A Rich Earl And Swamp

A rich earl has become the owner of a piece of land, which to his dissatisfaction turned out to be nothing more than a big swamp. The earl wants to get rid of the swamp. 

A salesman advises him to use his fast-growing plants which can cover the swamp very quickly. "This plant doubles every day, tomorrow you will have two, the day after tomorrow four, etc. In 80 days, your swamp will be completely covered." The earl reacts: "80 days? This takes far too much time. Then just give me eight of these plants."

Question 1: What did the earl think?

Question 2: And what do you think?

Go to the answers directly!

Planting Trees Covering Swamp

What's the exact story? 

The earl must have thought that planting 8 trees on first day itself would cause him to wait for only 10 days. That's totally wrong conclusion.

Though started with 8 trees, on other day number will be doubled only not tripled or increased to x8. Starting with 8 trees is like skipping 3 days (2,4,8) if started with 1 tree.That is only 3 days would be saved. 

In short, with 8 plants, the earl need to wait for 77 days!   

Correlation Of Playback Speed & Duration

Recently youtube added speed control on video playback on mobile app. Previously it was only for desktop browsers. Now, if I increase the speed to 1.25 then how much time I would save while viewing particular video? Would it take 25% less time than original video? 

Interpreting it like that way is totally wrong way. Without going too much into technical terms, let's name 'content' for the whatever video has for it's entire duration. One thing is sure with playback speed of increased the duration for which we would view is reduced. The (oversimplified) formula in this case should be,

Just A Spare Thought...

I always had this concept in my mind but absolutely no idea whether it's possible or not.

We know, light takes 8 minutes 20 seconds to travel from Earth to Sun. So if we are looking at Sun at any time it's 8 minutes 20 seconds old. Now if we place a very high power camera with a great optical zoom at few light years say 10 years from Earth & zoom at Earth then wouldn't it possible to observe what was going on Earth 10 years ago? Wouldn't it be a time machine only difference it's not taking us physically at that time.

I know it would be literally impossible to place such camera but who had thought communications without wires few centuries ago! Just a crazy thought shared.

What Is The Test Cricket?

Yesterday, I was looking score updates of ongoing England Vs South Africa Test match on a TV sports channel. South Africa was struggling at 205/5 in reply of England's first inning total 458. After looking at the score, a young man of next generation asked me - 'Now South Africa need 254 to win, right?'

I was shocked. That young man is equally passionate about Cricket; he knows rules, players, records everything but of T20 & ODIs only. He didn't even know what is follow on leave alone the term night watchman! So where we are taking cricket to? It's really heartbreaking to see what's happening with the purest & traditional form of cricket.

Every ODI series always hyped & T20 series even more (IPL is good example). Never seen any Test cricket series hyped (probably except Ashes). Even ICC arranges events only for ODI & T20s.

Cricket

Reading Decimal Number System

We know how to read any number without decimal point like,

8430 is read as Eight Thousand Four Hundred Thirty 

But when it appears after decimal point then,

0.8430 need to be read as Point Eight Four Three Zero.

Why I can't read it as Point Eight Thousand Four Hundred Thirty?

Answer is pretty simple one!

After decimal point, places are referred as 1/10, 1/100, 1/1000 & so on; not Thousands,Hundreds etc.

So reading in thousands & hundreds are only valid for the numbers before decimal point not after. 

Shortcut For 2 Digit Multiplication

Multiplying Shortcut

So instead of regular 2 steps, we can achieve in a single step. For understanding how it works we need to get basics right.

What we do in multiplication,

(a + b) x (c+d) = bd + ad + bc + ac.

Here, 

(80 + 6) x (70 + 8)  = 6708.

This is based on mathematical expression,

(a + b)(c + d) = ac + ad + bc + bd.

Here it is in form of,

(10a + b)(10c + d)

Lack of Video Recording Pause Feature

Few years back I was crazy behind making creative videos using 'Pause' while recording using phone camera. At that time, camera in phone was new thing & I thoroughly  enjoyed those 'experiments' by following this. 

Sooner I purchased a mid range point & shoot camera & shocked when I came to know that I can't pause video recording. I thoughts what's use of investing in such pricey device when basic phone at that time used to have that feature. I googled the reason but I couldn't find it.

Point & Shoot Camera

  
This could be the reason! 

I am absolutely not sure if this is the correct reason. To know what I am saying we need to know how the point & shoot camera works. The imaging sensor of such camera is only exposed after the shutter button is pressed fully. Till then whatever in the 'range' of camera is displayed on the LCD screen by some mechanism. 

Now when we press video record button the mechanical parts inside moves such that  light to fall on imaging sensor. Now to pause video recording one need to stop light falling on the imaging sensor.And on removing pause again that sensor should be exposed to external light. This is bit difficult but not impossible at hardware & software level. 

 Note : I haven't purchased any latest point & shoot or DSLR. So have absolutely no idea whether such feature included in those or not.