Solar System in a Can May Reveal Hidden Dimensions

dylanduck writes "A model solar system, made of tungsten and placed in space, could reveal hidden spatial dimensions and test alternative theories of gravity. If the system's 'planets' moved slightly differently to the way predicted by standard gravity, it would signal the presence of new physical phenomena." From the article: "Once at the Lagrange point, the artificial solar system would be set in motion inside the spacecraft. An 8-centimetre-wide sphere of tungsten would act as an artificial sun, while a smaller test sphere would be launched 10 cm away into an oval-shaped orbit. The miniscule planet would orbit its tungsten sun 3,000 times per year."

Gotchas, we got em

[Ancient_Hacker]

This sounds mighty dubious. The gravitational attaction of the spacecraft is likely to be much larger than the effect looked for.

Outside effects?

[Clazzy]

If the minature solar system is sent into space, then would it also come under the effect of the gravity of the actual solar system? Granted the effect will be very small (considering one object is very small and is far away anyway) but surely it would cause enough of an effect to make a difference? I'm sure they're trying their best to cancel out these forces, but they'd need absolutely minute amounts of gravity or (impossibly enough) none at all for a good reading.

Yeah, but...

[jamestheprogrammer]

You would need to be extremely precise for that to work. The masses of the model planets would have to be PERFECTLY scaled. Do we actually know for a fact the masses of all the other planets, and can we make something that precise?

Then you have to consider the gravitational effect of the asteroid belt. Do we know the mass of that, too? That might affect the model when put in use.

Any conclusions made from this experiment would be debated over endlessly because of this...

Re:Why L2?

[addie]

Well actually the article did say:

A spacecraft placed there would stay fixed in space, relative to Earth, making it easier to monitor. The Earth would also shield it from the Sun's radiation, which pushes gently on any objects it shines on. Any such push could change the spacecraft's position relative to the tiny "planets" held inside it.

So they've got that much of it thought out. But in regards to the mass of the spacecraft carrying this jar:

And the spacecraft components themselves would exert gravitational forces on the spheres. These forces could be minimised by making the spacecraft as symmetrical as possible and putting its heaviest components as far from the artificial solar system as possible.

"Such an experiment would be quite challenging to set up, but I don't think it is technologically impossible," says MOND expert Stacy McGaugh of the University of Maryland, US.

So while they're full aware of the problems the mass of the craft can cause, they seem to think it's possible to minimize the effects to a reasonable level.

My question is, aren't Lagrangian points going to start to get a bit crowded? There are only five to work with in our neighbourhood and who gets to say who uses which and for how long?

Sounds like a fancy version of...

[exp(pi*sqrt(163))]

...Cavendish's [wikipedia.org] classic experiment. I look forward to seeing the results.

I am sure someone has thought of this already.

[wickedsteve]

But can anyone explain to me why gravity would be the only force bleeding into other dimensions? Or is it the only one? Also is there any evidence of extra dimensions already? I would think there would already be some evidence since it does not sound very scientific to me to base the very popular string theory on imaginary notions with no basis in reality. If we are just gonna make up dimensions to make the math work isn't that just as bad as making up Thor to explain the thunder and lightning?

Re:Suspect this is rubbish - NS has been had?

[njchick]

Fortunately, thermal velocities of macroscopic objects are much lower than those of atoms.

Too many uncertainties

[mcguiver]

It seems to me, after reading the article, that there are just too many influential factors to be able to conclude anything by such a test. From the article If gravity is leaking into extra dimensions, the slight change in its force should cause the planet's oval-shaped orbit to rotate, or precess, slowly... the orbit would precess by 1/3600 per year - "a reasonable quantity to try and measure," they say.
I wonder how they could conclude that a change of this magnitude would come from gravity leaking into other dimension and not from any of the other myriad of possible effects. It is a good idea, I just don't see how it could work.

semantics

[v1]

Once at the Lagrange point

Lets review this. Lagrange point. Last I checked, a point is not a "region". So there's no way to put a titanium anything completely within a Lagrange Point. At the very best they might put the "sun" part of it centered at the LP, but then the "planetoids" would all be outside the LP, and however minorly, would be affected to varying degrees by the gravity of the earth and of the sun.

This test is invalid. The use of a LP is not going to nullify the effect of gravity of the earth, let alone of the sun. If they are going to do a test that is this sensitive, there is nowhere in the solar system they can hold it and get accurate results.