50 Question Challenge #8, Science: answers and sources
Spoilers ahead! Play the video first. Here is every answer, the fun fact and the source we checked it against.
Scores: 0-19: Lab rookie · 20-29: Lab assistant · 30-39: Rocket scientist · 40+: Nobel material. Don't forget your Couch Wager. Spotted a mistake? Email hello@ahaville.com with the question number.
Level 1: Easy
- 1
What force keeps your feet on the ground?
Gravity Earth's gravity pulls everything toward its center.
Source: wikipedia.org/wiki/Gravity
- 2
What is at the center of our solar system?
The Sun It holds about 99.8% of the solar system's mass.
Source: science.nasa.gov/sun/facts/
- 3
What do we call molten rock flowing out of a volcano?
Lava Underground, the same molten rock is called magma.
- 4
Which tool makes tiny things look bigger?
A microscope Robert Hooke named “cells” after viewing cork through one.
Source: wikipedia.org/wiki/Robert_Hooke · wikipedia.org/wiki/Micrographia
- 5
Which gas makes the bubbles in soda?
Carbon dioxide It's dissolved under pressure, then fizzes out.
- 6
What do you call a scientist who studies rocks?
A geologist Geologists also study volcanoes and earthquakes.
Source: wikipedia.org/wiki/Geologist · wikipedia.org/wiki/Geology
- 7
Which part of a plant takes in water from the soil?
The roots Tiny root hairs help soak up the water.
Source: wikipedia.org/wiki/Root_hair
- 8
What happens to water when it freezes?
It expands Ice takes up about 9% more space, so it floats.
- 9
A compass works because Earth acts like a giant what?
A magnet Its needle points to magnetic north, not true north.
Source: wikipedia.org/wiki/Earth%27s_magnetic_field · wikipedia.org/wiki/North_magnetic_pole
- 10
What is a shooting star, really?
A space rock burning up Scientists call the streak of light a meteor.
Source: science.nasa.gov/solar-system/meteors-meteorites/facts/
Level 2: The human body
- 11
What is the common name for the patella?
The kneecap Babies' kneecaps start out as soft cartilage.
Source: wikipedia.org/wiki/Patella
- 12
Which blood vessels carry blood away from the heart?
Arteries Veins carry the blood back to the heart.
Source: wikipedia.org/wiki/Artery
- 13
How many baby teeth do children usually have?
20 They usually start falling out around age six.
- 14
When you bump your funny bone, what makes it tingle?
A nerve It's the ulnar nerve, just under the skin.
Source: wikipedia.org/wiki/Ulnar_nerve
- 15
What are your fingernails mostly made of?
Keratin Your hair is made of keratin too.
Source: wikipedia.org/wiki/Nail_(anatomy) · wikipedia.org/wiki/Keratin
- 16
Which organ makes insulin?
The pancreas Insulin helps your cells take in sugar.
Source: wikipedia.org/wiki/Insulin
- 17
What is the proper name for your voice box?
The larynx Your vocal cords sit inside it.
Source: wikipedia.org/wiki/Larynx
- 18
What carries oxygen inside your red blood cells?
Hemoglobin It also gives blood its red color.
Source: wikipedia.org/wiki/Hemoglobin · wikipedia.org/wiki/Blood
- 19
Which vitamin prevents scurvy?
Vitamin C British warships began a daily lemon juice ration in 1795.
Source: wikipedia.org/wiki/Scurvy
- 20
Where is the smallest muscle in your body?
In the ear It steadies the body's smallest bone, the stapes.
Level 3: Quick elements
- 21
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Level 4: Space and physics
- 31
Which scientist gave us the three laws of motion?
Isaac Newton He published them in 1687.
- 32
Why do we have seasons?
Earth's tilt Earth is closest to the Sun in early January.
Source: spaceplace.nasa.gov/seasons/
- 33
Sound travels fastest through which of these?
Steel In empty space, sound can't travel at all.
Source: wikipedia.org/wiki/Speed_of_sound · wikipedia.org/wiki/Sound
- 34
What mainly causes ocean tides?
