Warning: Cannot modify header information - headers already sent by (output started at /home/content/70/7481070/html/appsrc/doyouknow.php:18) in /home/content/70/7481070/html/header.php on line 20

Warning: Cannot modify header information - headers already sent by (output started at /home/content/70/7481070/html/appsrc/doyouknow.php:18) in /home/content/70/7481070/html/header.php on line 21
Do You Know
Questions & Answers on General Knowledge.

The earth's surface is moving at something like 950 mph as it rotates. Why don't we notice this when we are in an airplane?
It's true that the earth's surface is moving eastward rapidly relative to the earth's center of mass. However, that motion is very difficult to detect. When you are standing on the ground, you move with it and so does everything around you, including the air. While you are actually traveling around in a huge circle once a day, for all practical purposes we can imagine that you are traveling eastward in a straight line at a constant speed of 950 mph relative to the earth's center of mass. Ignoring the slight curvature of your motion, you are in what is known as an inertial frame of reference, meaning a viewpoint that is not accelerating but is simply coasting steadily through space. You'll notice that I keep saying "relative to the earth's center of mass" when I discuss motion. I do that because there is no special "absolute" frame of reference. Any inertial frame is as good as any other frame and your current inertial frame is just as good as anyone else's. In fact, you are quite justified in declaring that your frame of reference is stationary and that everyone else's frames of reference are moving. After all, you don't detect any motion around you so why not declare that your frame is officially stationary. Since the air is also stationary in that frame of reference, flying about in the air doesn't make things any more complicated. You are flying through stationary air in your old stationary frame of reference. The only way in which the 950 mph speed appears now is in comparing your frame of reference to the rest of the earth: in your frame of reference, the earth's center of mass is moving westward at 950 mph.
--- >>>
More Questions:
  • What’s an Achilles heel?
  • Why is a secret enemy amongst us referred to as a “fifth column”?
  • When did the first cycle roll?
  • Why can't CD's be recorded onto other CD's?
  • Did Napoleon inspire other leaders?
  • How do seabirds catch their food?
  • What is a desert?
  • How can I make an electric generator from scratch?
  • How many countries make up South America?
  • Why does criss-cross mean back and forth?
  • In modern car alarm systems, people can start the engine with a push of a button from a remote. How is this done?
  • Was theatre popular in the United States?
  • Why are swept wings preferred for transonic/supersonic flight, but not for lower speeds?
  • Why are hurricanes called monster storms?
  • Why do people wear uniforms?
  • Why do monarchs refer to themselves using the “royal we”?
  • How do insects breathe?
  • Was one of the early Egyptian calendars a 365-day calendar?
  • Can a plant grow in ice and snow?
  • How can heat be trapped?
  • Why do we tell someone to “get off his keister” when we mean stand up and do something”?
  • How do oil spills/spots (i.e. in parking lots and streets) create rainbows?
  • Did dinosaurs get sunburned?
  • Which country is the biggest?
  • What is the relative insulating value of various levels of vacuum? For example, how insulating is 1/2 atmosphere as compared to full atmosphere?
  • World Adventures
  • Quick Tips To Build Brawn
  • Galileo Galilei
  • Allergy
  • Mouthwatering Foods to Try
  • Worlds Most Beautiful Small Towns

  • The Lion and Rabbit

    Lion and Rabbit Step 15

    That was the end of the lion and all animals lived happily in the jungle.

    Chourishi Systems