It is dubious to call this movement a “heartbeat”; there is no heart to speak of. Doctors do not even call this rapidly dividing cell mass a “fetus” until nine weeks into pregnancy. Yet, the current debate shows how effectively politicians have used visual technology to redefine what counts as “life.”

Since the mid-1990s, opponents of abortion have deployed ultrasound in their attempts to restrict abortion access. Five states have enacted “informed consent” laws, which require doctors to show their patients ultrasound images, and in some cases to describe the images, before performing an abortion. Two of those laws have been struck down by state courts. Twenty other states require a doctor to at least offer to show a woman seeking an abortion ultrasound.

These measures are based on two assumptions: First, that an ultrasound image has an obvious meaning. Second, that any pregnant woman who sees an ultrasound will recognize this meaning. Science does not bear either assumption out.