IISC Open Day 2023

The previous Open Day was at the end of February 2020, when Covid cases had just begun surging. After all these years, Open Day was back again to enthrall scientific minds! The great thing about a science crowd is that everybody is well behaved and organized. Even the human-trains of school kids that snaked their way through everywhere, were organized and well behaved. 

Here's a video of some of the interesting exhibits:

Although IISc put up a map of the place, and it had a grid to help figure out where we were, the map turned out to be useless, since when people photographed it and ventured to other parts of the campus, referring the map ended up making them confused. We really need a better, more responsive map that recognizes locations and perhaps even helps us plan out our path of visiting exhibits and provides info on the transport vehicles.

Click to view it larger

Neural network meant for physics-specific calculations

An autoencoder that compresses data and de-compresses it with some loss

A catapult without the conventional friction joints

A robot-fish fin showing how turbulence is created in water and propels the fish forward

An anti-gravity structure that pulls the string in various directions and can even support a load

A demonstration of immiscibility of fluids of various densities

Drones display and demo

Silicon chip manufacture

You can move the arms of the robot on the left, and it'll copy the same motion on a robot placed in another room. It vibrates to let you know you have reached a boundary. Useful in robotic surgeries done remotely

An Augmented Reality gun which you can use to play a game

A circuit that calculates using analog signals instead of digital. Meant to mimic the human neurons. It performs calculations with much lower power than digital processors.

A circuit assisted with quantum computing

Tiny ML for use in ecological conservation and gesture recognition

Industrial control systems and security

Seeds encased in manure and mud, forming a ball which can be thrown in areas that need aforestation

A travelling salesman game

Ice cream made from milk cream, milk, vanilla essence and frozen with liquid nitrogen. They give you samples to taste, and it's delicious!

Flexible solar panels

Toys that make learning mathematics fun

Rainwater harvesting model

Tender coconuts at an outrageous price of Rs.40

A bus driving simulator you can try. The simulator is actually used to train BMTC drivers to handle Indian roads. Surprisingly, there were no potholes on the road. So much for trying to simulate "Indian" roads.

A toll-gate game where they design the game to see if you choose to use the toll and then switch to a non-toll road and then switch back to the toll road based on traffic. This game had a lottery for players, based on how often they used the toll road.

A traffic junction game where you control the signals. The player who reaches the highest level wins a pen

Robot football

A robot kit for children to create their own robots

The high voltage lab setup

Testing aircraft for lightning strikes

More on the lightning strikes

The demos shown at the high voltage lab. The queue is quite large here

The brain research centre

If you ever wondered how many idlis you need. Apparently, idlis contain protein too.

Click to view bigger

Explanation of flash floods

Hydrogen fuel cell powering a toy train

Tactile robot arms

Some people travelled all the way from Kerala just for Open Day

What's shown here is a minuscule subset of the massive number of exhibits and interactive games that IISc had organized. Kids can win chocolates and prizes too in the games organized. One day isn't enough to go through all the exhibits. There are so many.

Parking is available at IISc Gymkhana ground for free. However, be prepared to end up with a dusty vehicle, and if you don't find a shady area, your vehicle gets baked in the afternoon sun.

Each of the departments have toilets that you can use. There are plenty of food stalls available, but it's better if you bring sandwiches on your own, since the stalls are overpriced. There are plenty of places on the lush green campus where you can sit and relax. Everyone is helpful.

Real path to linked files

In Ubuntu, when you click on a link to a folder and reach that folder via Nautilus, you are only shown the path you came from, rather than the actual path of the folder or file. 

For example, it'd be:

/media/nav/Link_to_folder/folderOrFile

However, the actual path of the file would be:

/media/nav/Transcend_NTFS/NavData/backup/folderOrFile

Even if you open a terminal in the linked folder, a pwd command would still show you only the linked path, rather than the actual path.

To view the actual path, simply use:

realpath fileOrFolderName

Comparing video quality by viewing videos side by side

When you convert videos to a different quality, you'd want to compare them. While there are objective methods of comparing it, the subjective evaluation by a human is generally more accurate. When looking for solutions, I found a brilliant solution named Vivict. It not only allows you to compare streaming videos, it also allows you to compare local videos, by using the little white icon near the address bar. The best part of Vivict, is that it shows half of one video and half of another, and allows you to move the mouse to view more or less of the video.

Limitation of Vivict: It does not support all video file formats. When I wanted to play an mkv file, it didn't work.

