How Science Defines A Year

The video celebrates a year since the first upload, highlighting personal achievements and exploring the concept of time. It discusses how time is measured, biological changes over a year, and astronomical distances. The differences between sidereal and tropical years are explained, emphasizing the importance of Earth's tilt and the calendar system. The video concludes with reflections on time's passage and curiosity about the future.

What challenges does the speaker mention regarding the synchronization of seasons and the calendar?

Explain the concept of a tropical year as described in the text.