Invisibility - Is it possible?

Invisibility is a state of which an object cannot be seen, and is a myth that has dated back to many fantasy and science fiction books, such as Harry Potter's cloak of invisibility, or Artemis Fowl's high-vibration suit.

Basically, we can see an object when light reflects off it. Lighttravels in straight lines, and shadows are caused by an object blocking the rays of light, making them cut-outs on a surface with light. Imagine a black wall. If you shine a torch on the wall, it will make a circle of yellow light on the wall. However, if you put an object between the light source (the torch) and the receiving object (the wall), this will make the light shine on the object in-between, and since light travels in straight lines, it will block the rays that reach the object between from reaching thewall. This creates a black cut-out among the yellow light. Rays of light alone cannot normally be seen. Try this. shine a torch onto a wall, and you can only see faint light in the path of it, but there is a circle of light on the wall. The visible ray of light is because the dust and small particles in the air are reflecting the light, making it visible. However very powerful beams can be seen, creating a beautiful display.

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So how are they attempting to achieve this great feat of invisibility?

They intend to bend light around an object. Logically, if the light never reflects off the object, it will never be seen. but since light travels straight and cannot turn without reflecting, scientists think that making "Light waves" are possible, much like radio waves and something like that -dattebayo

So what do you guys think? Is it possible or this whole thing is just waste?

I believe in near future this will be possible...i dunno where i read but scientists from UK have developed something called "Surface Wave Cloak" that can make curved surfaces appear flat when it comes in contact with the electromagnetic waves. So if they keep pushing it, it might be possible -dattebayo

It's possible but I think the technology required won't exist for a long time.

In an episode of White Rabbit Project (available on Netflix), the former Mythbusters build team pretty much proved that invisibility was impossible, even through all the methods that they've tried.

The closest thing I've seen (ha) is a system of cameras and screens where one side of an object projects an image of what the other side is seeing. It's not anything near viable or even that convincing. Maybe in 20 or more years it would be possible, but I imagine it would still take a lot of energy and would need immensely small and precise devices to work even a little bit effectively like invisibility.

Esper said:

The closest thing I've seen (ha) is a system of cameras and screens where one side of an object projects an image of what the other side is seeing. It's not anything near viable or even that convincing. Maybe in 20 or more years it would be possible, but I imagine it would still take a lot of energy and would need immensely small and precise devices to work even a little bit effectively like invisibility.

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Yep, I saw that demonstration as well and it certainly did have its flaws.

Also, cameras don't necessarily interpret light and color the same way that the naked eye does, which is a flaw by design. Plus, frame interpretation as well. I can't even imagine the amount of technology growth and development it would take for a camera to precisely be able to mock the vision of the naked eye.

I don't think that there are any impossibilities with science, just that some things'll take way longer than others. Like that, invisibility is possible, just not in the near future, probably not in the far future either.

Invisibility would be pointless anyway.

You need light hitting your retina to see things. So if, by some miracle, they make a cloak that can somehow reflect all beams of light to make you invisible, then logic dictates that none of those beams of light are acting on your retina. Essentially, while you wear this cloak, you'll also be blind.

i think one day it will be possible for invisibility to exist just like it is possible for a plane to not appear on the radar you know like stealth bomber for example

Frozocrone said:

Invisibility would be pointless anyway.

You need light hitting your retina to see things. So if, by some miracle, they make a cloak that can somehow reflect all beams of light to make you invisible, then logic dictates that none of those beams of light are acting on your retina. Essentially, while you wear this cloak, you'll also be blind.

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Reflecting can not make one invisible. It's the contrary. The reflection from a surface makes us see the surface. So if such a cloak is made, it would have to reflect no light, instead it would have to absorb it all, which will make it black.
I wonder if we can call it invisible.

Invisibility is a tricky one.

I guess much of it depends on what do we want: do we want the object to truly not be seen, or do we merely want to not perceive it?

The former is very problematic. Not only is there the issue pointed above regarding being blind on the inside, but there's also the lesser remembered fact that light transmits information about how the space is curved. If a material reflects or twists somehow all light (visible or not, let's think UV cameras) to make an object invisible, then the object itself becomes a sort of "hole in the world". it is not reachable by light, yet it is by touch so what are we supposed to see when eg.: rain fals on the cover? If the object deflects all photons and thus all means of receiving information from the outside world, would it be able to position itself via GPS or receive a cell phone signal? And then there's some esoteric theoreticals: if photons can not reach past the cover, isn't it functionally equivalent to an event horizon? At what speed does time flow under the covers? Can the object under the covers receive sound?

The latter is IMO more interesting, as there are more than one kind of invisibility or blindness. If we want to merely not be able to perceive an object, then it suffices to shield it from light in our perception spectrum, perhaps in that of common cameras as well. That should be more easily doable than blocking all light from reaching the object, and IMO it would produce more sensible results. A wearable superprocessor that is capable of something like Adobe's "context fill" on the material, replicating the characteristics of the surrounding environment just as chameleons can do. It won't be perfect, but since it only has to fool human perception it won't have to: it will be able to fall back on all the science we have on such things as optical decay and optical illusions, like alternating opposite colors on cross patterns, or producing a strips pattern that deviates the observer's attention to the surroundings.

And then there's going the path of the Laughing Man in Ghost in the Shell: Stand Alone Complex. A superb hacker, in order to protect his identity he headed to the simple and obvious answer to the problem: rather than trying to make himself invisible, which would have required him to break physics, he made people not "willing" to see him; he hacked people, who were always online and overreliant on technology, so they would register no mental record of his face -or rather, he substituted the concept of "his face" in people's minds for that of a logo, producing both a physiological and a behavioural (social) effect.

But maybe that's cheating. It might also be boring. I mean, who doesn't want to take jabs at the laws of physics?