There was no point in discussing the laws of physics here. If someone had been able to bring a radar device here, the reflected waves would not have detected anything there.

This deadly weapon sliced directly into someone’s perception.

It used a technique of conveying one’s meditation to someone else.

It was the magic known as Spiritual Tripping. The name did not sound very sharp, but it linked the user’s body to the target’s just like with a voodoo doll and it synced up their motions. But this usage allowed the user into the target’s mind. The gesture would send the power of the indicated weapon into the target’s mind.

Toaru Majutsu no Index New Testament vol.18 ch.3 pt.13