While there are many inventions in contention for most impactful on humanity--the car, the gun, the telephone, the internet--the invention that stands out as the current star of the lineup happens to be the one that determines the stars themselves: the illustrious camera.
The camera is enjoying its most rapid proliferation and abundant usage in the history of the Earth, and it doesn't look to be slowing down any time soon. When used correctly, it captures the beauty of our world in a fragment of time or helps to communicate harsh realities better than words and across languages.
But it is also an instrument of tremendous power, which can be used in service of our baser instincts: vanity, greed, lust, paranoia. Any truly great invention will demonstrate the full spectrum from darkness to light, because inventions are great for their ability to extend the capabilities of ourselves. The story of humanity could never be convincing without the presence of both a deep darkness and a redemptive bright light, and nothing reflects that truth better than the camera.