US-based researchers have demonstrated the fastest light pulse ever developed, a 53-attosecond X-ray flash, beating the 67-attosecond record set by the same team in 2012. Attosecond pulses help scientists capture images of fast-moving electrons in atoms. This duration is so small that light, which travels at 3 lakh km/sec, covers less than one-thousandth of a human hair during 53 attoseconds.