RINGS propels satellites without propellants
http://www.gizmag.com/rings-satellite-iss/28712/

Astronauts on the International Space Station (ISS) are testing a new propulsion system … inside the station. While this might seem like the height of recklessness, this particular system doesn’t use rockets or propellants. Developed in the University of Maryland’s Space Power and Propulsion Laboratory, this new electromagnetic propulsion technology called the Resonant Inductive Near-field Generation System (RINGS) uses magnetic fields to move spacecraft as a way to increase service life and make satellite formation flying more practical.

more…

I posted a thread on this and even provided a buckey ball challenge to make it more interesting. My attempts to provide mental challenges recieve little attention. shrug

i thought you got good scientific answers to your queries. of course we could make shit up.

Riff-in-Thyme said:

I posted a thread on this and even provided a buckey ball challenge to make it more interesting. My attempts to provide mental challenges recieve little attention. shrug

Sorry Riff-in-Thyme, you can paste its link here, you know some of my threads get little attention as well, Ive noticed that emotion can roll a thread along

Boris said:

i thought you got good scientific answers to your queries. of course we could make shit up.

There was a high degree of explanation was there?

CrazyNeutrino said:

Riff-in-Thyme said:

I posted a thread on this and even provided a buckey ball challenge to make it more interesting. My attempts to provide mental challenges recieve little attention. shrug

Sorry Riff-in-Thyme, you can paste its link here, you know some of my threads get little attention as well, Ive noticed that emotion can roll a thread along

I might get back to that a bit later.

Boris said:

i thought you got good scientific answers to your queries. of course we could make shit up.

or you could do the research

if you wont to make things up you go right ahead boris

You will never get an emotional response from me, ever

http://tokyo3.org/forums/holiday/topics/3421/

conservation of momentum was mentioned as was an explanation of what needed to be done to overcome that problem.

Riff-in-Thyme said:

Boris said:

of course we could make shit up.

I’d prefer you simply made a fair effort, or simply withhold derogatory opinions

don’t be a dick cn.

Boris said:

http://tokyo3.org/forums/holiday/topics/3421/

conservation of momentum was mentioned as was an explanation of what needed to be done to overcome that problem.

Mentioned is right. If a little more effort to illustrate the answer in contrast to the suggested scenarios it may have been more helpful

you got the reason why your proposal wouldn’t work. what more do you want? as for the making shit up that was a tic. it is also what posters who don’t like real physics seem to want to do.

pm explained.

I’m happy that I’m more friendly than Boris

Boris said:

you got the reason why your proposal wouldn’t work. what more do you want? as for the making shit up that was a tic. it is also what posters who don’t like real physics seem to want to do.

I disagree. I got a generic answer with no actual illustration of how it specifically applied within the scenarios I was proposing. Absolutely no help at all mostly

Boris said:

pm explained.

in a very brief manner. last post still applies

Riff-in-Thyme said:

Boris said:

you got the reason why your proposal wouldn’t work. what more do you want? as for the making shit up that was a tic. it is also what posters who don’t like real physics seem to want to do.

I disagree. I got a generic answer with no actual illustration of how it specifically applied within the scenarios I was proposing. Absolutely no help at all mostly

What I actually understood from those answers was “I really couldn’t be bothered thinking about it”. Why bother answering if that is the case?

Earth has a magnetic sphere imagine all the possibilities of using it

on small scales and large scales

exciting stuff

you could ask for an explanation. the last post is just a more complicated version or previous ones. the same law applies.

CrazyNeutrino said:

Earth has a magnetic sphere imagine all the possibilities of using it

on small scales and large scales

exciting stuff

That was my thought. If these were sensitive to the earth’s EM field as well as each other, I thought the possibilities presented by a massive formation that circled the globe might be a far more sensitive application of EM than previously possible. The uses I suggested were intended to promote debate more than anything.

Boris said:

you could ask for an explanation. the last post is just a more complicated version or previous ones. the same law applies.

point taken

Boris said:

you could ask for an explanation. the last post is just a more complicated version or previous ones. the same law applies.

course, the purpose of the original question was to seek an explanation

Riff-in-Thyme said:

Boris said:

you got the reason why your proposal wouldn’t work. what more do you want? as for the making shit up that was a tic. it is also what posters who don’t like real physics seem to want to do.

I disagree. I got a generic answer with no actual illustration of how it specifically applied within the scenarios I was proposing. Absolutely no help at all mostly

Huh?

