metacogitans

 

My question is how is the brain capable of making us aware of the location of the touch? I know it deals with nerves and the messages sent from the brain to that particular part of the body, but how can we spatially feel the location of the touch? Sorry if this seems confusing.

The brains mechanism for mapping nerves responsible for the sensation of touch throughout the body is, like many other mechanisms and processes in the brain, almost completely subconscious. You'll never have to think about it. Although the shape of your body may change as you gain or lose muscle mass, body fat, or as bone growth makes you taller, nerve mapping and the sensation of touch is one of the oldest and most instinctively rooted jobs the brain performs. The constant input from those nerves to the CNS allows for it to be intuitive and subconscious, and re-mapping of never location is done constantly, efficiently, and instantaneously.

If gravitons were responsible for gravitation then gravity would not bend light.

I found this thread while googling to see if anyone had came up with the answer to the thread's question before me.

I have a very simple but entirely plausible explanation as to why mass dilates space-time if we can assume the following:

- 'Spacetime' itself must consist of something, and this backbone of space-time is physically present among everything else residing in it.

- Since, simply put, two things can not occupy the same exact location simultaneously, then matter with intrinsic mass and it's own self-maintained volume pushes whatever makes up space-time out of the way. When considering a large quantity of mass on the scale of a planet or star in this regard, we can account for the curvature of space-time and the phenomenon of gravity.

To further illustrate my point, imagine space-time as an x,y,z coordinate grid; now imagine a particle as a sphere at the point (0,0,0) on this coordinate grid. However, the grid does not lay on top of the sphere overlapping it; but is warped around the sphere. Now, imagine many spheres, and the effect they have on the surrounding grid. What it starts to resemble is identical to the phenomenon of curved space-time described in general relativity.

Another analogy: imagine we plop a boat into a lake. The water of the lake moves out of the way of the boat as it is plopped in. The boat represents a particle with mass, and the water of the lake represents whatever it is which makes up the backbone of space-time.

So there you have it, an entirely sensible explanation. Although I couldn't begin to tell you what this backbone of space-time is made out of, I can at least assume that it is physically present among the other contents of the universe and interacts with them.

To put it in just one sentence: the curvature of spacetime resulting from the presence of mass is a geometrical consequence of the inherent nature of mass occupying volume.

Also, I've got a link to a good PDF that really helps one visualize the dilation of space-time in a gravity-well and the breakdown of Euclidean geometry in General Relativity; it points out that the diameter of the sun is many kilometers greater than what we would expect if we took the sun's circumference divided by pi, due to the dilation of space-time towards the center of the sun. It also uses existing widely-accepted equations in physics (such as actually using the Einstein field equations, for example), so it should appease those who want all conclusions to be backed up with hard math. http://www.johnstonsarchive.net/relativity/stcurve.pdf