Photograph taken on July 2, 2005 in Colonia Acueducto de Guadalupe, north of Mexico City, at 5:45 pm.

According to the explanation offered by Mexican physicist and researcher Mario Torres Luján, former director of CONTACTO OVNI Magazine, the phenomenon of the so-called "invisible UFOs" is based on low-frequency sounds and speed.

The scientist explains: :"Strange structures are moving through the sky at high speeds, becoming imperceptible to us. This oscillation may cause an infrasound imperceptible to the human ear, but somehow perceptible by our brains' neurons, and that is the reason why witnesses press their cameras' shutters at a given place and manage to capture images that the unaided eye could not see."

"This low-frequency sound is picked up by animals and for this reason we see alterations among them during sightings. I definitely do not believe in the existence of chance UFOs...rather, there is more of a causality involved."

Profra. Ana Luisa Cid

source and references:

Source: Prof. Ana Luisa Cid

Date: 07.02.05

www.analuisacid.com.mx