Hydraulic Elevator

This is a hydraulic lift kit for kids that was purchased online for only S$2.10 from Shopee, with free shipping! I am not, in anyway, affiliated to this, but simply sharing about one of several fun and cheap educational sets that I bought to occupy my kids during this mid-term break.

Other than the syringe, joints and tube, the parts are mainly laser-cut from a piece of wood with a thickness of two millimetres. The instructions come with pictures for each step so even though the words are in Chinese, there is no need to read them.

This kit demonstrates Pascal’s principle which states that a pressure change in one part of a closed container is transmitted without loss to every part. Hence, the pressure change is transmitted from one syringe to another, allowing work to be done. Do not expect it to lift up very heavy weights, though as the syringes are not perfectly sealed.

I shall share about other kits that I bought for this break soon, including a $6.62 Tesla coil that I am looking forward to testing.

Documenting this website’s migration

After years of hosting my website on a traditional webhosting service that has seen multiple service disruption over the years, I have switched to Amazon Web Services, which is more reliable and scaleable. I want my students to be able to access new features in my website with faster loading speeds. AWS is much harder to set up as there is so much to learn and a lot of SSH commands to key in. The first key decision is to decide whether an EC2 or Lightsail instance is better suited to my needs. In the end, I decided to go with Lightsail as it seemed easier to update the necessary DNS records.

One of the first features I am experimenting with is a Udemy-style LMS plugin that allows me to create lessons and quizzes within a course structure and comes with a mobile-friendly user-interface. I wanted a platform in which my GeoGebra apps, as well as other online resources such as YouTube videos, can be stitched together for students to review or learn new topics at their own pace, as well as for classroom activities.

I initially wanted to use LearnPress, a fuss free and user-friendly plugin for this purpose, and even designed a course within it. However, I soon realise that it does not have a feature for analysis of students’ results. So now I have installed Tutor LMS and will be putting in content soon. Tutor LMS also comes with many more question types including ordering and fill-in-the-blank.

I experimented with Google OAuth in another Lightsail instance and will be implementing it here so my students can log in using their school gmail account.

The next necessary plugin was Mathjax for LaTex input. I needed to make some edits to the lesson sidebar in the Tutor LMS plugin in order to fix a bug that prevents the equations from rendering when navigating using the sidebar.

I have also updated some CSS to customise the Tutor LMS pages to fit the general style of my current website theme.

Home-Based Learning Using Google Meet

I conducted an online lecture this morning using Google Meet for the students who had to stay home due to the Leave of Absence mandated by the Ministry since they had recently returned from another country during this period of the Covid-19 pandemic. I feel the need to document this as things might become bad enough that schools have to close, so it serves as a place where fellow teachers can pick up some tips on how to manage this.

The G Suite account that I used is that of my school’s, not MOE’s, because it allows me to record the session in case I need to show the session to students who did not “turn up” for the Meet. I am the G Suite admin for the school so I changed the setting to allow Google Meets to be recorded. After the session, the recorded Meet is automatically found in a G Drive folder after it has been processed in the backend. ICON’s Google Meet (part of MOE’s Google Suite service) does not allow recording.

My hardware setup is simple: just my laptop to capture my face and control the Google Meet UI and a second screen with which to show my slides. I also entered the Meet as another participant using my mobile phone as I wanted to see what my students would see for added assurance.

Google Meet is very user-friendly, with a minimalist and intuitive design that one can expect from Google (after all, that was what made it the preferred search engine in the early days of the internet). All we needed to do was to sign in to and start a session. You can also schedule a session on Google Calendar.

When a Meet is created, a URL is generated, which you can communicate to your students via text message or email, or through a system announcement.

When students log in, be sure to ask them to switch off their video and mute their voices so as not to cause any interference.

Note that what is shown in the presenter’s screen in Meet using the front camera of a laptop is laterally inverted as presenters generally want to see themselves as though they are looking at a mirror. So if you were to write things on a whiteboard or piece of paper, you will not be able to read the writing through your screen. However, rest assured that students can still read the writing if they are looking at you through the feed from your laptop’s front camera.

Instead, what I did was to toggle between showing my face on the camera and projecting a window or a screen.

For today’s Meet, I projected a window where my Powerpoint slides was on but did not go into slide mode (which will take up both my screens) as I wanted to be able to see the Google Meet UI at all times in order to know if anyone asked questions or raised an issue using the Chat function. This backchannel was very good as students could immediately tell me if they could see or hear me. I wanted them to be able to ask questions through that but nobody did, unfortunately.

