Welcome to BYJU’S ‘Tell Me Why’ where we explain to you the ‘why’ behind anything and everything that’s been on your mind! So go ahead and ask us a question that starts with ‘Tell Me Why’. We’ll pick the most intriguing questions and feature them along with an illustrated answer on our blog.
To ask your question, fill up the form here:
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Today we are answering a very interesting question asked by class 10 student Vivek Kumar, from Hyderabad. He wants to know:
Wait, what? The Earth is actually flat, haven’t you heard?
Kidding! We’ve actually known that the Earth is round for at least 2,000 years. In fact, the vast majority of objects in our solar system are spherical, from the Sun to planets to moons.
But before we answer that question, we must actually ask ourselves how do we know for sure that our home is a globe and not a flat flying disk.
Fair enough! As students of science, we must not accept any truth without asking for proof.
The most optimal way to determine whether our planet is a thick disk or a huge sphere is to view it from a more distant perspective. One such picture would be enough to falsify one hundred claims about the Earth being not a globe.
Satellites and astronauts have provided us with many pictures of Earth’s blue curvaceous body, but apparently, these pictures are not enough. Those who believe that the Earth is flat could claim that they all are fake pictures. The technology to make such realistic fake images does exist and can be quite easily afforded by multi-billion-dollar government-funded organizations like NASA. So, fair enough.
Simple yet undeniable evidence that proves a curved Earth was gathered more than 2,000 years ago. Around 250 B.C., a few Greeks realized it with just two sticks. They fixed two sticks on the Earth’s surface 500 miles apart from each other in two different cities.
If the Earth was flat, the Greeks would have observed that both sticks cast no shadow when the Sun was directly above them. However, what they observed was that the stick located 500 miles towards the north did cast a shadow while the other one did not!
It’s a no-brainer that this is possible if and only if the Earth’s surface is curved such that the other stick is “inclined”.
Two sticks, that’s all it takes!
Here is another proof. Greek philosopher Aristotle observed that the shadow Earth casts on the moon during a lunar eclipse is shaped like an arc. It is then Clark-Kent-is-Superman kind of obvious that such a shape can only be witnessed when the illuminated object is curved, more precisely, a sphere.
This is a reasonable question to ask: if the earth is round, why don’t I “feel” or “see” this curvature. The surface does appear flat when viewed from the top.
Actually, people can’t “see” the curvature because they simply haven’t climbed high enough. For a six-foot-tall person, the curvature is approximately 3 miles away. Studies place the threshold altitude for seeing Earth’s curvature at about 35,000 feet. Even at this height, it is difficult to discern the curve as the observer requires a wide angleview.
That’s the same reason why it is impossible to see the curvature of the Earth even from an aeroplane that flies up to 28,000 feet above sea level.
If you really want to see the curvature of the Earth, you just have to climb up high enough. Or take a trip to space like Jeff Bezos did!
Now that we know the answer to how do we know that the Earth is a sphere, we must ask the ‘why’ question.
Seriously, why are planets spherical? Why don’t we live on a cylindrical or cube-shaped planet?
The main culprit is gravity. Gravity is a force, which means that it pulls on things. But the Earth isn’t the only thing which has gravity. In fact, everything in the universe, big or little, has its own pull because of gravity – even you.
Why does everything have gravity? Because everything has mass. Mass is a measure of how much material there is in anything. It could be in the form of rocks, water, metal, gases, people – anything..
Isaac Newton was one of the first scientists to figure out the rules of how gravity behaves. And one important rule of gravity is that it always pulls toward the center of mass.
The Earth and all planets are round because when the planets formed, they were composed of molten material – essentially very hot liquid. Since gravity always points toward the center of a mass, it squeezed the stuff the Earth is made of equally in all directions and formed a ball. When the Earth cooled down and became a solid, it was a round ball.
And voila! We have our round abode! What if Earth stops rotating all of a sudden? What would that lead to?
We hope we have answered all the questions. And thank heavens that the planets are spheres! If they were tetrahedrons or toruses or pentagonal prisms, it would be much trickier to make a solar system model.
Read more Tell Me Why stories like these here!
