What is Scientology? Famous Celebrities like Tom Cruise and John Travolta Are Believers

The word Scientology literally means "the study of truth."
Who is Ron Hubbard?
Ron Hubbard is the founder of Dianetics and Scientology and the author of the Scientology scripture.

Background

Scientologists believe in some "certain fundamental truths".
- Man is an immortal, spiritual being.
- His capabilities are unlimited, even if not presently realized and those capabilities can be realized.
According to scientology.org:
"In Scientology no one is asked to accept anything as belief or on faith. That which is true for you is what you have observed to be true. An individual discovers for himself that Scientology works by personally applying its principles and observing or experiencing results."

Beliefs

Man consists of three parts. The first of these is the spririt. The second is the mind. The third is the body.

Other things that are used in Scientology

A principle in Scientology is affinity, reality and communication. The three form an interdependent triangle and add up to understanding according to Scientologists.

The Tone Scale is a tool used in everyday life to understand what is occurring with individuals and how best to communicate with them.

The Dynamics of Existence- information from scientology.org

8th Dynamic INFINITY, also commonly called God, the Supreme Being or Creator.
7th Dynamic SPIRITUAL - anything spiritual with or without identity, life source.
6th Dynamic PHYSICAL UNIVERSE with its four components of matter, energy, space and time.
5th Dynamic LIFE FORMS including all plant and animal life.
4th Dynamic MANKIND as a species.
3rd Dynamic GROUP SURVIVAL whether friends, a club, company, nation or race.
2nd Dynamic FAMILY and children and all other creativity.
1st Dynamic SELF - the individual, including his body, mind and immediate possessions.

What is an E-meter?
According to scientology.org, The Electropsychometer, or E-Meter measures the mental state or change of state of a person. It is used to locate areas of spiritual distress so they can be addressed and handled.

Why did Tom Cruise freak out on tv about drugs?
Scientologists believe that in addition to physiological damage, drugs decrease mental alertness and perception and can contribute to many undesirable states, from unfeeling to hostile. It is a barrier to spiritual freedom.

Is this a real religion? What is the controversy?
It has been attacked by governments as a pseudoreligion, a cult, or a transnational corporation.
A Reader's Digest article of May 1980 quoted Hubbard as saying in the 1940s "Writing for a penny a word is ridiculous. If a man really wants to make a million dollars, the best way would be to start his own religion.

I read this on Wikipedia:
Hubbard died at his ranch at age 74, reportedly from a stroke. He had not been seen in public for five years. Scientology attorneys arrived to claim his body, which they sought to have cremated immediately. They were blocked by the San Luis Obispo County medical examiner, whose examination revealed high levels of a drug called hydroxyzine. The Church of Scientology announced Hubbard had deliberately "discarded the body" to do "higher level spiritual research."

How many people practice this?
This is very debatable. Here in the U.S., I have read the numbers are 50,000, 100,000, and everything in between. The general consensus seems to be that there are 100,000 or less, with the most being in California.