Compare the light-gathering powers of one of the Keck telescopes (10 m in diameter) and a 6 m telescope.?

Question

Compare the light-gathering powers of one of the Keck telescopes (10 m in diameter) and a 6 m telescope.
Keck/6 m =

Answer 1

The light gathering power of a telescope is linearly dependent on the amount of surface area the telescope has, minus any obstructions of the optical path. Since I have no idea how large of a central obstruction the Keck has, or a 6m telescope, we'll just assume they are the same percentage, and basically ignore that.

Surface area of a circle is Pi * R * R (Pi times R squared). Pi * (10^2) = Pi * 100 = 314m^2. Pi * (6^2) = Pi * 36 = 113m^2.

You can divide the two to see how they compare:

314 / 113 = 2.78.. So the 10m Keck scope gathers 2.78x the amount of light that a 6m telescope would.

Answer 2

Keck Telescopes

Answer 3

it is difficulty-free, a 10 meter telescope collects 2.8 situations as lots gentle as a 6-meter telescope will. it is assuming each and every telescopes' optics have coatings that mirror the comparable share of light, the equivalent gentle loss as a effect of the presence of the secondary mirror etc. In sensible words, a 10-meter telescope will see gadgets an entire value dimmer than a 6 meter telescope can, under the comparable stipulations on the equivalent internet web site.

Answer 4

That's easy, a 10 meter telescope collects 2.8 times as much light as a 6-meter telescope will. That is assuming both telescopes' optics have coatings that reflect the same percentage of light, the same light loss due to the presence of the secondary mirror and so on. In practical terms, a 10-meter telescope will see objects a full magnitude dimmer than a 6 meter telescope can, under the same conditions at the same site.

Answer 5

Bill C has the right answer, though he took the long way around. Light gathering power is proportional to area, and area is proportional to diameter squared. So the ratio of light gathering power is equal to the ratio of diameters, squared: (10/6)^2 = 2.78. One of the Keck telescopesscopes gathers 2.78 times as much light as a 6m scope.