The article discusses the extension of attosecond spectroscopy techniques to study electron dynamics in condensed-matter systems and on surfaces. The authors demonstrate the ability to observe electron motion in real time with attosecond resolution by probing photoelectron emission from single-crystal tungsten. They reveal a delay of approximately 100 attoseconds between the emission of photoelectrons from localized core states and those from delocalized conduction-band states. This work provides a powerful tool for exploring fundamental electronic processes on the attosecond timescale in condensed-matter systems and surfaces. The experimental setup involves combining photoemission spectroscopy with attosecond temporal resolution, allowing for the first direct attosecond time-resolved observation of electron transport in a condensed-matter system. The results highlight the potential for future research into processes such as charge transfer, charge screening, and collective electronic motion.The article discusses the extension of attosecond spectroscopy techniques to study electron dynamics in condensed-matter systems and on surfaces. The authors demonstrate the ability to observe electron motion in real time with attosecond resolution by probing photoelectron emission from single-crystal tungsten. They reveal a delay of approximately 100 attoseconds between the emission of photoelectrons from localized core states and those from delocalized conduction-band states. This work provides a powerful tool for exploring fundamental electronic processes on the attosecond timescale in condensed-matter systems and surfaces. The experimental setup involves combining photoemission spectroscopy with attosecond temporal resolution, allowing for the first direct attosecond time-resolved observation of electron transport in a condensed-matter system. The results highlight the potential for future research into processes such as charge transfer, charge screening, and collective electronic motion.