World Science Scholars

2.4 Speed

discussion Discussion

Discussions are a place where registered users can click on Reply to share their ideas and questions that follow from the material we’re covering. All users can view the conversation and indicate their like or dislike for a specific comment.

Viewing 21 reply threads
    • What direct evidence do we have that the Earth is spinning? After all, much as in the example from the lecture in which George and Gracie are floating in space, we don’t seem to feel the Earth’s motion. (Hint: Is the rising/setting of the sun convincing evidence? Have you ever encountered a Foucault Pendulum?)

    • stars changed position cause the earth rotates

    • Foucault pendulum or the rotation of high/low pressure systems.

    • The shifting of the shadows show the world we live in is as much a shadow world as a world of light.

    • Day and Night due to rotation of Earth

    • Day and Night, Foucault pendulum

    • Day and night and Foucault pendulum. I would like to add perspective. Physics tells us that the earth is in constant motion, so now when I think of stillness, I remember this. This is kind of cool for me as an elderly woman coming back to physics. So much I have forgotten..

    • Position of stars change in the sky due to rotation of Earth.

    • the changes in position of stars

    • The Foucault pendulum proves the earth is rotating. The day night cycles shows us that the earth is rotating and the changing of shadows length also adds to this conclusion.

    • gnomon shadow changes, Coriolis Force, Faucoult Pendulum, movement of the stars,

    • day and night

    • so in the case of earth, the sun is moving for us means from our perspective, so this is same as car example the car is moving but from our perspective the world is moving, so in this earth case from our perspective the sun is moving but actually the earth is moving similar to the car example actually the car was moving

    • I would come to this by thinking like Copernicus in the 16th Century. It wouldn’t have been possible for the regular tilts/shifts in position in the movement of Sun and other Planets and Constellation throughout the year if it would have been “Geocentrism”. And by observing the motion of nearby planets we can tell about the movement of Earth as well. And once we step into the concept of “Heliocentrism” from the previous one, we can prove day/night, seasons, revolution, etc.

      • And then, of course, we have Foucault Pendulum, Coriolis Effect, etc.

    • Polaris, the North Star, appears to be stationary and all other stars appear to spin around this star, indicating that the Earth spins on this axis.

    • No comment

    • we can say we are not in inertial frame because we feel a force on us , either sitting we have presure from the seat, walking we have presure on feet, We do not feel any lateral force on us if we are not moving. Then since we feel forces on us we are not in inertial frame.

    • We know we are not in an inertial frame because we know we are moving due to earth’s spinning and orbiting around sun. So our velocity is changing. But your argument doesn’t apply.There is no net force on us if we sit in a chair. If we sat on a chair on a non-spinning earth floating in space we would still feel pressure from the seat, yet would be in an inertial frame.

    • Changing of season…simple terms earth goes far from sun we encounter the winter season. It comes near the sun we get the summer season

    • Observed apparent movement of the sun and stars in the sky, and wobbling of natural pendulums such as church chandeliers.

    • How water flows in a vortex and how it is different between north and south of the equator. Note, changing of seasons has to do with the earth’s orbit about the sun and its tilt on its axis in relation to the orbital plane and not with the Earth spinning.

You must be logged in to reply to this discussion.

Send this to a friend