23 hours 59 minutes 60 seconds—this is what a leap second
looks likeDid you make good use of the extra second you received in 2008? A little extra sleep perhaps? Did you notice the extra time?

Probably not, but there it was:  a leap second was added to the end of 2008, such that the world's precision timekeeping system held its breath for a second at 11:59:60 PM, December 31st before declaring 12:00:00 AM January 1st, 2009….

So why all the fuss about adjusting clocks by a second? As accurate as I try to keep my own clocks, they're never better than plus or minus a minute or so anyway.  For most of us, this level of nit-pickery is unnecessary– but there are many functions in our modern digital, computerized society that rely on extremely accurate timekeeping and coordination.

Ever used a Global Positioning System (GPS) device to locate your dog or stolen car or help guide you to a desired destination? The GPS satellite system requires hyper-accurate timekeeping to do its job.

Computer networks are coordinated with precise standard time.

Some cutting-edge scientific research depends on accurate time, sometimes to millisecond.  The observatory I worked at in Flagstaff, Arizona– the Naval Prototype Optical Interferometer– was so dependent on accurate time that one night our interferometric observations could not be made because there had been a leap second no one had taken into account!

So why do we have leap seconds? When it is explained that leap seconds have something to do with the fact that the Earth's rotation slowly changes over time, people often make the assumption that the Earth's rotation has slowed down by a second since the last leap second (and leap seconds occur roughly every 20 months).  But if this were so, then in a mere 144,000 years the Earth's spinning would grind to a complete stop! In reality, at present, the Earth's rotation slows by about 1.7 milliseconds per century (a millisecond is one thousandth of a second).

With leap seconds, it's important to understand that the adjustment doesn't reflect how much the Earth's rotation has changed since the last leap second, but rather the difference in the length of a day between two different time systems that have gradually drifted apart over a century or so:  mean solar time and coordinated universal time (UTC).

For a long time, the second was defined as 1/86,400th of a mean solar day.  But around the middle of the 20th Century it was realized that a mean solar day, based on Earth's rotation, slows over time through tidal friction, and also varies due to mass shifts, such as glacial rebound.

In 1956, the second was redefined to be based on the Earth's revolution around the Sun:  one second was set to be 1/31,556,925.9747th of the mean solar year of 1900.  But even this was decided to be too variable over time to be the basis for a uniform time system.

So, in 1967, another, far more uniform natural rhythm was used to again redefine the second:  oscillations of the atom Cesium-133, which can be measured with an atomic clock.  One second in the new time system (UTC) was equal to 9,192,631,770 oscillations of a particular ground state of Cesium-133.  As it was contrived, the length of one second of mean solar time and UTC time were exactly equal in 1820…

…but since 1820, the Earth's rotation has slowed so that now, the mean solar day is about 86,400.002 seconds long as measured by the UTC system—2 milliseconds longer than in 1820.  So every 500 days that difference grows to 500 x 0.002 = 1 second.  A leap second is born.

That makes 2008 an exceptionally long year, since it was also a leap year:  366 days, 1 second.  I hope you enjoyed it!

The Bush Administration has recently passed dozens of so-called "midnight regulations" - last-minute rules and amendments. Many of those new laws affect the environment, including a change to the Endangered Species Act that has California environmentalists deeply worried.

Listen to the Last Minute Rules radio report online.

Bad for the Lab, Good for the Country

Staff at Building Solutions, a home performance
company, install PV on a roof in Oakland. Next year, the renewable
and energy efficiency business will be even better.
Credit: Kate KenkeDr. Steven Chu, Noble-prize-winning physicist, and director of Lawrence Berkeley National Laboratory, was named as President-elect Barack Obama’s nominee for Secretary of Energy. Home Energy is a nonprofit magazine, but our offices are at Lawrence Berkeley Lab and the magazine was founded by Alan Meier, a lab scientist. People around here are saddened by the loss of Dr. Chu as director of the lab, but extremely excited about his nomination as Secretary of Energy. Dr. Chu believes in science and the important place of technology in helping us meet our energy goals and fight global warming—think cellulosic bio-fuels, nanotechnology, and yet undreamed of solutions to the present energy and environmental crisis.

Weatherization Works!

Word in energy efficiency circles is that the funding for Department of Energy (DOE’s) Weatherization Program will increase several-fold with President Obama’s proposed economic stimulus package. The Weatherization Program is managed state by state from money provided by DOE, and the funds pay to retrofit the homes of low-income families. Homes become healthier to live in, more energy efficient, and more comfortable for the occupants. For every one dollar the Weatherization Program spends, almost two dollars in energy savings results. Hundreds of thousands of homes have been retrofit so far, leaving about 99.5% of existing homes. Talk about green jobs potential! Many nonprofit and for profit organizations do weatherization work, and, basically, you retrofit the home of a low-income family the same way you retrofit a mansion. Lots more skilled people will be needed to do the work, and the jobs will provide a good income, benefits, and the possibility of future advancement. Community colleges, unions, professional training organizations, online trainers, and other players are gearing up to train the new green workforce.

