Top 10 Tricky Science Questions: Answered

Why is the sky blue? Find the answers to this and other tricky science questions!
Why is the sky blue? Find the answers to this and other tricky science questions! | Source

How to Answer Children's Questions

Science is all about asking questions, and some of the most interesting and thought provoking questions come from the imaginations of children. They can be staring out of a window and then drop such bombshells as:

"How much does the sky weigh?"

The media often laments how few parents are equipped to answer these questions. Fortunately we live in the information age, with answers just a few clicks away; the important thing is never to dismiss or dodge these questions. This inquisitive nature passes by all too quickly—if you are unsure of an answer, seek it out with your child! Children crave parental attention and this is a great opportunity for you to spend time together whilst learning something new.

Here are some of the science questions I am asked quite often (particularly by my younger students). Each question has a simple answer, followed by a slightly fuller explanation and, where necessary, a link for more information. Enjoy!

1. Why Is the Sky Blue?

Light arrives on Earth from the sun in every colour (including 'colours' we can't see like UV and infrared). When the sunlight hits the Earth's atmosphere it collides with certain particles that 'shine' blue.

Explanation: What we see as white light is actually a mix of different colours, all with a different wavelength. We see colours when a particular wavelength of light gets reflected into our eyes (the other wavelengths get absorbed or pass through an object). Our atmosphere is around 78% nitrogen; when light collides with our atmosphere, the red and green wavelengths of light pass through unobstructed. The blue wavelength is reflected by the nitrogen in the atmosphere and eventually reaches our eyes. As there is so much nitrogen, you can see the blue light from everywhere—hence the colour of the sky!

Read "Why Is the Sky Blue?"


2. Why Is the Moon Sometimes out in the Day?

The Moon does not produce its own light—we see it when light coming from the sun is reflected off of the surface of the moon. Whenever the Moon reflects the Sun's rays we can see it —even in the day time. Just like in pool—it all depends on the angle! When the moon and sun are on the same side of Earth, the moon is 'out' in the day; when the moon and sun are on opposite sides of the Earth, the moon is 'out' at night.

Explanation: Just like the stars, the moon is always 'out.' Celestial objects do not go anywhere during the day, they are just outshone by the Sun and any remaining light is scattered by our atmosphere. When the sun, Earth and moon align correctly, enough light is reflected off the moon's surface to be seen from Earth, even during the day. The reason we can see the moon and not the stars is that the light reflected from the moon makes it 100,000 times brighter than the brightest star in the sky—bright enough to be seen during the day.

Ask an Astrophysicist

Are YOU a Question Master?

3. How Much Does the Earth/Sky Weigh?

A. The Earth weighs around 6,000,000,000,000,000,000,000,000 kg.

Explanation: This is particularly tricky: technically, the Earth weighs nothing, because weight depends on the gravitational field strength of the planet the object is on. The Earth is falling through space around the sun. However, some clever mathematical tricks returns the answer above. Basically, we look at the strength of the gravitational pull from the Earth on nearby objects to calculate this number

B. The sky weighs the same as 570,000,000,000,000 adult Indian elephants (according to the UK's Science and Technology Facilities Council).

Explanation: Air weighs something, but we don't notice it as it presses on us evenly from all directions and we are used to it. Helium balloons float because helium weighs less than air. Air pressing against us is called air pressure. Barometers work because the atmosphere has weight. If you are still struggling with the concept of air having weight, just think of a hurricane: all that is is moving air.

4. How Do Planes Stay Up?

Planes stay in the air because of the shape of their wings. Air moving over the wing gets forced downwards, which pushes the wing up. This 'push' is stronger than gravity and so makes the plane fly.

Explanation: This is a very technical subject that the video deals with very nicely. Planes take advantage of Newton's Third Law: for every action, there is an equal and opposite reaction. As air moving over the wing gets forced down, there is an equal and opposing force generated. This is a combination of the bottom of the wing getting 'pushed' up, and the top of the wing getting 'pulled' up.

Read "NASA: How Do Planes Fly?"

5. Why Is Water Wet?

'Wet' is ultimately just a word that applies to water. What we feel as wetness is actually coldness as the water evaporates. Below is an experiment from the Institute of Physics to test the feeling of 'wetness' between two different liquids:

"The feeling of wetness is actually coldness. You can test this by comparing water with another liquid - cooking oil - which doesn't evaporate so freely. Fill two small cups (egg-cups are ideal) - one with water, and the other with cooking oil. (Young children should ask an adult to help.) Let both liquids come to room temperature for a day, or overnight. Dip one index finger in each liquid, lift them out, and then observe for a few minutes."

