他山之石：美國科學教師所認知的科學教育現況

美國科學教師協會(NSTA)在2009年8月24日公布一項美國科學教育現況的非正式調查結果，調查對象為分布全美的科學教師，人數超過3500人。調查聚焦在科學教育觀點、科學教學現況、及專業成長等三個範疇:

科學教育觀點

美國國小教師79%同意要有統一的國定課程，但是51%的大學教育者反對。

53%的國小教師支持全國性評量，但是52%的高中教師不贊成。

科學教學現況

科學教師最關心的議題是：學生學習動機(30%)、州測驗(17%)、缺乏科學教材(15%)、大眾對教學的看法(12%)。

超過半數的老師認為科學教師最重要的能力是能把教材內容轉換成學習。67%的老師同意把日常生活中的問題融入課堂教學是使學生關心科學並對科學發生興趣的最佳方式。

這項調查同時也揭露「不讓任何孩童落後(No Child Left Behind，NCLB）」這項政策一直困擾教師，55%的科學教師認為這項政策對他們的科學教學造成負面衝擊，同時48%也認為對學校產生負面影響。為什麼? 有一個明顯的理由就是：NCLB在閱讀和數學的年度測驗及負責條款，迫使許多國小教師顯著降低了科學的教學時間。另外，29%的科學教育者希望能在小學階段加強科學，19%希望小班教學，16%希望能有與他人合作的機會。

教師專業發展

許多科學教師(58%)反應他們並未接受足夠的專業成長機會，尤其是在科學方面。74%的國小教師回應，提供給他們的非科學領域的成長機會更多。

老師們只會參加他們認為最有助益的專業成長研習，51%的老師喜歡1至4天與同事一起參加的活動，49%喜歡研討會，26%喜歡一個星期或數星期的課程和研習班。

Arizona州立大學的科學教育教授Julie Luft說：支持學生成就的唯一最重要因素就是高品質的教學。當老師接受能使其科學知識及教學技能都跟上時代潮流的專業成長研習，學生的成就會極有效率地提升。

原文請看

http://www.nsta.org/about/pressroom.aspx?id=56420&print=true

調查結果:

http://www.surveymonkey.com/sr.aspx?sm=DLUwDYbQn0ii5SWdN3YN1ZoovGdpnp3j6C94PMIct7w_3d

看來美國老師也有一綱多本的問題，而且多數小學老師偏向一本，而大學教授偏向多本。嗯，「德不孤，必有鄰! 」(抱歉，引用不當)

還有，立意良善的No Child Left Behind在將近半數的美國老師眼中，居然對學校造成傷害，看來政策不能以立意良善來辯護，實施策略或施行細則可能「狐假虎威」(抱歉，又引用不當)。

不過有一句話倒是放諸四海皆準：學生的成就有賴於高品質的教學，而高品質的教學則來自優秀的教師。優秀的教師要具備怎樣的特質呢? 看來美國老師認為教材內容不等於學生的學習，優秀教師的最重要能力是將教材內容「翻譯」成學生的學習! 這點倒與我們對台灣教師的調查結果一致。可見，「英雄所見略同」(應該沒有引用不當!)。

歡迎您提出看法! 請按下列的[回應]，來查看別人的意見或發表你的意見!

美國高中生在太空總署噴射推進實驗室的暑假

除了上暑期輔導外，我們可以給學生什麼樣的暑假? 學生的暑假活動是否可以更有啟發性? 更有意義? 更有助於他往後的學習?

今年暑假，美國太空總署(NASA)噴射推進實驗室(JPL)提供300多位美國高中生一個充滿挑戰性的暑假。他們可以參與冰雪圈(Cryosphere)監視，或是參加木衞二--木星系統任務小組，測試任務軌道的合適性，或是加入ATHLETE月球六足機器人計畫小組，進行影像處理工作，讓機器人可以自動搬運貨物。

以下是三位參與這項NASA/JPL教育計畫的高中生訪談:

文字稿如下:

My (High School) Summer at JPL (09.14.09)

Dot Silverman:

I'm working on classifying different features on the Earth's surface by analyzing remote sensing data from satellites orbiting Earth.

I was...very exciting, [laughs] because it works. I took a lot of different pictures.

I wrote an algorithm, a cryosphere algorithm, classifying ice, dark ice, water and land.

I came here and, truthfully, I didn't know what an algorithm was.

You pick a lot of stuff up here. And it's nice, because there's so many opportunities to learn new things.

Pepito Escarce:

I'm working on the Europa Jupiter System Mission. I'm working with their team.

And I'm working on the project that possibly will be sending an orbiter to Europa in 2020.

We're helping them determine if the trajectory they have right now is in fact the best trajectory.

The engineers were joking that I could go to college, get a master's, get a PhD, come back and the satellite still would barely have launched.

I think the greatest thing about this experience has been getting to go around and look at all the different parts of JPL, because there's just so much that the...that the Lab does.

Even if I like what I'm working on now, there's just so many other things I could work on.