Raza has been writing since 2008, be it fiction, poetry, or articles on science, politics, and history. He believes that words can change the world, and he uses them to inspire and empower people through his writing. When he is not working, he is watching nature documentaries or playing with his cats.
Arya C is a 4th grader who talks about her transition from the US to India and how BYJU`S has helped her at that. She also loves how BYJU`S has made learning a lot more fun.
Meet Sourabh who has a ton to say about his BYJU`S learning experience. His love for quizzes, games and other fun activities are paying off!
V Shriya is a class eight student who has been using BYJU’S for a year now. She shares her experiences with using the app and how it has helped her in improving her academic performance.
Aanvi from class 9 has been with BYJU`S for just 6 months and hear what she has to say about her learning experience with the app.
Comments
Sniti
April 12, 2022
Earth is like a sphere bcoz of
Gravitational force of sun .
Moon n earth
ANANTHA bhavaani prasad
April 11, 2022
Kidding! We’ve actually known that the Earth is round for at least 2,000 years. In fact, the vast majority of objects in our solar system are spherical, from the Sun to planets to moons.
But before we answer that question, we must actually ask ourselves how do we know for sure that our home is a globe and not a flat flying disk.
Fair enough! As students of science, we must not accept any truth without asking for proof.
The most optimal way to determine whether our planet is a thick disk or a huge sphere is to view it from a more distant perspective. One such picture would be enough to falsify one hundred claims about the Earth being not a globe.
Satellites and astronauts have provided us with many pictures of Earth’s blue curvaceous body, but apparently, these pictures are not enough. Those who believe that the Earth is flat could claim that they all are fake pictures. The technology to make such realistic fake images does exist and can be quite easily afforded by multi-billion-dollar government-funded organizations like NASA. So, fair enough.
Simple yet undeniable evidence that proves a curved Earth was gathered more than 2,000 years ago. Around 250 B.C., a few Greeks realized it with just two sticks. They fixed two sticks on the Earth’s surface 500 miles apart from each other in two different cities.
If the Earth was flat, the Greeks would have observed that both sticks cast no shadow when the Sun was directly above them. However, what they observed was that the stick located 500 miles towards the north did cast a shadow while the other one did not!
It’s a no-brainer that this is possible if and only if the Earth’s surface is curved such that the other stick is “inclined”.
Two sticks, that’s all it takes!
Here is another proof. Greek philosopher Aristotle observed that the shadow Earth casts on the moon during a lunar eclipse is shaped like an arc. It is then Clark-Kent-is-Sup
This is a reasonable question to ask: if the earth is round, why don’t I “feel” or “see” this curvature. The surface does appear flat when viewed from the top.
Actually, people can’t “see” the curvature because they simply haven’t climbed high enough. For a six-foot-tall person, the curvature is approximately 3 miles away. Studies place the threshold altitude for seeing Earth’s curvature at about 35,000 feet. Even at this height, it is difficult to discern the curve as the observer requires a wide angleview.
That’s the same reason why it is impossible to see the curvature of the Earth even from an aeroplane that flies up to 28,000 feet above sea level.
If you really want to see the curvature of the Earth, you just have to climb up high enough. Or take a trip to space like Jeff Bezos did!
And voila! We have our round abode!
nice to meet you byjus
Aaradhya Pandey
April 11, 2022
I Like this video please send me
Ayush Dekate
April 10, 2022
A planet’s gravity pulls equally from all sides. Gravity pulls from the centre to the edges like the spokes of a bicycle wheels. This makes the overall shape of a planet a sphere, which is a three- dimensional circle.
Harsh Gupta
April 10, 2022
1.)What is Holographic Universe?
2.)Why we cannot enter in the Black Hole?
Shaikh Fatima Zikra
April 10, 2022
A planet is round because of gravity. A planet’s gravity pulls equally from all sides. Gravity pulls from the center to the edges like the spokes of a bicycle wheel. This makes the overall shape of a planet a sphere, which is a three-dimensional circle.
Ananya Kumari
April 10, 2022
Very interesting ?