Explanation: Liquids make surfaces wet (i.e. they stick to many solid surfaces) due to the electrostatic (opposite charges) forces between molecules. Water is polar—it has an uneven spread of electrical charge—which makes one end of the molecule positive and the other end negative. This causes water to be attracted to many surfaces and also explains many other properties of water.


6. What Makes a Rainbow?

When sunlight goes through droplets of water, the beam of light is 'split' into the different colours that make up light. The same effect can be seen if you shine a light through a glass prism.

Explanation: White colour is actually a mix of several different colours. Each constituent colour of a rainbow is caused by a specific wavelength of light. When light hits a medium that forces it to slow down, the light ray bends...but not equally. Each wavelength bends by a certain amount, which causes the different coloured rays of light to exit the raindrop in slightly different directions. This results in the colours 'fanning out.'

Read "Frequently asked questions about the rainbow."

7. Why Don't Birds get Electrocuted...

...when they land on electrical wires?

Because the birds are sat on only one wire and do not complete the circuit. Take a look at the video below for extra detail.

Explanation: To be 'electrocuted' you must be part of a complete circuit. You must touch both a positive wire, and a negative or neutral wire. If the bird was touching the ground, the ground would act as a neutral wire and the current would flow through the bird (i.e. electrocuting it). If the bird was sat on the wire and touched the metal of the pylon or another wire, it would also complete a circuit and get electrocuted. Because the bird is only sat on one wire, it is safe.

8. Are There Such Things as Aliens?

Short answer: We actually don't know.

Explanation: Whilst we know there are planets orbiting stars at the right distance for liquid water to exist, we have no idea if there is any form of life outside of our planet.

Read about the SETI Institute

9. Where Do Birds Go in Winter?

Many birds don't like our cold winters and fly south for the winter—it's like a six month holiday! Other birds like our winters and either stay, or fly here from further north. The reason we don't see many birds during the winter is that most of them have left!

10. Where Do Babies Come From?

This is one question where the scientific content actually comes second to the choice of the parents. Give an answer you feel comfortable with, whether that is the stork, each parent giving special gifts that grow into a baby...anything! The important thing is that you don't dodge this question. You must nurture this inquisitive nature! Have an answer ready—you never know when this question might pop out!

The Hardest Question?

Which Question do you think is most difficult to answer?

  • Why is the sky blue?
  • Where do babies come from?
  • Why is the Moon sometimes out in the day?
  • Why is water wet?
  • How do Planes stay up
See results without voting

More by this Author


Farmer Brown profile image

Farmer Brown 4 years ago

Great hub! Now to tackle the baby question...!

TFScientist profile image

TFScientist 4 years ago from Peterborough, UK Author

Thanks! Yeah...that is a tricky one. Answering with "They come from the fusion of two gametes to form a zygote that undergoes repeated cleavage, division and specialisation over a 9month gestation period" is likely to raise more questions than it answers!

Kris Heeter profile image

Kris Heeter 4 years ago from Indiana

Fun hub! Those are definitely great questions that aren't so easy to give the answers to kids:)

cclitgirl profile image

cclitgirl 4 years ago from Western NC

This is a great hub for parents to explore with their children. Voted up and awesome. :)

TFScientist profile image

TFScientist 4 years ago from Peterborough, UK Author

Thanks Kris and cclitgirl! I learnt a few new things researching this hub, and its great to know it has hit the mark! :)

Marcy Goodfleisch profile image

Marcy Goodfleisch 4 years ago from Planet Earth

What a neat hub! This would be great for kids as a learning tool. Fun stuff, and informative! Voted up and interesting.

scottcgruber profile image

scottcgruber 4 years ago from USA

I have a one year old and can't wait till he starts asking these questions. I've been studying up on Rayleigh scattering so I'll be prepared.

alocsin profile image

alocsin 4 years ago from Orange County, CA

Excellent hub for parents of 4-year-olds who are always asking these questions. Voting this Up and Useful.

Don Crowson profile image

Don Crowson 4 years ago

Excellent hub. Answers questions for older perople as well as the children. Thanks

TFScientist profile image

TFScientist 4 years ago from Peterborough, UK Author

Thank you all for your kind words. Glad to know that the hub is useful to others. I am planning a follow up to this hub with hubbers questions - take a look at the question I have posted if you have a science question that has always puzzled you

lobobrandon profile image

lobobrandon 4 years ago

Great hub ;) I liked the one of water being wet. The term came after water and not water after the term. So, water has to be wet otherwise wet wouldn't be wet :D

SolveMyMaze profile image

SolveMyMaze 4 years ago

Excellent hub, especially question ten!