If...if I ever came to work here. Which would be really neat.

Jourdan Hoapili:

Currently I'm working on ATHLETE, the robot. And I kinda do an image processing deal, where I can make it autonomously pick up cargo.

The basic idea is that it would be going to the moon.

And it would be able to manipulate and move and help astronauts pick up cargo, move around habitats, stuff like that.

It's amazingly cool. I could be doing some boring task or something. But, no. I got to work on a really cool robot. And it's exciting.

And maybe, one day, you know, if it's on the moon, I'll be like, whoa! You know, I worked on that! That's cool!

And if I ever see, like, it go pick up cargo, or, like, I see a marker, I'll be, like, Hey, I designed that!

教學資源: 凸面鏡成像

太空人的面罩反光就像凸面鏡。請仔細觀察面罩，透過面罩可以看到另一位太空人的像。凸面鏡形成的像是正立縮小虛像。下面網址Java程式可以用來說明凸面鏡的成像情形。

你可以使用滑鼠拖曳左邊的紅色物體，來觀察像的變化。
http://www.physics.uoguelph.ca/applets/Intro_physics/kisalev/java/dmirr/index.html

冰雪圈之旅

您知道甚麼是冰雪圈(Cryosphere)嗎?

冰雪圈是由地表上水以固態存在的區域所組成，包括雪地、海冰、冰河、永凍層、冰原、以及冰山。

您知道全球暖化對冰雪圈產生甚麼影響嗎?

讓我們透過NASA衛星多年來的觀測資料，來一趟穿越時空的冰雪圈之旅，了解一下冰雪圈，以及冰雪圈的變遷所帶來的衝擊。

旁白文稿如下:

A Tour of the Cryosphere 2009 (09.02.09)

Narrator: Though cold and often remote, the icy reaches of the Arctic, Antarctic, and other frozen places affect the lives of everyone on Earth.

We start our tour in Antarctica. Where they meet the sea, mountains of ice crack and crumble. The resulting icebergs can float for years. Ice shelves surround half the continent. They slow the relentless march of ice streams and glaciers like dams hold back rivers. But the region is changing. As temperatures increase, we see a growing number of melt ponds. As this heavy melt water forces its way into cracks, ice shelves weaken and can ultimately collapse. After twelve thousand years, the Larsen B ice shelf collapsed in just five weeks.

Offshore, sea ice forms when the surface of the ocean freezes, pushing salt out of the ice. The cold salty surface water starts to sink, pumping deeper water out of the way, powering global ocean circulation. These currents influence climate worldwide.

Most ice exists in the cold polar regions, but we see glaciers like these in the Andes all over the world. Most are shrinking.

Here in North America, millions of people experience the cryosphere every year. Eastward moving storms deposit snow like thick paint brushes. Mountain snow packs store water. Snow melt provides three-quarters of the water resources used in the American west. Substantial winter snows produced a green Colorado in 2003, but dryer conditions the previous year limited vegetation growth and increased the risk of fires.

In the Rocky Mountains, there are patches of frozen ground called permafrost that never thaw. These regions are unusual in the mid-latitudes. But farther north, permafrost is more widespread and continuous, covering nearly a fifth of the land surface in the Northern Hemisphere.

Sea ice varies from season to season and from year to year. Data show that Arctic sea ice has shrunk dramatically in the last few decades. The effects could be profound. As polar ice decreases, more open water could promote greater heating. More heating could lead to faster melting, reinforcing the cycle. If this trend continues, the Arctic Ocean could be ice-free in the summer by the end of the century.

These changes in ice cover are not limited to oceans. Greenland's ice sheet contains nearly ten percent of the Earth's glacial ice. Glaciers in western Greenland produce most of the icebergs in the North Atlantic. After decades of stability, Greenland's Jakobshavn ice stream, one of the fastest flowing glaciers in the world, has changed dramatically. The ice has thinned, and the front retreated significantly. Between 1997 and 2003, the glacier's flow rate nearly doubled to five feet an hour.

These are just some of the cryospheric processes that NASA satellites observe from space. Continued observation provides a critical global perspective, as our home planet continues to change - day to day, year to year, and further into the future.

Find this article at:

http://www.nasa.gov/multimedia/podcasting/TourOfCryosphere09.html

全球暖化對蜜蜂有何影響?

全球暖化讓春天每年提早半天報到，植物開花期歷年來已經提早超過十天。那麼對未能提早報到的蜜蜂寶寶而言，將找不到花蜜；對提早開花的植物而言，則沒有足夠的蜜蜂來授粉；對人類而言呢? 應該不只是影響餐桌上的內容!

