Considering that the density of the Big Bang obtained by using photons is not more than and the radius of the Big Bang sphere will be from the Earth to Jupiter. So, it could not be a suitable choice for the Big Bang, because it does not meet the definition that we expect for the Big Bang. In order to achieve our desired goal, we define a particle whose radius is one billionth of a photon.

density of the Big Bang
photon
Cidtonium
most condensed matter
size of the Big Bang

In this video we defined a particle which named sub-photon that is one thousandth, one millionth, or one billionth of a photon in terms of radius. According to the calculations and definitions, it can be proved that there is a particle whose radius is one billionth of a photon's radius and its volume is 10 to the power of minus 27 meter of the photon's volume.

In this video we introduce a particle that is a subset of the photon, and its radius would be about 10^-9 times the radius of the photon that this particle has been the creator and constituent of the Big Bang.