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If you shine a laser into diamond centered and perpendicular to the table face, the beam will be split and returned out of the table to show a pattern of dots (
by rbobby 5y ago
If you shine a laser into diamond centered and perpendicular to the table face, the beam will be split and returned out of the table to show a pattern of dots (some bright, some dim). The pattern is unique to each diamond.
Gemprint.com uses this to fingerprint diamonds. You can see some images of "gemprints" here: https://www.gemprint.com/light-performance.html https://www.gemprint.com/light-performance.html
- cronix 5y agoI did something similar in college in the 90's, except using cut crystals. One laser in, hundreds of beams out (faded, of course). You know the kind of faceted crystal balls that some people put in their cars and hang from the rearview mirror that cast rainbows everywhere when the sun hits it. Looked cool with a fog machine in the dorm.
- Pulcinella 5y agoLooks similar to an X-ray crystallography diffraction pattern, except that requires X-rays.
- boxed 5y agoX-rays are just one frequency of light. You can use any. Also you can use electrons to get electron crystallography which is (arguably) more powerful as you can reform the original image after, it requires WAY smaller crystals, can see lighter atoms, and more.
- Iwan-Zotow 5y agoYou could use neutrons as well
- herodoturtle 5y agoThis is precisely the sort of randomly insightful comment I’ve come to love from HN.
- dylan604 5y agoI agree. I actually found the GP link more interesting than the posted link. Not that the original wasn't interesting.
- peterburkimsher 5y agoSounds like a Swiss watch company could use that for proving authenticity. Company Seals are also a pretty big deal in East Asia, which are usually a red stamp. If several could be combined (e.g. CEO, CTO, CFO seals all generating a unique interference pattern), that would be a provable signature that the document is legitimate.
- 02020202 5y ago
- 7373737373 5y agoNow I wanna know whether this can be reversed, constructing a 3d model from the dot pattern!
- berkut 5y agoUsing Differentiable Rendering (reconstructing scene setup parameter(s) from an image), possibly, although it would depend on the number of unknown params. Mitsuba2 had an example of matching caustic patterns by modifying geometry I think...
- voldacar 5y agoMy gut tells me it would work like a hash function, the diamond -> dot pattern function being trivial, but the dot pattern -> diamond function taking exponentially more effort
- garmaine 5y agoThere is nothing intrinsically hard about it. Crystallography is the science of reversing this dot pattern.
- s5300 5y ago> The pattern is unique to each diamond. Oh boy, don’t let the NFT folk hear about this
- rbobby 5y agoGemprint... the OG NFT.
- copperwater69 5y agothats really neat, i wonder if you can use this print during manufacturing to get a more perfect cut