# Estimation skills - Question 1

## How many Calories in a Cubic Light Year of Ice cream?

• ### way more than 10^100

• Total voters
18
• Poll closed .

#### GopherT

Joined Nov 23, 2012
8,012
Estimation skills have become a lost art. With the ever present smart phone, the answer to every question can be googled or calculated on the spot. But, just as a shoot-from the hip estimate: what is your first guess. No pencil/paper/google/smart phone/calculator/computer - just 30 seconds of your thinking before you throw a number out there. The ranges are huge so some error is obviously allowed.

#### Hypatia's Protege

Joined Mar 1, 2015
3,226
How many Calories in a Cubic Light Year of Ice cream?
My guess assumes you are referring to nutritional content (as opposed to 'manifest heat' ) and, by corollary, dietetic Cals (i.e. Kcals) --- Ambiguity is da getter!

Best regards
HP

EDIT -- For the record my vote was item 1 (i.e. ≈10^50)

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#### MrChips

Joined Oct 2, 2009
21,635
yebbut... cals and kcals is only 10^3 difference. What difference does that make between the choice of 50-75-100?

#### Hypatia's Protege

Joined Mar 1, 2015
3,226
yebbut... cals and kcals is only 10^3 difference. What difference does that make between the choice of 50-75-100?
True! -- However the difference between nutritional value and manifest heat content would likely be many orders of magnitude! --- My clarification of Cals vs 'dietetic Cals' was merely by way of aquainting folks with the disparity

Best regards
HP

#### GopherT

Joined Nov 23, 2012
8,012
True! -- However the difference between nutritional value and manifest heat content would likely be many orders of magnitude! --- My clarification of Cals vs 'dietetic Cals' was merely by way of aquainting folks with the disparity

Best regards
HP
We were talking about food so, yes, dietetic calories (capital C is the convention in biology/food science literature, when such unit was fashionable). I realize I may have added confusion by capitalizing Cubic Light Year. For clarity, those are standard cubic light years, not k cubic light years.

#### Hypatia's Protege

Joined Mar 1, 2015
3,226
capital C is the convention in biology...
I'll take your word for it -- though I'm bound to say I've always used the capital 'C' --- Golly, Golly! I can but imagine all the 'non-life science types' whom must have enjoyed a clandestine laugh at my expense over the years

But, Hey! -- I won't be a poor sport -- I've learned something today! -- Always a good thing

Best regards
HP

#### Hypatia's Protege

Joined Mar 1, 2015
3,226
So... Do we receive our 'scores' on the 28'th (i.e. the polls' closing date)???

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#### Wendy

Joined Mar 24, 2008
22,155
If you tried to eat that much you would be dead. So it is a negative number.

#### GopherT

Joined Nov 23, 2012
8,012

#### OBW0549

Joined Mar 2, 2015
3,503
I voted for >>10^100.

#### Hypatia's Protege

Joined Mar 1, 2015
3,226
I voted for >>10^100.
I dunno... 1 ly^3 is a large volume - howbeit 10^100 (or, for that matter, 10^50) is a positively gargantuan value!

Best regards
HP

PS -- Nice to see you on the fora again, @OBW0549 !

#### GopherT

Joined Nov 23, 2012
8,012
If you tried to eat that much you would be dead. So it is a negative number.
My biggest concern about that much ice cream is that the dairy farm co-products necessary to make that much milk would be less than one light year from the ice cream.

For every gallon of milk a cow produces (about 8 per day), it makes 8 gallons of solid waste and 4 gallons of liquid waste.

#### #12

Joined Nov 30, 2010
18,210
For every gallon of milk a cow produces (about 8 per day), it makes 8 gallons of solid waste and 4 gallons of liquid waste.
Twelve cubic light years...
I think we're in the realm of a black hole worth of poo.

#### Hypatia's Protege

Joined Mar 1, 2015
3,226
Twelve cubic light years...
I think we're in the realm of a black hole worth of poo.
We could but hope so... Even a singularity for a neighbor compares favorably to a 0.346 pc^3 dung heap!

TTFN
HP

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#### KL7AJ

Joined Nov 4, 2008
2,225
Estimation skills have become a lost art. With the ever present smart phone, the answer to every question can be googled or calculated on the spot. But, just as a shoot-from the hip estimate: what is your first guess. No pencil/paper/google/smart phone/calculator/computer - just 30 seconds of your thinking before you throw a number out there. The ranges are huge so some error is obviously allowed.
Assuming 2000 calories a gallon, I come up with about 3^44 calories per cubic light year.

#### WBahn

Joined Mar 31, 2012
26,049
Doing it without pencil and paper is a bit hard for me since my stroke a number of years back -- it's hard for me to keep several numbers at hand at the same time. So it's pretty easy for me to drop a few orders of magnitude. Is writing in the air with my finger allowed? That's about the only way I can have a change of keeping track of things.

My best estimate (using about 200 kcal/cup -- don't know how reasonable that is) is 10^53.

#### WBahn

Joined Mar 31, 2012
26,049
Estimation skills have become a lost art. With the ever present smart phone, the answer to every question can be googled or calculated on the spot.
Absolutely agree. The huge degradation was due to common availability of cheap calculators and their subsequent overreliance in primary school education. The smart phone has simply patted down the last few shovels of dirt on the grave. It really is heart-breaking to see so many engineering students that can't multiply single digit numbers or tell you want ten square is or, heaven forbid, the square root of one hundred.

#### #12

Joined Nov 30, 2010
18,210
Is writing in the air with my finger allowed?
I use an imaginary blackboard. It works for me, but people I am talking to keep looking where I'm looking, trying to figure out what I'm looking at.

#### recklessrog

Joined May 23, 2013
985
I wonder if any new engineers know how to use a slide rule??? That's all we had, oh, and a pencil (not a Biro) and paper!

#### djsfantasi

Joined Apr 11, 2010
6,694
I found my old slide rule recently. Had to relearn how to use it. What a trip!