Gravity.

a reply to: Out6of9Balance

Look, in defining an object you simultaneously define a boundary for that object by default. A boundary, beyond which, that object no longer exists. "Modern science" cannot clearly delineate the "edge" of the universe, much less what lies beyond it.

Common theory is the universe (as we understand it) is expanding, but even this is subject to debate. However, many traditional mathematical models suggest the universe should actually be contracting. This is where things like 'dark matter' come into play. So, when you refer to "modern science" and the universe, you either want to talk about these things, or you don't want (or are unable) to talk about "modern science".

a reply to: Flyingclaydisk

So we don't know really.

They had me jumping to conclusions.

a reply to: Out6of9Balance

Don't jump too high - you might float away!

a reply to: oldcarpy

Really?

a reply to: Out6of9Balance

No. Of course not. That would just be silly, wouldn't it?

a reply to: oldcarpy

Not if could jump a few hundred miles.

Or is my knowledge of modern science wrong again?

a reply to: Out6of9Balance

Perhaps, make that a few thousand.

a reply to: Out6of9Balance

If you could reach escape velocity you might get to do a bit of floating, I suppose.

originally posted by: Out6of9Balance
a reply to: oldcarpy

Not if could jump a few hundred miles.

Or is my knowledge of modern science wrong again?

Science doesn't say that. Science says if you jumped up a few hundred miles (heck -- let's say a few thousand miles), gravity would pull you back down to the ground with a splat.

a reply to: Soylent Green Is People

Let's say a few ten thousand miles then.

a reply to: Out6of9Balance

Yes, Gravity is very real.

originally posted by: Out6of9Balance
a reply to: Soylent Green Is People

Let's say a few ten thousand miles then.

At what speed and which direction relative to the surface? Yes...this matters.

a reply to: Soylent Green Is People

To add to my post above, even tens of thousands of miles up the Earth's gravity is still quite strong and is able to pull things back down.

The Moon is 240,000 miles away, but Earth's gravity is still keeping the Moon from floating away. The Moon orbits (rather than being pulled down to Earth's surface) due to a balance between Earth's gravity and the Moon's "sideways" motion relative to earth.

That is to say, things in orbit are not in orbit due to a lack of gravity, but orbit because of gravity.

a reply to: Soylent Green Is People

earthobservatory.nasa.gov...

shouldn't the satellites fall down according your theory?

originally posted by: Out6of9Balance
a reply to: Soylent Green Is People

earthobservatory.nasa.gov...

shouldn't the satellites fall down according your theory?

No. Satellites are in orbit moving sideways at a speed that is fast enough relative to their height so that while they are being pulled back to Earth, the Earth "curves away" under itself, so the falling (i.e., orbiting) satellite "misses" the ground.

That's what an orbit is. Like I said, things in orbit do not experience a lack of earth's gravitational pull, but are in orbit because of Earth's gravitational pull.


A good way to illustrate how the surface of the Earth curves away from an orbiting spacecraft before the spacecraft can hit that surface is the following thought experiment Isaac Newton proposed back in 1687 that has become known as "Newton's Cannonball".

In this graphic representation of the thought experiment, cannonball A with the least velocity quickly falls back to earth due to gravity. Cannonball B has a bit more velocity that allows it to go almost to the edge of the curve, but not quite. Both A and B hit the ground because the ground "gets in their way" (so-to-speak).

Cannonball C, which has a greater velocity than both A and B, also gets pulled back down, but because of that greater velocity it can goes further out over the curved surface.

In fact, cannonball C so far out over the curved surface of the Earth that as gravity pulls it back down the surface curves away allowing cannon ball C to miss the ground.



Now, instead of cannonballs, imagine these are satellites moving "sideways" to the ground at orbital speeds.

hubpages.com...

By the way, even a geostationary satellite is moving at a sideways speed realtive to Earth's surface, but that speed matches the rotational speed of Earth, so the satellite remain over the same spot on Earth as Earth turns.

This link has a good "quickie" explanation (excerpted below): www.astronautix.com...

This was the first and best explanation of what an orbit is. An object in orbit is weightless not because 'it is beyond the earth's gravity' but because it is in 'free-fall' - just like a skydiver. The difference is that it has enough horizontal speed never to hit the ground.

a reply to: Soylent Green Is People


That's too complicated, I think the cannonballs are floating through the non-gravity.

originally posted by: AugustusMasonicus
a reply to: Soylent Green Is People

That's too complicated, I think the cannonballs are floating through the non-gravity.

Only when you Masons allow it.

originally posted by: Soylent Green Is People
Only when you Masons allow it.

We're not big fans of gravity, nor the electroweak interaction, it's all pseudo science.

Turtles baby, turtles all the way down.

a reply to: Soylent Green Is People

But satellites don't have gravity of their own.

originally posted by: Out6of9Balance
But satellites don't have gravity of their own.

Yes they do.