S.m.thamizharasan
April 9, 2022
Good
Araminta Ajith
April 9, 2022
The planets are round because of the gravitational pull the gravitational pull that I mean is not the gravitational pull of the Sun which keeps the planet in their orbits or the pull of the earth that keeps all of us on the ground it is none of these it is the pull of each and every planet the gravitational pull of all the planet in the solar system is to the centre of the planet the gravitational pull of the earth is coming from the centre of the earth gravity act as a machine that all keeps us on the ground in gravity is very important for all the first to survive even a disaster could happen if gravity is absent for just 5 seconds gravity all of us to the centre of the earth that does not mean we will be pointed to the centre of the earth It means that gravity acts on us downwards so that if we are in any position gravity will act us even if we are at the bottom of the earth It will act on us
Ayush Shah
April 9, 2022
Why the moon is cold and looking white from Earth ?.
Amey Jangam
April 9, 2022
Planets are round because of gravity.
Shafquat Zabin
April 9, 2022
Thankyou byjus for this informative series
I have one question:-
Why Our nails have no blood?
Amogh Kottada
April 9, 2022
If gravity made the planets round, them why are we not round. Because even we have gravity. And if the size is the answers then what about moons, asteroids and meteroids?
Vishaya
April 9, 2022
Earth is round because it has infinite states.
Other planets are round because it has infinite space / cities
Ranodip Paul
April 9, 2022
The earth is round because of the sun’s ultimate gravity.The sun’s gravity makes everything round and if the object is not round , the sun’s gravity starts working and the pressure pressent in gravity makes it round
Mayuri Priti Dayama
April 9, 2022
1.A planet is round because gravity.
Aaradhya
April 9, 2022
This answer is very useful for me ?and now I will also tell ‘”Why planets round in shape” to my friends
Daksh Deepak Swami
April 9, 2022
Planet is round because gravity of planets gravity pull equally from all sides gravity pull from the centre to the age like the smoke of a bicycle wheels these make the over all shape of a planet a sphere which three dimensional circle
Sneha Khan
April 9, 2022
•The force of gravity from all sides of the earth may cause the round shape.
• but the earth is not totally round it’s really looks samne as orange ( fruit) figure
mounish.R
April 9, 2022
The gravitational force of a planet’s mass pulls all of its material toward the center, smoothing out any jarring non-roundness. Many of the smaller bodies of the solar system are not round because their gravity is not enough to smooth out their shape.
Anishka Mohanty
April 9, 2022
The earth is round . The proof is if you start walking from a point and keep on walking you will reach on the same point
Sagnik Chowdhury
April 9, 2022
Today I came to know that all planets are round due to presence of gravity in them.
Krishna gupta
April 8, 2022
Because earth has gravitational force or due to magnet force always rational north to south movement that s way sphere.
Maanav
April 8, 2022
Nice?????????
Khushi
April 8, 2022
Earth planet’s gravity pulls equally from all sides
Vidya Reddy
April 8, 2022
Why is the land flat ?
Shoaib Mohammadali sayyad
April 8, 2022
The Sun and all eight planets of the solar system are round. Why? The gravitational force of a planet’s mass pulls all of its material toward the center, smoothing out any jarring non-roundness. Many of the smaller bodies of the solar system are not round because their gravity is not enough to smooth out their shape.
Tanishq s daharwal
April 8, 2022
What is atmosphere
Tejas Burkul
April 8, 2022
a planet is a round because of gravity. A planet gravity pulls equal from all side gravity pull from the center to the ages like the spoke of bicycle wheel this makes the overall shape of a planet a sphere which is a three dimensional circle
B.Lakshmipathy.
April 8, 2022
Because of Gravity of the Earth and other planets.
Bhavya Dashrath Panchal
April 8, 2022
1.Why the temperature of inner core of earth is very high like sun?
2.Why Jupiter and saturn are made from gases?
3.Why do humans are very intelligent and capable of doing such great things but other animals can’t?!
Pls give me the answer
Arpita Das
April 8, 2022
Nice…..??
Gunin
April 8, 2022
The gravitational force of the planets mass pulls all of its material towards the center smoothing out any jarring non roundness
Dhatrisree
April 8, 2022
Is there a chance for the Multiverse to exist?
