Monday, October 29, 2012

Hot Air Balloon 2

Good thing this time we were allowed to use our own materials to build the hot air balloon.

After discussion with our group we had decided to build a smaller sized hot air balloon. The materials are as follows: one small, lightweight garbage bag, one piece of cardboard, some floss strings (only string we could find), two pieces of fuzzy, bendable wires, and four candles.

First, we bent the two fuzzy wires to form a circle and taped the ends together. Next we taped the wire circle to the plastic bag so it would retain its shape. 

Our idea was to make a "basket" similar to a real hot air balloon's. To make this we poked holes in the cardboard to fit in the four candles. Then we taped one end of the floss strings to the cardboard corners and the other end to the bag. This is our finished product.





It kind of looks like a jellyfish.
Anyway we thought our design was going to work because it was lightweight. However, when we lit the candles we realized the strings were too close to the candles. In the following picture you can see that some strings are burnt along the edges. If the strings were burnt, then our basket would entirely detach itself from the balloon. Also, the distance from the candles to the bag was still relatively large. We are positive that if we move up the candles a bit more while having sturdier strings (think yarn) that are farther from the candles the hot air balloon would've worked. We won't really know unless we build another one, but I think Mr. Chung has had enough with all these failures. Anyway, other groups' hot air balloons failed also so I guess we didn't do that bad. :D



Sunday, October 21, 2012

Hot Air Balloon 1



With no success to our egg landers, we were determined to make a working hot air balloon this time.
The materials allowed were 10 straws, some tape, a plastic bag that you can cut to your preferred size.
The balloon was supposed to run on a maximum of 10 birthday candles. This was the tricky part: more candles meant more fuel, but they also meant a heavier mass. The trick was to find the right balance.

Our design was really simple. It consisted of five straws joining each other in a shape of a star. The bendy ends of the straws stood up perpendicularly to allow the bag to be taped on. Since our candle holder was quite large (and thus heavy), we decided to use all 10 birthday candles. We cut out small holes in the straws so that the candles can fit snugly in them. Next, we tried to tape our candle holder's perpendicular ends to the bag.

The problem was, the bag was too big (it was a regular sized garbage bin bag). We were running out of time, so we didn't bother to cut the bag into a smaller size and instead tried to tape the whole bag. However the tape wasn't sticky enough. Our attempts were fruitless as the tape just fell off. We didn't have time to test our balloon but it would've probably failed anyway.


To sum it up, our hot air balloon failed, but so did everyone else's. In my group's defence I guess we didn't do that bad. :)

Viewing the Night Sky

The night was chilly and a bit misty, but I was able to see a fairly round moon and several other stars. I was never really interested in the moon, but seeing it up close made me think otherwise. 


This is a picture of the moon taken with just my phone. It actually looks better than that, trust me.
Here are pictures taken with the telescope.


Pretty neat, huh? The Big Dipper was also visible that night, but it was too faint for my phone to capture an image of it. One of the astronomers showed us through the telescope the star Albireo. The speck of light we saw was actually two stars together, Albireo A and Albireo B, but the telescope cannot zoom far enough.

We were also lucky enough to see Neptune, the farthest planet from the Sun. It appeared as a tiny dot, however.

A very faint Triangulum galaxy can be seen through the telescope. Here's what the constellation looks like:




This is from a constellation book that the astronomers had supplied us. I flipped through the pages to find Leo, my horoscope sign.


The brightest stars in the constellation form an image of a lion, but I think it looks more like a dog. Oh well.

Anyway, I thought that the star gazing event was quite entertaining despite the cold temperature. One astronomer even gave us his Tumblr url: http://astrogeoguy.tumblr.com/. Have fun reading through astronomical posts!