Silwen profile image

Silwen 4 years ago from Europe

Great hub. It seems that I know physics, but sometimes it is very hard to answer such tricky questions. Your answers are clear and easy understandable. Thank you.

TFScientist profile image

TFScientist 4 years ago from Peterborough, UK Author

Thank you to all the commenters - I am so pleased that people are finding this hub interesting. I think it is my favourite so far! I hope this demonstrates that science doesn't need to be lofty and difficult to understand.

Simone Smith profile image

Simone Smith 4 years ago from San Francisco

What an enjoyable read this was! I had been told many of these explanations but enjoyed reading them again. Fabulous Hub!

Sun Pen 50 profile image

Sun Pen 50 4 years ago from Srilanka

"Each question has a simple answer, followed by a slightly fuller explanation and, where necessary, a link for more information. Enjoy" Yes,dear Scientist, I enjoyed the hub a lot. Pity that i do not have children of that age and grandsons are just passing that inquisitive stage. The granddaughter living faraway. Wish I had this info three four decades back. Thanks for a nicely designed and well explained hub up/awesome

chrisand profile image

chrisand 4 years ago

Wow, I really enjoyed these science facts. It was interesting to find out exactly what makes a plane stay up in the air, especially for someone like me who gets a little nervous when a plane I'm in is taking off :)

TFScientist profile image

TFScientist 4 years ago from Peterborough, UK Author

@Sun Pen: I'm sure you will still find some use for a couple of these facts - grandchildren tend to ask grandparents the tricky questions too!

@chrisand: Maybe you can settle your nerves now you know that planes get both a lift and a pull up :)

@Simone: I'm glad you enjoyed it

Thank you all for the positive comments!

Robin profile image

Robin 4 years ago from San Francisco

You have made the explanations so clear! I'm going to read this Hub to our 9 year old. She just asked us this morning, "Why if Mercury is closer to the sun is Venus hotter?" We had a great discussion about the sizes of the two planets and their atmospheres. She's only in 3rd grade, I know there will be a lot of questions that I can't answer and we'll have to look up very soon! I really appreciate this Hub!

DzyMsLizzy profile image

DzyMsLizzy 4 years ago from Oakley, CA

Ah, yes--very well written! My own kids are now adults, but I did strive not to dodge any questions, and help find the answers if I did not know.

On the baby question--the answer must fit the age of the child.

Airplanes--ah, yes--because my father worked in the aviation industry, and my ex-husband was into R/C planes, I've known that answer for a long time. But how much does the sky weigh? WOW! I'm glad I never had to field that one! "The sky," can be anything--our own atmosphere--but up to what altitude? Or it can be the entire vastness of space, which ends...who knows where?

And rainbows. They usually only happen when it is still raining...and are always opposite the direction of the sun. The common wisecrack in our (New England) family upon seeing a rainbow was, "Ah--the devil is fighting with his wife."

Voted up, interesting, useful, awesome and shared.

(P.S.--love your profile picture!)

Jennifer Essary profile image

Jennifer Essary 4 years ago from Idaho

Great Hub with excellent explanations! Voted up, useful, and sharing.

BlissfulWriter profile image

BlissfulWriter 4 years ago

I always liked reading about science. This is good.

MoiraCrochets profile image

MoiraCrochets 4 years ago from Cagayan de Oro City, Philippines

If I were still a science teacher I'd surely make this an assignment for my students.

anuramkumar profile image

anuramkumar 4 years ago from Chennai, India

Great hub. Will use this hub to teach my kid science.

TFScientist profile image

TFScientist 4 years ago from Peterborough, UK Author

Thanks to all! I am blown away by the positivity shown to this hub. I am trying to collate questions for a follow up hub - so if there are science questions that are bugging you, let me know!

janmejay 4 years ago

its good

Cre8tor profile image

Cre8tor 4 years ago from Ohio

What a great hub. Every one of these questions are ones that children ask and many don't have the answer to. Ups and bonuses!

coelocanth 4 years ago

I'm sorry but water is not wet. Water makes things wet but it is not wet in and of itself. Saying that water is wet is like saying that the film Love Story was sad. It wasn't; it made it's audiences sad, but the film itself was merely the projection of shades of colours designed to form images themselves designed to produce feelings of sadness in those viewing.

Also, the sky does not weigh anything because it has no physical entity. The answer you have given, imaginatively, in terms of Indian elephants, is, in fact, the weight of the atmosphere, which is an answer to a completely different question.

As for the rest of your hub, well done, 8 out of 10.

TFScientist profile image

TFScientist 4 years ago from Peterborough, UK Author

These are questions asked by 10 year olds. I am equating the sky to the atmosphere...I thought that was obvious.

