Relativistic Time Dilation by Thermal Motion

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Relativistic Time Dilation by Thermal Motion

• Chintan Hossain

MIT Junior Lab March 7, 2005
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Outline

• Background Relativistic Time Dilation,
  Mossbauer Spectroscopy
• Experimental Setup
• Data and Results Comparision to classical
  relativistic predictions
• Conclusion

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Relativistic Time Dilation

• Basic Time Dilation
• We are measuring photon frequency
• Relating T and v
• Frequency shift in terms of T

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Mossbauer Spectroscopy

• Gamma rays are released by a source and absorbed
  by an attenuator
• Recoilless emission allows for very narrow
  emission lines GE/E10-13
• Energy of emission line is varied by Doppler
  shift ?E/Ev/c

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Experimental Apparatus
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Primary Calibration Using Interferometer
Calibration Function (bin-545 24)(8.28
0.18)10-3 mm/s
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Secondary Calibration Using Fe-57
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Secondary Calibration Using Fe-57
New Calibration Function (bin-535 24)(3.43
0.08)10-3 mm/s
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Absorption Data for A Heated Absorber
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Peak Velocity vs. Temperature
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Final Results

• Slope 3kB/(2mc) -gt kB (1.3 0.4)10-23 J/K
• Agrees with known value of kB 1.410-23 J/K
• Our results agree with the theory of relativistic
  time dilation.

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Sources of Error

• Velocity nonlinearity/ instability 27
• Poisson Error 7
• Velocity calibration 2.3

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Conclusion

• We observe relativistic time dilation due to
  thermal motion.
• kB (1.3 0.4)10-23 J/K, agrees with known
  value of 1.410-23 J/K
• Improvements to experiment
• Try to make the velocity more stable
• Do a calibration that accounts for nonlinearity
• Take measurements for more time