Astrophysicist Neil deGrasse Tyson shared a theory about death in a recent episode of his podcast StarTalk.

According to Tyson, death doesn’t make one disappear as the body just transforms because its molecules still contain energy.

“If I’m buried and I decompose, all that energy gets absorbed by microbes, by flora and fauna dining upon my body the way I have dined upon flora and fauna my whole life. In that way, giving back to the earth,” Tyson said, the New York Post (NYP) reported.

If the body is cremated, the heated molecules radiate infrared energy. “It radiates it out into space, moving at the speed of light,” he explained.

“If they were cremated four years ago, they would have reached the nearest star system, Alpha Centauri. So that in a way you’re still a part of the universe, just in a different form,” Tyson said, according to NYP.

Meanwhile, researchers from Memorial University in Newfoundland and Labrador (MUNL) in Canada claimed that the tissues of a sea creature do not die.

After amputating fragments of the sea cucumber Psolus fabricii, which is native to the North Atlantic Ocean, MUNL doctoral student Sara Jobson and her team noticed that the severed parts did not simply decay and die but healed themselves and even managed to absorb nutrients despite lacking a mouth, CNN reported.

The severed tissues did not regrow into a whole new organism, however, prompting Jobson to call the explants “zombies.”

“If the sea cucumber tissues were confirmed to be immortal, they would have applications in medical research and cell biology,” Jobson said, according to CNN.