That's my exact definition, so how can we come to differing conclusions? Because you're practicing a type of scientism in an attempt to leave God or human spirituality out of it. This method is wholly incapable of answering any of life's serious questions.
You couple this with a type of halo effect over "scientific" explanations and definitions you agree with. This is serious bias. Look at your very next paragraph:
For as long as I provide food, water, oxygen, carbon dioxide, and warmth, they remain verifiably alive
Clearly, that's not the natural environment of human cells. Do these cells naturally seek you out? Do they normally occur in Petri dishes? So you've just violated your own definition. They may be cells from or of humans, but they're not human beings. You've not grown and killed numerous human beings have you? Of course not, so what are we discussing here?
My point is that as a Christian and given my beliefs it makes the most sense that a human zygote becomes a human being when the physical part of its humanity attaches to the uterine wall allowing it to meet the operational definition of life that you state above and that I accept. It is at this point that God would give it a spirit thereby completing it's humanity. If one leaves the spirit out of the equation you don't clarify, but muddy the waters.
Are you familiar with Genesis Chapters 1-3. They would be worth discussing particularly in this context.
I am not "practicing scientism", as you say. Science is a methodology concerned with characterizing the real world; it does not deal with religious or philosophical matters.
The reason I concentrate purely on the scientific matters when discussing abortion is that the moment you bring up religion, many of those who are pro-abortion automatically dismiss you as a religious freak intent on controlling women. Focusing on the science makes it impossible for pro-abortion zealots to dismiss pro-life arguments as religious beliefs that they do not share.
You couple this with a type of halo effect over "scientific" explanations and definitions you agree with. This is serious bias. Look at your very next paragraph
As I said before, science is a methodology dedicated to describing the real world. There is no "agreement" here; the purpose of science is to be as objective and accurate as possible when describing natural phenomena. Everything I have said concerning the aliveness of sperms, ova, zygote, blastocysts, and embryos is verifiable by simple biochemical tests that can be performed by anyone. Ditto for everything I said about their being human.
Clearly, that's not the natural environment of human cells. Do these cells naturally seek you out? Do they normally occur in Petri dishes? So you've just violated your own definition. They may be cells from or of humans, but they're not human beings. You've not grown and killed numerous human beings have you? Of course not, so what are we discussing here?
You are completely missing the point, which is that, scientifically (i.e. objectively), there is no distinct point at which life begins. You can make valid arguments for destroying that life, based on objectively observable characteristics, but to argue that a growing human embryo is not alive or is not human is nonsensical and unsupportable by any objective measure. If that is your basis for being pro-abortion, then your abortion advocacy is based on a lie. If you acknowledge that the embryo is always a living human, but you feel it is okay to kill it up until it crosses some developmental point, you move the abortion argument away from the science and into the realm of opinion, which is not objective.
You have noticed that I have not discussed human beings, or my opinion of what constitutes a human being. Although you are using that to try to "prove" some inconsistency in what I have said, my avoidance of that specific issue is completely intentional.