Another solution, is to simply use ffplay like this:

ffplay -f lavfi "movie=leftVideo.mp4,scale=iw/2:ih[v0];movie=rightVideo.mp4,scale=iw/2:ih[v1];[v0][v1]hstack"

Comparing videos using ffplay

A simpler solution:

I created a program (https://github.com/nav9/splitVideoQualityViewer) similar to Vivict which shows the videos like this:

 

Feel free to either fork and modify the repository or contact me on the repository's discussion tab, to collaborate.

Automatically detecting audio video async and correcting it

It's a bit disorienting when in you see a lack of sync in the lip movement of a person and the audio. There are various reasons this can happen. If on a live stream, it could be because of network congestion or because the program doing the video encoding didn't get enough of CPU cycles. It can also happen when re-encoding video or splitting it.

Whether you want to measure how much of an async there is or even to fix it, machine learning has thankfully come to our aid. I created a simplistic open source program that finds periods of time when a person begins to speak after a silence, and matches it with audio to find out how much of an async there is, and then I use FFMPEG to fix the async.  

Code: https://github.com/nav9/audio_video_synchronizer

MediaPipe was used to identify the lip movements. I was surprised at how robust it is. Even if the person's face is turned sideways, it still tracks and estimates the face point positions as x,y,z points. Almost 400 points are tracked.

To identify human speech in the audio, I used a voice activity detection algorithm.

There's a lot more work to be done to make this program generic. Ideally, a Recurrent Neural Network (perhaps even LSTM) could be used to analyze lip movements temporally and figure out which lip movements are actually speech and which aren't. Then a probability score needs to be generated based on the actual sounds detected and matched with the lip movements. There are pre-trained models like Vosk, which can be used offline to estimate which words are spoken. Python's speech_recognition package comes in handy here.

Add shutdown and reboot menu options to GRUB

I have ALWAYS wished for this, and can't believe it was only now that a lightbulb lit up in my head. There are plenty of times you'd be at the GRUB (Grand Unified Bootloader) menu, and wish you could simply shutdown from right there, instead of pressing the power button or booting into the operating system and then shutting down. 

This should have been a default option in GRUB. Anyway, here's how you add it:

I saw this technique here, and this is why I like Linux more than Windows or Mac. There are tons of things you can customize.

This file allows you to add custom menu options to GRUB:

 sudo gedit /etc/grub.d/40_custom

Add these options to the end of the file, save and exit:

menuentry "Reboot" {
      reboot
}

menuentry "Shut Down" {
      halt
}

Update GRUB:

sudo update-grub

Reboot the computer.

Why a Macbook is no longer good for Linux programmers

I have relatives who use a Mac because somebody told them it's a good quality product or because they want to go with the brand-hype created around the Macbook. I understand brand-craze or the desire for a product that makes one feel good or something that offers the right features. So if a programmer is comfortable with (and actually wants) a Macbook (after evaluating if it’s really going to help be productive), let them buy one. The rest of them would be more-than-happy with any other good computer which has Linux installed. For non-technical people who don't understand why many Linux programmers abhor the Macbook, I'm listing out the reasons here so that you don't inadvertently purchase them a Mac, thinking you are doing something nice for them (there was a time when I heard a relative was planning to buy me an expensive Apple product for my birthday, and I promptly sent back a message through the grapevine that I'm not fond of Apple products).

Linux is not Unix.

There’s no more of the “good build quality” that was once synonymous with Apple. There’s no more of the good design decisions either. 

I’ve used Mac’s for almost four years, and the only thing I’ve liked about it is the absolutely amazing display quality. Besides, for programmers who work on Linux, it’s far better to have a computer that runs Linux and has a hardware architecture that is compatible with the software they commonly use.

Reasons not to use a Macbook

• No Type A USB ports: This is by far the biggest horribly deranged decision that Apple has taken. Not having Type A USB ports means that you can’t use your existing pen drives or mouse unless you buy a Type C USB 3 adapter. What drove this decision? Greed?

• No cut and paste in Finder: You can’t right-click to cut a file and paste it. You are expected to copy it to a destination folder and then come back and delete the original file. There is of course a shortcut, and you can drag and drop the file to move it, but somebody in Apple doesn’t seem to understand good engineering.

• Hardware architecture changed: Macbooks now have an ARM-based architecture. I’ve already had trouble compiling certain programs on it. I've also had trouble building some Docker containers that used x86-based programs, because of this underlying ARM architecture.
  
• Glassy monitor: Even when I turn the monitor away from any windows, and it’s facing a wall, I still see my own reflection and the wall on the monitor. Constant glare.

