How long would it take a light wave of frequency 835 Hz to traverse the distance between Jupiter and Earth? (1 mile = 1.61 km; speed of light in a vacuum = 3 x 108 m/s) How long would it take a radio wave with a frequency ...
Find the distance in parsecs to Sirius, the brightest star in the night sky, which has an annual parallax of 0.376 arcsec. Calculate the circular speed of an object that orbits the Sun at a distance of 0.2 AU. (1 AU = 1.5e^{+11} meters, the distance be...
When considering such things as resolving power and image scale from the optical standpoint (ignoring the receptor/sensor part), all the action is occurring *between* the entrance pupil and the image surface. The relationship between wavelength of light, entrance pupil aperture and focal length as ...
The National Art Collections Fund has given a slab from the stone balustrade of a staircase of the palace at Persepolis, dating from the reign of Darius the Great or Xerxes, somewhere between 520 and 460 B.C. It is carved in relief with the figure of a human-headed lion, winged and ...
• Distance to Earth: 11.46 light years • Star Type: white main-sequence Procyon A (F5 IV–V), white dwarf Procyon B (DQZ) • Mass: Procyon A: 1.499 solar mass | Procyon B: 0.602 solar mass • Radius: Procyon A : 2.048 solar radii | Procyon B : 0.01234 solar radius ...
Between 5 and 10 percent of stars surveyed have planets at least 100 times as massive as Earth with orbital periods of a few Earth years or less. Almost 1 percent of stars have such giant planets in very close orbits, with orbital periods of less than one week. Some of these planets se...