The identification of spiral nebulae as large groupings of stars outside of our own galaxy was proven by ____.
a. photographic plates made by Edwin Hubble showing stars and Cepheid variables
b. the results of the Shapley-Curtis debate
c. Immanual Kant's island universe theory
d. William Parsons' observation and description of their spiral structure
e. Harlow Shapley's observations of their radio spectrum
Question 2
What does a refracting telescope use to gather and focus light?
a. eyepiece
b. mirror
c. lens
d. photometer
e. active optics
Although large, the cougar is more closely related to smaller felines.
Albatrosses, of the biological family Diomedeidae, are large seabirds
Southern Royal Albatross, Diomedea epomophora, is a large seabird from the albatross family.
Lung cancer. Photograph of part of a lung removed after death. The yellow area is a large tumor and
Stars and the Interstellar Medium
Dynamics of a Grand-Design Spiral Galaxy