If you needed a more detailed explanation for how the law of conservation of momentum applies to your scenarios why didn’t you say so?

Or do want to know why conservation of momentum is a law?

:puzzled:

Riff-in-Thyme said:

Riff-in-Thyme said:

Boris said:

you got the reason why your proposal wouldn’t work. what more do you want? as for the making shit up that was a tic. it is also what posters who don’t like real physics seem to want to do.

I disagree. I got a generic answer with no actual illustration of how it specifically applied within the scenarios I was proposing. Absolutely no help at all mostly

What I actually understood from those answers was “I really couldn’t be bothered thinking about it”. Why bother answering if that is the case?

WTF?

Here’s the key (my bolding)

“Satellites can change their polarity to attract or repel one another, turn, or shift their relative positions in any manner that doesn’t require changing the center of gravity for the entire formation.”

dv said:

Here’s the key (my bolding)

“Satellites can change their polarity to attract or repel one another, turn, or shift their relative positions in any manner that doesn’t require changing the center of gravity for the entire formation.”

Yeah. Rev & I said that in the other thread.

PM 2Ring said:

dv said:

Here’s the key (my bolding)

“Satellites can change their polarity to attract or repel one another, turn, or shift their relative positions in any manner that doesn’t require changing the center of gravity for the entire formation.”

Yeah. Rev & I said that in the other thread.

That statement sounds like a limitation until you decide to make the center of gravity extremely generous. ;)

The terms “centre of gravity” and “centre of mass” are generally used interchangeably, although they are not actually equivalent in a non-uniform gravitational field. But that can get complicated…

http://en.wikipedia.org/wiki/Centers_of_gravity_in_non-uniform_fields

In physics, a center of gravity of a material body is a point that may be used for a summary description of gravitational interactions. In a uniform gravitational field, the center of mass serves as the center of gravity. This is a very good approximation for smaller bodies near the surface of Earth, so there is no practical need to distinguish “center of gravity” from “center of mass” in most applications, such as engineering and medicine.

In a non-uniform field, gravitational effects such as potential energy, force, and torque can no longer be calculated using the center of mass alone. In particular, a non-uniform gravitational field can produce a torque on an object, causing it to rotate. The center of gravity seeks to explain this effect. Formally, a center of gravity is an application point of the resultant gravitational force on the body. Such a point may not exist, and if it exists, it is not unique. One can further define a unique center of gravity by approximating the field as either parallel or spherically symmetric.

The concept of a center of gravity as distinct from the center of mass is rarely used in applications, even in celestial mechanics, where non-uniform fields are important. Since the center of gravity depends on the external field, its motion is harder to determine than the motion of the center of mass. The common method to deal with gravitational torques is a field theory.

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

In physics, the center of mass, of a distribution of mass in space is the unique point where the weighted relative position of the distributed mass sums to zero. The distribution of mass is balanced around the center of mass and the average of the weighted position coordinates of the distributed mass defines its coordinates. Calculations in mechanics are simplified when formulated with respect to the center of mass.

In the case of a single rigid body, the center of mass is fixed in relation to the body, and if the body has uniform density, it will be located at the centroid. The center of mass may be located outside the physical body, as is sometimes the case for hollow or open-shaped objects, such as a horseshoe. In the case of a distribution of separate bodies, such as the planets of the Solar System, the center of mass may not correspond to the position of any individual member of the system.

The center of mass is a useful reference point for calculations in mechanics that involve masses distributed in space, such as the linear and angular momentum of planetary bodies and rigid body dynamics. In orbital mechanics, the equations of motion of planets are formulated as point masses located at the centers of mass. The center of mass frame is an inertial frame in which the center of mass of a system is at rest at with respect the origin of the coordinate system.

That explains the earlier references for me, thanks PM.

No worries.

When people use the phrase “centre of gravity”, they generally really mean the centre of mass. And so when we’re discussing the centre of gravity of some system, we generally aren’t that concerned about the gravitational attraction between the parts of the system.

I guess that that could lead to some misunderstanding & confusion.

PM 2Ring said:

No worries.

When people use the phrase “centre of gravity”, they generally really mean the centre of mass. And so when we’re discussing the centre of gravity of some system, we generally aren’t that concerned about the gravitational attraction between the parts of the system.

I guess that that could lead to some misunderstanding & confusion.

It is a very important distinction to identify in the ring formation scenario.