Imagine a tiny videoscope placed in a woman's womb well before she became pregnant, and connected by a wireless hookup to a motion picture camera that is outside her body. Let the make—believe camera run continuously until she delivers and the newborn baby placed in the hospital's nursery. Then play the nine—month film in reverse. Your objective is to decide when the baby's human life began.

Being a physicist and not a physiologist, I thought about the Big Bang, which is the theory of the origin of the universe and which —— believe it or not —— has some relevance to abortion: Of course not the event itself, but in the ways that the astronomers researched it.  I'll explain later. 

Next came a thought experiment, Einstein's concept popularized by the scientific community in a famous example: in developing his renowned equation (E=mcｲ), he imagined himself riding the leading edge of a light beam flashing through space at the speed of light. We'll not undertake anything quite so grand, but please bear with me for a moment.  

Last came the idea behind the title of this paper, the running of a reel of film backwards.  It's one of the methods used by astronomers in their studies explaining the creation of the universe — which is a process covering some 13—plus billion years. We'll follow a process that is more manageable, of only some nine months: But in the broadest of principles, the methods will be similar.

Even with the Supreme Court's Roe vs. Wade decision, the point at which a human life, with all its rights and protections, comes into being has been debated for three decades (centuries actually).  And yet, there is no consensus about the point of transition from non—human to human, nor is any hope of one imminent because there are a number of possible points of transition from non—human to human.

Starting with the ancient Hebrews, it was illegal unless the mother's life was at risk. Later, the early Christian Church considered that it might be justified before animation, the point at which the fetus received a soul, some 40 to 80 days after conception. In the Nineteenth Century, it was not a crime in the US if the abortion took place before quickening, the time when the mother first feels the fetus moving. At about the same time, the Roman Catholic Church's Canon Law was changed to prohibit abortion from the moment of conception. At present the Church has eased a bit by permitting indirect abortion, which occurs as a result of medical treatment designed to save a mother's life. However, all other forms of direct abortion (the intentional ending of a pregnancy) are condemned by the Church.

There are those who believe that abortion should be unrestricted up until the fetus becomes viable, i.e., when it would be able to live outside the mother's body; after six or so months. Others who separate human life from personhood. They describe personhood as occurring when the unborn has an ability to experience self—consciousness and so be accepted as a member of a community.

Then there is the transition occurring at the end of the first trimester, implied by the 1973 Supreme Court decision, Roe vs. Wade.

Regarding the question," When does human life begin?' I have touched on a goodly number of possibilities that range between the moment of conception and delivery. Later, you might use these as steps, plus any others of your choosing.  If you want more just see 'abortion' in Google for more than 30,000 references.

Running the Film

Now, let me describe the thought experiment and give some background on the notion behind the phrase "running the film backwards." To do so, we must return to the Big Bang and the subsequent creation of the universe.

Astronomers use a number of methods to study the creation of the universe, one of which is film reversal. It was and is a help because with it astronomers can work the laws of physics backward from a known state of affairs —— from the universe they see in the night sky. No assumptions needed.  By contrast, if astronomers follow the usual route and start their work at the beginning of time, they must make assumptions about the condition of the universe before time began (now, there's a philosophical enigma) and about the events in the very, very early times after the Big Bang, (horribly complex physical reactions at unbelievable temperatures).  And then they must bring in every branch of science to progress through 13 billion years to get to tonight's sky.

So, to get back to the baby in the nursery: Use your thought experiment to play his development movie in reverse and track the baby all the way back to conception, in a fashion similar to the astronomer's going from our night sky back to the Big Bang. The film will take you from the nursery to the delivery room, to the operating table, to when the obstetrician had the baby part way out of the birth canal. He, or she, is about twenty inches long and at this point just a few of these inches are exposed. Now ask yourself: 'Has his status changed? In the nursery he was a human being. Is he now?'

Reverse the film a few more minutes to when the baby is inside its mother's uterus entirely. Does the film tell you that the baby has changed from moments before when he was at the operating table or in the nursery? So, ask the same status question: 'Is this baby now a human being or not?'

OK. You get the idea.  You can repeat this procedure continually, for the full nine months if necessary. You might want to use the list of items cited earlier, (animation, quickening etc.), adding whatever other points of reference you wish. Continue until getting a definite: 'No, this baby no longer is a human being' —— or else go all the way back to conception. Either way, you will have reached your definition of the human to non—human transition.

Joseph L. Masi is a physicist and a retired US Air Force officer.  He is a graduate of the US Naval Academy and holds a Ph.D from Kings College, London.  Dr. Masi resides in the San Francisco Bay area and welcomes your comments at jlmasi@aol.com.