Strange Images on Google's Street View.

[K7SGJ]

Hey, John, speaking of lasers, I was given a dead DVD player. I disassembled it and salvaged a few parts including the laser diode head. Is there anything interesting that can be done with one of those things?

Eye surgery.

[NQ6U]

Google Street View is full of strange artifacts caused by the method they use to take the photographs and splice them together. In an earlier version, there was only half a Ford Ranger in my driveway.

[NA4BH]

Google Street View is full of strange artifacts caused by the method they use to take the photographs and splice them together. In an earlier version, there was only half a Ford Ranger in my driveway.

Partial repo?

[N2CHX]

In case you guys didn't notice, Google's ingenious process of stitching together billions of images in Street View isn't flawless. The capture of the person sitting on the bench which shows their upper body looking like a tree or a bush on the page in the OP clearly shows how the stitching process sometimes goes awry (the other captures do too, but even you guys are smart enough to realize that there aren't human/tree half-breeds running around.)

Much ado about nothing. And who said lasers can't be seen? Seriously? Have you never played with one?

[n2ize]

And who said lasers can't be seen? Seriously? Have you never played with one?

I have several and as I pointed out above, depending on the wavelength and power the beam is clearly visible to the human eye both in the dark and in some cases even in daylight.

[N2CHX]

I have several and as I pointed out above, depending on the wavelength and power the beam is clearly visible to the human eye both in the dark and in some cases even in daylight.

Yes, I know. My first laser was a HeNe glass tube laser with a 3 kV power supply brick, scrapped out of an old grocery store scanner. That was almost 20 years ago now. Fun times. Used to point it at water towers and the Xerox Tower in downtown Rochester and such and I experimented with using it as a backup STL for an FM I worked for. Modulated the laser with a big old transformer. It actually sounded pretty good (albeit mono) -- unless it was raining. Rain induced this cool sounding popping noise into the receiver at the other end. Would have been much better if I had gotten really fancy with it and frequency modulated a subcarrier, but it just wouldn't pass that kind of bandwidth. Fun toy though.

[K7SGJ]

Yes, I know. My first laser was a HeNe glass tube laser with a 3 kV power supply brick, scrapped out of an old grocery store scanner. That was almost 20 years ago now. Fun times. Used to point it at water towers and the Xerox Tower in downtown Rochester and such and I experimented with using it as a backup STL for an FM I worked for. Modulated the laser with a big old transformer. It actually sounded pretty good (albeit mono) -- unless it was raining. Rain induced this cool sounding popping noise into the receiver at the other end. Would have been much better if I had gotten really fancy with it and frequency modulated a subcarrier, but it just wouldn't pass that kind of bandwidth. Fun toy though.

With the rain, the right choice of mind alteration, I'd say we got us a party.

[n2ize]

Yes, I know. My first laser was a HeNe glass tube laser with a 3 kV power supply brick, scrapped out of an old grocery store scanner. That was almost 20 years ago now. Fun times. Used to point it at water towers and the Xerox Tower in downtown Rochester and such and I experimented with using it as a backup STL for an FM I worked for. Modulated the laser with a big old transformer. It actually sounded pretty good (albeit mono) -- unless it was raining. Rain induced this cool sounding popping noise into the receiver at the other end. Would have been much better if I had gotten really fancy with it and frequency modulated a subcarrier, but it just wouldn't pass that kind of bandwidth. Fun toy though.

As a kid (about 12) I wanted to build a pulsed ruby laser. But the components and parts were a bit too expensive and the project too daunting for me at that age. Wound up building a 0.5 Mw HeNe when I was in high school. I bought the tube and built up the power supply and, it worked. Used to shine it at trees, telephone poles and into the fog at night. I also doscovered that if I aimed it at the street light it would cause the photocontrol to shut the light off until the beam was interrupted. Thought of modulating it or getting into holography but never did.

These days I work mostly with diode or Diode Pumped Solid State types. Usually I salvage the laser diodes from old DVD burners. With a suitable driver and a couple of 3 volt lithium batteries I can get anywhere from 250 - 350 mW of power in the red wavelength from a DVD burner diode which is pretty intense and will easily burn holes through dark plastics, fabrics, etc.. Some guys salvage diodes from blue ray burners or projectors and some of those diodes can produce close to a full watt of power, which is quite intense. All in all it's a lot more power than needed for communications experiments. For most project < 5 mW is more than enough power and much safer,

I would like to build a CO2 laser. I have seen a few videos and they look quite interesting.

[N2NH]

And who said lasers can't be seen? Seriously? Have you never played with one?

I did and no, I haven't played with one. I did toy around with the idea of using one as a transmitter for line of sight morse code for awhile, but with all the helicopters flying at low altitude in NYC, I got cold feet on that.

[n2ize]

I did and no, I haven't played with one. I did toy around with the idea of using one as a transmitter for line of sight morse code for awhile

It wouldn't do much good unless you had someone else to receive it. More interesting would be to use a low power ( < 5mW ) laser and modulate it to transmit audio or digital data. Or, to build a stealth eavesdropping device.

, but with all the helicopters flying at low altitude in NYC, I got cold feet on that.

It is a federal offense to deliberately point a laser at any aircraft. However, there are several solutions you could have used. One is to make sure it is not aimed skyward or in a direction or altitude where an aircraft might cross the beam,,, The other is to notify the FAA and get special clearance (unlikely). A third possibility is to use a low power ( like a 1 mW ) infrared laser which is invisible. Just make sure you detector on the receiving end responds to infrared.

I would never point anything higher than 5 mW laser in any outdoor space unless suitable precautions are taken and a suitable backstop is used to keep the beam within controlled boundaries. Anything over 5 mW has the potential to cause instantaneous eye damage and must be used with extreme care.