Thursday 26 November 2015

Kenapa Perlu Berdiri Di Belakang Garisan Kuning?

Tahukah anda kenapa kita perlu berdiri di belakang garisan kuning ketika kita berada di stesen kereta api aliran ringan atau LRT (Light Rail Transit)?

Apabila LRT bergerak dengan laju, ia akan menghasilkan kawasan yang berhalaju tinggi dan bertekanan rendah di sekeliling badan LRT itu. Jadi sekiranya kita berdiri terlalu hampir dengan LRT yang sedang bergerak, ini boleh menyebabkan tubuh badan kita tertarik kehadapan menghampiri badan LRT yang boleh menyebabkan kecederaan. Konsep sains ini adalah berdasarkan 'Prinsip Bernoulli'.

Garisan kuning telah diukur sebagai tanda aras 'jarak paling selamat' kepada pengguna LRT dari berlakunya kejadian yang tidak diingini. 

Jadi sekiranya anda berada di stesen LRT, pastikan kita SENTIASA berada di belakang garisan kuning. Amalan ini juga boleh dipraktiskan  sekiranya kita sedang menunggu bas di stesen bas.

Posted by Ayu

Tuesday 24 November 2015

'Dentin Duty'

Why do we need to brush our teeth? We do it when we wake up in the morning, between meals and before we go to bed. 

Tooth decay is due to bacteria that grow in the space between our teeth and gums. These bacteria will feast on the tiny food particles that are stuck in between the gaps of our teeth and produce acids. These acids in turn will dilute the enamel part of our tooth, creating a hole for the bacteria to go deeper into our dentin and when these bacteria penetrate into the pulp of the tooth, it may cause severe damage to the tooth which is very painful. This may require a visit to the dentist to pull out that badly damaged tooth, leaving a gap in between the rows of our teeth which makes chewing slightly more difficult. 

The thin layer of bacteria that grows on our teeth is called plague, usually pale yellow. Simple sugars (which are found in canned drinks and sweets) are the plaque’s favourite food. Getting rid of these sugars is important if we do not want the plaque on our teeth to build up any further. This can be achieved by using a mouth-rinse after meals, flossing, and regular brushing. 

Besides the toothbrush, you can also clean your teeth with twigs from the mustard tree. These teeth-cleaning twigs are known as miswak

A good oral hygiene can save a lot of money and pain. Also, it is good to drop by a dental clinic at least twice a year for a professional check-up. Smile!

Experiment: Make your own toothpaste.

baking soda, glycerin, hydrogen peroxide, peppermint oil, squeezable container (you can buy glycerin, also known as baby mouth rinse, and hydrogen peroxide from a pharmacy).

1. Add six teaspoons of baking soda into the container.
2. Add one teaspoon of glycerin and hydrogen peroxide into the container.
3. Add a few drops of peppermint oil.
4. Mix them thoroughly.
5. Ready to use.

The use of miswak (known as kayu sugi in Malay), dates back to the time of the prophets of Islam.

Enamel [ih-nam-uhl] a glassy, usually opaque, substance on hard surfaces.
Dentin [den-tn] the hard tissue, that is similar but denser than bone, that forms the major portion of the tooth.

Shared by Surain A. Victor
Guest Blogger

Thursday 19 November 2015

‘Community Sciencing’

‘Science’ has always been a noun as we learned it from our good old English classes. The Oxford Dictionary defines Science as “The intellectual and practical activity encompassing the systematic study of the structure and behavior of the physical and natural world through observation and experiment.” Yes, Science is a noun indeed.

But, consider this… it is actually the ‘action’, the ‘process’, and the ‘effort’ of doing those observations and experiments, thus the verb that really matters. Hence, Science is arguably a verb as well as it is an active process of learning.

Sciencing’ is one particular word occasionally used as a present participle form of the verb ‘Science’. The Urban Dictionary has ‘Sciencing’ as ‘the act of doing science.” There are also a few cool expressions on this such as ‘I’m sciencing as fast as I can’, ‘I’m busy sciencing’, ‘let’s go sciencing’, and ‘What scientists do? Sciencing!’

Let me join the fray. Have you heard of the phrase ‘Community Sciencing’? If you haven’t, then I could have the honor to coin it. What does it mean? Think of ‘Community Policing’ which loosely means ‘the philosophy that promotes organizational strategies and the systematic use of partnerships and problem solving techniques, to proactively address the immediate conditions that give rise to public safety issues, such as crime, social disorder, and fear of crime.’

Put this in the context of the science education awareness in Malaysia, then let’s define ‘Community Sciencing’ as ‘the systematic use of partnerships and problem solving techniques, to proactively address the immediate conditions that give rise to the science education issues, such as the decline in the interest on science subjects in schools and to pursue science-related careers.’

In a bigger picture, ‘Community Sciencing’ can be a rallying platform for the government agencies, education institutions, businesses, non-government organizations and other socially responsible parties and individuals within a particular community to collaborate in creating awareness among its members on the importance of science education.

The Petrosains Science Festival (PSF) is an excellent example of a ‘Community Sciencing’ initiative whereby hundreds of organizations and individuals come together in a single platform of promoting science education by reaching out to hundreds of thousands people in Kuala Lumpur City Centre. Visitors from our past festivals in 2013 and 2014 were enthralled with various inspiring education activities such as booth exhibitions, talks and forums by scientists, interactive workshops, captivated science shows, lively show performances, and personality appearances.

