Time travel is like perpetual motion impossible you can not get free energy.you can not eat your lunch Travel back in time one day and eat your lunch again ,and again.thair are not multiple realitiese energy Can not be created or destroyed energy only Chang form and shape not multiple it self,like my imaginary friends adopted an imaginary child. Time is not real it's not a thing its an measurement and as is gravity and space.yes space is Cold DoS t that prove space exist or if you believe space is not cold what DoS that prove.