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Pluto Probe Snaps Jupiter Pictures
sighted writes "The New Horizons probe, on its way to Pluto and beyond, is now speeding toward Jupiter. Today the team released some of the early data and pictures, which are the first close-range shots of the giant planet since the robotic Cassini spacecraft passed that way in 2001."
I'm glad to see some of Nasa's deep space work getting publicity; most people seem to just focus on stuff like the ISS which has been a disaster from start to finish, when there is much succesful work being done at the outer reaches of the solar system.
One of the main problems, however, is communication at these distances is extremley problomatic; it takes 8 minutes to send a signal as far as mars and 4 years to send one to Alpha Centuri, which Voyager 1 is predicted to reach in later 2009. here in the lab, however, we are working on some technology that should help alleviate this problem.
The solution relies on one of the properties of gravitons. Now as you keen physicists will be aware, the four forces (electromagnetism, gravity, strong, weak) are all caused by force carrying particles. For the electromagnetic force, for example the force carrying particle is the photon; particles under the influence of the electromagnetic force will emit and absorb photons thus changing their momentum and energy. Gravity uses the same mechanism and we call the force carrying particle the graviton.
Now gravity is different from the other forces in that it can be felt over long distances, a quality that tells us a great deal about the nature of gravitons. If 2 particles are 10 light minutes from each other, then any change in the gravity of one particle will not be felt by the other for 10 minutes. The traditional explanation for this is that the graviton can only travel at the speed of light and as such will take 10 minutes to travel from one particle to the other, so far so good. Unfortunately the situation breaks down if one of the particles is moving. As it won't be in the same position in 10 minutes time, the graviton should miss it and no gravity should be felt. As we know, however, gravity is always felt by moving bodies so the graviton must intercept the moving particle in order for the force to be expressed. By conventional theory the graviton must 'know' where the particle will be in ten minutes time.
Now perhaps that doesn't seem unreasonable but if you move the particles 10 light years apart then things get a bit more tenuous. As the graviton would take 10 years to travel the distance, this means that the particles must 'know' where each other are going to be in 10 years time. This is quite frankly ridiculous!
The explanation is in fact that the gravitons do not move at the speed of light but instead are exchanged instantaneously with their effects not being felt until a time equal to the distance between the 2 particles divided by the speed of light. In this way the rule limiting the exchange of information is kept intact and the rules of physics remain unchanged. We can however use this quality to solve our problem of communicating with deep space probes. Think of it as follows.
Here in the lab we have a massive ball which emits a large number of gravitons. As previously mentioned these gravitons will instantly arrive at our deep space probe regardless of how distant it actually is, but will not act on it until some time later. The key part is that we have a graviton detector on our probe which measures the number of gravitons received. By changing the mass of the ball (simple enough to do with a powerful laser) we can cause the number of gravitons detected by the probe to fluctuate and thus transmit a signal. As gravitons travel instantaneously the signal travels instantaneously and we have faster than light communication. Although the system is never going to carry gigabits (changing the mass of the ball is difficult to do on a picosecond time interval) it should be enough to perform simple operations such as steering the probe or powering on systems, thus revolutionising space travel.
-- physicsExpert