Gravity’s Role in Earth’s Journey
Context:
An article by Adhip Agarwala (IIT Kanpur) highlights how gravity acts as the invisible force that keeps us grounded while the Earth travels at a speed of 1,07,000 km per hour.
The Discovery of Gravity:
About 400 years ago, Isaac Newton conceptualized gravity.
Popular folklore suggests he discovered it while watching an apple fall.
He realized that objects attract each other simply because they have weight (mass).
On Earth, we fall downwards because the Earth is the heaviest object around us
Theories that explain Gravity:
Gravity is a phenomenon where things with mass or energy are brought toward each other (force of attraction).
This force is proportional to the product of masses of the objects and inversely proportional to the square of the distance between them.
It is independent of medium.
The Roller Coaster Analogy:
While we feel stationary, the Earth is actually spinning and orbiting the Sun at a staggering speed of 1,07,000 km per hour.
We can compare this to being on a "roller coaster traveling in space," yet gravity acts as an "invisible seatbelt" that keeps us grounded and prevents us from flying off.
Friction and Aether:
Why don't we feel the speed?
Unlike a car moving on a road, Earth moves through the vacuum of space where there is no air and no friction.
This makes the journey incredibly smooth, similar to a plane flying at a constant speed in calm weather.
Disproving Aether:
Historically, scientists believed space was filled with an invisible medium called "aether" to facilitate movement.
Modern physics and experiments eventually disproved the existence of aether, confirming that space is a vacuum
The Advent of Space Study:
Understanding gravity allowed humanity to move from superstition to science.
Predicting Events:
We can now accurately predict solar and lunar eclipses and the motion of planets
Technology:
This knowledge enables us to launch satellites that power GPS, global communication, and the internet, which are now essential parts of daily life.