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  • Since the dawn of humanity, an estimated 100.8 billion people have lived and died, a number that increases by about 0.8% of the world's population each year.

  • What happens to all of those people's bodies after they die?

  • and will the planet eventually run out of burial space?

  • When a person's heart stops beating,

  • the body passes through several stages before it begins decomposing.

  • Within minutes after death,

  • the blood begins settling in the lower-most parts of the body.

  • Usually eight to twelve hours later,

  • the skin in those areas is discolored by livor mortis, or post-mortem stain.

  • And while at the moment of death, the body's muscles relax completely

  • in a condition called primary flaccidity,

  • they stiffen about two to six hours later in what's known as rigor mortis.

  • This stiffening spreads through the muscles,

  • and its speed can be affected by age, gender, and the surrounding environment.

  • The body also changes temperature,

  • usually cooling off to match its environment.

  • Next comes decomposition,

  • the process by which bacteria and insects break apart the body.

  • Many factors affect the rate of decomposition.

  • There is, however, a basic guide of the effect of the environment on decompositon

  • called Casper's Law.

  • It says that if all other factors are equal, a body exposed to air decomposes twice as fast as one immersed in water and eight times as fast as one buried in earth.

  • Soil acidity also greatly affects bone preservation.

  • High-acidity soils with a pH of less than 5.3

  • will rapidly decompose bone,

  • whereas in a neutral or basic soil with a pH of 7 or more,

  • a skeleton can remain in relatively good condition for centuries.

  • Different cultures throughout history have developed unique approaches to burials.

  • As far back as the first Neanderthal burials,

  • death was accompanied by rituals,

  • like the positioning, coloring, or decorating of corpses.

  • Traditional Christian burials decorate the body in dress,

  • while in traditional Islam,

  • a body is wrapped in a piece of ritual fabric

  • with the face oriented toward Mecca.

  • Traditional Hindus ceremonially burn the body,

  • and Zoroastrians, followers of one of the oldest monotheistic religions,

  • traditionally place bodies atop a tower to expose them to the Sun

  • and scavenging birds.

  • Before the Industrial Revolution, burials were simple and accessible.

  • These days, with suitable burial land running out in high-population areas,

  • purchasing private gravesites can be costly,

  • and many people can't afford simple burials.

  • Even cremation, the second most common burial practice in the world,

  • comes with a high cost.

  • As for the question of running out of space,

  • the issue isn't so much about total land in the world

  • as it is that large populations cluster together within cities.

  • Most of the big cities in the world

  • may run out of suitable burial grounds within a century.

  • For London, it's even sooner.

  • That may happen by 2035.

  • So are there alternatives to traditional burials

  • that might help with the space issue?

  • In some countries, skyscraper cemeteries enable vertical burials.

  • Some options focus on the body's relationship with the environment.

  • Promession, for example, freeze-dries and pulverizes the body,

  • creating a powder that can turn into compost

  • when mixed with oxygen and water.

  • There are also green burials that use special materials,

  • such as biodegradable caskets,

  • urns that sprout trees,

  • and burial suits that grow mushrooms.

  • Eternal reefs take that concept to the depths of the ocean

  • using a mixture of ashes and cement to create marine habitats for sea life.

  • Death is an inevitable part of the human condition, but how we treat bodies and burials continues to evolve.

  • We may each have different spiritual,

  • religious,

  • or practical approaches to dying,

  • but the ever-increasing demand for burial space

  • might give us a push to be creative

  • about where our bodies go after the final stages of life.

Since the dawn of humanity, an estimated 100.8 billion people have lived and died, a number that increases by about 0.8% of the world's population each year.

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B1 US TED-Ed burial body traditional decomposition environment

【TED-Ed】What happens to our bodies after we die? - Farnaz Khatibi Jafari

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    Flora Hu posted on 2016/10/15
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