One of America's most popular scientists has revealed what happens after we die - and why it led him to choose a burial over being cremated.
Neil deGrasse Tyson, the famed astrophysicist, writer and podcast host, recently explained the science of what happens after death, revealing how the human body breaks down and is consumed by microbes and bacteria, feeding on a person's leftover chemical energy.
Since scientists believe energy cannot be created or destroyed, Tyson noted that a person's body is still full of energy, mostly from the food they took in over the years, even after the heart and brain stop functioning.
That leaves two options people have for releasing this energy. One is cremation, which sees a person's remaining energy converted to heat after the body is burned, which then travels out into space.
The other choice is a traditional burial, which lets the body decompose naturally, allowing the Earth's microscopic organisms to absorb all of your remaining energy in the endless cycle of renewal between humans and nature.
Tyson said: 'That's my choice. So that the energy content of my body, which is still there when you die, your molecules were built up from your lifetime of eating and exercising and the building of your organs and your muscles and other tissue.'
'In death, those 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.'
While the astrophysicist chose a burial for himself, he revealed that cremation did not mean people were wasting their energy, and even said their final journey would have more far-reaching consequences.
Tyson explained that the heat produced by cremating a body does not stay on Earth. Instead, that radiation is capable of reaching other planets within our galaxy.
'The energy content of those molecules, it doesn't go away. It gets transferred to heat that then radiates infrared energy that was once the energy content of the molecules of your body, radiates it out into space, moving at the speed of light,' the scientist detailed on his StarTalk podcast on March 31.
From the moment someone is cremated, Tyson said their loved ones could actually keep a timeline of where their radiant energy had traveled to in the Milky Way.
'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's thoughts on what happens after death were more than just a theory. The scientist's comments were grounded in some of the most fundamental laws of science.
It all begins with the first law of thermodynamics, also known as the law of conservation of energy. The law states that energy cannot be created or destroyed; it can only be changed from one form to another.
In this case, the chemical energy, which had been stored in a person's molecules mostly from everything they ate or drank, will transform either through decomposition or cremation.
In a natural burial, decomposition is carried out by bacteria, fungi and other microbes that break down the body's proteins, fats and carbohydrates after death.
This process converts most of the original chemical energy into heat that warms the soil. However, a small portion of a person's remains becomes new chemical energy stored in the microbes and is then passed up the food chain to more complex plants and animals.
Tyson's comments have been viewed more than a million times and sparked a public conversation about how people want their remains handled once they die.
However, many of his followers disagreed with his funeral plans and chose cremation for themselves.
'I will return to the stars,' one person replied.
'That travelling to Alpha Centauri at the speed of light sounds much more romantic and appealing than being eaten by bugs,' another commenter said.
'Being eaten by bugs and microbes, the particles you're composed of get recycled on Earth and stay a useful resource for long past your passing. One day you'll be a tiny but functional part of billions of creatures and plants,' one person countered.
Some of the replies to the StarTalk YouTube channel claimed that modern coffins would make it much harder for a person's microbes to actually reach the soil and contribute to Earth's ecosystem.
Others suggested opting for a 'green burial,' where people request their remains to be placed directly in the ground without embalming chemicals, metal caskets or concrete vaults.
Families or burial grounds often plant a tree right above the grave. As the body decomposes, it releases nutrients such as nitrogen, phosphorus and potassium into the soil - exactly what a young tree needs to grow strong.