Everything has a sphere of influence. In scientific terms, the point where that sphere of influence ends is called an event horizon.
Lets look at this in simple terms.
The moon is a ball of rock in space and yet beyond its physical boundary it shifts billions of tonnes of water each day in our tides.
The Earth, beyond it's physical structure has a gravitational or energetic pull which the moon is caught in.
The Sun's event horizon reaches all the way to Pluto and then half the distance again, spreading light, warmth and a gravitational energy.
Let's look at humans.
Adolf Hitler had a sphere of influence that spread across the entire planet. One solitary bag of flesh and bones with a few thoughts in his head, and his influence remained for years and generations.
Buddha walked a dusty path among some villages 2500 years ago and decided to seek something profound under a Bodhi tree. Today on our planet millions of people are being guided and inspired because of his existence.
We are all leaving an imprint, or legacy, behind. Everywhere we go we are influencing peoples lives in some manner.
If you yell, scream and curse at someone at the traffic lights because they pulled in front of you, then there's a good chance they will take that energy home with them and spread it into their family.
Or it can be as simple as helping an old lady cross the road, carrying her shopping bags to her house. This will leaving her vibrating with a sense of gratitude and lightness.
So the question is, what energy field do you want to spread out across the planet? What sphere of influence do you want to leave behind?
We've all heard the quote from Gandhi, "be the change you want to see in the world".
If you're stressed and angry, then this will probably the be the imprint you leave, and if you are light, joyful and calm, then that will be your legacy.