Your physical form is composed of carbon, oxygen, hydrogen, nitrogen and a smaller mixture of the other 96 naturally occuring elements.
You bring these atoms into yourself with every breath, every drink and every meal, change their relationships into new ones that form your body, give you energy to perceive the world around you, and to remember, think, and move.
You expell the atoms when you are done with them and these, along with the other things that escape you (your actions, your words) move out from your focus and create changes outside of you. This pattern, the atoms flowing together towards your focus, the change within you, the flowing out again, and the changes in the world around you are the prime characteristic of the process of life. All living creatures create themselves and maintain their existence within this 4-step process.
You can prove this to yourself right now by simply exhaling all of the air in your lungs and not breathing in again while you read the next small paragraph. Try it now, breathe out completely but don't breathe back in until you finish the next paragraph. This is an experiment through which you can establish the truth.
Within seconds of stopping the continual flow of atoms through your focus you will become desperately aware of the reality of the requirement for the atoms of oxygen to enter into your focus. The longer you hold off refreshing the atoms the more aware you will become of the absolute fact of the flow of atoms through yourself. You surely feel the truth of it by now if you are still waiting to breathe in again. Feel it, then breathe in and admire the feeling of satisfaction as the atoms flood into you again.
If you breathe in and hold your breath for 20 seconds you will feel an increasingly sharp awareness of the need to release the atoms from your focus. How long can you hold your breath before you fully and completely acknowledge that the movement of earth atoms through you is no theory, no opinion, no model, but an absolute fact of life? Try it and see.
By this simple experiment prove to yourself that the atoms of the planet flow through you, and that you change them into your form, and that the atoms not only form your body but also energize your movements and your perceptions and your memories and your thoughts.
Science has proved what you cannot feel or know directly. All of the atoms that now form your body will enter your focus from a wide area of the world around you and then leave you again within a surprisingly short time. Every atom of your brain will be exchanged for new atoms within a week. Almost every single atom in your entire body, including your bones and teeth, will be exchanged for new atoms within a year.
You can verify this as well. Reduce the flow of atoms through your focus by minimizing the intake of food and drink to one drink of water and one mouthfull of rice per day for 20 days and you will see your physical form deflating and your strength leaving you as new atoms flowing into you do not keep up with the atoms flowing out of you. You don't need to perform the experiment to realize the truth of this constant flow.
The atoms that now are in you will soon be exchanged for new ones and the atoms in you now will soon become rain, the ocean, the plants, and other creatures as they are recycled in the flow of life on our planet.
To experience the thread of awareness, you must be able to visualize this flow and be absolutely sure, totally convinced, of this pattern of the atoms flowing in towards you, your changing them into new relationships, and then releasing them back into the world in a changed form where their relationships are changed again into the water, soil, bacteria, plants, and other creatures that surround you.
It is a provable, and essential fact.
The atoms that are moving through you at this moment are the same atoms that were here when the earth formed 4 billion years ago. The carbon, oxygen, nitrogen, hydrogen and other elements creating you now have recirculated through living creatures and through the ocean and the clouds and the plants - changing their relationships and their movement, but they are the same atoms.