I didn't say water was wet - I said there was no such thing as wetness. You didn't read that very well now did you?

Thanks for the patronising 8/10. I give your comment 6/10 as there were many irrelevent points and you did not read the hub thoroughly before commenting.

An AYM 4 years ago

Thumb up, for I adore science.

v1p3r 4 years ago

Excellent hub

Oilersmyth profile image

Oilersmyth 4 years ago from Edmonton, Alberta, Canada

Amazing hub! I'm following you right now!

Marcy Goodfleisch profile image

Marcy Goodfleisch 4 years ago from Planet Earth

I'm so glad to see this as a Hub of the Day - it is so full of interesting Information, and it answers all those questions our kids ask in the car, or when they're eating dinner, etc. Congrats on the HOTD - so deserved!

wayseeker profile image

wayseeker 4 years ago from Colorado

Congrats, TFT! Couldn't have happened to a better scientist! Now there's more for my kids to read, though I might wait a bit on that last question.

Great work,


KDuBarry03 4 years ago

Congrats on the HOTD! Well deserved and straight to the point :) Consider being a science teacher?

jpcmc profile image

jpcmc 4 years ago from Quezon CIty, Phlippines

Well done on the HOTD. Just try talking to kids and you'll never run out of difficult questions to answer. :)

jennzie profile image

jennzie 4 years ago from Lower Bucks County, PA

This is a great hub! I've wondered myself why birds don't get electrocuted on wires, and now I finally have the answer. :-)

rebeccamealey profile image

rebeccamealey 4 years ago from Northeastern Georgia, USA

Nice Hub. I enjoyed reading it. I use to drive my grandmother crazy asking where babies came from.....all she would tell me is from the cabbage patch!

yougotme profile image

yougotme 4 years ago from Manila

This is a wonderful hub that is so much informative. I enjoyed reading this because it somehow refreshed some memories. Great job!

jessefutch profile image

jessefutch 4 years ago from North Carolina

Incredible hub. My oldest son is only 7 and he is asking questions like "What would happen if we find dinosaur DNA and splice it with a lizard's DNA then create a clone with it?" and "What would happen if the Sun suddenly started to rotate the other way?" Maybe a future hub "Questions ahead-of-their-class kids ask and how to answer them" is in order? I really need help with these! Keep up the good work!

DzyMsLizzy profile image

DzyMsLizzy 4 years ago from Oakley, CA

Stopping back to say congrats on HOTD!! ;-)

Hui (蕙) profile image

Hui (蕙) 4 years ago

Children are much smarter than adults. They always have pure, simple but meaningful, and adults may feel ridiculous, questions out of imagination about nature and humans. They ask in an absorbing voice and a unique, while adults may feel bizarre, way of thinking, which is actually where the science begins.

This is a great hub, meaningful and educational.

Farmer Rachel profile image

Farmer Rachel 4 years ago from Minnesota

Great hub! I love the parts about the sky and the weight of the earth, especially. Congrats on Hub of the Day!!!

alexandria shinn 4 years ago

What is a kind of digestion where food is broken down by chemicals produced by the body.

cheetah786 4 years ago

great explantions, the wet water questions is answered greatly..

Pablo 245 4 years ago

I asked my mother were do babies come from once....(Ps I knew)

She told me they come from God.

Ankita 4 years ago

Great job :) :)..........

Jaffer 3 years ago

Nice hubs ANd Thnx

carrie Lee Night profile image

carrie Lee Night 3 years ago from Northeast United States

Fun and interesting hub ! :) Thank you for the explanation of science that we don't think about every day. Have a great week.

raymans 2 years ago

Hi, This is great hub and I came across it while looking for answers to my kid's questions.

About the blue sky, Nitrogen refelcts blue so we see blue sky. What color does oxygen reflect? that's what my son asked me and I couldn't find the answer elsewhere too so came back here.

I understand nitrogen makes up most of the atmosphere so we will only see blue but just to answer my kid I would like to know what color/s other gases in atmosphere reflect...If you have the time.



Haybae 13 months ago

I know the answer to where do babies come from but it is hard to explain it to a five year old. So I tell them they are tadpoles who swim into mama's tummy through a river. It keeps them quiet until they figure it out on there own. :)

abdulla 11 months ago

ha giid

kushagra singh 5 months ago

Which came first ?

1. Space

2. Time

erison10 2 months ago

this is weard it all easy

    Sign in or sign up and post using a HubPages Network account.

    0 of 8192 characters used
    Post Comment

    No HTML is allowed in comments, but URLs will be hyperlinked. Comments are not for promoting your articles or other sites.

    Click to Rate This Article