I keep seeing this commercial for a laser level thingy that attaches to walls and casts a laser beam along the wall so that if you want to hang things up in a strait line or something, you just follow the laser.

Well in this commercial, it also says the laser goes around corners. I was under the impression that lasers were a form of light, and so they cant bend. but this laser wraps right around a corner, with no mirror or anything to reflect it around. It looks the same as if you were to take a peice of string and wrap it around the corner. So can anyone tell me how in the name of kak this thing works? Has anyone else even seen this commercial?

That sounds damn cool, and I have no idea how they did it if it's true.

Goes around corners? WTF? I haven't seen the commercial, but that is complete bull****. There is only one way to bend light without using mirrors or refraction, and that's gravity. So unless they're also selling miniature black holes that you attach to the wall where you want the light to bend around it, they're just pulling stuff out of their collective asses.

I see it all the time. It's a 'Craftsman Laser Level' or some crap like that.

And yes, it probably is just them pulling stuff out of their collective asses.

And if not, then they'd be sued for false advertisement by everyone who buys one.

There's a small print message at the bottom that clarifies (if you can read it in the 1.5 seconds its there) that you have to point it at a corner. Like so:

(Apologies for crappy illustration)

I found the website for it:

http://shop.store.yahoo.com/asseenontv/bstlale.html

It has a little video of the commercial, including the part about going around corners. It makes NO SENSE to me how this could possibly work.

EDIT: Okay, the picture that cybrid posted makes sense. I'd say that's pretty shaky as a basis for saying that "it goes around corners", though.

Then buy one, try it out and report your findings.

What about, like, diffraction?

This was always my question when I saw this commercial, and now I know the answer. Definitely not as cool.

They've turned corners massive, I'll tell you.

...you'd have to aim it perfectly... But... even that wouldn't work, would it? Cause wouldn't it just put a dot on a small portion of the wall?

(sorry for my even cruder .bmp)

That's why they have the almost undetectable disclaimer. I had to see the commercial 3 times before I could catch what it said.

Yeah, I just dug up a laser pointer and tried this, and it just put a dot on the corner. It has to be flush with the wall. And when I aimed it along the wall, I had to kinda wiggle it to really track the line all the way down the wall. Maybe their laser is more powerful or magical or something, but it sounds like another infomercial rip off to me.

well.. from what I know of laser pointers, if you line them up along the wall just right, you can get a line... but for that you have to basically be running parrellel with the wall. And eventually, that line will end, and it sure as heck won't go around corners.

hmm...

howstuffworks.com? *shrug*

Apparently, according to the following article, it does actually go around a corner... but barely... I'm looking to see what else I can find

http://www.thekcrachannel.com/station/4204983/detail.html

I am sorry I didn't tell you guys this earlier (my dad owns one of these) - they have different lens apertures that make it either a dot or a line. So a larger laser width makes corner levels far more practical.

meh... still doesn't make sense... even with a wider laser, wouldn't the extra width just project on whatever was across from where the wall turned (ie, another wall)?

and.. check out this picture.. Doesn't really have anything to do with this, but I came across it while researching this issue, and it's cool looking. Gotta love NASA.

ok... seems we're not the only ones wondering...

http://www.scienceforums.net/forums/showthread.php?t=6322
http://forums.netphoria.org/showthread.php?s=&threadid=75298&highlight=laser+straight <--warning, swearing in this one.

and, this seems to be the most likely explanation... Is this what you were getting at Heeb?

As the owner of one, I'll tell you!

The Laser is shot at a mirror right inside the barrel of the device that makes not just a point with the beam, but a small line that tapers off. This allows it to make the line across the wall. It does that very well, and for a considerable distance. The "corner" feature is done in one of two ways:
1.) If you point the laser at the corner, like many have diagramed, you will get your laser "around" the corner.
2.) There is a position you can place your laser to actually do what they showed in the commercial, which is, place the device on the wall, and shoot it at a corner. The laser, because it's reflected from the small mirror, will go a SHORT distance around the corner. It's nothing major, and is for SURE not impressive, but it does work.
The device is very useful however, for many interesting uses such as the dreaded Compact Mirror versus Laser Straight battles we have in our office.

There you have it!

/me is reminded of the Incredible Machine 2.

Post count +1

People around here seem to be under the impression that a laser is only a straight line with a dot...it's light, you can focus it into many shapes. Including lines.

Hmm, so it does go round corners, but badly?

the lasers beam which is very narrow is usually scanned.
there is a tiny little mirror in the unit that spins very fast. as the lasers beam hits the mirror it reflects at the different angles of the mirror as it spins. this gives it the illusion of drawing a line. it's the same in supermarket scanners. it's why they are called scanners.
take your laser pointer and wiggle it back and forth really fast. as fast as you can. it'll look like you are drawing a line or shape. same thing except the scanner mirror is precisely aligned to the normal of the lasers beam.
if you block it at any point the beam will not go around your hand (a corner) to shine on the wall.

Yes, that was logical.

Leave him, half his posts are spam

Yeah lasers are light, but can't the corners shown on the commercial bend the laser around (I'm talking about not splitting the laser beam, but wrapping the beam)?

a light beam cannot be wrapped. well it can if you have the mass (and gravity) of a star. it's called gravitational lensing.
light can be reflected from a surface like a wall but it wouldn't have the intensity of what you would see with one of those laser levels. they are scanned and if the wall is not in line of sight then the light will not be seen on that part of the wall.

I just noticed that in the commercial during the part where they show it going around the corner, they dont actually show the laser device being attached to the wall, which means the laser had to be somewhere else off camera, as many people have diagrammed in pictures here.

So it doesn't actually go "around" the corner, rather it is being reflected onto the corner. It all makes sense now.

The cool ones are the ones that can put a line on all the walls of a room. I see those at work all the time. Of course, being a painter, I have no use for them, but the guys who put in ceiling tile just love them. They also love to put them right at my eye level, stupid buggers...

Paint a picture of their face being stabbed with a rusty spoon. They won't shine lasers in your eyes when you're sitting in the mental hospital, will they?

Paint of a picture of them stabbing you in the eye, then give it to the police and say they're terrorists.

Wonder if they'll ever use green lasers. That would be cool.

Or purple.

red are the least expensive to make.

The commercial I saw on TV was misleading. At the part where it says it goes around corners, they show one on the wall and supposedly it's the one that bends the laser around the corner (I guess they had another one aimed at the corner that they don't show). They must've lined everything up nice and neat to get it to do that.