Is Poincaré's Space Dilemma the Key to Understanding Gravity?

  • Thread starter Wes Tausend
  • Start date
  • Tags
    Space
In summary: Afterall, it doesn't follow from the Equivalence Principle that "falling" objects accelerated. According to the principle, the earth, consisting of matter as cause, acts just as though it's surface is moving outward, or at least outward in an accelerated manner. The floor rises to meet "falling" objects.
  • #71
yoron said:
How do you differ between a flat space and a flat space time?

Because "spacetime" is the entire history of the universe, including all times, and "space" is just the universe at one instant of time. At one instant of time, the universe (according to our best current model) is flat; but when you include the time dimension, the universe is expanding, i.e., changing in time, and that means spacetime is curved.
 
  • Like
Likes Mentz114
Physics news on Phys.org
  • #72
Pleased to meet you Peter :)
 

Similar threads

B Calc Excess Rad on Earth in Curved 3D Space | Feynman Lectures 6-2
Replies
29
Views
2K
B What if You Were Completely Still in Space? Exploring the Effects of Motion
Replies
25
Views
2K
I Can a Gyroscope on a Satellite Detect Orbit?
Replies
20
Views
2K
B Is Mach's Principle the Key to Understanding Rotatory Motion?
Replies
6
Views
1K
I Twin paradox for (accelerated) dummies?
2
Replies
36
Views
4K
I Question on the space shuttle Challenger experimentation, in 1985
Replies
2
Views
856
B My paraphrased explanation of the Twin Paradox
Replies
24
Views
2K
I Understanding Michelson Morley Experiment
Replies
14
Views
2K
I Deriving Einstein's Relativity Postulates from Minkowski Spacetime
Replies
8
Views
2K
I Force on Scale in Rocket Scenario: Calculation & Discussion
Replies
33
Views
2K

Hot Threads

Recent Insights

Back
Top