h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

From Clive:

What in the natural world has bright green stripes; no collective noun upon which biologists can agree, in spite of being seen moving in large groups; can move at up to 1 metre per second and - if you could capture one - would have more heat energy than a lit match?

Well, one thing ice does is to melt under a weight and re-form around it and over it where appropriate.

is this a latent heat thing???

the berg is absorbing heat from the sun all the time and when ice absorbs enough heat it changes from ice at 0o to water at 0o

if you took all that heat from all over the berg and compressed it , like a ground source heat pump does would it be hotter than a match???

Hmm okay - but that's not connected to the answer though.

See? Taff Not just the King of klaxons..

Correct +3.

I'll sort out the specifics when I write up but yeah basically that's it - the amount of heat energy it takes to change state: for a match it's tiny compared to an iceberg which not only has more latency stored within it but tend to be rather massive.

It's also got nothing to do with temperature.

What in the natural world has bright green stripes; no collective noun upon which biologists can agree, in spite of being seen moving in large groups; can move at up to 1 metre per second and - if you could capture one - would have more heat energy than a lit match?

-----------------------

Let's take this apart layer by layer then.

The answer was rather surprisingly "icebergs"

Here's a photo of the one that sent my elf-wheels-a-spinning

http://listverse.files.wordpress.com/2009/08/image001-4-tm.jpg?w=400&h=272

I think you'll agree it does look rather reminiscent of a mint humbug.

http://www.stockleyssweets.co.uk/images/product/mint_humbug.jpg


The "green stripes" are frozen layers of algae that got incorporated when the berg encountered some, maybe when it fell off the end of the glacier. Who knows. The dark lines are the result of dirt and dust, similarly accumulated.

You can also get "blue striped" icebergs - usually when melt water fills in a crevasse and freezes very quickly. if there are no bubbles within the ice (unlike say compacted snow) it shows up as a distinctive and glassy blue.

http://img.dailymail.co.uk/i/pix/2008/03_03/BergBAR1703_800x538.jpg

http://img.dailymail.co.uk/i/pix/2008/03_03/BergALAMY1802_468x643.jpg

But I decided to go with the green ones because they were more interesting.


Everything else was pretty much miss-direction intended to hide this fact and put you in mind of something insectoid or fishy, but even if I did snag one straggler (today mueller - fireflies) Mal sussed me out fairly early on, spotting my ruse about biologists which scuppered most of my klaxons.

As I was writing the question, I was looking for the collective noun for ice bergs and couldn't really find one, variously people refer to a drift of icebergs or occasionally a crush.
the later seeming to be the most portmanteau expression and "drift" or alternatively "pack" seems only really to apply to "pack ice" the fragmented surface ice that (used to) litter the water ways of the arctic - icebergs coming off the glacier and joining that can be referred to as part of a pack - but there genuinely seems to be no collective noun for just a groups of three or four icebergs moving with the current.

So I have to ask: was the biologists bit too much?
I was giggling myself silly when I thought of putting my own failure to find the collective noun for icebergs into the mouths of my fictional biologists!

As for how fast they move, well it varies really according to the strength of the current, the wind, how aerodynamic they are. etc The fastest I could find was that mentioned of a metre per second, and while that's not the limit, that was a nice round figure I could throw into the mix.

Because they are so big, unlike say bugs or fish might be, icebergs are quite tricky to capture (though not impossible of course) but I wanted images of nets and lures lurking with ill-deserved confidence in the periphery of your imaginations.


First let's deal with a problem of language.


So onto the bit with the match.

We're used to in day-to-day conversation talking about heat as if it's contained in something. This distinction between heat and temperature is subtle, but very important.

Heat always refers to the transfer of energy between systems (or bodies), not to energy contained within the systems (or bodies).

The iron is hot, so it's reasonable to say it must have a lot of heat in it. Reasonable, but wrong. It's more appropriate to say that it has a lot of energy in it (i.e. it has a high temperature), and touching it will cause that energy to transfer to your hand ... in the form of heat.

"Uhh. okay but aren't icebergs not like irons - help I'm confused"

Okay, as I've already mentioned heat and temperature are two different things but come again? Alright. So the temperature of the match is obviously much higher than the frozen iceberg but the iceberg has more potential heat energy stored within it's structure by dint of the fact that it is frozen.

If you were to heat up to standing pools of water one 10 times larger than the the other, to the same temperature, even though the temperatures would be equal the larger of the two would contain more heat energy and also radiate it away faster.

To raise the temperature of 1g of water by 1 Celsius requires 4.186 Joules of energy. that what's going on in our heated standing pools, but when it comes to changing states from solid - liquid or solid - vapour

you have to overcome and loosen the bonds that keep the molecules tightly packed together (as with the move from ice to water. Energy is necessary to effect the change.

I've copied and pasted this next bit because it involves and equation but read it, then read it again and it does make sense.

-------------------

The amount of energy needed for one gram of ice to change to water is 80 calories (335 joules)

Take something smaller like an ice sculpture.

If you think of the mass of ice at say -10°C. EACH GRAM first requires 2.05J/g/°C x 10°C = 20.5J.
or.. 0.5cal/g/°C x 10°C = 50cal.
Each gram then needs 334J (80cal) of heat energy added to melt it to water at 0°C.
Assume the sculpture has a mass of 1kg.
1,000g x 2.05J/g/°C x 10°C = 20.5kJ.
It will then need 1,000g x 334J/g = 334kJ of heat to melt.

