4 ms·

The radius of curvature is much bigger than distances we daily measure, for a similar reason when dealing with small distances on the surface of the earth you c

by m_j_g 7y ago

The radius of curvature is much bigger than distances we daily measure, for a similar reason when dealing with small distances on the surface of the earth you can use flat, Euclidean geometry. We can measure the curvature of space(time), for example, Gravity Probe A managed to measure the curvature of space-time in the vicinity of earth.

hi41 7y ago
I followed the gravity probe b experiment when it was happening. It tried to measure two effects of Einstein’s theory. In layman terms how far should one be to see the curvature of spacetime? My son was asking and I couldn’t offer an explanation as to how much the earth curves the spacetime around it. How could one use gravitational force value of 9.8 m/s2 help in grasping it the curvature of spacetime, since that is something we are aware of.
- m_j_g 7y ago
  As curvature of space is affecting measurments of distances in angles, the curvature of spacetime is affecting both measurements of time and distance. Concerning the curvature of space: If you measure sum of angles of triangle on the surface of earth, it will be grater than 180 deagrees thanks to positive curvature of earth surface. For triangle in your backyard the diference will be immesurable, but if your measure traingle with segments spanning for 6 thousends kilometers sum of the angles will be closer to 270 deg than 180 deg. For the spacetime in the vicinity of earth you don't have to necessarly think about large distances, here (https://www.reddit.com/r/askscience/comments/2pu2o0/is_there_any_time_dilation_between_us_and_the/cn03iuf/ https://www.reddit.com/r/askscience/comments/2pu2o0/is_there...) someone calculated diference for two clocks so you can se scale : "If so the clocks on Earth's surface and 7km down would see a relative drift of 0.001ns per second, so the lower clock would tick that much slower as viewed by someone on the surface. At that rate over the course of a billion years the surface clock would pull ahead by 525.6 minutes."

by m_j_g 7y ago

hi41 7y ago

I followed the gravity probe b experiment when it was happening. It tried to measure two effects of Einstein’s theory. In layman terms how far should one be to see the curvature of spacetime? My son was asking and I couldn’t offer an explanation as to how much the earth curves the spacetime around it. How could one use gravitational force value of 9.8 m/s2 help in grasping it the curvature of spacetime, since that is something we are aware of.

m_j_g 7y ago
As curvature of space is affecting measurments of distances in angles, the curvature of spacetime is affecting both measurements of time and distance. Concerning the curvature of space: If you measure sum of angles of triangle on the surface of earth, it will be grater than 180 deagrees thanks to positive curvature of earth surface. For triangle in your backyard the diference will be immesurable, but if your measure traingle with segments spanning for 6 thousends kilometers sum of the angles will be closer to 270 deg than 180 deg. For the spacetime in the vicinity of earth you don't have to necessarly think about large distances, here (https://www.reddit.com/r/askscience/comments/2pu2o0/is_there_any_time_dilation_between_us_and_the/cn03iuf/ https://www.reddit.com/r/askscience/comments/2pu2o0/is_there...) someone calculated diference for two clocks so you can se scale : "If so the clocks on Earth's surface and 7km down would see a relative drift of 0.001ns per second, so the lower clock would tick that much slower as viewed by someone on the surface. At that rate over the course of a billion years the surface clock would pull ahead by 525.6 minutes."