In the Lighthouse Model:

Question

Quizplus · Accepted Answer

The Lighthouse Model states that if the beam of radiation from a pulsar sweeps across us, we will detect a pulse of radiation. This is because the pulsar's magnetic field is aligned with its rotational axis and as the star rotates, the magnetic poles sweep past us causing the beam of radiation to sweep across our line of sight. The lighthouse model states that if the beam of radiation emitted by a pulsar sweeps across us, we will detect a pulse of radiation. This is because the pulsar's magnetic field is tilted with respect to its rotation axis, causing the beam to sweep around like a lighthouse beacon. Choice A is incorrect because the star doesn't actually turn on and off, but rather the beam of radiation sweeps across us. Choice B is incorrect because while it is true that pulsars have their magnetic poles pointed towards us, this doesn't necessarily mean that the beam will sweep across us. Choices D and E are both incorrect because they describe effects that don't actually occur in pulsars. The period of pulsation (i.e. the time interval between detected pulses) can slow down over time due to various factors, such as magnetic braking or accretion of matter, but it doesn't speed up as the neutron star collapses.