The first barrier to study is not having the real thing there that you are studying about.
The real things or the object that you study are called mass.
If you were studying about cars, you could get the mass of a car by going to a real car and looking at it and touching it.
If you were reading about animals, you could get the mass of animals by going to a zoo or a farm.
Additional resources on L. Ron Hubbard:
L. Ron Hubbard the Humanitarian| L. Ron Hubbard, A Profile| L. Ron Hubbard the Philosopher| L. Ron Hubbard, Founder of Scientology| Scientology Disaster Relief| Scientology Drug Rehabilitation| Scientology Theology| Scientology Founder| Scientology Members|