PART 1: Help us evaluate "Live from the Hubble Space Telescope"
PART 2: Mars workshop this summer in Washington, DC
PART 3: Challenge Questions: last week's answer
AND A GREAT INCENTIVE TO THE FIRST TO RESPOND!
PLEASE DO AN EVALUATION
If you were part of the Live from the Hubble Space Telescope journey in any way, please, please, please do an evaluation of the project. We have formal evaluations for both teachers and students available.
We are looking for input particularly from teachers who used the project with students, but we would also like to hear from folks that tuned in but didn't involve students. Maybe you were lurking to experience an electronic field trip personally before involving students. Maybe you are a curriculum developer, or someone studying to be a teacher, or someone else. Whatever your circumstances, we would really like to hear from you.
The feedback we receive from you during this process is crucial for two reasons. First, we need to better understand what you liked and didn't like so that next year we can improve. Also, our funders like to know that many people participated in the project; evaluations forms help us demonstrate that.
We really hope you'll respond because you care about innovative Science education. But just to push you speedily over the top into immediate action, "Passport to Knowledge" is offering an incentive to respond!
Remember, we are interested in >your< evaluations, and those of your students. For the first 500 folks who send us an evaluation, we will reward your effort with a free science education CD (either Astronomy Village or a Mars resource CD).
You can provide us with feedback in one of three separate ways:
To prepare for next year's Live From Mars project, Passport to Knowledge is holding a summer teacher workshop (with NASA JPL and The Planetary Society as partners). The workshop is planned for July 19-21, 1996 in Washington DC. NASA will pay for some of the attendees' travel expenses.
For those that can't physically attend, we plan to cybercast the workshop using a variety of online and TV technologies. So if you can't make it to DC, stay tuned for more information about how you can virtually attend.
Last week we asked:
This question is focused on Mars, which is the subject of the next
Passport to Knowledge adventure. This project, called Live From Mars,
promises to be lots of fun for everybody. In that spirit we bring you
this last Challenge Question :
Let's say you have just been appointed Baseball Commissioner for Mars. You would like the game to be similar in difficulty to the game as played on Earth. With that in mind, how far back should you place the center field fence (so that it is just as hard to hit a home run).
Assume that a center field fence on Earth is 410 feet from home plate.
Answer from Alan Federman:
As a first approximation, we need to look at the relevant equation:
F = MA Force is equal to Mass times Acceleration.
The acceleration we are interested in, is due to the gravity field of Mars. Mars gravity is equal to 0.38 of Earth's, so as a first approximation, the "A" on Mars is .38 * 980 cm/s/s = 370 cm/s/s. If the Force of Gravity were the only effect on the ball, 410ft / 0.38 = 1079 feet (or 323 meters).
To make the game "play the same" Other factors need to be considered. For example, atmospheric effects. The thin atmosphere means less air resistance so balls will carry further. How fast people can run wearing space suits, would also be a problem. Maybe changing the mass of the players and their equipment is an option.
While rain-outs are not going to be a problem, games may need to be called on account of wind or sandstorms!
Good Luck, Commish!
Answer from Bryan Glenn:
The old baseball Commish will have quite a problem on his hands placing
that fence in the right location. There are actually 2 variables he will
have to consider, gravitational differences and atmospheric differences.
Both will have a significant impact, but the latter will be much less
predictable that the first.
When gravitation is compared, Earth's would be +/- 978 cm/sec2, while Mars' is estimated @ 371cm/sec2. 978/371= 2.64, so the 410 ft x 2.64 = 1081ft. That would seem a mighty drive for anyone, if the two atmospheres were comparable. But they are anything but!
Earth's gravity and Venus' gravity are almost identical, but if we were putting up a fence on Venus, a 410 ft fence might as well be 2 miles away. Atmospheric pressures on Venus are 100 times that of Earth, so driving a ball through that layer of carbon dioxide smog would require a mighty, mighty bat.
Mars' atmospheric pressure is estimated at .005% that of Earth's. Again, some quick calculations should yield the lower atmospheric drag on the bat and ball to determine the "atmospheric" adjustment. But it is not so simple; here again we cannot think of this in Earthly terms. The extreme thinness of the atmosphere and the generally colder temperatures will produce some very "Mars Only" considerations. This thin atmosphere is easily varied by minor climatic events that would produce far less change in Earth's heavier atmosphere. Martian temperature changes could easily produce sudden gusty winds roaring over 100 miles/hour. As winter approaches and more of the CO2 becomes crystallized at the poles, the already thin atmosphere will become even thinner. Parks near the poles will play far differently than those near the Martian equator. Home runs will be even easier to hit then, unless the ball runs into an unexpected 200 mile/hr blast of wind on its way to the fence!
Good luck commissioner. Your Martian game will add elements never dreamed of back on good ol' Earth!
