[alancalverd]

What happens to a moving photon starts from zero distance before Planck time?

Planck time is an interval of about 10^-44 s.  Nothing special "happens" at t = 0, -P, +P or anywhere else on the time axis.

[Yahya A.Sharif (OP)]

What happens to a moving photon starts from zero distance before Planck time?

Planck time is an interval of about 10^-44 s.  Nothing special "happens" at t = 0, -P, +P or anywhere else on the time axis.

What I said is: if measurements are limited to Planck scale, motion of a mass with velocity v and starts from time t =0 must occur after Planck time because it has no meaning that a mass traveled some distance after 10^−90 seconds " before Planck time" because it is smaller than Planck time. If no motion occurs then the mass will stay at stationary.

[Kartazion]

if measurements are limited to Planck scale

This ratio of the measurement is not made in relation to the Planck scale, but rather in relation to the measurement itself (Heisenberg's uncertainty principle)

If no motion occurs then the mass will stay at stationary.

If you measure an immobility it can only be done in time. IOW time passes to be able to determine an immobility.

[alancalverd]

The words "Planck scale" have no physical meaning. It is a human construct, like the metric system.

[Deecart]

What I said is: if measurements are limited to Planck scale, motion of a mass with velocity v and starts from time t =0 must occur after Planck time because it has no meaning that a mass traveled some distance after 10^−90 seconds " before Planck time" because it is smaller than Planck time. If no motion occurs then the mass will stay at stationary.

I think you do the confusiion between the possibility you could observe something and the reality behind the observation.
Measurement are limited to Planck scale, you say it yourself, and it is true.
This do not mean that the space itself cant have some smaller scale.
This only says that, because energy is quantizied, we cant do the observation... at our scale.
At other scale, so the scale of the smalest possible scale (planck scale) the reality can observe itself without our help, so physicality remain.

The best argument for that is that String Theory go beyond the Planck Scale.