Beside LOA, there is law called law of vibration. Law of vibration had a strong relationship with law of attraction. What is it exactly? Simple word to describe this law is energy. You can see more scientific description from one of 'the Secret' teacher after this.
As living creatures, you do have energy. While you are thinking, feeling, and/or saying something, you are radiating energy and sure there are vibration send out. It could be either positive or negative. For example, words no, not, don’t, can’t, but, and because are negative and vibrate negatively. Even before you said that, you had thought that and sure vibration created. No matter what you say, think and feel, all of them send out vibrations and law of attraction will respond.
Law of Attraction is not as simple as one, two, three. For some, it will require changing limiting beliefs about themselves. What are limiting beliefs? These are negative, self-defeating beliefs created by thoughts and feeling of doubt and fear. They are learned, become habit and are repetitive.
Your words, thoughts and feelings must all vibrate positively. If your words are positive, but your thoughts are negative, then the two will cancel each other out. It’s the same for words and feelings. Your words, thoughts and feelings must all vibrate positively together in order for you to get what you want.
One of "The Secret" teacher talk about it on that book. He explained it more scientific. Let see what he said.
"The Law of Vibration decrees that everything moves. We live in an ocean of motion. Well, your body is a molecular structure. Your body is a massive energy at a high speed of vibration. Your body is casting off millions of cells every second. Your brain is an electronic switching station. Now, you are not a brain, but you have a brain. And you, the soul, have the ability to activate brain cells, the positive or negative pole in any cell. And when you do, the brain is an electronic switching station. It alters the vibration you're in. The vibration you're in is going to cause you to act the way you act, but it’s also going to determine what you attract to you.
If you’re in a negative vibration, you're going to attract negative people to you, and you're going to attract bad situations and uncomfortable circumstance.
But if you're in a positive, a very highly evolved positive vibration, you’re going to attract positive things.
We have been attracted to one another. Everything that comes into your life or into my life comes through the Law of Attraction. So, the more we understand this, the better off we're going to be."