Speckle Pattern in Unclotted Whole Blood (VIDEO) Optica This video is under embargo. Please login to access this video. To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video Caption This video shows the rapid "twinkling" or intensity fluctuations of the speckle pattern in a drop of unclotted whole blood. The rapid "twinkling" is due to the fast thermally-driven motion of blood cells that scatter light. Credit Seemantini Nadkarni Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.