How do we know that pulsars must be neutron stars? a) We have observed massive-star supernovae produce pulsars.
b) This is only a theory that has not yet been confirmed by observations.
c) No massive object, other than a neutron star, could spin as fast as we observe pulsars to spin and remain intact.
d) Pulsars have the same upper mass limit as neutron stars do.
e) Telescopic images of pulsars and neutron stars look exactly the same.

Acommon technique in analysis of scientific data is normalization. the purpose of normalizing data is to eliminate irrelevant constants that can obscure the salient features of the data. the goal of this experiment is to test the hypothesis that the flux of light decreases as the square of the distance from the source. in this case, the absolute value of the voltage measured by the photometer is irrelevant; only the relative value conveys useful information. suppose that in part 2.2.2 of the experiment, students obtain a signal value of 162 mv at a distance of 4 cm and a value of 86 mv at a distance of 5.7 cm. normalize the students' data to the value obtained at 4 cm. (divide the signal value by 162.) then calculate the theoretically expected (normalized) value at 5.7 cm.