A new and so far the most precise deter-mination of the gravitational constant G has been made byJun Luo and colleagues at the Huazhong University of Science and Technology(HUST)[1].rnThe combination of G with two other most fundamental physical constants,the speed of light c and Planck's constant h,can together construct the natural units(a.k.a.Planck units)of time,length and mass.These relationships inform us that,among the aforementioned three con-stants and three units,a total of six physi-cal quantities,three and only three quan-tities should have their values defined.In the SI system,just updated in 2019,the following were chosen to have de-fined values:the second as the unit of time,c and h.Today,G remains to be measured.