• Key functionality like Home and End don’t work: There are keyboard shortcuts for the Home and End buttons, but they don’t work when using the Terminal. They’ve also wrongly named “Backspace” as “Delete”. Programmers use Home, End, Del, Page Up, Page Down, and Backspace a lot. Not having these keys tends to get frustrating.

• Caps-Lock and other keys sometimes not detected: This is one example of the poor build quality. When I press the caps-lock key, the key press does not always get registered. The same happens even for the Ctrl and Command keys. This is on a brand new Macbook.

• Ctrl sometimes; Command sometimes: In Linux, a lot of functionality just uses Ctrl+some.other.key. On Mac, it’s sometimes Ctrl and sometimes Command. I know the functionality can be changed to some extent in settings, but it doesn't always work out the right way. Why did Apple have to meddle with such a basic functionality?
  

• Terminal not available on right click: For a programmer, one of the little pleasures in life is to open up any folder, right click on an empty space there and open a Terminal. That’s not available on Mac. It can be enabled, but being disabled by default shows that a Mac is clearly not designed for programmers. There are more terminals that can be installed.
  

• Headphone not detected on startup: I keep my headphones plugged in, and when I start the Mac, sound plays through the default speakers. Only when I disconnect the headphone jack and re-connect it, the sound is played via the headphone. An example of poor testing procedures.

• Vim lazy exit won’t work: The vim editor has a shortcut for saving and exiting. You can press Esc and then Shift+ZZ. It’s called the “lazy exit”. On a Mac, if you’ve opened a file using sudo, the lazy exit won’t work. You’ve got to use the “hard-working” exit ;-) Esc, wq!. Or Esc, x.
  

• Keyboard backlight not available at login screen: Yet another example of poor testing. At the login screen, the keyboard backlight does not turn on.

• psutil won’t work without sudo: This is meant to protect programs from accessing other program’s memory, but it’s really annoying that if I’m using a Python program that uses psutil, I’m expected to run the program each time as sudo python3 prog.py and type the password. The least that the designers of the OS (Operating System) could have done, was to provide a modal box that asks and marks a program as trusted, so that Users won’t have to keep using sudo.

• psutil functions like io_counters not available: So if I want to create a Python program to measure network I/O, it’s not easy. Wonderful.
  

• bashrc and profile don’t work: Apple shifted those files to /etc/profile, so it’s only after a lot of searching that you get to have your aliases and startup scripts work. Then after restarting, you realize that even that doesn't work. Use ~/.zshrc.
  

• Barely any good default favourites in Finder: Normally, it helps to have commonly used folders like Home, Downloads, Desktop etc. in the Finder favourites pane on the left by default. But no. You are expected to drag and drop them to create it.
• Icons don’t auto-align in Finder: Even setting the icons to snap to grid and making it the default for all, won’t make it work for all folders.

• Properties being “Get Info”: In Windows and Linux, when you want to see the properties of a file, you right click and find the properties option at the bottom of the menu. In Mac, you’ve got to adapt to recognizing it as “Get info”, and it’s not at the bottom of the menu. Nice in some ways, but annoying in other ways.

• Workspaces need work: Being able to use Ctrl+Alt+Arrow keys to switch between workspaces is one of the pleasures of using Linux. Mac OS seems to allow it only if you go to settings and enable it. Moreover, the “hot corners” tend to get confusing when one accidentally takes the mouse pointer to one of the corners and all windows suddenly disappear.

• Can’t dual-boot Linux natively: On modern Mac’s that have a silicon chip, you can’t install a dual-boot Linux OS on the Mac anymore. Great way to create a monopoly and drive away people.
• Bash history not enabled by default: There are plenty more people asking about this. It was a silly decision not to save history...and then make it even more difficult to find the right options to enable history.
• Exit does not exit: If you select the "Quit" option from the menus on the top right, the application does not actually quit. You are expected to go to dock and right click and exit. This gets annoying when using apps like GEdit, where if it's opened from the terminal, you can't proceed unless it has fully exited.
• Shutdown does not shutdown: Select shutdown from the menu, and the Mac does not shutdown. You have to select shutdown again for it to shutdown. Who are these people ruining the Mac UX?
• Updates downloaded for different version: I was shown update suggestions for some software and a suggestion for upgrading to the next version of MacOS. I didn't want to upgrade, but I decided to update the other software. So I start the time-and-resource-consuming 1.5GB update and lock screen. I come back after a while to see that the downloaded update encountered some error. After another try, I realize that these updates are meant for the next version of Mac OS. Why on earth did it download before the OS was upgraded? Such large updates even for installed software are another issue with Apple.
• Renaming is a pain: Right click to rename a file or folder, and even though the name is shown as highlighted, when you start typing, you realize that the text isn't getting edited. Then you have to right click or click again to make it work. 
• Pointless audio previews: If you click the middle of a video file, it starts playing the audio from the file, when you just wanted a video player to open the file. So you have to be careful to click at the edge of the file icon. Who designed this usability nightmare?
  

