Using a laser pointer to display secret shapes?

Hey, all,

I'm working on a puzzle for an escape room right now and am wondering if there's any way that I can use a laser pointer to display a number. My hope is that the number is not on the lens of the pointer, but rather is discovered after the laser pointer is shined through a specific spot on a piece of plexiglass.

The players are asked to set up a tripod in a specific spot with a specific angle, mount the laser point to the top of it and then move the point around the room. Ideally, as the point is traveling around the room, it will shine directly on a small part of a plexiglass display and then refract a number on the wall behind it.

Any ideas on how or if this is possible? Any and all thoughts are welcome.


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iceng5 months ago

I use blackrock geode slabs that are non-interesting in white light but light up under those dollar store laser pointers. Any engraving on the back side show up..

You could make holograms that would project a single number on a diffused laser.

DrewP36 (author)  iceng5 months ago

Thank you! Can you point me to a place to purchase online?

iceng DrewP365 months ago

I'm a rock hound in the black rock mountains near burning man and cut my own geode slabs, sorry Not for sale....

Holograms you have to make youself..

sparkor5 months ago

It is very interesting

Downunder35m5 months ago

You could just use paint - more or less...
Tiny glass speres as used for the paint in road markings act like a reflector.
The problem with these is that the light is always reflected directly back to the source.
Having light from above would have no effect for someone walking around in the room.
If a wall is painted with something that does not make these tiny spheres visible directly you can embed them into the last layer.
Best method I found for this is "sandblasting" with a stencil.
While the paint is still wet enough hold the stecil in front of the wall (as close as possible) and blow the glass spheres through the stencil onto the wall.
If the number is big enough you only need a few spheres here and there but not like a coating.
Once the laser with a wide beam hits the spheres the person using it and those close by will see the reflection on the wall where the glass spheres are.

steveastrouk5 months ago