Enter the amount to be converted in the box to the left of the currency and press the convert button. To show Bangladeshi Taka and just one other currency click on any other currency. The Bangladeshi Taka is the currency in Bangladesh (BD, BGD). The symbol for BDT can be written Tk.
Mass, Size, and Density of the Universe. The mass density of visible matter (i.e., galaxies) in the Universe is estimated at 3e-28 kg/m^3 (3e-31 times the mass density of water). The radius of the visible Universe is estimated at 1.7e26 m (18 thousand million lightyears) plus or minus 20 percent or so.
Somebody say that as the universe is just about 13.7 billion years old from the big bang to now, so if we measure the mass of photon through any quantum effects, we will ultimately arrive at a threshold under which we can not push on. In other words, we have no method to measure the absolute zero mass of photon.