Okay this is what I found when I looked in the dictionary
1.Capable of living, developing, or germinating under favorable conditions.
2.Capable of living outside the uterus. Used of a fetus or newborn.
I don;t see anything about 50 %
also this is the law in kentucky...
"a viable fetus is a person under the state's homicide law, so killing a viable fetus can result in homicide or manslaughter charges, the kentucky supreme court ruled yesterday.
In doing so, the court overturned its own 1983 decision requiring a live birth before homicide charges may be brought. Modern technology now makes it possible to determine whether fetuses could have survived outside the womb, the court ruled."
this is on various news sites....
Also..Wasn't scott peterson charge with killing his wife
and unborn son??????