Alvaro Gregori, blogs sobre e-Learning y tecnología para la formación on-line

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

Today on Australian Seven's "Deal or No deal", it is a classic probability case.In the last round, the contestant was left with his and his daughter's cases to open. The board has $4000 and 50cents. The host has been playing up for a mega-guess which would be $10,000. The bank offers $2020, should he accept it? (Answer in white below. Highlight to cheat and see my answer.)No. We can do much

One of my complain of the eBook reader is its display size. They are mostly 6" display, fitting a typical letter size or A4 size document to such a screen means displaying the document in 30% - which is very demanding on the eyes.Other larger format eBook readers are prohibitively expensive. Amazon's Kindle DX is like a fresh air in this dull market. Is there any cause of excitement for

Thisor thisEastern vs Western. You choose!

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.

It is the number originally from http://3.141592653589793238462643383279502884197169399375105820974944592.com. You can now get it as an attachment to pito1millionplaces.Hope I won't kill the server as http://3.141592653589793238462643383279502884197169399375105820974944592.com did.

Some pdf come formatted in two columns. As the device's screen is small, I read it in landscape mode and need to go up and down to continue reading after the first column.Recently, I found papercorp [more info here] which converts pdf into image sequence (and then save back as pdf). The software can detect multiple columns and save them in sequential images - I don't need to scroll up and down

If you click on the logo of the Pirate Bay, you will be able to download a pdf announcing the acquisition of TPB by Warner Brothers for 13.37 billion in a stock for stock transaction.TPB is currently the largest bit torrent sharing website with over 1.6 million torrents on tracker and over 9 million seeders and another 9.4 million leechers.This news would be the greatest surprise for me! Given

Recently, I bought a Sony PRS-505 ebook reader. After using it for a few days, I generally like it. Because of my eye sight, I read in medium font in landscape mode. All the reading I have done are pdf files. I can use it under direct sunlight - which is good.Apart from the default "s" mode (which can stand for standard or small), medium and large fonts are available. However, these later

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

Today's 4corners on Australian ABC is about a former Federal Court Judge Marcus Einfeld who were sent to jail because of lying about a $77 speeding ticket. It seems that Marcus had a habit of lying about the drivers of his car when caught in traffic infringements.It is amazing to contemplate how people, a judge in this case, would lie and thus committed crimes just to get out of some relatively

Mercury(II) thiocyanate (Hg(SCN)2) is a chemical compound. It was formerly used in pyrotechnics for the long snake-like ash Pharaoh's serpent that forms when a pellet of this compound, often with a small amount of a sugar such as glucose added to serve as supplemental fuel, is ignited. This is extremely dangerous because it produces poisonous mercury vapors. [source]

That's a fun way of handling the unwelcome tele-marketer.

Watch this to get motivated.Want to make one for yourself. Here is how from instuctables. This is a really simply oneThe following videos demonstrate how to convert a dead butterfly into a walkalong glider. (a dead butterfly and nail polish were used.)More info at sites.google.com/site/controllableslopesoaring/.

A very insightful talk on play. We should introduce more into our schools.

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

About 4:00 into this video, Richard Dawkins gave two insightful approaches of Science education: Carl Sagan's and NASA non-stick frying pan. Personally, I am the admirer of the beauty of the Universe. Enjoy!

Many teenage girls are easily influenced by the images of celebrities they saw on magazine or catwalks. Here are some before and after images which should point them to a more realistic images of themselves. Enjoy.[more]

Although the following video is making round in blogsphere recently, it is in fact an old news[2004]: A monkey at the Jerusalem Zoo has been walking upright after recovering from a stomach flu that nearly killed her [see also]:Back in 2001: Monkeys walking on two feet have long been an integral part of circus acts. The way they waddle from side to side appeals to our sense of comedy. Now,