Even though it’s an inexorable part of life, for many people, death — or at least the thought of ceasing to exist forever — can be a scary thing. The disturbing things that happen to the body during decomposition — the process by which cells and tissues begin to break down post mortem — are bad enough.

More specifically, let’s look at how our energy is redistributed after we die. In life, the human body comprises matter and energy.

The same can be said about plants, which are powered by photosynthesis, a process that allows them to generate energy from sunlight. The process of energy generation is much more complex in humans, though.

Mostly, we get it through the consumption of food, which gives us chemical energy. That chemical energy is then transformed into kinetic energy that is ultimately used to power our muscles.

It simply changes states. The total amount of energy in an isolated system does not, cannot, change.

The universe as a whole is closed. However, human bodies (and other ecosystems) are not closed — they’re open systems.

We can gain energy (again, through chemical processes), and we can lose it (by expelling waste or emitting heat). In death, the collection of atoms of which you are composed (a universe within the universe) are repurposed.

Therefore, your “light,” that is, the essence of your energy — not to be confused with your actual consciousness — will continue to echo throughout space until the end of time. If nothing else can assuage some of the fear of death, the below advice from physicist Aaron Freemen via NPR should do it:

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.

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 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.

According to the law of the conservation of energy, not a bit of you is gone. you’re just less orderly.

Dealing with the death of a loved one can be difficult. As a medium who communicates with spirits, I know that the smallest message or sign from a loved one in spirit can mean the world.

There are countless cases of loved ones contacting their living counterparts after they’ve passed, or in some cases while they’ve been clinically dead, before being brought back to life.

Raymond Moody, the researcher who coined the phrase near-death experience or NDE, a surgeon once told him that while operating on a young man, his patient went into cardiac arrest. Believing he had lost the patient, the man’s wife burst into the room screaming that her husband had visited her in the waiting room and told her the doctor thought he was dead, but that he was still alive and able to be saved.

After-death communication is very common soon after a loved one passes away. And while everyone’s loved ones have different ways of communicating this, the signs we see are usually more than sheer coincidence.

When looking for the sign of a loved one visiting or communicating to you after they pass, think of things from their life that they had a predilection for, whether that’s a particular animal, flower, or song. These personal affections typically appear in their attempts to reach you, and rightfully so, if there’s one thing you’d associate strongly with them, it’s sure to stand out.