Wednesday, July 20, 2011

Climate sceptic fail...

Hahaha! Yet another demonstration of the cluelessness and lack of scientific literacy of many climate 'sceptics'.

Saw a post at Climate Realists (h/t Skeptical Science daily article summary) claiming "Greenhouse Gas Theory Trashed by Groundbreaking Experiment"

Here's some quotes from the article summary, with my comments after.
Assumption One: Gases that absorb infrared light thereby block infrared light.

Reality: Such gases radiate, i.e., “scatter” or spread out the light they absorb, thus releasing light in all directions rather than blocking it.


Real Reality: Well, no. They absorb the IR. They do then re-radiate it in all directions, but that's a different physical process to scattering. Look it up sometime...

Assumption Two: Blocking the exit of light while allowing free entry will increase the temperature of an irradiated object.

Reality: The light an object emits is a function of its temperature; its temperature is not a function of the light it emits. Accordingly, if incoming light raises an object to a certain temperature, the object will remain at that temperature whether it emits light to its surroundings or not. Any temperature increase in a confined condition is only due to reduced convective cooling.


Real Reality: Um, are you perhaps familiar with the law of conservation of energy? You're effectively stating that Same energy in + less energy out = No Change in Temperature. Claiming that the only reason temperature increases is because convection is blocked, is like claiming the Titanic wouldn't have sunk if it wasn't for all that water in the ocean.

The obvious next question - what makes a sceptic think that climate scientists don't consider convective heat transfer when figuring out the response of the Earth's atmosphere to greenhouse heating? And if convection can 'carry away' all that heat, where does it go, other than into the Earth's atmosphere?

This is easily answered by actually looking at what climate science says. Oh, look, amazing, climate scientists include a convective heat transfer term... just look at the figure showing the heat balance in this article. Here's a link to just the figure. Here's the figure itself:

Global heat balance from Trenberth et al 2009

17 W/m2 from thermals. That's convection, right there.

Like I said at the top.

Climate sceptic fail.

Thursday, August 26, 2010

Fun with (caffeinated) numbers...

I saw this post on Slashdot earlier:

This is a student project so the correct unit of energy is a "Library of Congress Stacked with Red Bull Instead of Books."

Now, you may convert that into Joules, if you care to.

I couldn't pass up that challenge...

The Library of Congress has 1,199km of shelf space.
A Red Bull can is 52mm in diameter.
A 250ml Red Bull can contains 481kJ of energy.

Doing the sums, I made the following estimate.

Assuming a single row of cans: 23,057,692 cans, and 1.109x10^13 Joules.

If we have a nominal shelf depth of, say, 250mm - let's call it 5 rows of cans - we get 115,288,461 cans, and 5.545x10^13 Joules.

For comparison, a kiloton of TNT releases 4.184 terajoules, so a Library of Congress of Red Bull contains the equivalent of about 13.25 kilotons of TNT - about 1 Hiroshima Bomb, give or take.

Fascinating stuff.

Tuesday, August 10, 2010

A taste of the future?

Headline from a news story this morning:

"Morgues fill as deaths double in sweltering Moscow"

Now, some of you will say "that's weather, it's got nothing to do with climate change". And you'd be right, mostly.

The difference is that, in a warming world, we can expect that extreme heat waves (and the forest fires that go along with them) will become more common. Already, record high temperatures are more than twice as likely to be broken as record lows. The last winter in Europe & the eastern US brought very heavy snowfalls & low temperatures. It was the coldest January in the UK for 23 years, according to the UK Met Office. At the same time, it was unseasonably warm over much of the Arctic, & the northwest US & western Canada (remember the problems they had with not enough snow for the winter olympics? They had to truck it in to some venues!).

Since then, it's been a pretty warm year. This Wikipedia page, listing all-time record temperatures for various countries, shows no less than ten new records have been set so far in 2010. Another 12 have been set in the last decade. That's all-time records, folks. 22 out of 58 have been broken in the last ten years.

The NOAA says that the January to June 2010 period was the warmest 6-month period on record. June 2010 is the warmest June on record, and is the fourth month in a row to set an all-time record.

Indications of a warming trend? Well, not in isolation, no - there's too much variability in weather for climatic trends to be statistically significant for anything less than about 15 years worth of records. However, it's certainly consistent with a warming trend. And if we go back far enough to get that statistical significance, there is quite a definite trend, so it's more appropriate to ask: "are current temperatures indicating any change from the previously established warming trend?" The answer is a categorical no. If anything, the current temps are tending toward an increased warming trend. There's definitely no evidence whatsoever that global warming is showing any sign of slowing down, more the opposite.

