|Left: a typical Ra theology era (3000-1000BC) depiction of the afterlife: (a) right: the ba or soul leaves the body, (b) left: the body is taken through the afterlife door, where the person's morality, based on his or her soul weight, a mass determined by the negative confessions, is weighed against the feather of truth, in the judgment hall, after which, depending on the scale measurement, the person either enters heaven or hell.  Right: a typical modern day Ab-ra-ham-ic depiction of the afterlife: (a) left: the spirit or soul leaves the body, (b) right: the person enters the afterlife through some type of door, tunnel, or white light.  This view of death, or some variation of this, is common to over 53 percent of the world's belief system.|
A 2007 Pew poll of Americans found that 74% of Americans believe in the existence of the afterlife, and that 50% believe with "absolute certainty." (Ѻ) A 2014 CBS poll found that 75% of Americans believe in the existence of heaven or hell, including 66% who think both exist. (Ѻ) Other polls, on the high end, indicate that upwards of 95% of Americans believe in life after death. 
The following is the modern-day experimental psychology view of the afterlife theory: 
“Afterlife is a cognitive illusion churned up by a psychological system designed to think about unobservable minds. The soul is distinctly human all right, a product of reasoned evolutionary thinking.”
The following is the typical American view of the afterlife: 
“Where did we come from? Why are we here? Is there any meaning or purpose to life? Is there life after death? The question of our origin is very important, and continues to be a topic of great difference of viewpoint and intense controversy.”
Afterlife, in detail, is a theory that which holds that following the point of inception synthesis or birth, i.e. the transition state period when a person is brought into the universe into the form of a bound state animate molecular entity, that during the reaction span of time when a person thinks and therefore is, that he or she is ‘alive’, and that following the point or demarcation of cessation of existence, according to the doctrine of continuity, that one transits into a new state of existence, in whatever form that may be, termed the afterlife or ‘next life’, or something to this effect, wherein one, supposedly, has some form of ‘life’ after the point of death or cessation.
Recent 2005 polls indicate that the following three queries, in ranked descending prominence of respondents, are the three greatest philosophical conundrums of modern times: 
What happens when you die?
What is love?
What is the meaning of life?
Hence, searches for the so-called "afterlife theory" is the biggest weakspot in things lacking explanation in modern science.
|A 90,000 year-old version of the afterlife, a prehistoric tomb: showing two women, in the twenties or early thirties, both featuring traumatic injuries to the skull, surrounded with antlers (food or hunting prowess), wearing necklaces (beauty or status), and surrounded by sea shells (water or rebirth). |
The two dominate historical versions of the ‘afterlife theory’ are Ab-ra-ham-ic version (53% of the world’s belief system), which utilizes a resurrection afterlife model which holds that one is reborn, in the same body, into either a hypothetical land of pleasantries, if one has been morally good, or into a hypothetical land of unpleasantries, if one has been morally bad, determined by ones moral essence (soul weight), and the B-ra-hma-ic version (20% of the world’s belief system), which utilizes a reincarnation resurrection afterlife model which holds that one is reborn, in multiple cycles, in different bodies (human and animal), into upgraded states or degraded states of existence, based on one's morality or karma (karma weight). These to afterlife theories are both derivatives of the Ra theology life-death cycle, which in total accounts for 72% of the modern world's belief system.
The alternative to the standard "doorway version" of afterlife is what is called the "materialist version of death", as American experimental psychologist Jesse Bering puts in 2006 chapter section on this topic, which holds that one becomes becomes fertilizer, worm food, cosmic dust, or something along these lines, a view which she calls the "ultimate killjoy null hypothesis". 
Theories of human afterlife, according to burial findings, indicate that variations of belief in life after life, or life after death, or that some form of state of existence follows the termination of a person, dates back to 50,000 to 100,000 years ago, with people burying things with the dead such as red ochre, stone tools, necklaces, sea shells, and animal bones, such as deer antlers or wild boar mandibles, placed in the hands of the bodies, the latter of which are reasoned to signify hunting prowess ability or to insure it in the next life. 
1. Bering, Jesse. (2006). “I Believe There’s a Solution to Unamuno’s paradox”, in: What We Believe But Cannot Prove: Today’s Leading Thinkers on Science in the Age of Certainty (pgs. 32-35), ed. John Brockman. Harper Perennial.
2. (a) Afterlife door: Press release [Mar. 29, 2010]: Cairo: Archaeologists have unearthed a 3,500-year-old door to the afterlife from the tomb of a high-ranking Egyptian official near Karnak temple in Luxor, the Egyptian antiquities authority said. These recessed niches found in nearly all ancient Egyptian tombs were meant to take the spirits of the dead to and from the afterworld. The nearly six-foot-tall (1.75 meters) slab of pink granite was covered with religious texts.
(b) Egyptian Body and Soul (2010) – ShadowOfTheNile.BlogSpot.com.
3. Lieberman, Philip. (1993). Uniquely Human: the Evolution of Speech, Thought, and Selfless Behavior (pg. 163). Harvard University Press.
4. Ancient burial (reconstruction) – Wikipedia.
5. Ken. (2011). “Human Beings are Souls with Spirits and Bodies Too: We are Not Merely a Collection of Atoms”, CreationOutReach.com.
6. Thims, Libb. (2007). Human Chemistry (Volume One) (pgs. 301-02). Morrisville, NC: LuLu.
● Roach, Mary. (2005). Spook: Science Tackles the Afterlife (Gerry Nahum, pgs. 97-106, 290, 297). W.W. Norton & Co.
● Thermodynamics and the afterlife? (2006) – Forums.Randi.org.
● An Afterlife is Impossible (2009) – Debate.org.
● First law of thermodynamics and life after death (2008) – AboveTopSecret.com.
● Thermodynamics Disproves Afterlife (2008) – Forums.AstralDynamics.com.
● Afterlife – Wikipedia.