A few times, I toggled to use the camera. Once, it was to show a simple physics demonstration which I felt added some badly needed variety.

For future sessions, I intend to project a single window with Chrome is so that I can project the slides using Google Slides in an extended mode. This will also allow me to switch to an online video with ease instead of selecting the window via the Google Meet UI, which might throw up too many options if one has many windows open (which I tend to do). I also intend to use Nearpod to gather some responses from the students.

Review of Sci-sational Christmas at Science Centre Singapore

In a nutshell, Sci-sational Christmas offers value-for-money interactive family festive fun.

Open from 1 to 25 Dec 2019 at the Annexe of Science Centre Singapore, visitors will enter 3 main activity zones:

Zone 1: Hot vs Cold Experiments

Watch as two “elves” try to outdo each other by performing scientific demonstrations based on opposing ends of the temperature range – under very carefully controlled conditions of course.

The number of asterisks show the loudness of the explosion. The heat experiments in the “Fuel Efficiency Department” are:

  1. Lighting of a hydrogen balloon (**),
  2. Lycopodium powder combustion (*), and
  3. Ethanol-powered propulsion (***)

Over at the “Alternative Energy Department”, the elf tried to impress us with:

  1. Boiling of liquid nitrogen, increasing gas pressure to burst a balloon (***),
  2. Liquid nitrogen propelled plastic bottle rocket (*), and
  3. Liquid nitrogen cloud formation with hot water

To me as a science teacher, these experiments would have made the tickets worth the money already. After all, demonstrations like these are usually the highlight of science museums all over the world. But there are more…

Zone 2: Scented Candle Making

After exiting the first workshop, visitors are brought to the candle making workshop. We were each given a rubber mould, some melted soy wax, colouring and a few drops of liquid scents to make our own Christmas tree candles.

Do take care not to add too much colouring or the tree may not freeze evenly and hence, break easily. On hindsight, I should have used mainly non-coloured wax with a little green colouring for the base of the candle (to pour in last) to get a snow-covered Christmas tree.

Zone 3: Escape Room

The escape room offers plenty of fun for the kids in the group. There are clues planted all over Santa’s office and the session is facilitated by an “elf”. The aim is to unlock a number lock under the fireplace in the office for the kids to crawl out from.

There is a secret door for the grown-ups, though, so we need not worry about our outfit or painful knees.

The only downside is that visitors are placed in groups of 15-20, most of whom are strangers – unless you register as a big group of friends. However, most kids would often get quite involved and interactive despite not knowing one another.

I highly recommend this activity for families with kids aged 5-12. At a price of $15 that includes general admission to the Science Centre, it is far more worthwhile than a conventional escape room experience in Singapore and is something my own kids find meaningful and exciting.

I have a feeling that the Science Centre might organise more escape-room styled activities in future as they are quite the craze nowadays.

Visitors might want to note that the 3 zones would last a total of about 50 min. The entry timings are: 11AM, 12NOON, 1:30PM, 2PM, 2:30PM, 3PM, 3:30PM, 4PM and 4.30PM. You will need to indicate your preferred timing when purchasing the ticket and show up on time at the entrance, which is near the fire tornado exhibit.

one-north Festival 2019

Happening now from 13-14 Sept 2019 at one-north.

My colleagues and I took the opportunity to visit the exhibitions during lunch time today. I learnt about 3M’s solar films and retroreflection material, I^2R’s speech-to-text recognition app with code switching capabilities (i.e. the app is able to transcribe English-Chinese mixed sentences) and cell-based prawn meat from, among other things.

There was also an informative booth on Project Wolbachia (where male aedes mosquitoes infected with Wolbachia bacteria are released into the wild to control the population). I learnt that they could separate the male from the females at the pupal stage because male pupals are larger and got to stick my hand in a box full of male Wolbachia-Aedes mosquitoes.

Very hands-on booth on Project Wolbachia.
Looking forward to a future where meat is grown in labs so as to reduce animal suffering

Do check out the apps developed by the Bioinformatics Institute that can be used for science experiments or related applications.

Iconic Voices from MIT: Opening a New Window into the Universe with Dr Nergis Mavalvala

This is a free public lecture by Dr Nergis Mavalvala (an astrophysicist from MIT) on how her team detected gravitational waves generated from colliding black holes and neutron stars at the Laser Interferometer Gravitational-wave Observatory (LIGO).  Held on this coming Friday 26 Jul 2019 from 5 to 6 pm, the venue is at the Singapore University of Technology and Design (SUTD)’s Auditorium, along 8 Somapah Road, Singapore 487372.

Click here to sign up.