Your mind is a electromagnetic manifestation

[anagogy]

It would be detectable if it wanted to be.

13.20 ↥ Questioner: Is there any physical difference between first and second density? For instance, if I could see a second-density planet and a first-density planet side by side, in my present condition, could I see both of them? Would they be both visible?

Ra: I am Ra. This is correct. All of the octave of your densities would be clearly visible were not the fourth through the seventh freely choosing not to be visible.

I agree completely.

But I still maintain that those "detectable portions", even were they to choose to make themselves visible, would still, in fact, be red ray spectrum energies.

We only see the red ray expression, of 1st density, of 2nd density, of 3rd density. And if 4th through 7th made themselves visible we would still just be seeing their red ray physical expression. The other rays are not, properly, physically perceptible, though, you could perceive them with other, more subtle, bodies we have nested within us.