How long does a instructable take to get approved for a contest? Answered

I posted two instructables for the duct tape contest last night around 10 p.m. and the deadline is today. I was just wondering will it be approved in time or if it gets approved tommorow will it still count?

Question by Iam4NUru 8 years ago  |  last reply 8 years ago


Tape

There seems to be a lot of types of tape. The most famous, Duct Tape, but there have been variations on it. Gorilla tape, a stronger and stickier version, Marine Reflective Tape, X-Treme Tape, and gaffer tape.What's your favorite type of tape and uses for it?

Topic by starwing123 10 years ago  |  last reply 9 years ago


Joining carpet pieces

I'm looking for ideas on how carpet pieces might be joined together into a whole (e.g. rugs made from carpet samples). The gaffer tape solution which is posted all over the web in tutorials isn't strong, only lasts a few months and doesn't work well with small carpet pieces.  I've successfully sewn carpet piece in the past with fishing line (so the stitches are strong and invisible) however this technique only works well with larger pieces due to the time it takes and amount of work.  Has anyone here tried any other techniques and been successful with both large and small carpet pieces?  My other idea was to use wood glue to glue the pieces to a hessian sheet.  I haven't tested this but the hessian base on most carpet pieces should merge well with the hessian sheet. thoughts or ideas appreciated.

Topic by garrettlynch 2 years ago  |  last reply 2 years ago


Observing single photons (may be future Instructable)

In a thread on building a DIY Geiger counter, I mentioned that it's possible to do an experiment to see single photons directly with your eyes. This is a lab we did when I was an undergraduate, more than 20 years ago. I haven't done the setup myself since then, so I'm just going to describe it; if I have the opportunity run it again, then I'll make an I'ble.If someone else decides to tackle it, please feel free to write it up yourself!The human eye detects light via a family of proteins called opsins. Different forms of photopsins are sensitive to different wavebands, which is what gives us color vision. Rhodopsin is sensitive mainly to greenish-blue light, and provides us with monochromatic night vision. Rhodopsin works by changing its conformation when it absorbs a photon; that change of conformation allows ions to flow through the rod cell's membrane and generate a signal. The signal from each rod cell is processed through the retina and passed to the visual cortex, where a representation of the visual field is constructed.Human rhodopsin has a quantum efficiency of about 25% (there's a 25% chance a single photon will be absorbed and produce the rod-cell signal). By comparison, cat rhodopsin is more than 90% quantum efficient. 25% QE is sufficiently high to be observable -- a source of single photons can be seen by a dark-adpated person with normal vision.You'll need a steady source of well-collimated photons. A green laser pointer (~532 nm) will do nicely. But how many photons does it generate? A wavelength of 532 nm corresponds to 3.53×10-19 joules. So a small 1mW laser pointer puts out 2.8×1015 photons per second (watt = joule/s). How do you reduce that to one photon at a time? With filters. An ND3 neutral density filter reduces the output light by 10-3 compared to the input, so a stack of just five ND3's in front of this laster pointer would result in (on average) just 2.8 photons per second! A stack of four ND4's would give you 0.28 photons/s on average.If you don't have neutral density filters, you can make a decent approximation, by stacking sheets of black trash-bag plastic. To make this work you have to measure the attenuation yourself, so you'll need a photodetector, something which gives an output (voltage, resistance, current, whatever) proportional to the intensity of light.Once you have your single-photon source, you need to set it up in a completely dark room. If you have access to an old-style photographic darkroom, use it. Otherwise, use thick (3-5 mm) black felt and gaffer's tape to seal any windows and doorframes. Put the laser on a table or stand pointed at your face, with the stack of NDs (or trash bags) in front of it. If you're doing this by yourself, you may want to have a piece of tape set up to hold the pointer's button down. Otherwise, your lab partner will take care of it.Sit in the dark for 20 to 30 minutes. This will seem like forever, so you may want something to help you keep track of the time. A standard CD will be about half finished, or you can get through ten pop sons on your iPod, when your eyes become dark adapted.Turn on the laser. You'll see intermittent flashes all coming from nearly the same place in your visual field; if you turn your head, the location will move in the opposite direction. If you've used filters to get down to a few flashes per second, POV will make them easier to see. At less than one photon per second, you'll see them individually.

Topic by kelseymh 10 years ago  |  last reply 9 years ago