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Gravitational Relativistic Physics (GRP)
Low Temperature and Condensed Matter Physics
    PRESENT: Ongoing Reseach

Launch Date: Flown in 1991 and 1994
Mission Duration: During Space Shuttle Missions
Principle Investigator: Prof. Robert Gammon, University of Maryland


Key Questions We Want to Answer:

The most readily observable result of entering the critical region of a material's liquid-gas phase transition is the appearance of a cloudiness, a sign that the density fluctuations are scattering light. In the Critical Fluid Light-Scattering Experiment (ZENO), scientists looked for this light- scattering phenomenon in xenon. Their goals were to measure the size of the density fluctuations and to determine the length of time the density fluctuations existed. There are several theories as to why this light scattering occurs and how these fluctuations relax - ZENO endeavored to test them.

What We Already Know:

By getting a uniform sample, which is possible only in the microgravity of Earth orbit, ZENO's data were 100 times better than similar observations made on the ground.

How We'll Conduct Our Experiment:

The experiment was conducted in 1991 and again in a 1994 reflight on the Shuttle. The first time researchers ran into problems because the transition temperature couldn't be located well enough. A new strategy was devised in the way the experiment temperature was controlled before the experiment flew a second time. ZENO's experience illustrates that these experiments are complex and will not always work the first time. Making adjustments in the experimental process and continuing to attempt ground-breaking investigations is crucial to the scientific method.

The sample region of the experiment was approximately one cubic inch in size, with a larger container of the optical elements and the thermal control devices needed to make it work. Overall the experimental apparatus was about 5 feet by 3 feet by 2 feet in size.

Additional information:

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