Index out of range on ray declaration

I feel retarded at having to actually post this, but reading through everything and google for hours not helping.

Im just simply trying to make the console type HIT when i touch a rigidbody but its currently also dumping "ArgumentException: Index out of bounds. PlayerController.FixedUpdate () (at Assets/Scripts/PlayerController.cs:25)"

over and over

 using UnityEngine;
 using System.Collections;
 [System.Serializable]
 public class Boundary
 {
     public float xMin, xMax, zMin, zMax;
 }
 
 public class PlayerController : MonoBehaviour {
     public Ray ray;
     public float speed;
     private Rigidbody rb;
     public Boundary boundary;
     public float tilt;
 
     void Start ()
     {     
         rb = gameObject.GetComponent<Rigidbody>();
 
     }
     void FixedUpdate ()
     {
             
             //mobile movement stuff)
         ray = Camera.main.ScreenPointToRay(Input.GetTouch(0).position);
 
         if(Input.touchCount < 0)
             {
             if(Physics.Raycast(ray,Mathf.Infinity))
                     Debug.Log ("hit");
             
             
             //old movement stuff
             float moveHorizontal = Input.GetAxis ("Horizontal");
             float moveVertical = Input.GetAxis ("Vertical");
 
             Vector3 movement = new Vector3 (moveHorizontal, 0.0f, moveVertical);
             rb.velocity = movement * speed;
 
             Vector3 position = new Vector3 (Mathf.Clamp (rb.position.x, boundary.xMin, boundary.xMax),
                                   0.0f,
                                   Mathf.Clamp (rb.position.z, boundary.zMin, boundary.zMax)
                               );    
         
             rb.position = position;
             rb.rotation = Quaternion.Euler (0.0f, 0.0f, (rb.velocity.x * -tilt));
         }
     }
 }