2016-04-16 Sat

Yo-Yo Dieting

You’ve heard of the term. We go on a diet, lose weight, often enough attain our goal, and then put the weight on. We reduce, increase, reduce, increase.

It strikes me that this is the same situation when we drive around with junk in the trunk and back of the car – every time we drive up a slight incline the engine burns gasoline to lift that junk up a hill, and we never get that energy back. We lift the same junk again at the next hill, and the next. Better to leave all that junk at home and not burn money just to lug it up and down every hill on the way there, and every hill on the way back.

So ... I took a look at my gathered data, gathered from weighing myself daily.

Over the past 1,165 days (3.2 years) I have registered accumulated increments in weight of 600 pounds. 600 pounds is about 3.6 times my body weight.

Over the past three years I have doubled my body-weight EACH YEAR!

How did I calculate that 600 pounds? I compared each day’s weight to the day before. If the scales indicated an increase over the previous day’s weight, I added that into the total. If my daily weight figure was less than the previous day, I ignored the change.

Junk in the Trunk

Christopher Greaves JunkInTheTrunk.png

Pick your trip. I shall pick a trip from the corner of Mill Road and Bloor Street east along Bloor Street, south down Auckland Drive to Kipling subway. You can think of this as “Picking up a friend from the subway and driving them home”.

There are three hills along this route:

(1) The rise from the corner of Mill/Bloor to the intersection of Bloor/Mapledawn

(2) The bridge over Highway 427 – Bloor Street between the West Mall and the East Mall

(3) The rise from the East Mall to Shaver Avenue

After that it is a long slope to Auckland, and slope down across Dundas and down to the valley of the Kiss’N’Ride at Kipling subway station.

The return trip has the same three hills, but in reverse order.

I estimate the three rises to be about twenty, fifty, and eighty feet respectively. That is a total of one hundred and fifty feet of up-slope on the trip out. Of course we have the same one hundred and fifty feet of up-slope on the trip home, so a total of three hundred feet.

If your car has forty pounds of junk sitting in the trunk and on the back seat, then the car engine has to lift that forty pounds through a vertical distance of three hundred feet when you collect your friend and run them home.

That junk requires 40 times 300 or 1,200 foot-pounds of energy to achieve the lifting up those slopes, and you don’t get the energy back when you go down hill. Energy is a one-way street (unlike Bloor Street!).

No wait!

It gets worse!!

A regular gasoline engine in a car has to dissipate 80% of the gasoline energy as heat; the water-jacket around the engine block has to carry away excess heat, otherwise the engine block would melt. Eighty percent of the gasoline you burn is sent through the radiator and carried away on the air.

So to obtain that 1,200 foot-pounds of energy your car engine has to burn five times that much energy in gasoline. (You get only 20% or one-fifth useable energy from each litre of gasoline).

So to obtain that 1,200 foot-pounds of energy you have to burn 6,000 foot-pounds worth of gasoline.

Now you can get 25,000,000 foot-pounds of energy from a litre of gasoline, and at $1.00 per litre, that 40 pounds of junk drains $??? From your wallet on a short trip to the subway and back.

And the same amount when you run your friend back to the subway after lunch.

Imagine what it costs when you drive across Toronto to go to Aunt Griselda’s for lunch every Saturday!

How on earth do they manage in Pittsburgh Pennsylvania?