02 October 2019

Copy pasting and clearing screen in the Ubuntu terminal

Copy pasting with Ctrl+c and Ctrl+v works fine on the MacOS terminal, but doesn't work in Ubuntu. I assumed this may be some security feature or because Ctrl+c is the age-old command for an interrupt, so I didn't give it much thought and just used the mouse to copy paste.

But today it just struck me that I should find out the real reason, and viola! It's just a matter of pressing Shift.

To copy:
Shift+Ctrl+c

To paste:
Shift+Ctrl+v

and as a bonus:
To clear screen on the terminal:
Ctrl+L

This clear screen also supposedly works in Matlab, MySQL etc., though I can confirm it works on the Python terminal.

01 October 2019

Aquaplaning, and how to avoid it

Long back, I was curious about why Formula One racing cars had such "smooth" tyres. The racing slicks. Turns out, when there's no water on the road, it's actually more beneficial for more of the tyre to make contact with the road and provide more grip. Having grooves would lessen the grip. When the road is wet however, the grooves/treads on the tyres are absolutely necessary to prevent aquaplaning. The rain tyres allow water on the road to enter the grooves, thus allowing the remaining part of the tyre to make contact with the road and give better grip. Without this, the car would go completely out of control.

Exactly the same principle is used when designing footwear. The process of cutting such slits is called Siping. Recently, I purchased a new pair of rubber slippers and noticed that it didn't give any grip on wet surfaces. I even slipped and fell down once.

On examining the sole, I realized why.


No grooves.


So I took a knife and cut out some crude grooves all along the front, mid and back portions of the slippers. Just these crude grooves were enough to give a good grip on wet surfaces. I also wrote to the company, chiding them for not considering this basic design element. They wrote back thanking me for the valuable feedback and stating that they were the number one footwear brand in the country. The number one brand? With a safety aspect like this disregarded, I definitely don't consider them number one, but I'd be willing to consider it if they make the necessary design changes.

Update: The horizontal groove I made was a mistake. When the slippers flex when walking, the groove deepens and causes the rubber to break at that point. So the better option is to either cut grooves vertically or just buy new slippers with better soles.