Request for 'Over the Horizon' Photos

I only have a 2d screen.

Everything I see on it is 2D

 

The video is a helpful but misleading simplistic analogy and to quote from the video "think of empty space-time as a rubber sheet" the clue is a sheet is 2 dimensional, the difficulty with this concept is it only covers one heavy object and one satellite.

If you consider the Earth and the non-geostationary satellites, that would include all the debris, each piece will need to have its own rubber sheet all intersecting one another, visualising that is beyond me.

What would the rubber sheets for the planetary system look like or a binary star? It cannot represent reality.

The video does include time as movement occurs.

 

Frosty; what are you doing so early looking at Uranus?

 

he is studying the rings around Uranus.

 

Yes, it does include time (frame by frame) . But not space/time which is the fourth dimension, and cannot be represented graphically

"Spacetime is usually interpreted with space as existing in three dimensions and time playing the role of a fourth dimension that is of a different sort from the spatial dimensions."

http://en.wikipedia.org/wiki/Spacetime

The previous Youtube video is a graphical interpretation of a physics lesson I saw Julius Sumner-Miller do when I was a kid. This is where the 'rubber-sheet' analogy comes from.

Like the video below, you put a heavy sphere on a rubber sheet fastened to a frame. Then you shoot a smaller ball on to the surface and watch it as it 'orbits' the larger sphere. Just like satellites work



In these 3d demo's you have length, height and the depth of the hollow , caused by the central weight. The demo will only work for horizontal 'satellites' for obvious reasons, and they 'dip' as the circle the central sphere.

In real life, satellites don't run down a physical slope, as they do on this rubber sheet. They run 'down' the sides of a gravity well, caused by the distortion of 'space/time' by massive masses, as light does.

 

An elegant and scientific representation of Flat Earth. Thank you rwatson for coming out of the Round Earth closet. Welcome to the fold of the true believers.

 

hmmm, I assume thats a bit of humour. I'm only parroting the current scientific understanding, as per the quote from Wikipediae, and ther speres are definitely round.

 

Gonzo, you are one of the bravest men I have come across, you deserve a medal. How you could summon up the courage to travel from the UK to the USA knowing that at any moment you might drop off the edge of the Earth is amazing.

rwatson it appears we will have to agree to differ, my original point was "trying to visual curved space in 3D is beyond most people" if it can not be represented it must be difficult to visualise.

 

Nothing a human sees or learns is not reality (unlike mechanical devices) but an interpretation of that persons brain. I guess that is why it is so easy to indoctrinate our young into believing the many funny ideas that abound. consider the field of art and the acclimation for some rubbish there.

 

yes, I understand what you were saying, but as you say, I don't agree with the statement.

From my point of view, as soon as I saw JS Millers 'rubber sheet' demonstration ( a 3d one with length, width, depth ) I twigged immediately to the 'attractive' effect of large masses in space.

The little ball performing 'perfect orbits' around a large sphere that 'deformed' its immediate space was a real eye opener for me.

The 'rubber sheet' is a single plane, it is true, and the travel of the satellite has deviations in its path that dont occur in reality, but the concept becomes immediately visual. It has been used by academics for over 50 years to illustrate the principle , so it cant be that ineffective.

 

We are probably closer to agreeing than these exchanges suggest. I too find the rubber sheet experiment very powerful and instructive. Without it I would be at a complete loss as to what curved space was about.

The demonstration is indeed 3D but it is of a distorted 2D system. As the little ball can not leave the surface of the sheet, the Z co-ordinate (depth/height) will always be zero.

 

yes indeed - not only 'distorted', but also 'limited' by its layout. I have said as such multiple times.

The important concept it displays, is that it is shows two spheres interact using the actual 'invisible' effects of gravity, which is only possible because of the depth of the 'curve' in the sheet so it is 3d.

A lot of animated planetary videos are much more accurate, prettier and more complete, ( and they are 3d as well. ), but to view physical objects interacting without the trickiness and illusion of the animator, is a much more powerful and instructive tool for 'hands on' people like me.

 

Joking aside, the idea of flat and round can become so distorted as to lose meaning.

 

Yes, anything is possible, but you can probably get professional help for that

Just as an obtuse sideline, we must remember that really, not even the brightest person alive knows what is going on with gravity.

The huge Hadron collider might result in some more clues, but why and what gravity is, is still a huge mystery.

All us humble civilians can do, is to stand by and observe its effects and behaviour, and hope one day someone comes up with a believable explanation.

Meantime, I will peruse YouTube and look at all the 'working' anti-gravity machines.

 

Apologies - I lied about no visualising 4D,

I found this :-



along with one of the best discussions on multi-dimensions I have ever come across.