Strobe light makes water drops fall in slow motion

[wellthatisgr8]

Awsome, keep,making vids!!!!

[incargeek]

Thats great!

[derinsherman62]

@incargeek This is but a pale imitation of the great Dr. Harold Edgerton's work. If you really want to see true greatness in action, do a Google search on "edgerton stroboscope techniques" then click on the Edgerton Digital Collections website to view his original device in action with explanation by Doc Edgerton himself.

[gumdrops27]

Omfg thats amazing

[Fromzon]

Why didn't you time it in such a way that they seem to float statically without moving up or down? Just asking cause I think it would've been cool :-P

[derinsherman62]

@Fromzon Yes, it would be cool. Unfortunately, the strobe I was using didn't flash at a consistent rate: the flash frequency would slowly drift, so even when the drops started out motionless, they would start to slowly drift up or down after about 10 seconds or so. The solution to this problem is to synchronize the pump and strobe electronically, and that's something I'm working on doing.

[Goatsnarfer]

Why didnt you put your finger under it :(

[derinsherman62]

@Goatsnarfer Simple answer: because I'd get spattered with the fluorescein dye, and I was wearing a nice jacket when I made the video. I guess the real question is: why wasn't I wearing an easy-to-wash lab coat when I made the video? Darned good question! You should check out the video of Doc Edgerton sticking a pencil into the water stream on YouTube: search for "Waterdrop experiment, stroboscope light" and you'll also see a "motionless saw" cut through a board.

[Goatsnarfer]

@derinsherman62 I sure will, thank you for the answer!

[BrentBXR]

and @derinsherman62 stfu.

[BrentBXR]

lol this fucktard is trying way to hard to sound smart. 'the period nature of the pump' = 'the pump is falling a single rate of speed'. 'every 60th of a second a droplet is psuhed out by the recepricating pump' = '1 drop every 60th a second'. and lol @ 'and of course this is not hour gravity works'

[novkaxfire]

great video tnx

[fruitytuterjjc]

Imagine an array of water dropers with a laser under each. by modulating each laser in the array right you could form 3d objects!!!

[derinsherman62]

@fruitytuterjjc Neat idea! You could also use a single modulated laser reflecting off a spinning mirror onto a static array of mirrors positioned under each stream of drops. You'd need a computer to control the modulation, but you'd only need one laser. BluRay laser pointers should work well since fluorescein will readily adsorb the blue-violet light and emit strongly in the green. Alternatively, you could use a TEA laser that produces nanosecond ultraviolet light pulses.

[BlueRice]

@derinsherman62 as an average person i dont understand what you guys are talking about -.-



[derinsherman62]

@BlueRice It's easier to see how this works with a spinning fan. If the fan blades spin around 60 times a second and the strobe flashes very briefly once every 60th of a second then the fan blade will always be in the same position each time the light flashes. Your eyes blend the flashes together (persistence of vision) so you don't see the flashes and the result is the fan appears to be standing still. There's a Wikipedia article on the "stroboscopic effect" showing how this works.

[TheSquishy200]

how did you make the uv strobe light? is it an arduino with a 555 timer or a pic? im interested in making this but im trying to make it all in a portable wooden box >_<

[derinsherman62]

@TheSquishy200 Hi - there are really two separate components: the strobe and the pump. My circuit uses a 555 timer to control LEDs driven by transistors. You can read more about this circuit by doing a Google search on "strobe droplets slow motion gravity" as my page appears near the top of the list. The pump is a standard AC pump operating at 60 Hz, so the drops all come out at 60 Hz. It is also possible to use a battery pump, but you then need to carefully control the rate of the drops.

[klazzera]

@TheSquishy200 you can easily make a strobe light with a stroboscobe. you also won't ruin your light bulb while it continuosly glows.

[EmergencyRoom21]

is the strobe light just a regular white light, like is the fluorescentness of the liquid just the liquid, not like a black light or anything?

[derinsherman62]

@EmergencyRoom21 Hi - the liquid is water with fluorescein dye (do a Google search on flurescein to see some cool pictures). The dye is red-brown in pure form, but fluoresces vividly when even trace quantities are added to water. I added a small pinch to a couple gallons of water to make the solution you see in the video. Fluorescein will fluoresce in blue, violet, or ultraviolet. White light contains a sufficient amount of blue light to make it glow brightly.

[EmergencyRoom21]

@derinsherman62 hey thanks

[sNerd]

i like this video alot better than others cause it gave a clearer explanation to what's happening. Thanks for the upload :D

[derinsherman62]

@sNerd Hi - thanks. Most of the demos I've seen online fail to make the connection between gravity and the drop spacing. You can use the ruler in the figure to measure gravity, although your measurement won't be all that accurate because the ruler should be placed at the same distance from the camera as the drops. Incidentally, if you shoot the water horizontally, you get an almost perfect parabolic trajectory and you can see that the horizontal velocity is constant.

[lindseynoelani123]

okay keep me updated =) (*giggle*)

[lindseynoelani123]

i want one sooo badly!! and show all my little cousins that im magic and if they upset me i'll turn them into green droplets of water! lol

[derinsherman62]

@lindseynoelani123 My students and I have made our own stobe lights using white LEDs (which are pretty cheap) and I'm now working on making a simple battery-powered water pump using some inexpensive ($3) fountains that I've picked up at local stores. I'll be posting more info on my web site as we build this.

[lindseynoelani123]

EPIC!!!!



[derinsherman62]

@lindseynoelani123 Thanks - this device was invented by the late Dr. Harold Edgergon at MIT. You can find out more about this device by doing a Google search on "Edgerton Piddler"