Recent content by dotancohen

Thank you. Turning the LEDs off is certainly preferable to popping them with a plier!

it does not matter what I want them to do. What matters is that they may have unintended consequences of being lit. I was hoping that someone familiar with light, specifically the reflection of IR and human physiological responses to IR, would address the concerns mentioned. I might be able...

I am considering purchasing an in-car camera such as this: http://www.ebay.com/itm/Vehicle-Car-DVR-Recorder-Camera-Road-Safety-Guard-6-LED-270-2-5-TFT-LCD-Screen-/281082214101?pt=US_Surveillance_Digital_Video_Recorders_Cards&hash=item4171ce36d5 The device has six infrared lamps to...

if you have a phone with an accelerometer then you could probably write an app to record video and the readings of the accelerometer. The video would prove that you were not deliberately causing the vibrations.

Perhaps you mean that this does not happen to ALL wet materials. You are right, I should have mentioned that the phenomenon affects only particular materials. However, it is worth noting that those are the materials that super-secret messages are mailed in and women's breasts are covered by, so...

Many materials, such as paper and cloth, are transparent when wet. Of course I understand that water is transparent, but why does a non-transparent material become transparent when something is _added_ to it? If there is some material that blocks the path of the photons, how does adding yet...

I come in irregularly, but I came in today due to the newsletter. The newsletter mentions issues logging in, so I logged into check. By the way, I can confirm that logging in works fine in Firefox on Kubuntu Linux with the Lastpass password manager. I didn't see any specific thread related to...

Thanks, Chris. Due to problems with the output buffering, the input stream was running on minimum bandwidth. Things are returning to normal now, though. I think posting about it helped. Oh no, I've become this: http://www.penny-arcade.com/comic/2008/4/23/

I just found this thread: https://www.physicsforums.com/showthread.php?t=69402 "Water won't splash in a vacuum" The OP of the thread asks about useful applications of this knowledge. I don't want to be the one to tell him about this application!

That's a good idea, thanks. For the interested, talcum powder works as well by increasing the surface tension. Protip: powder it in when you leave so that it will be ready for when you return. You won't have the patience to powder properly when you need it.

That's a great idea, seeing how unsuccessful I've been in increasing the viscosity of the effluvium. I'll see if I have some gelatin, though I don't know how well it will work without cooling. I suppose that is a better moniker than "Uranus' endearment".

That's pretty much the reverse path of how I got to posting: I tried to reduce the problem to something academic-sounding in the hopes that bells would start ringing. But I'm not a chemical engineer. But it sounds like time for a contest! I'd love to see what others here come up with...

Thanks, Cragar. The tank is actually a toilet, and that would be hard to clean! I did find that draping two layers of toilet paper over the water does help, though.

Is there a term for the height that a liquid splashes above it's surface when a body falls into it? There is a certain system in our house that is designed to drop viscoplastics at quasistatic speeds into a water vessel from a height of about 20 cm. Under normal operating conditions the water...

So we could say that today Aldebaran is different than how we see it? I ask because I seem to remember it being mentioned in Physics 3 (a course that I took years ago) that in our frame of reference things are as we see them today (for us). I am referring to light cones and simultaneity and...