity” that is felt beyond the tight limitations of our inner circle of acquaintances. We accept the effects of the gravity of a star billions of miles away from us and yet we fail to accept that good or evil thoughts could in any way affect us if they are not spoken or acted upon within five meters of where we stand.
We have created a material world around us.
And our immaterial soul suffers…
Listen to the waves breaking on the shore.
It is not their “activity” which makes you cry with longing emotions…