Space-Time ninjutsu of Tobi


Why can't Tobi attack while he is dodging an attack using his [Jikūkan
Ninjutsu](http://naruto.wikia.com/wiki/The_Secret_of_the_Space%E2%80%93Time_Ninjutsu)
?  

> what Tobi actually does is warp away the part of his body that was being
> attacked to the other dimension.

During the entire anime it is portrayed that Tobi cannot attack while using
Jikūkan Ninjutsu because his attacks will pass right through the target.  
  
[![enter image description
here](https://i.stack.imgur.com/ooMM3.jpg)](https://i.stack.imgur.com/ooMM3.jpg)  
But while Kakashi was in Tobi's space-time dimension, he managed to punch him,
thus indicating that Tobi wasn't intangible.  
Is there any explanation or any theory on this matter ?




**Is there any explanation or any theory on this matter?** Yes.

Kakashi discovers Obito's weakness, to which he explains how
[Obito's](http://naruto.wikia.com/wiki/Obito_Uchiha) space-time justu works in
the manga chapter 597, and utilizes it against him.

> Although Kakashi cannot use Kamui against Obito directly, he can use his own
> access to the other dimension to negate the advantages Obito makes use of:
> by teleporting attacks or allies to the other dimension at the same moment
> that Obito's body resides there for defence, he can be attacked successfully

Kakashi states that attacks "passing through" is Obito is incorrect - Obito
sends his body into a different dimension; where he is completely tangible.

Kakashi begins to understand how this justu works when he sends a kunai into
the other dimension using his own Kumai ability at the same moment Obito
teleports his head to dodge an attack from Naruto.

[![enter image description
here](https://i.stack.imgur.com/HYfgll.png)](https://i.stack.imgur.com/HYfgll.png)
[![enter image description
here](https://i.stack.imgur.com/EF6wjl.png)](https://i.stack.imgur.com/EF6wjl.png)
[![enter image description
here](https://i.stack.imgur.com/mdnDil.png)](https://i.stack.imgur.com/mdnDil.png)
[![enter image description
here](https://i.stack.imgur.com/wPIO3l.png)](https://i.stack.imgur.com/wPIO3l.png)
[![enter image description
here](https://i.stack.imgur.com/8ULbul.png)](https://i.stack.imgur.com/8ULbul.png)

