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Gravitational Relativistic Physics (GRP)

Gravitational and Relativistic Physics (GRP)

    PAST: Gravity Probe A Seperator Dot Viking Seperator Dot Lunar Laser Ranging Seperator Dot LAGEOS I & II
PRESENT: Ongoing Research
    FUTURE: Gravity Probe B Seperator Dot AMS Seperator Dot STEP Seperator Dot LISA Seperator Dot SUMO

Launch Date: 2006
Mission Duration: One year
Principle Investigator: Prof. John Lipa, Stanford University


SUMO image

Key Questions We Want to Answer:

The Superconducting Microwave Oscillator (SUMO) experiment will place in orbit a superconducting cavity-stabilized oscillator (SCSO) system. This is a distinctive type of clock that can be used for experiments in relativity. To date, only atomic clocks have been used in space-based relativity missions, however, it is known that SCSOs are extraordinarily stable clocks with similar accuracy.

What We Already Know:

A SCSO clock is built out of a microwave cavity constructed of a superconducting metal that operates at cryogenic temperatures. Being based on a different timekeeping mechanism, from an atomic clock, means that a comparison between the two can give a fundamental understanding about changes in the universe. Scientists have found that it is particularly useful to compare the rates of different types of clocks as a function of speed and gravitational pull. Placing this unique type of clock in the microgravity of space, will provide a new tool for probing the laws of physics at the highest possible level.

Additionally, comparing the SUMO clock against a more standard atomic clock, will help answer the question of whether presently known physical laws really are indisputable, or whether they vary for different places or velocities. This experiment will also help to determine how gravity and other factors have an affect on the speed of time.

Additional Information:

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