The Moon's gravity The Sun's tidal pull is about half the Moon's.
Source: oceanservice.noaa.gov/education/tutorial_tides/tides02_ca...
- 35
How much would you weigh on the Moon?
About a sixth as much Your mass stays the same; only gravity changes.
- 36
After the Moon, which natural object shines brightest in the night sky?
Venus Its thick clouds reflect most of the sunlight.
Source: science.nasa.gov/venus/venus-facts/ · wikipedia.org/wiki/Venus
- 37
Which planet spins tipped over on its side?
Uranus Its axis is tilted about 98 degrees.
Source: science.nasa.gov/uranus/facts/
- 38
In E = mc², what does the c stand for?
The speed of light Einstein published the idea in 1905.
- 39
Which star is closest to our Sun?
Proxima Centauri Its light takes about 4.2 years to reach us.
- 40
What sits at the center of our galaxy?
A giant black hole It has about 4 million times the Sun's mass.
Level 5: Impossible
- 41
What is the most common element in Earth's crust?
Oxygen It makes up about 46% of the crust by weight.
Source: wikipedia.org/wiki/Abundance_of_elements_in_Earth%27s_crust
- 42
Which metal conducts electricity best at room temperature?
Silver Most wires use copper: nearly as good, far cheaper.
Source: wikipedia.org/wiki/Silver · wikipedia.org/wiki/Copper_conductor
- 43
At what temperature are Celsius and Fahrenheit equal?
−40° It's the one point where both scales meet.
Source: wikipedia.org/wiki/Fahrenheit
- 44
Which of these is smallest in diameter?
Pluto Pluto is only about two-thirds as wide as our Moon.
- 45
What is the densest natural element?
Osmium It's about twice as dense as lead.
Source: wikipedia.org/wiki/Osmium
- 46
What is missing from a mature human red blood cell?
A nucleus That leaves more room for hemoglobin.
- 47
What does DNA stand for?
Deoxyribonucleic acid Its double helix shape was described in 1953.
Source: wikipedia.org/wiki/DNA
- 48
Which bone doesn't form a joint with any other bone?
The hyoid It sits in your neck and anchors your tongue.
Source: wikipedia.org/wiki/Hyoid_bone · my.clevelandclinic.org/health/body/hyoid-bone
- 49
Which planet has a giant hexagon at its north pole?
Saturn This six-sided jet stream is wider than two Earths.
Source: science.nasa.gov/mission/cassini/science/saturn/hexagon-i... · wikipedia.org/wiki/Saturn%27s_hexagon
- 50
Who is the only person with Nobel Prizes in two different sciences?
Marie Curie Physics in 1903, then chemistry in 1911.
Source: wikipedia.org/wiki/Marie_Curie · nobelprize.org/prizes/facts/nobel-prize-facts/
The Big Aha stories
- The mirrors on the Moon: In 1969, the Apollo 11 crew left a panel of 100 special mirrors on the Moon. Scientists on Earth still fire lasers at mirrors like it, and time how long the light takes to bounce back. That's how we know the Moon moves about 3.8 cm (1.5 inches) farther away every year. That's roughly how fast your fingernails grow! Sources: wikipedia.org/wiki/Lunar_Laser_Ranging_experiments · jpl.nasa.gov/news/apollo-11-experiment-still-going-strong... · nasa.gov/image-article/retroreflectors-from-apollo-mars · wikipedia.org/wiki/Nail_(anatomy)
- The spacecraft lost to a unit mix-up: In 1999, NASA's Mars Climate Orbiter reached Mars. Then it was lost. One team's software gave thruster data in US pound units. The navigation team expected metric units. So the spacecraft flew far too close to Mars, and it was never heard from again. A simple unit mix-up cost a whole spacecraft. Always check your units! Sources: wikipedia.org/wiki/Mars_Climate_Orbiter · llis.nasa.gov/llis_lib/pdf/1009464main1_0641-mr.pdf
Bonus question
What color is the Sun, seen from space? We reveal the answer in the pinned comment under the video.