While there's no single individual credited with the *first* attempt to calculate the age of the universe, Edwin Hubble is widely recognized for making the first reliable estimate in the early 20th century.

Here's why:

* Hubble's Law: In the 1920s, Hubble observed that galaxies are moving away from each other, and the farther away they are, the faster they're moving. This relationship, known as Hubble's Law, provided a way to estimate the time since the expansion began (i.e., the age of the universe).

* Initial Estimate: Using his observations, Hubble initially calculated the age of the universe to be around 2 billion years. However, this estimate was later found to be significantly off due to uncertainties in measuring distances and the value of the Hubble constant.

* Refinement and Modern Understanding: Over time, scientists refined the measurements and developed a more accurate understanding of the expansion rate. Today, the most accurate estimate of the universe's age is around 13.8 billion years, based on data from the Planck mission and other cosmological observations.

While Hubble's initial estimate was inaccurate, his groundbreaking work laid the foundation for modern cosmology and our understanding of the universe's age.