Planets Orbit Not Because Of Gravity Energy But Because Of Griff Energy Closed Thread

[Klaynos]

Telling me to look at the maths is irrelevant as its man made and could contain mistakes.

 

Gravity is a force, so everything effected by it must slow down whatever angle of travel.

 

If I fire a firework into the air at an angle it returns to the earth because of gravity.

 

If I fire the same rocket, do you honistly believe that the angle matters wether it returns to the earth? your saying that speed changes things and then things don't slow down ever.

 

But gravity doesn't affect the sideways motion of the firework in any way. If it is going sideways fast enough it will miss hitting the earth when it falls back, a continued missing is called an orbit. You've already said you understand that the sideways motion will not be affected by gravity acting at 90degrees to it.

 

Newtonian gravity and GR have been tested massively, the maths is well tested/

[gafferuk]

You've been misinformed

 

 

 

Not true either.

 

so if i drop a brick and an orange, they fall at different speeds?

[Klaynos]

Please don't mix einstein with newton, im told einstein math is less acurate.

 

Mass is irrelevant, all things fall at the same speed.

 

There is time, there is space, i double the two are really connected like all of einsteins theorys. Heys right out there.

 

GR is better at predicting the universe than newtonian gravity. Any suggestion you come up with as a replacement MUST make more accurate predictions than these.

[Moontanman]

Moontanman, you are not helping here.

 

You are right i am sorry, i can't take this seriously anymore

[gafferuk]

You've already said you understand that the sideways motion will not be affected by gravity acting at 90degrees to it.

 

the planet has no force, only energy. Gravity has force.

 

gravity force acting against planet energy should cause it to slow down regardless of angle.

[Klaynos]

the planet has no force, only energy. Gravity has force.

 

gravity force acting against planet energy should cause it to slow down regardless of angle.

 

I point you back to where you said you understood how a force acting one direction will not affect the motion in the other direction.

[gafferuk]

is gravity much different from that of a magnet as to say it pulls?

 

if i use a magnet near some metal it pulls to the magnet regardless of angle of travel.

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I point you back to where you said you understood how a force acting one direction will not affect the motion in the other direction.

 

perhapse i mis understood you but no, i believe that to be incorrect.

 

things pull regardless of angle when gravity is applied. else if you fired a rockett at different angles you would get different results.

[Bignose]

Telling me to look at the maths is irrelevant as its man made and could contain mistakes.

 

This statement is completely meaningless, because it can be 100% equally applied to anything you write as well. As in: "looking at gafferuk's idea is completely irrelevant as gafferuk is a man and his idea is manmade and could contain mistakes."

 

Math is the universal language of physics. Whether you understand them or not, does not take away the fact that the mathematics of gravity and orbits have been verified an incredible amount of times.

[Klaynos]

http://www.scienceforums.net/forum/showpost.php?p=545661&postcount=81

[gafferuk]

I point you back to where you said you understood how a force acting one direction will not affect the motion in the other direction.

 

 

how can that be true. gravity pulls you towards the center of the earth regardless of angle of travel.

 

if i throw a ball at 45 deg, then its effected in both x and y

[Bignose]

else if you fired a rockett at different angles you would get different results.

 

you do get different results. The reason golfers carry 14 different clubs with 14 different lofts on the club heads on the end is so that they can hit the ball at different angles so that they get different results. If different angles didn't end up with different results, you'd only need 1 golf club.

 

You know this -- if you throw a ball parallel to the ground and then throw a ball at 45* to the ground with the same force, the ball ends up in a different spot.

 

Therefore, your idea that "things pull regardless of angle when gravity is applied" is wrong.

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Have you played around with any of the simple gravity simulators on the web? Like http://www.arachnoid.com/gravitation/

 

This program it a pretty good simulation of the solar system, and yet doesn't have to include any new ideas to create a good simulation.

 

Especially, please play around with the "Simple Orbit" simulation available on the drop down. You get to change the initial velocity of the green dot at it orbits the yellow dot. Note specifically what happens when you change the value higher or lower than the value needed for perfect orbits.

Edited February 20, 2010 by Bignose
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[gafferuk]

you do get different results. The reason golfers carry 14 different clubs with 14 different lofts on the club heads on the end is so that they can hit the ball at different angles so that they get different results. If different angles didn't end up with different results, you'd only need 1 golf club.

 

You know this -- if you throw a ball parallel to the ground and then throw a ball at 45* to the ground with the same force, the ball ends up in a different spot.

 

Therefore, your idea that "things pull regardless of angle when gravity is applied" is wrong.

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Have you played around with any of the simple gravity simulators on the web? Like http://www.arachnoid.com/gravitation/

 

This program it a pretty good simulation of the solar system, and yet doesn't have to include any new ideas to create a good simulation.

 

if the earth was not really there then the golf ball probably would be pulled towards the earth centre by the time it fell that far.

[Bignose]

if the earth was not really there then the golf ball probably would be pulled towards the earth centre by the time it fell that far.

 

What does that have to do with anything. The point is that different launch angles DO end up with different results. Are you going to try to argue that they don't?

[gafferuk]

were told that objects fall at the same speed when droped at the same height, an orange and a brick for example will both fall towards the earth at the same speed.

so weight and size is irrelevent when it comes to gravity.

