Invisibility: Theory and Practice - v2

http://timeandquantummechanics.comInvisibility: Theory & Practice - FOSSCON, Aug 10th 2013

Invisibility:Theory & Practice

John Ashmead

Friday, August 9, 13

http://timeandquantummechanics.comInvisibility: Theory & Practice - FOSSCON, Aug 10th 2013

Invisibility:Theory & Practice

John Ashmead

Newly updated for FOSSCON!


Invisibility: Theory & Practice - FOSSCON, Aug 10th, 2013 http://timeandquantummechanics.com

Transparent Motives


http://www.timeandquantummechanics.com



Transparent Motives

•Wicked cool





Transparent Motives

•Wicked cool

•Very practical: not just for war anymore!





Transparent Motives

•Wicked cool

•Very practical: not just for war anymore!

•And of great scientific value





Outline





Outline

•A brief history of invisibility





Outline


•Reflections on materials





Outline


•Reflections on materials

•War, peace & the future





The Invisible Man

“If a sheet of glass is smashed, Kemp, and beaten into a powder, it becomes much more visible while it is in the air; it becomes at last an opaque white powder. This is because the powdering multiplies the surfaces of the glass at which refraction and reflection occur. In the sheet of glass there are only two surfaces; in the powder the light is reflected or refracted by each grain it passes through, and very little gets right through the powder. But if the white powdered glass is put into water, it forthwith vanishes. The powdered glass and water have much the same refractive index; that is, the light undergoes very little refraction or reflection in passing from one to the other.” -- Griffin…

“Yes, yes,” said Kemp. “But a man's not powdered glass!”





Sucker Bet





The last cry you hear could be “Mimicry”











Yellow touches red, you be dead. Red touches black, eat Cracker Jacks.






Yellow touches red, you be dead. Red touches black, eat Cracker Jacks.





Spicebush swallowtail






Spicebush swallowtail





Camouflage

“The soldiers of France will never abandon their pantaloons rouge!”





Camouflage

Modern camouflage began in 1915, when, after a crushing defeat by the Germans, the French army abandoned their stylish white gloves and red pantaloons and enlisted a cadre of artists to develop stealthier attire. The U.S. followed suit in 1917. In addition to hand-painted uniforms, these camoufleurs created false bridges, decoy tanks, and, as seen above, paper-mache horse carcasses that snipers used as blinds.





Dazzle





Dazzle

•Ships in WWI & WWII





Dazzle


•Confusion to the enemy





Dazzle



•Moral boost at least





Dazzle



•Moral boost at least





Stealth





Why so Boxy?





Why so Boxy?

•Reflections angle away from source





Why so Boxy?


•Also, paint eats radar waves





Why so Boxy?



•But, hard to fly





Why so Boxy?



•But, hard to fly

•And, crashes a lot




Invisibility: Theory & Practice - FOSSCON, Aug 10th, 2013 http://timeandquantummechanics.comFriday, August 9, 13




Pay no attention…





Physics of invisibility






•Invisibility cloaks







•Negative refractive indexes








•Metamaterials








•Metamaterials

•Optical transformations








•Metamaterials

•Optical transformations

•General relativity helps make it simple?





Invisibility Cloaks





Invisibility in Practice

“Invisibility is theoretically possible captain – the selective bending of light – but the power cost is enormous. They may have solved that problem”

– Lt. Cmdr. Spock





Lighten Up!





Lighten Up!

•Slow light





Lighten Up!

•Slow light

•Light that goes faster than light





Lighten Up!

•Slow light


•Stopped light - light that doesn’t go at all





Lighten Up!

•Slow light


•Stopped light - light that doesn’t go at all

•Backwards light





Cat’s eyes





Cat’s eyes





Cat’s eyes





Fermat’s principle

Direct but slow

Faster





Fermat’s principle

Direct but slow

Faster

Fastest!





Simple Lens





Lüneberg Lens





PositiveRefraction





Negative Refraction




http://www.loa.espci.fr/cargese2009/Cargese2009_Pendry.pdfInvisibility: Theory & Practice - FOSSCON, Aug 10th 2013

Time Reversal





Negative cancels positive





Super lens




Invisibility: Theory & Practice - FOSSCON, Aug 10th, 2013 http://timeandquantummechanics.comFriday, August 9, 13



http://www.loa.espci.fr/cargese2009/Cargese2009_Pendry.pdfInvisibility: Theory & Practice - FOSSCON, Aug 10th 2013Friday, August 9, 13







Warping space








Like water around a rock…





Hiding a lump under the carpet





Invisible Tanks





Invisible Tanks





Foreseeable Civilian Uses …





•Traffic light visibility







•Earthquake & tsunami avoidance








•Locating reactor core with muons








•Locating reactor core with muons

•Tourist revenue enhancement…






Black holes in the laboratory





Black holes as lenses

Einstein Rings





Time Cloak





Time Cloak





How to Vanish a Cat





How to Vanish a Cat

The apparatus uses the fact that the human eye can’t see phase information to help route light around the “space between”. With no need to preserve the phase, the design is much simpler!

Only works from a few directions, alas.

http://arxiv.org/abs/1306.1780







Seeing the invisible






•It’s all about the math (really the information!)







•Brains at play







•Brains at play

•Any sufficiently advanced science will look like magic





Be Seeing You





Be Seeing You•Forbes - Dazzled & Deceived - 2009 [Fun]






•Perkowitz - Slow Light: Invisibility, Teleportation, & Other Mysteries of Light - 2011 [Solid]







•Beech - Physics of Invisibility: A Story of Light & Deception - 2011 [Lots of pictures]








•Leonhardt - Geometry & Light: Science of Invisibility - 2010 [Brain-Frier]








•Leonhardt - Geometry & Light: Science of Invisibility - 2010 [Brain-Frier]




Technology

Invisibility: Theory and Practice - v2