Ghost Verified by Mark (IMAGE) American Institute of Physics Caption This is a schematic illustration of marked ghost imaging. Credit W. Chen and X. Chen/NUS Usage Restrictions This image may be used only with appropriate caption and credit. 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.