---------------------

Sea Icebergs are not only a lot colder than -10 Celcius, they are also A LOT BIGGER.

And that's important.

---------------------

The relationship is given as Heat per mass q (heat density) drives the particles to move/vibrate, but what we measure with a thermometer is temperature, the kinetic energy.

Thus, temperature at each point within a mass (T ~ q), temperature varies with the heat content of the body being measured.

Heat, like all energy, depends on the mass of the body. That is mq ~ Q, the total heat content, where q is the per mass quantity of heat the body contains.

Assume M > m; where M is your ice mass and m is the mass of the burning match. Then mT ~ Q(m) and Mt ~ Q(M) are the heat contents for the match and the ice at T > t temperatures respectively. Assume both have the same total heat content so that Q(m) ~ mT = Mt ~ Q(M); then we see that T = (M/m)t. Which means that both the match and the ice could have the same heat Q if the temperature of the match is (M/m) times the temperature of the ice.

Ice freezes at 273 deg K. A match (paper) burns at 486 deg K (415 F); so if T/t = 486/273 = 1.78 = M/m, then the match and the ice sculpture will have the same heat content (not counting latent heat in the ice). If the ratio > 1.78, then the ice sculpture will have more heat than the match. In the end, for this heat thing, size (mass) counts.

---------------------

The mass of a Iceberg will therefore contain MUCH more heat energy than the match even after lighting. You can see this in action If you held a lit match under the ice scupture, only a tiny fraction of the ice will melt and the match will burn out in seconds. The frozen solid state mass of the iceberg will barely have changed.

i have heard reference to ice berg fields, so a field of icebergs

and glaciers calf ice berg off so the are born calfs they should be a herd

QI - Humbug
------------------------



Correct (+3)
------------------------
Mal (5) - "not a job for a biologist"
Taff (3) - "Algae"
Hygienic Dispenser (80) - "Is it icebergs?"
Taff (103) - "Latent Heat"



QI Bonus (+6)
------------------------
Hygienic Dispenser (40) - The algae spirogyra has green stripes"
Hygienic Dispenser (66) - The Skunk Cabbage.

[worth pausing here a moment to say why this is is QI]

In the early spring, skunk cabbage (Symplocarpus foetidus) flowers often melt the snow around them. Biologists now understand these flowers use metabolic processes to raise their temperatures several degrees above their surroundings.

They use an unusual metabolic pathway: the thermogenic process. Normal metabolism oxidizes sugars, generates heat, and produces the energy-rich compound ATP for cell activity. Oxidizing sugars via the thermogenic process generates a large amount of heat, but no ATP.

The concentration of Salicylic acid increases 100-fold as the plant begins to heat up.
The skunk cabbage's spotted “flower” is a leaf, called the spathe, which is extremely thick for a leaf – up to 1/4 inch and filled with spongy air spaces that acts like the Styrofoam insulation.

The perfume of the skunk cabbage smells apparently like a mixture of garlic and dead mouse. But this is the ideal odor to use when attracting cold adapted carrion flies and beetles for pollination.]

How cool is that???


DGI Bonus (+1)
------------------------
Bob Stafford (8) - "the calories of sugar"
Hygienic Dispenser (67) - "cold conditions"
Taff (68) - "cold conditions"
Taff (86) - "They are big"


Klaxon (-5)
------------------------
Todaymueller (59) - "fireflies"


Elf Bonus (+2)
------------------------
Clive




Total to be added or subtracted.
------------------------

Hygienic Dispenser
1 x correct +3
2 x QI Bonus +12
1 x DGI +1
Total +16

Taff
2 x correct +6
2 x DGI +2
Total +8

Malabarista
1 x Correct +3
Total +3

Clive
1 x Elf +2
Total +2

Bob Stafford
1 x DGI +1
Total +1

TodayMueller
1 x -5
Total -5


Who's raiding the Raiding the Tuckshop tonight then?

At the front of the queue, guaranteed his weight in Mint Imperials for that outstanding and Quite Interesting performance, at the top of the class it's Hygienic Dispenser on +16 !!

Clutching fistfuls of purple jelly babies, and slurping strawberry bootlaces like they were going out of fashion - It's the class rascal - Taff with +8!

The Peppermint Patty to my Red Baron. Queen of the Comic strip, it Malabarista with a sweetly spearmint +3.

But oh dear. Fingers caught firmly in the mousetrap hidden in the cookie jar - Today Mueller: -5.

Re: field, and calf

Yes, I suppose but it's still not like there's one agreed collective noun is there?

i put all sorts of crap in for bonus points, sometimes it works others??????

ce la vie

The QI is a fickle mistress.

The test I have used from day one has been if it makes me startle / double-take < think "oh I didn't know that / that's quite interesting.' ) it gets +6.

Take heart my friend, no klaxons and you came 2nd. Not bad.

@ Today Mueller.

By chance, today I discovered the Sloth thread you mentioned.

F7180006?thread=417165

Spot the deliberate mistake.

F7180006?thread=4171658

Well done everyone

I want to eat an iceberg now

Thanks Clive. I'd forgotten most of the details of the Skunk Cabbage. I think you can see why it's the sort of thing that sticks in your head for nearly 30 years.