Another scientist would have to 'discover' it again. For example, say I invented a flying car, but kept the special rocket fuel formula a secret. Someone else would look at my work and be able to figure it out, or they would do trial-and-error to figure it out.
Is the secret sound the sound of someones footsteps as they walk
The Secret of Nikola Tesla was created in 1980.
In Area 51 scientist took a crashed UFO and found an alien body and thermal sight attached to top secret weapons
While the concept of thermal energy has been studied for centuries, the modern understanding and utilization of it can be attributed to scientists like James Joule and Sadi Carnot in the 19th century. Their work laid the foundation for the development of thermodynamics and the understanding of thermal processes.
In the movie "Real Steel," Atom's secret was that he was a highly advanced sparring robot, designed to mimic a human-like fighting style using advanced artificial intelligence. This secret was revealed during his fight against Zeus, the reigning champion robot.
Secret of the Stars happened in 1993.
The Secret of the Nautilus happened in 2002.
Secret of Mana happened in 1993.
Secret of the Solstice happened in 2008.
Secret of Evermore happened in 1995.
Secret Weapons of the Luftwaffe happened in 1991.
The Secret of Monkey Island happened in 1990.
Secret Wives' Club happened in 2002.
Secret Agent Clank happened in 2008.
Operation Secret Storm happened in 1992.
Secret of the Scarlet Hand happened in 2002.
Secret of the Silver Blades happened in 9801.