[Dartoid]

I am hoping some of you can help me. I have never posted before...

For the past dozen years or so I have written a syndicated humor column about darts. The column is the most widely read of its kind and is carried in numerous countries.

I am beginning research on a story about what it would be like to throw darts on the moon.

Here's the scenario. The dart weighs 24 grams. The board is 7' 9 1/4 inches from the throwing line (oche) and the center of the board (bull) is 5' 8" from the floor.

Can anyone out there help me understand what would happen, how it would feel -- to throw a dart under such conditions in zero gravity (on the moon). For example, how fast might the dart fly? If it missed the board, how far woud it travel? How heavy would a 24 gram dart be on the moon?

I know such questions may sound ridiculous. Perhaps you can cut me some slack. I dropped out of Algebra in 10th grade and blew up my Bunsen Burner in science.

Thanks for any help any of you can help me in building this story.

Dartoid

[Turtle]

___I have some general observations for you. Gravity on the Moon is approximately 1/6 of Earth's so the dart would weigh 4 grams. There is no atmosphere (to speak off) on the Moon so drag on the darts is absent & so flights (feathering) have no use. Mmmmm...now I see how interesting this is Dartoid.
___When I was a kid I threw a dart in my friends foot as we rolled the dart board across the yard. I would still try it though. On the Moon too.

[Qfwfq]

Welcome to Hypography, Dartoid.

Turtle speaks right about gravity on Moon being about 1/6 of that on Earth, it isn't zero-g but things feel lighter. What is the same is the mass of an object. 24 grammes is really a measure of mass, weight is given by multiplying mass by acceleration of gravity. It's only a habit that we measure weight in the same units as mass.

When you throw the 24 gramme dart you hardly care about it's weight anyway, it's a small weight that you hardly notice, you really feel it's mass as how much force it takes to impart a speed to it. The mass of your arm is greater anyway.

I imagine you might be talking of throwing darts inside a closed room with air in it otherwise, as well as having to wear a clumbsy space suite, your dart's flights would be no use in keeping its point forward as T says.

At the same distance from the board, you could throw the dart with a less arched path. You could instead throw the dart farther or higher with the same effort. What I mean is that imparting it the same speed, it will go farther/higher before falling to the floor or ground, according to the angle off the ground.

[nkt]

Don't forget that the inertia of the dart (and your arm) is eactly the same as before. You wouldn't throw it as fast as you think you would, I suspect.

Your game would be way off until you got used to the new conditions, too, since the dart would fall one sixth as far as it would on earth, at the same speed of throw. This means that your perfect triple twenty on earth would probably wind up just below the double twenty mark on the moon.

[Dartoid]

I have been away for the past few days and am just now catching up on your input to my question. Tnanks again to all of you. It appears I need to be a bit more specific...

My column envisions throwing darts outside, not inside. So, in addition to the effects of gravity and so on, what might it look like? What will I see? Is it light, dark? Does it rain. Etc. I gather that the dart will feel less heavy and fly straighter and essentially forever, if nothing blocks its flight, but at 1/6 Earth's gravity will it not eventually hit the ground -- as opposed to returning to hit me in the back (as in the one example above -- and how fast in miles per hour is 1700 meters per second)? What will I have to wear? What's a spacesuit cost? What did the last manned flight to the moon cost and how long did it take to get there? How far away is the moon? I seem to recall that someone once hit a golf ball on the moon -- where would that ball be now; is it still flying in space somewhere? If I drank a six-pack of Budweiser on the moon would it effect me differently than on Earth? What would happen if I lit a cigarette? What would happen if I took off my spacesuit? If a dart hits a wire on the board but bounces off, is it lost forever? How will it feel to walk back and forth to the board -- will it be easier or more laborious? Does the female breast sag only 1/6 as much on the moon???? Do I have any volunteers to go with me? Seriously, I know nothing about any of this and sincerely appreciate all of your input. I promise to post the column here when it is completed and, of course, to acknowledge your input when it it published. Thank you again and sorry for asking what to all of you must seem to be inanely stupid questions!

[Tormod]

Man, those are not stupid questions but uhm, perhaps a few too many? I don't even know where to start.

Okay...is it light or dark? Depends on whether it is night or day on the moon. If day, very bright. If night, very dark, since there is no atmosphere to scatter the sunlight (assuming that there has not been any terraforming done).

[C1ay]

A few things to consider. The moon's gravity is only about 1/6th of the Earth's so the dart would feel like it weighed about 6 grams. Throw with the same force you would use on the Earth it would fly much faster and the trajectory would be much flatter. As others have pointed out, there is no atmosphere on the moon so the flights would be useless. The dart would fly in whatever position it was in when you released it, i.e. if you threw it tail first then it would fly tail first.

[C1ay]

1700 m/s is approximately 3800 miles per hour, spacesuit are about $12 million each and India recently reported that they estimate a trip to the moon at around $82.5 million. Google could probably turn some of this up for you.

[nkt]

Originally Posted by C1ay

spacesuit are about $12 million each

I think that is a pretty low estimate, given that you would be needing a moonsuit, rather than a standard spacesuit. It also assumes that you are buying one from someone with the right available knowledge and a production line, rather than building it yourself from scratch.

The sharp dust chews through everything, coats things, holds static charges, etc. and caused all sorts of issues in the first moon landings. A lot of the problems are still being looked at today.

You can see the first part of a New Scientist article on it from a few weeks ago. http://www.newscientistspace.com/art...mg18625012.000

[UncleAl]

Earth's gravity is 980 m/sec^2. The moon's gravity is 162 cm/sec^2 or about 1/6 as much. A dropped, thrown, or shot object will accelerate downward 1/6 as rapidly on the moon as on the Earth. Vertical motion is not coupled to anything else to first approximation. A thrown dart will have a very flat trajectory. It will weigh 1/6 as much as it weighs on Earth (newtons are weight F=ma; grams are mass), but it will throw with the same force (inertial mass). If you do it on the outside, in vacuum, the fletching won't do anything - no air to grab and orient the dart in flight by aerodynamic drag at its tail.

For vertical drop,

s = (at^2)/2

where "s" is distance (cm), "a" is acceleration (cm/sec^2), and "t" is time (sec). In the first second a an initially vertically stationary mass will drop 4.9 meters on Earth or 0.81 meter on the moon.

Nastiness comes with horizontal acceleration. A space station or (suicidal) trip to Mars spinning to simulate gravity will have mammoth Coriolis acceleration. Tea will not pour "vertically." A thrown dart will progressviely swerve to the left or the right, the direction and amount depending on radius, the rate of spin, and the angle of throw vs. the direction of spin.

I had no idea darts were that sustainedly funny. Do you folks draw cute pictures on their noses like WWII bombers or the contemporary warthog airplane chewing up Arab tanks?