Physics Help Forum How can we become invisible.
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 Apr 8th 2019, 08:59 AM #1 Senior Member     Join Date: Feb 2017 Posts: 205 How can we become invisible. As per my understanding what we see is nothing but light reflected through an object. So if an invisibility gadget be invented it shd allow light to pass through the man. So in order to do so the gadget has to change the atomic number and atomic mass to that of a substance like glass or so. Well my question is that what is difference in objects is it atomic mass and atomic number due to which they appear different?
 Apr 8th 2019, 09:15 AM #2 Senior Member     Join Date: Jun 2016 Location: England Posts: 1,071 To get light to pass through a man you would have to change the structure of the material making up his body to such an extent that it would be impossible for him to survive. It is easier to cause the light to bend around the man such that it appears on the other side exactly as it would if he were not there. This has been demonstrated with small objects and micro-waves, but to get it to work with light (simultaneously at all visible frequencies) is not currently possible. __________________ ~\o/~
Apr 9th 2019, 12:18 AM   #3
Senior Member

Join Date: Feb 2017
Posts: 205
New problem.

 Originally Posted by Woody It is easier to cause the light to bend around the man such that it appears on the other side exactly as it would if he were not there.
But then when light bends around him I think he would be visible as a dark object since there is light everywhere else and all other things are visible. Isn't it?

 Apr 9th 2019, 04:22 AM #4 Senior Member     Join Date: Jun 2016 Location: England Posts: 1,071 The trick is to bend it around, and then back again so the light, after bending around goes back straight as it would have been if it had not gone around. Very careful measurement would be able to detect the time delay, because the light has traveled further, but that would be a very tiny difference. __________________ ~\o/~
 Apr 9th 2019, 04:32 PM #5 Junior Member     Join Date: Jan 2019 Posts: 25 the cloth of invisibility ... topsquark and zoey like this.
 Apr 9th 2019, 05:45 PM #6 Senior Member   Join Date: Aug 2010 Posts: 434 Ambrose Bierce wrote a short story titled "The Damned Thing" in which people were attacked by an invisible beast. It ends saying "There is a color we cannot see! The damned thing is of that color!" Of course, there is a color we cannot see! It is called "black"!
 Apr 9th 2019, 07:18 PM #7 Senior Member   Join Date: Mar 2019 Location: cosmos Posts: 666 lizard Woody's first post is right. You make him glass man you make him die. A lizard can survive in this thread.
 Apr 10th 2019, 02:34 AM #8 Senior Member     Join Date: Jun 2016 Location: England Posts: 1,071 When I posted my initial reply about curving microwaves I was thinking about an esoteric negative refractive index material I had read about in new-scientist. However on further thought, what is the principle mechanism behind the majority of disappearing magicians? "Smoke and Mirrors" Suitably aligned mirrors reflect the background around the magician (or assistant, elephant, etc...) so that the object seems to disappear. (The smoke is just to redirect your attention momentarily so you don't notice the re-alignment of the mirrors). __________________ ~\o/~
 Apr 21st 2019, 09:07 PM #9 Junior Member   Join Date: Apr 2019 Posts: 5 Did anything more come out of this research? https://www.techtimes.com/articles/8...nt-wear-it.htm? I haven't read anything else. It's interesting to see how man has wanted this for thousands of years, and yet it has not been one of the easier problems to crack. Last edited by zoey; Apr 21st 2019 at 09:09 PM. Reason: I wanted to add more.
 Apr 21st 2019, 10:04 PM #10 Senior Member   Join Date: Mar 2019 Location: cosmos Posts: 666 Die hard VS probability of survival.

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