Imagine a place that is 30 Kms or 18.5 miles away from your home. It could be your school, office, beach, anywhere. If you live in US like I do, your average speed on the freeway is 60 miles per hour or 1 mile per minute. That means if you are driving in your car, it will take you 20 minutes approx to reach your imagined destination.
Now if there were no speed limits and if your car could go as fast as the earth goes around the sun, which is 67000 miles per hour or 30 kms per second, all it would take to reach your destination is a mere ONE second! Yes, that’s how fast our earth is traveling on its orbit around the sun.
Another easy way to comprehend earth’s speed is to look up in the sky and spot a commercial airplane. Aeroplanes fly at a height of 10 kilometers from the earth. Now imagine 3 times that distance. That is the distance which earth covers in one second. Does it mean that the pilots of these airplanes need to be concerned about the earth moving forward and possibly hitting them on their belly? Obviously not, because the atmosphere and the plane also move along with the earth, thank God.
Hopefully the above explanation makes it crystal clear how fast of a joyride our earth is taking us on, all the time. However there is another side to this story which shows that relative to the earth’s size and the distances it needs to travel, it is actually not moving as fast as it seems.
It takes sunlight 8 minutes to reach the earth each morning which is why the distance between the earth and the sun is 8 light minutes. Apply some basic geometry (cirumference = product of PI and diameter), the distance traveled by earth in a year can be represented as approximately 50 light minutes. This means that the distance that earth travels in 1 year, can be covered by light in less than an hour. On the other extreme, an aeroplane will take a 100 years to cover this distance, and if you are driving, it will take you a thousand years. Boy, we humans are sure slow, but that still doesn’t mean earth is moving any faster. To get a better appreciation of the reasoning behind this claim, read on.
While a 67000 miles per hour speed of the earth sounds astonishing, taking into account the size of the earth, this is a very slow speed. It is easier for us to imagine with the analogy that follows. If we transpose the earth to the size of a 9 inch soccer ball, and also trasponse all the other distances, speed and time to more comprehesible units, we will see that the earth is like this soccer ball that is inching forward at a speed of 1.2 inches per minute. Now this is much easier to comprehend, and hopefully drives home the point that the earth is not moving as fast as it seems, or for that matter, does not seem.
Here is a summary of my calculations on which the above write-up is based:
Average distance between sun and earth 92,955,819 miles (93 million miles)
Distance that earth travels each year 584,293,721 miles (a little more than half billion miles)
Time to travel this distance 365.25 days * 24 hours = 8766 hours
Speed of the earth 66,655 miles per hour
Diameter of the earth 7,918 miles
Circumference of the earth 25,104 miles
Diameter of a soccer ball 9 inches
Corresponding speed of ball 72 inches per hour (or 1.2 inches per minute)
