[Europan Ocean (OP)]

If we look at light emitted from a far distant galaxy, on the other side of the initial explosion, so that the source is travelling away from us at 90% the speed of light but the light to the Earth's surface. And the light is intense. And between the to places is a tape, not destroyed by stars... made of something like lead oxide. And the tape is shaped like a triangle, a pointy end facing the star and a flat end near the Earth. There can be one such tape moving relative to the star and one to the Earth. And if there is a point looking down on the tape equidistant from each end of the tape. From there the tape is a flat triangle as light reaches the point near the star, it reflects some light up to the vantage point. As time goes on the tape widens as compared to the star light and from the high point more reflection comes from the white compound. I suppose there would be red shift. How fast would the tape appear to be lit up from the high vantage point? Considering two tapes, relative to the Earth and the other to the distant star? Since the light must be travelling at the speed of light, as it leaves and as it arrives.

[Bored chemist]

Reminds me of this
https://hitchhikers.fandom.com/wiki/Triganic_Pu
but makes less sense.

[Europan Ocean (OP)]

In space there is dust but the tape idea is imaginary. What does one see if observing light acting relatively to source and end point? Seeing from between source and end?