There may be more points I’d include soon. Linux is far more customizable and programmer-friendly. Do a favour to your Linux programmers, and give them a computer that has Linux installed natively. It is especially helpful when they need to test locally and deploy onto Linux-based servers. There's more discussed on Workplace Stackexchange.

Adjusting subtitles of a video

 

Many of us have been through the annoying feeling of viewing a video where the subtitles are off by one or two seconds. This is especially true when it's a foreign language video, and the subtitles are extremely important. Have you ever thought of using a software to adjust it? Well, there are plenty of them.

I tried Gnome Subtitles recently, and under the "Timings > Adjust" menu option, I could shift multiple selected subtitles by the number of seconds I wanted to adjust them (make sure the name of the video and the subtitle file are same, in order to ensure that the video opens up automatically when you open the subtitle file). Quite a handy tool! For more recent versions of Ubuntu, you can use many other software, including KDenLive.

You can also adjust subtitles using VLC or FFMPEG.

The SRT file

Although called "SubRip" files, the SRT stands for SubRip Text (in web format, they are Subtitle Resource Tracks). The time that each subtitle should be displayed is represented as <hour>:<minute>:<second>,<millisecond>. There's even support to specify the font colour, font style and even the coordinates to display the text at.

Generating subtitles

There are people whose jobs involve performing audio transcription. They'd listen to audio, type in the text and the time at which the text appears. The process is very cumbersome because they need to constantly move forward and backward along the audio track, while needing to type what they hear. This means their hands are always occupied. So some enterprising individuals decided to create a foot-operated pedal which the transcriptionists could use to control the audio playback. The pedal allowed them to rewind, pause, play or fast forward.

Of course, today there are machine learning algorithms which detect speech and automatically generate subtitles. Even if the transcription is incorrect at places, it's easier for the transcriptionist to fix it. 

I'll leave you with an amusing "interview" of a person who is quite confident that he does not require subtitles.

Does your food pass my Stomach Test?

Have you too been taught from a young age to “respect” food? To gobble it up without question? To politely compliment everyone’s cooking “skills” if they cook something for you? To chime in with everyone’s comments on “the food was good/great”? I’ve met many people who go through stomach pain, sleep loss, acid reflux, flatulence (fart attack?) and bloating, but they either have no clue about which foods are causing the problem, or they fear speaking up about the food quality. Perhaps it’s also a loss of hope that things would ever improve.

It’s time we brought The Stomach Test into the picture, to provide our digestive systems a beacon of hope. It’s not yet a comprehensive test. It’s a start. It needs inputs from your experience, to be refined and improved. “Stomach” here, is meant to encompass the entire digestive system.

The Stomach Test

When delving into finding The Real Cure for Eye Strain, I desperately had to figure out what caused my sleep loss. So I kept track of everything I consumed for a year. You’ll not realize the importance of these points if your digestive system recovers quickly enough. People tend to think they have a stomach of steel. However, as you age, or when you suffer on a daily basis, you’ll notice what I did. Food has to pass my six tests to qualify as “good food”:

