According to physicists, every particle that ever touched you will always remain in this world because in death your energy does not die with you. It may be comforting to know that so much of you surrounds those you love after you have died, just in a less orderly form.

Funerals as we know them are very interwoven with the traditions of religion. One's faith gives meaning to life and death. Knowing that the deceased is in a better place provides comfort to the grieving in an otherwise miserable time. Different religions have different beliefs as to what happens to us after we pass away. Abrahamic religions (Christianity, Judaism, Islam) believe that our soul will transcend to heaven and be judged by God on whether we go to heaven, purgatory, or hell. Dharmic religions (Buddhism, Hinduism) believe that you will be reborn into this world until you give up all attachments and achieve freedom of the rebirth cycle.

But what is believed by those without religious beliefs? Ask most atheists and their answer will be that it doesn't really matter what happens when they die, since they will be gone. But, surely the loss of a life has to have some sort of profound meaning.

In the words of the famous astrophysicist, Neil deGrasse Tyson: “I would request that my body in death be buried not cremated, so that the energy content contained within it gets returned to the earth, so that flora and fauna can dine upon it, just as I have dined upon flora and fauna during my lifetime”

Words such as these provide comfort to us, rather than the empty nothingness of simply ceasing to exist.

For a more detailed account of a secular view of what happens when we die, the following was written by journalist and author Aaron Freeman:

"You want a physicist to speak at your funeral. You want the physicist to talk to your grieving family about the conservation of energy, so they will understand that your energy has not died. You want the physicist to remind your sobbing mother about the first law of thermodynamics; that no energy gets created in the universe, and none is destroyed. You want your mother to know that all your energy, every vibration, every Btu of heat, every wave of every particle that was her beloved child remains with her in this world. You want the physicist to tell your weeping father that amid energies of the cosmos, you gave as good as you got.

And at one point you'd hope that the physicist would step down from the pulpit and walk to your brokenhearted spouse there in the pew and tell him that all the photons that ever bounced off your face, all the particles whose paths were interrupted by your smile, by the touch of your hair, hundreds of trillions of particles, have raced off like children, their ways forever changed by you. And as your widow rocks in the arms of a loving family, may the physicist let her know that all the photons that bounced from you were gathered in the particle detectors that are her eyes, that those photons created within her constellations of electromagnetically charged neurons whose energy will go on forever.

And the physicist will remind the congregation of how much of all our energy is given off as heat. There may be a few fanning themselves with their programs as he says it. And he will tell them that the warmth that flowed through you in life is still here, still part of all that we are, even as we who mourn continue the heat of our own lives.

And you'll want the physicist to explain to those who loved you that they need not have faith; indeed, they should not have faith. Let them know that they can measure, that scientists have measured precisely the conservation of energy and found it accurate, verifiable and consistent across space and time. You can hope your family will examine the evidence and satisfy themselves that the science is sound and that they'll be comforted to know your energy's still around. According to the law of the conservation of energy, not a bit of you is gone; you're just less orderly."

Read more:

Death, Dying, and Meaning | Humanism.org

Video: Neil deGrasse Tyson's view on death | Youtube.com