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09/15/2009 05:32:55 PM · #1 |
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09/15/2009 05:42:53 PM · #2 |
Dayum! And some of the links off that article are pretty cool, too...for example:
//www.perspectiveaerials.com/
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09/15/2009 05:43:31 PM · #3 |
| Thats realy realy good...just goes to show you...you dont need the most expensive equipment to take the best picture,and what a shot. great post ty for sharing :) |
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09/15/2009 05:48:44 PM · #4 |
| horizon is crooked, need to re-shoot. pretty cool. |
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09/15/2009 05:49:56 PM · #5 |
| that blue looks a bit oversaturated and the planet doesnt not follow the rule of thirds |
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09/15/2009 06:04:37 PM · #6 |
| Didn't someone in Europe do that last year? |
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09/15/2009 06:43:16 PM · #7 |
Originally posted by Linked Article:
The Canon was hacked with the CHDK (Canon Hacker’s Development Kit) open-source firmware, which adds many features to Canon’s cameras. The intervalometer (interval timer) was set to shoot a picture every five seconds, and the 8GB memory card was enough to hold pictures for the five-hour duration of the flight. |
The hack must let the intervalometer take more than 100 frames, unlike mine ... :-( |
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09/15/2009 08:05:22 PM · #8 |
| This is so very cool. Although I wonder about what it would be like to have a cooler (even one made of styrofoam) hit a person or property... I don't think there was a parachute. |
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09/15/2009 08:18:05 PM · #9 |
Originally posted by dahved:
I wonder about what it would be like to have a cooler (even one made of styrofoam) hit a person or property... I don't think there was a parachute. |
Almost trivial. The terminal velocity of a falling styrofoam cooler would be like a potato chip in the wind— air resistance would limit the speed. It didn't even break up the cooler on impact. |
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09/15/2009 08:18:47 PM · #10 |
Originally posted by dahved:
This is so very cool. Although I wonder about what it would be like to have a cooler (even one made of styrofoam) hit a person or property... I don't think there was a parachute. |
I was thinking that too. I wonder what terminal velocity is for a styrofoam cooler containing a cell phone and a cheap camera? |
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09/15/2009 09:17:43 PM · #11 |
| correct, air res would limit speed but it would still be going prettty fast. if i have time i might try for an estimate just for fun |
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09/15/2009 09:31:20 PM · #12 |
| The photo is cool, but other students have been doing the same thing for years. |
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09/15/2009 10:07:43 PM · #13 |
Originally posted by GeneralE:
The hack must let the intervalometer take more than 100 frames, unlike mine ... :-( |
Do you have the CHDK on your S3, Paul? When I was using my S3, I always booted up in to CHDK. Awesome little tool.
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09/15/2009 11:59:24 PM · #14 |
| soooooooo after a little math i came up with an estimated terminal velocity of 21.7 mph. that would for sure do some damage but seeing as they are mit students i assume that they did the calculations as well ( and much more accurately since they actually have the device and can run drag coefficient tests on it. so to calculate terminal velocity you need mass, gravity, density of fluid (air) area on resistance, and drag coefficient. on their site they provide the exact mass, but the rest are either averages or estimations. since we are dealing with a distance quite far from earth gravity varies slightly but since it wouldnt take the total descent time to reach terminal velocity i left it as 9.815 m/s^2. the density of air varies with temperature so i took a weighted avg b/w -60 celcius and 15 celcius (too lazy to get the avg integrated value). the area was the most "off" estimation b/c i have NO idea how big this thing was. i assume its square-like and by the pics i estimate about 14 inches per side (a highball thus giving me the slowest terminal velocity). i also had to fudge the coeff of drag which i guessed as about 1.0. a square falling flat faced is 1.1 ish. on an angle is .8 ish and a cylinder is 1.0 ish so i took the avg to be around 1.0 ( it may be lower b/c of the actual shape or higher b/c i see a SMALL chute on the thing. so with those numbers i got 21.7 mph aka pretty fast. this is all assuming it reaches terminal velocity ( im pretty sure it does at 93000 feet). anyways that was fun im probably way off but it is a little extra info lol. |
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09/16/2009 12:00:01 AM · #15 |
ps i know there are some engineers on this site so if anyone wants to give another , more accurate shot thatd b sweet
ETA: i didnt know that they had a parachute. that would significantly slow it down probably to the 10-12 mph range i imagine
Message edited by author 2009-09-16 00:46:40. |
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09/16/2009 01:38:33 AM · #16 |