1. No burnt food: Burnt particles in food cause digestive discomfort, which leads to sleep loss. I now throw off the black, burnt spots from bread toast, barbecued chicken, parathas/rotis, etc. If onions, mustard seeds, cumin seeds, curry leaves or anything else gets burnt when frying them, throw it away and start over.
2. No under-cooked food: Food that felt like chewing-gum, also resulted in sleep loss (it wasn’t cooked properly) and it’d result in flatulence and/or loss of appetite (I believe the digestive system creates this loss of appetite, to take time to recover). Cooking rice, parathas and other rotis properly is especially necessary. I’ve written more about it below. Well-cooked food also kills germs and tapeworm eggs, for example (you should also be aware that some bacteria form heat-resistant spores). I would also add unripe fruits to the category of “under-cooked” food.
3. A healthy, balanced proportion of ingredients: Spicy food is never really a problem if it’s balanced well with other ingredients. Avoid foods that contain excess salt, oil, or sugar (many processed/packaged foods have these in excess). It’s important to diligently follow the ingredient proportions of well-established recipes.
4. No adulterants: Oh I just don’t know what to say about the evil/ignorant scum who adulterate food. It’s not just adulterants. Ideally, this point should also encompass pesticides and formalin used to preserve fish. Why on earth are people not actively investigating and eliminating food adulterants? Water from certain water filters that left a “layery” feeling in my mouth and even the way certain coffee was prepared, resulted in stomach discomfort that led to sleep loss.
5. Hygiene: You know about washing hands before eating. What you may not know, is how Helicobacter pylori is transmitted and how it damages the stomach. Avoid places where people or situations can cause bodily fluids, dust, pollutants, insects, or filth to contaminate the food.
6. Spoilage: This one is obvious. Don’t let the “respect food” philosophy convince you into eating spoiled food just because you don’t want it to be wasted. Simply throw it away.

Miscellaneous info

• Rice and flat-breads: Remember this: It is not necessary that that rice grains should be separate from each other when cooked. It’s more important that rice is cooked with sufficient water for the right duration (or even boiled with excess water and then drained). Most varieties of rice need four or five cups of water per cup of rice. I know you’d be surprised if you’ve been taught to use just two cups of water. Do a bit of searching and understand the role of amylose and amylopectin. Freshly cooked rice has reasonably separate grains, and that texture feels good while eating. On cooling, rice will clump up, and that’s normal. Using less water to ensure that cooled rice grains remain separate, is counterproductive. Rice cooked with insufficient water can cause sleep loss. I’ve also noticed that many people don’t ensure that chapathis and parathas get fully cooked (inner portion).
• Cooking knowledge: There are many stalls and eateries, where the people who cook the food are not professionals. They need to be trained. Even people in well-to-do families are often not taught how to cook. This leads to serious errors not just in the way they cook food, but also in how they use cooking equipment. I’ve heard of certain European schools which teach children how to cook. Wouldn’t it be prudent to have a professional cooking course in school or at least in college? Cooking and cleaning are basic life-skills. Knowledge about what constitutes a well balanced diet (and why it’s necessary) is also essential.
• Hair loss: When the digestive system suffers from the effects of bad food, the body seems to go into a state of distress. Sleep loss is one characteristic, but I’ve noticed that excess hair loss (from the head) also happens. Given that DHT (DiHydroTestosterone) is one reason for baldness, I’d suspect that excess DHT or testosterone is produced when the body goes into this distress mode. I’m not sure about this, but I did notice a drastic reduction in excessive hair loss, once I started getting better sleep as a result of eating food that passed my Stomach Test.
• Identifying what causes it: Flatulence and loss of appetite can be signs that certain foods caused trouble in the digestive system. Different people respond to various foods differently, so over a period of time, diligently figure out which foods are affecting your sleep. It can be food from a hostel, a restaurant, a stall, a bakery, cafe or a packaged snack or even from somebody at home who does not understand the principles of cooking. Make sure you get well-cooked home-food.
• The best drink: It’s not coffee, tea, beer, or a carbonated beverage. The best drink is DiHydrogen Monoxide (water).
• Cooking time and water quantity: As mentioned above, rice requires 4 to 5 cups of water per cup of rice. Upma requires 3 cups of water per cup of rava. Chapathi’s and porota’s/parathas need to be heated until properly browned (but without any black burnt spots). It’ll become crisp at this stage. Alternatively, avoid flour and refined flour if it isn't cooked/baked properly. I’ve noticed a strong correlation with consuming it and the eruption of dandruff and skin flaking.
• Recognizing problematic meat and dairy: Although food-poisoning symptoms are well known, a recent problem has manifested after eating meat, which appears to be a urinary tract infection or kidney stone, but is probably not. So doctors will prescribe urine tests and ultrasound scans, and everything will turn out normal, but the excess urination, urinary incontinence and a cringing feeling at the kidney areas won’t stop. I’ve found this to happen with some purchases of chicken, fish and dairy. It sends the kidneys or bladder into overdrive. Causes excess urination, and the kidneys or bladder reacts adversely to various foods. Also, one loses appetite but does not feel weak. When this happens, and the doctors have confirmed that it isn’t a problem they recognize, the best thing to do is to throw away the meat and switch to eating very small meals of vegetables and upma only when hungry. Drink plenty of water and wait for a few days for the problem to resolve on its own. I don’t know what causes it, but my guess is that meat may be affected by diclofenac, poultry may be affected by antibiotics or hormones, fish may be affected by formalyn, and dairy may be affected by melamine.
• Meat diet: I came across a person who claimed to suffer ulcerative colitis on consuming grain, fruit or vegetables. He survived on a meat diet (which isn’t exclusively meat though, as per the stories of Vilhjalmur Stefansson). There is a critique on such a diet, and there’s speculation on whether the lack of a diverse microbiome or helminths could be a reason for the problems. In any case, this was interesting information, which is why I’m mentioning it here, but the advice and constant monitoring of a doctor is necessary if one chooses such remedies.