Back to heatwaves, the more serious implications are raised by this post on Skeptical Science. There comes a point where the human body is unable to shed heat, and body temperature starts to rise. At that point, you'd better have somewhere cool & air-conditioned to hide, or heat stroke is just a matter of time (just look at that Russian contestant in the Finnish sauna competition - 6 minutes in a 110º sauna, and he keeled over and died).

So we're looking at some nasty consequences for our high-carbon diet over the past few centuries. (And those forest fires & peat fires are releasing even more carbon!)

A nice analogy I saw on another post on Skeptical Science: if you crash your car into a concrete wall at 80km/h, there's a small chance you'll walk away with just a few bruises. But is that any reason to drive straight at it?

Sunday, May 23, 2010

Bagels FTW!

Sourdough bagels, that is.

Had one this evening with dinner.

Had a decent dinner, so was feeling quite full when I was done.

But I still wanted another bagel...



Monday, May 17, 2010

Sourdough #3

I'm getting the hang of this...

This week, I didn't want to waste a lot of flour/water by feeding the starter every day, so I fed it on Sunday night & plonked it in the fridge. Left it there until Friday, when I pulled it out and give it another feed. It had developed plenty of fine bubbles over the five days, but not quite as many as it had previously developed in a 12-hour period. 4-5ºC will slow things down a bit, which was the intended outcome.

After a day out on the bench (in some much cooler weather for Brisbane, ~15-20ºC), it was nice and bubbly again, so I gave it another feed to bulk it up on Saturday night, and made the loaf on Sunday morning.

It's still a bit time-consuming to make a sourdough loaf, but it's satisfying at the same time. Flour, water, and salt were the only ingredients, plus some sesame seeds scattered on the top. (Yes, I remembered the salt this time!)

So, without any further ado, here's loaf #3, 100% pure sourdough.







Two comments:
1) you've probably noticed I baked this one in a tin - thought I'd try it out, see how it goes - the shape is much better for toast / sandwiches, but maybe I'll buy a narrower tin, this one is pretty wide, and a higher-but-narrower loaf would be even better;
2) you've probably also noticed why it is sourdough loaves are usually slashed on the top - that oven spring is wicked! :-D

Tastewise, it's nice bread - a bit 'heavier' than commercial bread (this loaf was over 1kg, compared to a commercial loaf of bread that's a bit bigger weighing in at 700g), but with a nice texture and chewy crust. Makes great toast. A very mild flavour on this one, though, not very sour.

Saturday, May 15, 2010

Quote of the week

"But [scientific] journals have lots of big words, and lots of small print, and very few illustrations to make it easy for me. You can see why climate deniers don’t like them."



From the enlightening Climate Denial Crock of the Week.

I thought Viscount Christopher Monckton was getting it wrong, I just didn't know *how* wrong...



Friday, May 14, 2010

Mobile data rates

Here's a bit of a rant.

Device A connects to the internet via a 3G (UMTS) cellular network. So does Device B. Same carrier, same cellular network, same UMTS technology used to transmit & receive data.


For Device A, a $30/month plan includes 2000MB of data.
For Device B, a $30/month plan includes 500MB.

For Device A, when you exceed your quota, you pay $0.06 per MB for excess usage.
For Device B, when you exceed your quota, you pay $3.00 per MB for excess usage.

Same network, same data, from the same websites. But Device B pays 50 times more per MB for excess usage.

Device A is a 3G wireless internet modem you plug into a USB port on your PC or laptop.
Device B is a phone - which is why I'm not objecting too much to the different included data, because that $30/month also includes a fair amount of voice calls.

However, if you consider voice calls to be yet another form of data, it gets much, much worse.

GMS voice calls use about 30kbps worth of bandwidth for a digital voice signal. That's 1800 kilobits per minute, or 225 kB per minute. 0.225 MB per minute. At the $0.06/MB rate, that's 1.35c/minute. At the $3.00/MB rate, that's a princely 67.5c/minute. The actual call rates on the plan for Device B are 80c/minute.

If we priced voice & other internet data at the excess usage rate of Device A's plan, it would cost Device B $5.23 for the included voice data, and $30.00 for the included internet data.

Not too bad, $35.23 of value for $30!

But it would cost $120 for the data included in Device A's plan, which suggests the *real* cost of data is something less than the $0.015/MB that the included data for Device A is charged at.

That would price Device B's plan at something more like $8.81 for the included data.

However, I can live with paying a bit more for the GSM voice data, if it's given priority transmission to ensure good audio (having bits of lag here & there is bad for voice call quality). So I can live with paying $30/month for something that costs the carrier less than $9.

The worst bit, though? If you actually used a combined total of 2000MB of data on the phone, you'd pay a minimum of $4,500.00 in excess usage fees.

If both devices use 3000MB, Device A gets charged $90.

Device B gets charged $7,530.00.

For the same data. On the same network.



How is that even legal???