Think before you post

Online Sexual Exploitation

Compound parabolics

How can you design a parabola which can focus sunlight at the focus at different time of the day without tracking?

Here is the answer:


And a mould for creating the compound parabolic solar cookers

Online Image Tools

Fro those who have an account on worth1000, you most likely will have received the same email about the launch of a new online image editing site: aviary. If you are not those, and you will like creating images, aviary may worth your visit.

Periodic Table with Videos

The famous chemical periodic table with each element linked to video about the element. Interesting online resource to keep handy.

Along the River During the Ching- ing Festival

Click on the title of this post to view the argumented painting. Best view in full screen.

This is a very famous painting in China. This painting was originally painted, circa 1085-1145, during the Northern Song Dynasty. It was repainted during the Qing Dynasty. It measures 528 cm in width and 24.8 cm in height.

In this online version, artists have inserted three animations. Click on the small square on the bottom of the screen to scroll to the hot spot. Click on the hot spot to watch an animation clip showing more details of the time. Enjoy.

Yahoo! Answers: Teachers' Nightmare or Blessing?

From Slate:

The blockbuster success of Yahoo! Answers is all the more surprising once you spend a few days using the site. While Answers is a valuable window into how people look for information online, it looks like a complete disaster as a traditional reference tool. It encourages bad research habits, rewards people who post things that aren't true, and frequently labels factual errors as correct information. It's every middle-school teacher's worst nightmare about the Web.

This highlight the need to enable our students to be able to distinguish between correct and accurate information from false, incorrect or deceptive information. Teachers are no longer the gate-keeper of information. Instead, teachers should aim to help students develop critical analytical skill to handle the vast amount of information available.

Instead of asking students to provide information to some traditional essay type paper, why can't we ask the students to identify incorrect or misleading information from sources such as Yahoo!Answers. Is it a much more valid exercise?

Yahoo!Answers may be a nightmare for the librarians, for the creative teachers, it may be a blessing - a prefect opportunity to let students exercise their critical and analytical skills in processing information.

Free online citation tool - Zotero

from the website:

is a free, easy-to-use Firefox extension to help you collect, manage, and cite your research sources.

Look like I will be putting proper citation in future blog posts more.

GeoGebra

From the website:

GeoGebra is a dynamic mathematics software for education in secondary schools that joins geometry, algebra and calculus.

On the one hand, GeoGebra is a dynamic geometry system. You can do constructions with points, vectors, segments, lines, conic sections as well as functions and change them dynamically afterwards.

On the other hand, equations and coordinates can be entered directly. Thus, GeoGebra has the ability to deal with variables for numbers, vectors and points, finds derivatives and integrals of functions and offers commands like Root or Extremum.

These two views are characteristic of GeoGebra: an expression in the algebra window corresponds to an object in the geometry window and vice versa.

I would characterise the website as a tool for creating visualisation of mathematical equations. :-)

See examples and an article Creating Mathlets with Open Source Tools

A Giraffe is Born

The power of information has totally changed the role of teachers. Today, teachers are no longer is the gatekeeper of information. We should focus on helping our students to find and make sense of the information available.

Work Together: 60+ Collaborative Tools for Groups

As the title, it lists over 60 collaboration tools including online, sharable documents, spreadsheet, mind maps, desktop sharing.

5 Simple Ways to Store Your Files Online

The title said it all.

Which Word processor are you using?

Here is a review of 14 word processors including 3 online alternatives.

The author's (Zaine Ridling) summary:

my only advice is to look beyond any one word processor and seek openness in your choice of file format. Do not allow yourself and your data to be locked-in to the whim of any one vendor. ODF can be used by any word processor if the vendor so chooses, and it satisfies the criteria outlined by Sam Hiser of: "(1) being developed and maintained in an open, multi-vendor, multi-stakeholder process that protects against control by a single organization; (2) being the only openly-available standard, published fully in a document that is freely available and easy to comprehend; (3) being the only format unencumbered by intellectual property rights (IPR) restrictions on its use in other software, as certified by the Software Freedom Law Center; and (4) offering interoperability with ODF-compliant applications on the common operating system platforms of Windows, GNU/Linux, and OS X, along with most online word processing apps."

For me, I am still using Word 98 (on my XP laptop) and Google Doc for online sharing with collaborators. Reason: Inertia of change.