The Impact

When you see people who snap and get irritated at the slightest annoyance, there’s a good chance that they have not got proper sleep. Sleep loss does that to people. There’s a lot of friction in this world that can be avoided when people are calm and composed. Having access to food that passes my Stomach Test is one part of ensuring good sleep.

We really need to do a lot more, to ensure that our loved ones and the people of our country have access to well cooked, nutritious food. Knowledge, training and awareness are a large part of ensuring it happens.

Stop Google Chrome's annoying update notification

It's annoying. Open Chrome and click the address bar to type an address, and suddenly the cursor disappears and Chrome's annoying update notification is displayed and given focus.

Sure, updates are necessary. But not when I'm busy with something. This update notification is exactly as annoying as the silly forced wait time enforced by Microsoft Windows updates. Interaction designers at Microsoft and Google really need to educate themselves on improving user experience. There are better ways to implement security updates.

Anyway, on Ubuntu, the way to get rid of it is by setting a faraway simulated update date:

sudo gedit /usr/share/applications/google-chrome.desktop

Search for the lines starting with "Exec=" and add a --simulate-outdated-no-au='Tue, 31 Dec 2099 23:59:59 GMT' flag.

So a line that looked like this:

Exec=/usr/bin/google-chrome-stable %U

Would become this:

Exec=/usr/bin/google-chrome-stable --simulate-outdated-no-au='Tue, 31 Dec 2099 23:59:59 GMT' %U

That's it. Now you can start Chrome without the annoying update notification.

If you want it to start in incognito mode each time or in fullscreen mode each time, you could also add these flags: --start-fullscreen --incognito.

In Windows, as this answer states, simply use RegEdit to open the key [HKEY_CLASSES_ROOT\ChromeHTML\shell\open\command] and add this argument:

--simulate-outdated-no-au=\"01 Jan 2199\"

 

If you are an Engineer, remember this. Design software to be usable. Instead of making users go through this complex process of disabling the update notification, provide a checkbox to set a reminder date and time or to switch off those notifications.

Making Ubuntu recognize and use the swap partition instead of using the swap file it created

This happened when I deleted my old Ubuntu partition and re-installed a newer version of Ubuntu. Even though there was a logical swap partition present, Ubuntu simply ignored it and created its own swap file. A glance through the Swap FAQ showed me how to fix it.

First, you need to have a look at what the UUID of your swap partition is. Do that by running:

blkid

Search for the line containing TYPE="swap", and note the UUID at the start of the line. This is the UUID of the swap partition. For example, the UUID may be fdb91fbe-e580-467f-8819-b672d89261eb.

Now open up fstab.

sudo gedit /etc/fstab

If there's a line starting with "/swapfile", comment out that line using a hash at the start of the line "#/swapfile". This is the swapfile that Ubuntu used instead of using the swap partition you had created.

Now add a new line to the file, where you mention the UUID that Ubuntu can use to recognize the swap partition:

UUID=fdb91fbe-e580-467f-8819-b672d89261eb none   swap    sw      0       0

Save and exit. Reboot.

Voila! The swap partition will now be recognized.

Another of Google's Easter Eggs: Dog and cat paws. Even Batman zooming across the screen!

It's a relief from the daily grind to see one of Google's Easter Eggs in the form of some animations, games or silly suggestions. This time, it was to celebrate international cat day. When you Google "cat" on your desktop web browser, or with your mobile phone browser switched to "desktop mode", you'll see a paw icon animating on the right side. Click it and then click anywhere else on the screen, and a cat will leave a paw mark. You can see the same when you search for "dog" or "bruce wayne".

I decided to have a look at how they did it, and there was a difference in the code of the page when there is an animation and when there isn't. Just a bunch of JavaScript.

It's nice that Google allows its employees to show some creativity from time to time. Something that other companies could learn from.