The Impossibility of Invisibility

[Ron_Tomkins]

For a while, I had given a lot of thought on the idea of making a human being invisible. I remember, one day, I reached the following conclussion:

Given the premise that we discover through scientific methods, a way to make all of the body's molecules 100% transparent (meaning, 0% of the sunlight will be reflected, making them thus invisible), it would still be impossible to make the individual invisible to our eyes. It can be proved with the following experiment:

Walk barefoot for 10 minutes and then look at the bottom of your feet. What do you see?

The answer is dirt. When you walk, you acumulate a great deal of dust and dirt on the bottom of your feet. Therefore, given the premise that someone was invisible, we would eventually see two feet-shaped dust layers walking on the ground.

Is there another variable that I'm missing? Perhaps another possibility?

 

[Rob Lister]

yes, blindness

 

[Jeff Corey]

I am totally unable to see the point of this thread. According to Pesta's Law, it should generate many replies.

 

[technoextreme]

yes, blindness

I don't buy this argument especially when the closest thing we have to a cloaking device doesn't work in all directions. Even being partially invisible would be invaluble and you would still be able to see.

Given the premise that we discover through scientific methods, a way to make all of the body's molecules 100% transparent (meaning, 0% of the sunlight will be reflected, making them thus invisible),.

That's not how invisibility works. You aren't making the object transparent you are designing a material which diverts the light around the object.

 

[Ron_Tomkins]

I am totally unable to see the point of this thread. According to Pesta's Law, it should generate many replies.

The point of this thread is to generate discussion on whether the concept of Invisibility is actually impossible.

 

[Biscuit]

Oh this is too good to be true! No one thought of the implications this has to invisible bigfoot! His feet are BIG and no doubt dirty being that he hates the indoors and tromps through the forest!

We now have a way to track invisible bigfoots! Look for giant dirty feets!

One a side note my own knowledge of invisible bigfoot behavior is begining to scare me.

 

[Ron_Tomkins]

That's not how invisibility works. You aren't making the object transparent you are designing a material which diverts the light around the object.

AROUND?
What the?....

I was thinking more of light going through the object without reflecting any light?

How would this around theory work?

 

[Ron_Tomkins]

Oh this is too good to be true! No one thought of the implications this has to invisible bigfoot! His feet are BIG and no doubt dirty being that he hates the indoors and tromps through the forest!

We now have a way to track invisible bigfoots! Look for giant dirty feets!

One a side note my own knowledge of invisible bigfoot behavior is begining to scare me.

LOL!

Looks like you found the perfect post to expand on your invisible Bigfoot theory, didn't ya?

 

[Hokulele]

Did you include all the non-person organisms in a person when you came up with your "100% of the body's molecules"? This would include organisms such as bacteria, mites, fleas and ticks, etc.

Meh. The more I think about this, the more I agree with Jeff Corey.

 

[Ron_Tomkins]

Did you include all the non-person organisms in a person when you came up with your "100% of the body's molecules"? This would include organisms such as bacteria, mites, fleas and ticks, etc.

Meh. The more I think about this, the more I agree with Jeff Corey.

No, I didn't. That's why I came to this forum. It is filled with skeptics, many of them with far more knowledge of scientific facts than I do. I came here to exchange information. I'm not claiming anything at all (If anything, I'm claiming that invisibility is impossible. I just want to know exactly why and how is it impossible)

 

[Jeff Corey]

The point of this thread is to generate discussion on whether the concept of Invisibility is actually impossible.

I still don't see it.

 

[Ron_Tomkins]

I still don't see it.

Then maybe it's invisible?

 

[Skeptic Ginger]

AROUND?
What the?....

I was thinking more of light going through the object without reflecting any light?

How would this around theory work?

It's actually being worked on.

Scientists one more step closer to realising invisible technology

High tech cloaking devices

Edited to delete camera method. I've heard of it but didn't find a source yet.

 

[Dilb]

AROUND?
What the?....

I was thinking more of light going through the object without reflecting any light?

How would this around theory work?

The better question is, how on earth would it go through the person? People are made of things that absorb and reflect light. You can't change that. If it bends around the person, it can come out the other side, and appear to not have hit anything.

You can bend light around things, with materials with a negative index of refraction. My adviser has a grad student who works on that. It's even been in the news a fair bit, look up "metamaterials", like this article.

And it's been obvious to scientists and engineers for quite a while that actual story-book invisibility would be impossible. There's dust and dirt that would accumulate, there's the fact that if light entirely passes around you, you wouldn't be able to see anything, and there's the fact that it's simply impossible to ever build. For example, even a perfect metamaterial with a negative index of refraction necessarily will absorb some light, and it will have some dispersion, so different colours will bend differently, like what happens when white light is separated into a rainbow by a prism.

 

[Ron_Tomkins]

The better question is, how on earth would it go through the person? People are made of things that absorb and reflect light. You can't change that. If it bends around the person, it can come out the other side, and appear to not have hit anything.

You can bend light around things, with materials with a negative index of refraction. My adviser has a grad student who works on that. It's even been in the news a fair bit, look up "metamaterials", like this article.

And it's been obvious to scientists and engineers for quite a while that actual story-book invisibility would be impossible. There's dust and dirt that would accumulate, there's the fact that if light entirely passes around you, you wouldn't be able to see anything, and there's the fact that it's simply impossible to ever build. For example, even a perfect metamaterial with a negative index of refraction necessarily will absorb some light, and it will have some dispersion, so different colours will bend differently, like what happens when white light is separated into a rainbow by a prism.

I understand. Thanks for the clarification.

 

[wahrheit]

Didn't someone recently post a message which said, if you could really manage to become totally invisible, you would be blind yourself, simply because of physics?

That would suck big time, being invisible and blind at the same time.

 

[Jeff Corey]

..there's the fact that if light entirely passes around you, you wouldn't be able to see anything...

A true double blind.

 

[Hokulele]

Didn't someone recently post a message which said, if you could really manage to become totally invisible, you would be blind yourself, simply because of physics?

That would suck big time, being invisible and blind at the same time.

But just imagine the opportunities for some truly excellent party games! Just as long as I am not the one invisible and blind.

 

[Ron_Tomkins]

By the way, I was told about this other theory of an Invisible Suit. The suit would follow a principle of optical illusion, by having millions of tiny little cameras as well as millions of tiny little projectors. The way it works is: On both sides, the suit is "filming" and projecting. Therefore, if you look at a person on the front, the suit is "projecting", what the cameras are "filming" on the other side (and viceversa), so it looks like you're seeing through the person, when in reality, you're looking at a projection of what's behind the person.

Now, I know that explained like this, it sounds completely implausible because for one thing, a suit is a tridimensional thing. Such thing might probably work with a flat person, but with a tridimensional person, there just are too many perspectives and we would need the cameras to really project a tridimensional background on a tridimensional body. Also, the whole concept of a "projection" of what's behind, would imply that it would have to look exactly as if it was real, and not just some hologram.

Still, is there any way that this principle could be developed into something?

 

[Ron_Tomkins]

Didn't someone recently post a message which said, if you could really manage to become totally invisible, you would be blind yourself, simply because of physics?

That would suck big time, being invisible and blind at the same time.

Hehehehe, that's also true.
I wish I had read that post before.
That's the kind of scientific principles that I'm looking for. Basic and down to earth.