The Petrosains Science Festival has proven that ‘Community Sciencing’ is indeed alive in Kuala Lumpur! And we are hoping for a bigger participation by both the private and public members of the community for the sake of the community in 2016! For more updates on Petrosains Science Festival 2016, visit! 

Shared by Hasnan
Guest Blogger

Friday 13 November 2015

Siapakah Lebih Stabil? Lelaki Atau Perempuan?

Mari kita bincangkan persoalan mengenai siapakah yang lebih stabil. Adakah lelaki lebih stabil daripada perempuan? Cuba teka jawapannya? Apakah jawapan anda? Bagaimana cara untuk mengetahui samada lelaki atau perempuan yang lebih stabil? 

Sekarang cuba ingat kembali teori mengenai faktor yang mempengaruhi kestabilan bagi menjawab persoalan di atas. Kestabilan sesuatu objek bergantung kepada:-

a) luas tapak 
b) kedudukan pusat graviti

Bagaimana luas tapak mempengaruhi kestabilan?
Gambarajah di bawah menunjukkan 2 buah botol. Yang mana lebih stabil? Botol A atau botol B?

Ambil dua buah botol dan dirikan botol-botol tersebut seperti dalam gambarajah. Botol A akan kekal pada kedudukannya manakala botol B akan terbalik setelah beberapa ketika. Ini menunjukkan botol A lebih stabil daripada botol B. Ini adalah kerana sesuatu objek yang mempunyai luas tapak yang lebih besar adalah lebih stabil daripada sesuatu objek dengan luas tapak yang kecil. 

Aktiviti yang dilakukan dalam video berikut juga boleh dicuba di rumah bagi membuktikan bahawa luas tapak merupakan salah satu faktor yang mempengaruhi kestabilan.

Namun, adakah persoalan di atas sudah terjawab? Jika belum, mari kita lihat kepada faktor yang kedua pula.

Faktor yang kedua adalah kedudukan pusat graviti. Bagaimana pula pusat graviti sesuatu objek mempengaruhi kestabilan? 

Ambil dua buah botol lagi. Satu diisi penuh dengan air dan satu lagi diisi satu pertiga penuh sahaja. Sekiranya kedua-dua botol di atas diletakkan di atas meja kemudian meja itu di angkat, botol mana yang jatuh dahulu? Jika kita merujuk kepada pernyataan sesuatu objek yang lebih berat adalah lebih stabil daripada sesuatu objek yang lebih ringan dengan syarat kedua-dua objek mempunyai saiz dan bentuk yang sama, maka tentu sekali botol yang berisi penuh dengan air lebih stabil daripada yang satu lagi. Tetapi sebaliknya pula berlaku. Lihat penerangan dalam video di bawah:-

Eksperimen sebelum ini menggunakan botol bagi menguji kedudukan pusat graviti. Sekarang mari tonton video berikut pula:- 

Pelajar perempuan dalam video di atas berjaya berdiri dengan mudah. Ini menujukkan perempuan mempunyai pusat graviti yang lebih rendah. Sesuatu objek dengan pusat graviti yang rendah adalah lebih stabil daripada sesuatu objek yang mempunyai pusat graviti yang lebih tinggi.

Kesimpulannya adalah perempuan lebih stabil berbanding lelaki kerana kedudukan pusat graviti seorang perempuan adalah lebih rendah berbanding pusat graviti seorang lelaki.

Posted by Ayu

Monday 9 November 2015

How Does Sherpas Survive Living In Thin Air?

Who is Sherpa?
Sherpa is a tribe living in the mountainous area in Himalayan region, Nepal. They are concentrated in Solukhumbu region which is located at 3,440m above sea level. They are known for their remarkable adaptation to high altitude, rarely affected by acute or chronic mountain sicknesses. Their exceptional adaptation also gets them prowess in mountaineering and hiking porter.

Image credit:

What makes them super special than the rest of us here on 56m above sea level in Kuala Lumpur?
At 2,400m above sea level – normal human will suffer acute mountain sickness [symptoms: rapid pulse, nausea or vomiting]
At 2,500m above sea level – normal human will suffer from high altitude pulmonary edema [symptoms: dyspnea, rapid shallow breathing]
At 4,000m above sea level – intolerable to 40% less ATM environment. A normal human will suffer from high altitude cerebral edema [symptoms: altered mental state, retinal venous dilation]
And them? They reside at the altitude of 3,440m above sea level.

But how is that possible?
They succeeded the EPAS1 gene [high altitude living] from archaic Denisovan people from 40,000 years ago, which regulates the body’s production of hemoglobin.
They have low hemoglobin concentration, the scientist thinks this trait helps them avoid clots and strokes caused when the blood thickens with more hemoglobin-laden red blood cells.

They have more elaborated blood vessels hence this helps to transport smaller amount of oxygen efficiently.
As a conclusion, these super athletic humans can carry out normal life at 3,440m above sea level which could easily be fatal for us normal human being.

Image credit:

Dyspnea         : difficulty in breathing at rest
Mountaineering         : mixture of snow climbing, ice or rock climbing & glacier travel
Hemoglobin : protein molecule in red blood cells that carries oxygen

1. Genetic contribution of the endothelial nitric oxide synthase gene to high altitude adaptation in Sherpas (High Altitude Medicine & Biology, February 2006)
2. http://news
3. Medline Plus -

Shared by Hani Nordin

Guest Blogger