Sunday, January 13, 2013

Why Pluto isn't a planet?

Pluto was originally discovered in February of 1930 by Tombaugh and publicly announced in March of 1930. However, after the International Astronomical Union (IAU) formally defined a planet, it was demoted from its planet status in 2006.

The IAU defines a planet as,
1. Should orbit around the sun
2. Should have sufficient mass to attain round shape (hydrostatic equilibrium)
3. Should clear the neighborhood of its orbit

Pluto failed the third criteria, since it has other objects in its orbital neighborhood such as Charon, Orcus and Ixion. Any object that clears the first two criteria and fails to clear the third criteria is called as a "dwarf planet". Pluto is now redefined as a dwarf planet.
The objects in Pluto's orbit, also called as Plutinos
Some people argue that Pluto should be called as a planet and called for the IAU to redefine the Planet criteria again. Lets see some comparisons that gives validity to Pluto's new status of "dwarf planet".

Pluto isn't even the largest dwarf planet

Dwarf Planets to scale, size wise, left to right - bigger to smaller
Below table shows the numerical data used in above diagram. Notice that there are larger dwarf planets than Pluto. Pluto isn't even the biggest dwarf planet. If Pluto is to be accepted as a planet, then Eris needs to be accepted as a planet before Pluto.

Dwarf Planet
Diameter (in KM)

Pluto scores lesser than Earth's Moon

Pluto scores even lesser than Earth's Moon in terms of mass, radius and gravity (g).
Acceleration due to gravity (g) of solar system objects and planets compared visually in a graph

Mass of solar system objects and planets compared visually in a graph

Radius of solar system objects and planets compared visually in a graph

That settles it. Pluto is disqualified!


 The planets to scale. The infographic that inspired this post.

Saturday, January 12, 2013

Card on delivery from Flipkart

Flipkart is one of the very few online retailers in India to offer "Card on delivery" in addition to "Cash on delivery".
If users select this option at check out, they can pay up to the flipkart man (flipkart's delivery boy) using a credit or debit card. The flipkart-man will use a wireless POS terminal at delivery.

Cash on delivery with Card on Delivery option on Flipkart's checkout page
Cash on delivery is a very attractive option for Indian buyers due to the low penetration of credit cards and online banking among the general population.
Even users having credit or debit cards are reluctant to share their card details online, but are willing to swipe it at a local shop.
To cater to this audience, Flipkart had come up with the "Card on Delivery" feature.

"I've never understood how to pay by card online. The best I can do is use an ATM. I wish more websites had the cash on delivery option," says Sneha Anand, a school teacher. - HindustanTimes

As per a Nielsen survey, upto 80% of online transactions are paid for by credit or debit cards, net banking or PayPal and just 15% of deals were cash on delivery in developed markets.Flipkart states that 60% of their orders were on cash on delivery, which substantiates the Indian market for this mode of payment.

"Cash on delivery" came to be called as "Collect on Delivery" in other countries when options other than cash payment was offered to users. Flipkart prefers to call their "Collect on delivery" service as "Card on Delivery".

Online food store, which claims to be India’s largest online food store, also has this card on delivery option.

Cash on delivery is an option that is less profitable to ecommerce companies, since they incur additional charges in collecting the money and getting the money back to the company. Flipkart wouldn't have this problem since they have their very own delivery network. 
Most companies that accept cash on delivery have it as a precautionary measure to call up and confirm the order with the customer before processing the order. It is assumed that Flipkart does the same to reduce the rate of rejection of the product. states that rejection rates are as high as 45% for them. According to Avendus Capital, eCommerce firms cough up Rs.35-65 more for processing every cash on delivery shipment.