 

how can a floating astronaut in space be effected only a bit by gravity when at say 1000 miles from the earth, and the moon be effected more by gravity at a greater distance?

 

the moon is traveling a lot faster than the astronaut im sure, but size/weight/mass is irrelevant when it comes to gravity as everything falls to earth at the same speed when droped from the same height

 

Newtons law just don't add up to me.

Edited February 20, 2010 by gafferuk

[Sayonara]

Rating thread 5 stars.

[Sisyphus]

the moon is traveling a lot faster than the astronaut im sure,

 

No, it isn't. The astronaut in the closer orbit is moving faster. Much faster, actually, if the astronaut is only 1000 miles away.

[Klaynos]

how can that be true. gravity pulls you towards the center of the earth regardless of angle of travel.

 

if i throw a ball at 45 deg, then its effected in both x and y

 

No it's not, when working out the trajectory you split it into x and y, gravity is only used in one of the sets of calculations.

[gafferuk]

No, it isn't. The astronaut in the closer orbit is moving faster. Much faster, actually, if the astronaut is only 1000 miles away.

 

are you sure? the astronaut is floating over london 1000 miles above the earth, so heys not traveling very fast.

 

im not sure how fast the moon is traveling at though. and remember the moon is at a much greater distance, and size/weight/mass is irrelevant.

 

It just seems odd that an astronaut can float in space 1000 miles from the earth but the moon does not fly off and weight/size/mass is irrelevant and the moon is much furthur away.

[insane_alien]

an astronaut in an orbit only 1000 miles above the surface would not stay over one place for very long. he'd have to be travelling sideways at a few miles per second.

[Bignose]

were told that objects fall at the same speed, an orange and a brick for example will both fall towards the earth at the same speed.

so weight and size is irrelevent when it comes to gravity.

 

how can a floating astronaut in space be effected only a bit by gravity when at say 1000 miles from the earth, and the moon be effected more by gravity at a greater distance?

 

the moon is traveling a lot faster than the astronaut im sure, but size/weight/mass is irrelevant when it comes to gravity as everything falls to earth at the same speed.

 

You were told something that is true for all intents an purposes for everyday objects here on Earth, but not true in general.

 

Here's Netwon's Law of Universal Gravitation (in a scalar form):

 

[math]F= G\frac{m_1 m_2}{r^2}[/math]

 

F = force of gravity between the two objects, labeled 1 and 2

G = gravitational constant = 6.67428 * 10^-11 m^3/(kg*s^2)

m_1,_2 = mass of objects 1 and 2

r = distance between the objects

 

Now, let's look at an orange and a brick dropped here on earth.

 

Mass of the Earth is 5.9742 * 10^24 kg

Mass of a brick is: 2.7 kg (from http://wiki.answers.com/Q/What_is_the_weight_of_a_red_clay_brick_in_Kilograms first on a Google search of "weight of a brick")

Mass of an orange is: 9-11 oz. (from http://wiki.answers.com/Q/What_is_the_average_weight_of_an_orange again, first on a Google search of "weight of an orange) Let's call that 10 oz. that is equal to 0.28 kg

 

Let's do the math. Let's say that the brick and the orange are both dropped from a height of 10 m above the Earth. In this case, r = 10 + 6378100 (average radius of the Earth in m).

 

Force on the orange = 2.35 N

Force on the brick = 26.5 N

 

But, the speed at which the orange or brick actually moves is the acceleration. Force = mass * acceleretion. So, we divide the above forces by their masses and we get

 

Acceleration orange = 9.799792 m^2/s

Acceleration brick = 9.799792 m^2/s identical down to 6 decimal places

 

In fact, Open Office calculates the numbers to be identical for the 1st 14 decimal places given the numbers I put in (about 6 sig figures), and it isn't until that 15th decimal place that 1 digit is 1 greater than the other.

 

Why is this.... quite simply, the mass of the Earth is so much greater than the mass of the brick or the orange, that the gravitational effect of the Earth is for all purposes a constant. Hence, your being told that a brick and an orange do fall at the same speed on Earth.

 

However, if you start putting things in like the mass of the moon, 7.36*10^22 kg or the mass of the sun 1.99*10^30 kg, then the masses do become important and can be calculated from Newton's law given above.

[Klaynos]

The moons orbital speed (tangential velocity) is about 1km/s in a 'low earth orbit' an object must be moving at about 7km/s

 

All manned space flights excluding some of the apollo missions (the ones that went to the moon) were in low earth orbits.

[gafferuk]

If your saying that mass is important then fair enought, i have it wrong and goodnight!

 

stiff baffled why things planets dont slow down though because of gravity?

 

if the astonaut was at the same height as the moon, does he need to travel at at a different speed as the moon in order to stay in orbit?

 

and does that mean we can guess the mass of the planets based on there speed and distance?

Edited February 20, 2010 by gafferuk

[insane_alien]

no he would be travelling at the same speed as the moon.

[gafferuk]

no he would be travelling at the same speed as the moon.

 

then weight is irrelevant.

 

the weight of the planet does not set the speed of the planet when it comes to orbit.

 

what does?

[Cap'n Refsmmat]

then weight is irrelevant.

 

Everything falls at the same speed, regardless of how big or heavy it is.

 

Did you imagine the circles as I told you to?