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Science lesson with Dark_Lorde
SCIENCE FINALLY GIVES US INVISIBILITY!
And by Science, I mean the man above, Doctor John Choi, and his master, one Professor John Howell, a wizard of some nature within the dark art of physics at the University of Rochester. Unlike your more stereotypical, lightning-machine wielding prototypical scientist of today, Howell et al. decided to go back to basics and take an approach to this endeavour that uses the properties of light in accordance with itself to achieve the outcome. And you too can do at home for 100 of your human dollars! True story.
Basically you’ll be able to do this. And it’ll amuse people for TENS of seconds
So far the operating theatre is expected to be its primary place of usefulness as Choi says it will let a surgeon “look through his hands to what he is actually operating on”.
So how does it work? Basically the scientists have used distance between multiple lenses and some sexy, sexy maths to cancel out a certain range within range of the lens, allowing the light to reflect back only the light that bends around behind the object immediately in front of it and representing it as the initial layer. Brilliant!
Check out this laser to get a good visualisation of how this all goes down:
Speaking on current limitations, Choi advises that “This cloak bends light and sends it through the centre of the device, so the on-axis region cannot be blocked or cloaked”. The lens also suffers some minor blurring around the edges, but apparently this disparity clears up when the lens scaled up to a larger size to obscure bigger objects.
These larger lenses may also be useful for cancelling out blind spots on larger vehicles.
It’s no Harry Potter level piece of kit, but it’s a start.
And here’s how YOU can build you one of these little guys:
HOW TO BUILD YOU A ROCHESTER CLOAK!
For their demonstration cloak, the researchers used 50mm achromatic doublets with focal lengths f1 = 200mm and f2 = 75mm. Here’s what you’re gonna need:
Purchase 2 sets of 2 lenses with different focal lengths f1 and f2 (4 lenses total, 2 with f1 focal length, and 2 with f2 focal length)
Separate the first 2 lenses by the sum of their focal lengths (So f1 lens is the first lens, f2 is the 2nd lens, and they are separated by t1= f1+ f2).
Do the same in Step 2 for the other two lenses.
Separate the two sets by t2=2 f2 (f1+ f2) / (f1— f2) apart, so that the two f2 lenses are t2 apart.
NOTES:
Achromatic lenses provide best image quality.
Fresnel lenses can be used to reduce the total length (2t1+t2)
Smaller total length should reduce edge effects and increase the range of angles.
For an easier, but less ideal, cloak, you can try the 3 lens cloak in the paper.
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