The Planck time is the smallest unit of time that can be measured, at approximately 5.39 x 10^-44 seconds. It is named after physicist Max Planck and is often used in theories of quantum gravity.
The Planck mass is the mass of a particle at the Planck scale, which is the smallest scale at which the laws of physics are thought to be applicable. It is approximately 2.18 x 10^-8 kilograms and is often used in theories of quantum gravity.
The mass of the universe is estimated to be around 10^52 kilograms, which is significantly larger than the Planck mass. However, some theories suggest that the universe may have started at the Planck time, with a size and mass of the order of the Planck scale. Therefore, the Planck time and mass are important in understanding the early stages of the universe.
The number 65 kg is often used as a reference point for the mass of the universe, as it is roughly equivalent to the mass of an average human. This can be helpful in visualizing the vastness of the universe and the relative insignificance of human beings in comparison to its mass.
The exact mass of the universe is difficult to measure, as it is constantly expanding and contains both visible and invisible matter. Scientists use various methods, such as studying the cosmic microwave background radiation and measuring the gravitational effects on galaxies, to estimate the mass of the universe. However, these estimates are constantly evolving as our understanding of the universe improves.