Read about how & why Shiva is- The God of Gods

Shiva(term shiv: ,shivam means soul).
Shiva is the supreme soul, creator of gods & other souls.

Shiva in sanathana dharma worshipping as physical representation shiv ling(oval shape representing of light or jyothi). And also worshipping as one of the forms of Trimurthis lord mahadev(great god, Destroyer). 

How to recognize shiva is supreme and beyond all gods?

In sangatana dharma to every gods physical representation to worship include lord mahadev and goddess maa Parvathi devi as they are except shivling.  Behind science of worshipping gods also connect to supreme being.  From yugas supreme being worshipping as shiv ling. In history You can find ancient temples  about shiva & shivlings idols world wide.

What is science behind meditation to all benefits? 

Generally we know very well meditation cures much health, for law of attraction and inner strength.  (In sanathana dharma we have many stories regarding this. Mainly Rushis, Gods did thapasya for various purpose)

For spiritual seekers Meditation are practice to self realize, know about god and connect to supreme soul.

By doing meditation our soul itself start journey to supreme soul.