請看下面的影片。

影片旁白文稿如下：

Feeling the Sting of Climate Change

[music]

[music] Every year, farms and fields play host to a symphony, of sorts. Polination... the springtime syncopation of flowering plants and the animals that feast on the nectar and pollen they produce. Over millenia, pollinators like honey bees have evolved a well-timed dance with plants. But now, plants may be changing their tune. Spring green-up... ...when plants wake from winter and sprout leaves. It's such a global phenomenon that NASA satellites can see it from space.
[music]

[music] Sensors, such as Modis on NASA's AQUA and TERRA satellites, can show us how green our planet is throughout the year - and they've captured something strange. In the Northern U.S., spring green-up is starting about a half-day earlier each year. The likely cause? Our warming climate. But is pollination also moving earlier? The images can't detect individual flowers, so scientists have been left to guess... until now. NASA research scientist Wayne Esaias spearheads a special team gathering data directly in the field. They're the honey bees in his Maryland backyard.

[Wayne Esaias:] "Honey bees are great data collectors for understanding the processes of pollination. Bees fly two and a half miles in all directions to scout for bee forage and bring back pollen and nectar. So therefore they sample a very large range of environments." Weighing the hives, Wayne can detect when nectar peaks and ebbs each year.

[Wayne Esaias:] "During the winter, the hive loses weight as they eat the honey to feed the babies and keep warm. And then when plants start blooming in abundance, the hive starts gaining weight. It can gain a tremendous amount of weight. I've had a hive gain 25 pounds in one day." Wayne's been keeping tabs on his bees for less than twenty years. But in that time, pollination has moved more than ten days earlier.

[Wayne Esaias:] "That's completely in sync with what the satellite data shows - the world here getting greener earlier in the spring by about a half a day each year." here getting greener earlier in the spring by about a half a day a year."

[music]

[Wayne Esaias:] "If we have a few scale hive measurements with the wall-to-wall coverage of the satellite, we can then extrapolate those scale hive measurements of when the nectar flows occur extrapolate those scale hive measurements of when the nectar flows occur to very large areas of the country." Now, to get a bee's eye perspective of how pollination is changing in very different environments - say, deserts or mountains - Wayne's doing a little '"networking."

[Wayne Esaias:] "HoneyBeeNet is a network of citizen-scientist beekeepers that volunteered to weigh their hives to give us more data points, to see how the nectar flows are changing in all different parts of the country." If pollination dates keep creeping forward, plants and pollinators could move out of sync. Currently, young bees are able able to grow and get out on the hunt by the time plants bloom. But if plants bloom before bees are ready, both miss out. The plants don't get pollinated, and the bees go hungry. But more than just bees might miss a meal. NASA satellites can help us understand how climate change might affect what's on our dinner table.

[Wayne Esaias:] "Modern agriculture requires bees as part of the production. It's as mandatory for food production as as pieces of irrigation pipe and fuel for tractors. So if we're to understand the impact of climate change on our ecosystems, we must understand how this plant-pollinator interaction is being impacted by climate change."

Find this article at:

http://www.nasa.gov/multimedia/podcasting/HoneyBee.html

教學資源：透鏡成像

介紹一個"透鏡成像"的教學網頁，

http://resources.edb.gov.hk/itedu/phys/lens/index.htm

不僅可以學物理，還可以學英文，廣東話也可以!

高雄捷運「美麗」光害，是「折」射? 還是「反」射!

以下這則新聞來自YAHOO 奇摩新聞，是TVBS的新聞報導 ：

-----------------
高捷「美麗」光害　店家戴帽做生意

更新日期:2008/05/13 00:38 李惠珠

絢麗的高雄捷運「美麗島站」，竟成為附近商家的夢靨；高捷美麗島站因為站體建蓋四座「貝殼狀」玻璃帷幕，但沒想到帷幕玻璃因為陽光照射之下，折射的強光直接照射到附近商家裡，讓商家生意大受影響，捷運公司目前還在想補救的方法。

TVBS記者李惠珠：「千呼萬喚的高雄美麗島站，終於完工了，不過這4個玻璃造型的公共藝術，隨著陽光的折射，也成了附近商家的夢靨。」

鄰近商家：「陽光照射到眼睛，讓眼睛張不開，所以要帶帽子工作，不然眼睛張不開，反光，我們的客人來看到(光折射)，眼睛都會張不開。」

高雄捷運「美麗島站」，在路口4個角落架設「貝殼狀」的玻璃帷幕，美麗又特殊的造型，已經成為高雄市的新地標；但沒想到玻璃造型的設計，在豔陽照射下，竟造成鄰近商家嚴重的光害。

鄰近商家：「強光直接照射進(店家)來，整個好熱，要阻隔光害，設置(遮陽棚)怎麼可能？這樣要如何做生意？」

附近商家說，從去年10月份開始，就一直受到嚴重的光害影響，問題至今都未獲得解決，而捷運公司，還在想補救的方法。

高捷公共事務處長黃一中：「捷運公司跟店家我們密切跟店家，各自有想到方案，隨時提出來討論。」

美麗島位在捷運紅、橘線的交會處，捷運花費鉅資，特地請來日本設計師打造，還請總統揭幕營造氣氛，但卻沒想到這個斥資億元的公共藝術車站，因為光害卻成為當地店家的夢靨。
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對這新聞，在科學教育上，你有什麼想法?
你可以用這則新聞，做甚麼教學活動?