Aryan Sinha
April 8, 2022
Due to gravity and force
Joyshree Das
April 8, 2022
I can understand very easily
Raj Kumar Gupta
April 8, 2022
This is amazing about the earth . thank you for this information ??
Sushil kumhar
April 8, 2022
Ans: the gravitational force of a plants pulls mass and some materials of plants.
Vijay KUMAR
April 8, 2022
I like byju’s
Yogita
April 8, 2022
The answer is the gravity allows the planet to be sperical
Chirag jha
April 8, 2022
Most beautiful words you use in it
Avya Singh
April 8, 2022
1.) The planet is round because of gravity
Smital
April 8, 2022
Clouds are just water vapour, so why do they move?
Toufiq
April 8, 2022
Because of gravity
Abhishek Gupta
April 8, 2022
Due to the Force of Sun’s Gravitational Force.
Sneha Gautam
April 8, 2022
A planet is round because of gravity,A planet gravity pulls equally from all sides gravity pulls from the center to the edge like the spokes of a bicycle wheel this makes the overall shape of a planet a sphere, which is three-dimensional circle
Nargis Shahin
April 8, 2022
Just like our universe is there many universe.
Kashish Fatima
April 8, 2022
The gravitational force of planet’s mass pulls all of its material toward the centre, smoothing out any jarring non-roundness.
Shreya
April 8, 2022
Respected sir/mam,
These are my Tell Me Why questions??
1) Why there is no gravity in space?
2) Where does the sun goes in the night?
Please answer me.
Thank you
Anand
April 8, 2022
Because all planets made by rock and other particles also gases and because of gravity when Earth is made it get a shape called circle and also all planets get circle shape beacuse of gravity
SAYALI
April 8, 2022
All planets are round because they need to revolve around the sun. And if planets are square, rectangle, and triangle then we cannot drive boats in oceans
Priyanshi saini
April 8, 2022
A planet is round because of gravity
Prachi Vilas pimpale
April 8, 2022
Tell me why water ,air and all other components that is needed for the survival of animals is on the earth and why not on the other planets.
Ankit Kumar Pradhan
April 8, 2022
A planet’s gravity pulls equally from all sides. Gravity pulls from the center to the edges like the spokes of a bicycle wheel. This makes the overall shape of a planet a sphere, which is a three-dimensional circle
Om kadahatti
April 8, 2022
Why is it’s round
Rishab Jitendra Sharma.
April 8, 2022
Because earth have gravity
Priyal Patel
April 8, 2022
A planet is round because of gravity. A planet’s gravity pulls equally from all sides.
Hargun Singh
April 8, 2022
Earth is round because of gravity.
Ansh Sharma
April 8, 2022
?ℹ️ Cool ?
Avantikaa Das
April 8, 2022
Ummmmmm…….
I have been always wondering why every planet,star,and also the moon is round………………
Yay!!!!!!!!
I’m very happy that I got the answer
Thank you so much for the answer^_^^_^^_^^_^^_^^_^^_^^_^^_^^_^^_^(◍•ᴗ•◍)❤(◍•ᴗ•◍)❤(◍•ᴗ•◍)❤(◍•ᴗ•◍)❤(◍•ᴗ•◍)❤
Manas Nair
April 8, 2022
Gee! Never knew this as well as it has been explained in this article.
Thanks BYJU’S! really is informative. Keep it up!
Rajalaxmi dakua
April 8, 2022
Science
Ashish Mane
April 8, 2022
??
Kavya Kashyap
April 8, 2022
All the planet round because they are gravity are equal of all sides
Priyanshi
April 8, 2022
Because of there gravity.
C.Pooja
April 8, 2022
A planet’s gravity pulls equally from all sides. Gravity pulls from the center to the edges like the spokes of a bicycle wheel. This makes the over all shape of a planet a sphere,which is a three-dimensional circle
Aditi Sulgudle
April 8, 2022
Thanks ?
hanook
April 6, 2022
Is there any gravity in the centre of the earth, if so on which direction it pulls