Gravity in small scale

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DrewFraser

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As Gravity obviously has the effects to keep object on the ground by bending space. How could someone show gravity in a small scale to possibly look at how things came to be, like the solar systems from a possible big bang.
 
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BoJangles2

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There is no unified (accepted) theory of gravity on the sub atomic scale, which is a huge goal in science atm.

Oh welcome to SDC :)
 
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DrewFraser

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BoJangles2":2d6ofgrp said:
There is no unified (accepted) theory of gravity on the sub atomic scale, which is a huge goal in science atm.

Oh welcome to SDC :)

thank you for the welcome, and i was just talking not about an actual answer to the fact of gravity just about brainstorming possible answers to it, even though some theories might easily be fictional.
 
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aphh

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Gravity in small scale is difficult to demonstrate because most often there is a giant mass nearby that overshadows any small gravity that 2 objects otherwise would demonstrate between them.

Perhaps the best demonstration of gravity in small scale are some asteroids with tiny moons orbiting the asteroid and the system flying in perfect formation.

Extremely tiny gravity is holding the objects in close proximity in such case. Japan's aeronautics agency JAXA should be an expert in using tiny gravity as their asteroid visiting craft Hayabusa orbited asteroid Itokawa.

Probably a sneeze's worth of thrust was required by Hayabusa to escape the gravity of Itokawa.
 
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venator_3000

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DrewFraser":27n8vxx4 said:
As Gravity obviously has the effects to keep object on the ground by bending space. How could someone show gravity in a small scale to possibly look at how things came to be, like the solar systems from a possible big bang.

There were some pretty cool experiments done aboard the space shuttle about a decade ago that looked at microgravity and small-scale accelerations.

The principle behind measuring acceleration aboard the Shuttle goes all the way back to the 1680s and Sir Isaac Newton's second law of motion: a body at rest (or in motion) tends to stay at rest (or in motion) unless acted upon by an outside force. On the shuttle they used some fairly unique pieces of equipment and accelerometers to measure minute changes in a masses position caused by accelerations around the shuttle.

It should be noted that the "accelerometer" on your car is really a speedometer. Acceleration is the rate at which speed changes, and that is what affects science experiments. 30 mph is a measure of speed. 30 mph or 18000 mph, the Shuttle's orbital speed, is fine. 0 to 30 in 10 seconds is acceleration and that, or smaller changes, is what causes a mass or some material to shift in their containers. (Even you inside the car as it goes around a corner).

On the shuttle mission they used a spatial 3-axis electrostatic accelerometer (ASTRE) and a microgravity sensor package that were designed to measure minute changes of acceleration and the position of an object inside a chamber.

A gold "proof mass," about the size of a drafting eraser (1x4x4 cm) was floated inside a chamber lined with contacts that generated a static electric charge. The electrodes repel the mass so the mass stays centered in the chamber. When the space shuttle moved, the chamber moved so the mass, at its center, would move closer to one wall or the other. ASTRE's electronics measured the change in position and adjusted the electrostatic field to keep the tiny little mass centered.

In effect, the force needed to center the mass is equal to the force trying to offset it, just as you can feel the sharpness of the car's turn by how much force you need to stay upright.

Another experiment on this mission used the microgravity sensor package. It had 3 sensors. The sensors were all built on microchips. A small arm, called a cantilever, with a weight on the tip, extended across an empty space on the chip. If the chip moved sideways the arm would flex. Capacitors on each side of the empty space measured the change in position. Three sensors were needed, mounted at right angles to each other, to measure full movement. These axes are typically referred to as x, y, and z.

The experiments were succesful in that they were able to measure these minute changes, especially when the shuttle was in motion. It also measured tiny amounts of deceleration caused by the shuttle as it dragged through molecules in the rarefied upper, upper atmosphere. It's interesting that ASTRE was a french experiment, and Comité International des Poids et Mesures which is one of the bodies that helps maintain Le Système International d'Unités (or SI) has done so much work over the years in terms of establishing various measurements of mass, length, and time, just to name a few.

Today, you can buy tiny accelerometers on a chip via hobby outlets. They are very sensitive. They can be powered by USB cables and read via PCs.

V3K
 
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DrRocket

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BoJangles2":2v29dh6f said:
There is no unified (accepted) theory of gravity on the sub atomic scale, which is a huge goal in science atm.

Oh welcome to SDC :)

Sure there is. The available theories of gravitation, whether classical Newtonian gravity or general relativity do not have any inherent scale limitations. However, at the usual distance scales gravity is not important at the atomic level. It applies, but it is not important. At much smaller scales that might not be true, but we don't have any real understanding of physics at those extremely small scales anyway (I'm talking at the Planck scale and below where the "sizes" of subatomic particles are huge). What does not exist is a quantum theory of gravity.

"Unified" and "accepted" are two entirely different things. The electroweak theory unifies the theory of the electromagnetic force and the weak force. We don't have a unified theory that would include the electroweak and strong forces -- that would be a Grand Unified Theory or GUT. We don't have a unified theory that includes the electroweak force, the strong force and gravity -- that would be a Theory of Everything or TOE.
 
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