The first celebration of knowledge

Question 1

what is 100 billion in scientific notation?

Answer 1

1*10^11

Question 2

how many kilometers is one AU (Astronomical unit)

Answer 2

1.496*10^8 km

Question 3

what is an AU

Answer 3

Astronomical Unit; the distance between the earth and the sun

Question 4

if it takes light 8 minutes to reach earth from the sun, how long does it take for light to reach pluto, at a distance of 40 times greater than

Answer 4

about 5 hours

Question 5

what is the big bang

Answer 5

the “birth” of the universe about 13.7 years ago

Question 6

what was probably the most abundant element at the big bang

Answer 6

hydrogen (75%) (and helium (25%))

Question 7

formula for wave velocity

Answer 7

velocity = frequency * wavelength

Question 8

if a frequency of a wave were to double, how would a wavelength change if the wave velocity remains constant?

Answer 8

it would decrease by 2x

Question 9

the bigger the ______, the better

Answer 9

light gathering power (LGP)

Question 10

the smaller the ______, the better

Answer 10

Resolving Power (RP)

Question 11

bigger is SOMETIMES better with ______.

Answer 11

Magnification Power (MP)

Question 12

why do radio radio telescopes need to be built larger than other telescopes?

Answer 12

the larger they are built, the better resolution they have

Question 13

formula for LGP

Answer 13

pi(D/2)^2

Question 14

formula for RP

Answer 14

2.5 * 10^5 (wavelength/Diameter)

Question 15

formula for MP

Answer 15

focal point objective / focal point eyepiece

Question 16

why are telescopes built on remote mountaintops?

Answer 16

1. dark – far away from lights of civilization
2. dry – limits cloud cover and precipitation
3. calm – limits the the turbulence in the atmosphere
4. high – above the densest part of earth’s atmosphere

Question 17

what’s so important about LGP?

Answer 17

larger mirror = fainter objects

Question 18

The primary mirror of the Keck I telescope is about 10 meters in diameter. It is comprised of 36 smaller hexagonal mirrors that are each about 1.7 meters in diameter. How much LGP does the entire mirror have compared to a single hexagon?

Answer 18

36 times greater

Question 19

why can a telescope on the ground never reach its full resolution?

Answer 19

atmospheric turbulence can cause small deflections in light as it passes through atmosphere

Question 20

What is adaptive optics?

Answer 20

a method to compensate for the blurring effects of the atmosphere

Question 21

how can ground based telescopes achieve their maximum resolution

Answer 21

with adaptive optics

Question 22

What type of telescope can be used on the ground

Answer 22

radio telescopes; clouds don’t block radio waves.

Question 23

what is photometry?

Answer 23

measuring the brightness of objects at different wavelengths using different filters

Question 24

What is the focal length

Answer 24

the distance from the lens to where the light rays achieve a focus

Question 25

what does a refracting telescope do?

Answer 25

uses the lens as objective to collect and focus incoming light