Relative Relativity?
By Mangone
- 2121 reads
Although you might be forgiven for thinking that it is gravity that makes things fall you would still be wrong… it’s moving that makes things fall. Think about it. Nothing could fall if it didn’t move! :O)
Still, before we get into that let’s spend a moment considering diving into a swimming pool.
It’s like shooting a projectile into the air reflected in a horizontal mirror.
The steeper the angle the further you go in the vertical direction and the less you go in the horizontal direction.
So what effects your motion in the vertical direction - it’s your speed in that direction and as the water resistance slows your vertical speed you start to follow an almost opposite curve back to the surface. Essentially buoyancy has served as an upward force which illustrates that the effect of gravity isn’t that special, that it just exerts a force in a vertical direction and if there is also motion in a horizontal direction it results in a curved path.
Taking about curves, let’s consider a spiral galaxy. You look at its curves and it is obvious that it is spinning. Our Solar System is doing the same but it is simply less obvious. Now, I want to argue that it isn’t simply lots of bits spinning in space but actually space itself that is spinning.
If space can curve why can’t it spin?
Now I know this is stretching Relativity to the limit but could it be that the planets are rotating with space and so can be seen as relatively motionless - in other words, not moving through space but with it.
If you agree with Einstein that Mass warps Space to create gravity then how does that make things fall?
First we must consider weight - weight is generally seen as the product of mass and the gravitational force at that point in space, or simply, for people on Earth, it is how heavy things are.
However, I argue that weight is a vector quantity which has both magnitude and direction and so is a result not only of an object’s Mass but also the object’s Velocity.
More controversially, I argue that if an object remains Relatively motionless then it is also weightless.
So, what does Relatively Motionless mean?
Think about a spaceship in orbit around the Earth.
Now a circular orbit is the Universe’s method of keeping things where they are and the spaceship doesn't move - relatively speaking, it is motionless in space - but the space it is in is moving.
So, Relatively speaking, you can see the orbital body as motionless and hence it doesn’t fall because there is no gravitational force acting upon it :O)
Okay, you say, but why do things on Earth have weight when they aren’t moving?
Well, of course they are moving, it’s just that they are motionless relative to you.
Remember that you are orbiting the sun at about 1 light minute a week and the Earth is also doing a complete rotation around its axis once a day.
All you have to do to be weightless is to stop moving - but of course even if you were not being accelerated by the floor beneath your feet your inertia would keep you moving - just jump into the air and see :O)
So, you get into a spaceship and you get out of the atmosphere and then slowly adjust your speed until you are motionless (weightless).
Of course to those on Earth it looks like you are orbiting the planet.
Now, to an observer on Earth you are moving around a planet that is moving around its sun - but really you are motionless for the first time in your life :O)
I know, I know, you want to know what curved space has to do with it.
Well, it is simply that it is the curve which causes you to fall toward the mass at its centre.
In Newtonian physics obviously in orbit the steeper the curve the more ’Relatively Up’ you would go - by going straight :O)
However, going ’Up’ is forbidden by your inertia so you go ’Down’ by going ‘Relatively straight’ and so remain at the same height :O)
Since weight is a vector quantity but your forward speed is constant then your weight doesn’t change and you remain weightless.
Or, Relatively speaking, you simply remain where you are because there is no force acting on you to make you move.
However, if you are on a planet then your velocity relative to the curved space forces you downward which is apparent as increased weight and therefore velocity - if you can move down.
Obviously, as your weight increases then so does your velocity which increases your weight which increases your velocity… in an accelerative process which can soon have you moving very quickly.
Hence if you were on a high building and you jumped off then your weight and velocity would increase very dramatically and therefore jumping off a high building is NOT recommended unless you have a means of avoiding hitting any hard surface which would bring an abrupt halt to your decent! Inertia can be very unforgiving!
Obviously, once your velocity reduces then your weight reduces too and when you come to a relative stop (cease falling) then your weight returns to relatively normal.
Actually the gravity curve increases as your distance from the ground decreases so the acceleration increases slightly too but you are unlikely to notice it on Earth unless you have a push bike :O)
In a way then, gravity is simply a consequence of inertia and the struggle between the cube and the sphere as they move Relatively through Space :O)
I recently calculated that the Sun could be rotating at a speed consistent with the rotation of the Solar System.
Naturally, the rotational speed reduces as you move away from the sun - here's a rough table which uses Light Minutes instead of AU :-
Planet ……R (Lm)….. ……OC (Lm) …..OP (weeks)… ..OV (Lm/Week)
Mercury … 3.22 …. … ……20.232 ….... …12.52… … … …1.616
Venus ……. 6.01 ……. ……37.76.……. ….. 32.35 …… … …1.167
Earth ………8.32 ……. ….. 52.276.….. ….. 52.18 … …… …1.0
Mars ………12.70 …… ..… 79.80 ……. ….. 98.09 …… ……. 0.8134
Jupiter …… 43.30 …… ….. 272.0 …… ……618.84 …. ……. 0.4395
Saturn … … 79.20 …… … 497.6 …… …….1537.2 …. ……. 0.3237
Uranus … …159.6 ……. …1002.8 ….. …. 4383.64.….. ……0.2287
Neptune.. …249.6 ………..1568.28 …….…8599.26 …. …. 0.1824
Pluto ………. 327.8 ……….. 2060.0 ……….12925.0.….. ……0.1592
We can make this table more relative where all but R (the distance from the sun) are relative to the Earth :-
Planet ……R (Lm)….. ……OC (Lm) …..OP (weeks)… ..OV (Lm/Week)
Mercury … 3.22 …. … ……0.3876 ….... …0.2398… … … …1.616
Venus ……. 6.01 ……. ……0.7234.……. ….. 0.6197 …… … …1.167
Earth ………8.32 ……. …....1.0 .….. .. …... 1.0… …...… …1.0
Mars ………12.70 …… ..… 1.5287 ……. ….. 1.8791 ……...0.8134
Jupiter …… 43.30 …… ….5.21 .. …… ……11.855 ….. ……. 0.4395
Saturn … … 79.20 …… … 9.5325 …… ……. 29.45 …. ……. 0.3237
Uranus … …159.6 ……. … 19.21 ….. …. . 84.0.….. .……. 0.2287
Neptune.. …249.6 ……….. 30.04 . ….….… 164.74 …. …. 0.1824
Pluto ………. 327.8 ……….. 39.44 . . ……….247.6.….. ……0.1592
At 8.3 Light minutes or 1 AU the Earth is, on average, about 93 million miles from the sun.
I've included Pluto even though it is no longer classed as a planet because of its unusual association with the Earth...
Pluto’s average distance from the sun is the Earth’s distance x Pluto's relative circumference = 8.3Ls x (2Pi squared). Its orbital Period is (2Pi cubed) and it’s relative orbital velocity is the reciprocal of (2Pi squared).
- Log in to post comments
Comments
As always the science is
- Log in to post comments