Originally posted by david_c:
Originally posted by GeneralE:
The hack must let the intervalometer take more than 100 frames, unlike mine ... :-( |
Do you have the CHDK on your S3, Paul? When I was using my S3, I always booted up in to CHDK. Awesome little tool. |
I have some (1-2 year old) version of it on one of my memory cards, but I've never figured out how to use it, and I've never found any instructions which didn't assume you already knew enough to write the software ... if you have or know of a reasonable "user manual" please let me know! |
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09/16/2009 02:31:13 AM · #17 |
Originally posted by michaelmonn:
soooooooo after a little math i came up with an estimated terminal velocity of 21.7 mph. that would for sure do some damage but seeing as they are mit students i assume that they did the calculations as well ( and much more accurately since they actually have the device and can run drag coefficient tests on it. so to calculate terminal velocity you need mass, gravity, density of fluid (air) area on resistance, and drag coefficient. on their site they provide the exact mass, but the rest are either averages or estimations. since we are dealing with a distance quite far from earth gravity varies slightly but since it wouldnt take the total descent time to reach terminal velocity i left it as 9.815 m/s^2. the density of air varies with temperature so i took a weighted avg b/w -60 celcius and 15 celcius (too lazy to get the avg integrated value). the area was the most "off" estimation b/c i have NO idea how big this thing was. i assume its square-like and by the pics i estimate about 14 inches per side (a highball thus giving me the slowest terminal velocity). i also had to fudge the coeff of drag which i guessed as about 1.0. a square falling flat faced is 1.1 ish. on an angle is .8 ish and a cylinder is 1.0 ish so i took the avg to be around 1.0 ( it may be lower b/c of the actual shape or higher b/c i see a SMALL chute on the thing. so with those numbers i got 21.7 mph aka pretty fast. this is all assuming it reaches terminal velocity ( im pretty sure it does at 93000 feet). anyways that was fun im probably way off but it is a little extra info lol. |
Based on page:
//en.wikipedia.org/wiki/Terminal_velocity
Assuming a box of 20cm x 30 cm x 10 cm
Further assuming that the mass of box was 2kg. I think their actual mass would be less than this , may be 1 to 2 kg. So their terminal velocity shall be less than what we get here.
Based on these two assumptions (size and mass of box here are terminal velocities vs drag coeff).
CD --- vt (m/s) --- vt (mile per hour)
0.1 ---- 7.67 ---- 17.1041
0.25 ---- 4.85 ---- 10.8155
0.5 ---- 3.43 ---- 7.6489
1 ---- 2.42 ---- 5.3966
1.5 ---- 1.98 ---- 4.4154
So based on this their box hit ground with less than 5 miles per hour.
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09/16/2009 05:32:48 AM · #18 |
| This is pretty cool, but I would be more impressed had the included a sixpack of beer in the cooler for the celebration afterwards. |
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09/16/2009 08:31:21 AM · #19 |
| i missed a square or number somewhere in there i redid it and was getting numbers more similar to yours. i like you size estimation. the weight is 800 g |
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09/16/2009 08:48:37 AM · #20 |
some really nice light there in the sky, but this picture might lack some real foreground subject to focus your attention on....
I' learnt something from Heida's comment on my entry
.... just kidding ;-) |
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09/17/2009 05:59:13 PM · #21 |
Originally posted by GeneralE:
Originally posted by Linked Article:
The Canon was hacked with the CHDK (Canon Hacker’s Development Kit) open-source firmware, which adds many features to Canon’s cameras. The intervalometer (interval timer) was set to shoot a picture every five seconds, and the 8GB memory card was enough to hold pictures for the five-hour duration of the flight. |
The hack must let the intervalometer take more than 100 frames, unlike mine ... :-( |
At least your S3 has an interalometer. For some reason they diabled the function in my S5 so I have to use the hack to add it back when needed. |
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09/23/2009 10:29:01 PM · #22 |
I don't know about a styro cooler, but terminal velocity for an 8 lb watermelon is about 250 mph. We launched a hollowed out pumpkin with a video camera in it in 1999, but it stopped recording when we triggered the shot.
eta To find T.V. on something like the cooler, you could hang it on a fishing pole with a string, and move it through the air by using a truck or car and find the speed at which the drag equals the weight of the loaded cooler.
Message edited by author 2009-09-23 22:34:45.
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09/23/2009 10:32:27 PM · #23 |
| I think they had a parachute, and they tested it until an egg didn't break... |
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09/23/2009 10:40:28 PM · #24 |
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09/24/2009 09:11:51 AM · #25 |
| Immediately afterwards, the students ran every image through Topaz multiple times, upped the saturation, and added water drops to each image for maximum "likeability" |
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