Respiratory protective equipment, like all PPEs, are distinguished in many different types, each with its own sub-categories and specific uses and effectiveness.

During the two world wars of the 20th century, submarines were essentially surface ships with the ability to sail underwater for short periods. Usually they used their underwater capabilities during the final approach

The application of scientific methods to examine the evidences gathered in order to solve queries, thereby helping the legal system to acknowledge the truth is known as forensic science.

Ideas of time travel have existed for centuries, but when Albert Einstein released his theory of special relativity, he laid the foundation for the theoretical possibility of time travel.

In preparing to write my novel Tsunami, about a fictional undersea volcano on the verge of exploding and sending a monster tsunami smashing into California, I did a great deal of research into the world of natural disasters.

Many different species in the history of life on this planet have simply ceased to be. Gone but not forgotten these strange animals leave evidence of their existence entombed in the sedimentary layers of the earth's crust.