# Bowling ball rubber sheet analogy

#### Pete62

altonhare,

I don't understand why you are being so obstinate. As a layman trying to grasp GR I have found the 2D and 3D visualizations to be not just valuable but required to understanding the subject. I simply could not get it until I tossed out 2 space dimensions and focused on a 2D Time-space coordinate system. Emphasis on time.

BTW, the rubber sheet analogy was worse than useless, it set me back years. I kept imagining space as having an intrinsic pressure created by mass curvature and that is what created the force of gravity.

Last edited:

#### jefswat

If they are visualizing a 2D image but think they are visualizing a 3D image, then yes they are fooling themselves.
So if I see something in 2D like, for example, the eraser in my hand and see only height and width from a certain angle, your reasoning leads me to conclude that because I see it in 2D I am fooling myself by thinking it is really 3D

Your argument is clearly flawed, direct substituion with my eraser:

If they are visualizing a [2D eraser] (from the side view as per example) but think they are visualizing a [3D eraser], then yes they are fooling themselves

I believe that is what A.T is trying to get at. because I do not see the length of my eraser it doesn't mean it isn't there. And not seeing the length certainly won't affect my answer,for example, of the area calculation for the side with width and height. As for the bowliverse I have no contribution to make to that argument ................ ............................................................................... Preserve the bowliverse!

#### Edwin McCravy

The guy who first used it to explain GR should be stoned with bowling balls.
The problem is with words. The person who should have been stoned with bowling balls was the first guy to have ever used the word "curve" to describe gravitational behavior. All it did was confuse the lay public. Other language would have expressed it much better. For instance, "distort" would have been a better word.

#### Pieroz

OK, I am completely new here and have millions of questions lodged in my head and have had trouble finding an appropriate place to discuss them and am hoping that I finally have, LoL... but today I just have a quick question in relation to the GP-B Probe apparently having proven parts of Einsteins theory...

I think I have grasped the whole idea - but when looking at the diagrams and animations etc I find myself wondering why it is not shown to be surrounding the entire Earth in the same manner? as in 360 degrees? Surely this "dimple" would be surrounding the space around the Earth itself and not just around the south pole?

I suppose I am arguing that a flat rubber sheet certainly does not represent open space as the planets etc are not actually sitting on anything... From what I understand the space time is a dimple around the Earth not just beneath it - and that the Earth does not actually rest upon or within the dimple but simply creates it around the Earth...

Also do you think they will manage to measure the actual size of the Earth space-time vortex and hence be able to calculate similar for the rest of our solar system?

#### Naty1

I would point out this thread is over two years old now....funny, because I barely expected any reply when I posted it Feb 2009!!!!

#### Edwin McCravy

I've responded to older posts than yours. Sooner or later somebody is bound to Google most any topic you post and respond to it, even if it takes two years.

#### nitsuj

agreed physics moves much slower lol

### Physics Forums Values

We Value Quality
• Topics based on mainstream science
• Proper English grammar and spelling
We Value Civility
• Positive and compassionate attitudes
• Patience while debating
We Value Productivity
• Disciplined to remain on-topic
• Recognition of own weaknesses
• Solo and co-op problem solving