How Many Btu Do You Do?

I promised in my last blog entry to explain the concept of heating-degree day and cooling-degree day. Sometimes you will hear that a home uses so many Btu or kWh per heating- or cooling-degree day, per square foot, per year. The degree days indicate the heating or cooling load on a building’s HVAC systems. A degree day is the rise or fall of one degree Fahrenheit for 24 hours. The rise or fall in temperature is measured from a baseline of 65F°. For example, if the average temperature tomorrow is 45F°, than the heating load on your heating system is 20 heating-degree days. If on a hot summer day the average temperature over a 24-hour period is 85F°, than the load on your air conditioner is 20 cooling-degree days. The number of heating-degree days for a winter in New York is around 5,000. Barrow, Alaska has about 20,000.

You can figure out how much energy you use to heat or cool your home by subtracting the baseline energy use. During a month when you are using neither your air conditioner or heater, such as in October or March (called the “shoulder” months), your gas and electric use represent your baseline. The baseline covers energy for lighting, appliances, hot water, and plug loads. Subtract out the baseline from your winter or summer energy use and you have the amount of energy to heat or cool your house. If you know the square footage of your home, and you have weather data for your area (go to www.degreeday.net to find out heating-degree days and cooling-degree days for your area), you are in a position to brag to your neighbors (or not) about your energy use.

At our house we used about 90 therms of natural gas from September 7 through December 7, 2008. There were about 480 heating-degree days (HDD) in our area during that time. Our baseline use of natural gas is about 10 therms per month, for heating water and cooking, leaving 60 therms for heating over the three-month period. Our house is about 1,200 square feet (ft²). Therefore, we used 60 therms/(480 HDD x 1,200 ft²), or about 0.0001 therms/HDD·ft². Since one therm of natural gas contains about 100,000 Btu of energy, that equals about 10 Btu/HDD·ft². That’s not bad, but not great either. How about you?

This former free living bacterium now supplies our cells
their energy.Current theories hold that life began on Earth around 3.5 billion years ago. About a billion years ago, a single celled beast engulfed and absorbed another single celled creature. We are all descended from that hijacking.

The hijacked cell has over time become the mitochondrion. This organelle is responsible for making our energy. But it still has the marks of having once been a free living bacterium.

First off, mitochondria still have remnants of their old DNA. There isn’t much there in human mitochondria but there is enough to still get us into trouble. A big part of aging might be due to damage to this mitochondrial DNA (mtDNA). Some genetic diseases are also caused by mutations in mtDNA.

The DNA in mitochondria is also much more like bacterial DNA compared to the rest of our DNA. In fact, the mitochondrion has its own bacteria-like machinery for reading its DNA. This means that mitochondria can’t read the genes in our nucleus and vice versa. Mitochondria are so similar to bacteria that some antibiotics can damage them too.

Even though it was once free living, the mitochondrion doesn’t have a lot of its original DNA left. Over time, most of our mitochondrion’s original genes have traveled to the nucleus. These genes now work in the nucleus to make most of a mitochondrion’s proteins which are then transported back to the mitochondrion.

After all these years, human mtDNA is now only around 16,000 bases long and has only 37 genes left. This is a far cry from even the simplest of bacteria, Mycoplasma genitalium, with its 582,970 bases and 521 genes.

Humans are not unique in having mitochondria. Every plant, animal, and fungus cell in the world that has been looked at has mitochondria. But the DNA in these mitochondria is all wildly different.

The size of mtDNA can range from just 6000 base pairs all the way up to 2 million base pairs. Sometimes the mtDNA is a circle like ours. Sometimes it is spread out over lots of little circles. Sometimes it is one long, linear piece of DNA. Sometimes it is lots and lots of little pieces of linear DNA. And sometimes it is too weird to describe in a short blog like this.

Mitochondria from different species also have different numbers of genes. Some species have mitochondria with nearly 100 genes. While others have as few as 5.

With up to 2000 mitochondria/cell, evolution has had a free hand in tinkering with mtDNA. If a mutation or change in mtDNA causes a problem, that mitochondrion simply goes away. If there is some advantage to the new DNA structure, it is free to sweep through and take over. It is amazing what evolution has done to this bacterium!

Of course, evolution has made the mitochondrion a shell of what it once was. But we could argue that it is one of the most successful beasts ever.

It has gone from humble bacterium to being part of every eukaryote in the world. If humans die out, mitochondria will still be around somewhere else. Mitochondria will outlive us all.

More information on mitochondrial genomes: http://dx.doi.org/10.1016/j.tig.2003.10.012

Terrestrial snow at Chabot on December 16, 2008
Photo by Craig CoryellDriving to work today, I was amused to notice that the raindrops falling on my windshield were a bit grainy–and getting more so the higher up the hill I drove. I starting to think, is it starting to sleet? By the time I reached Chabot–at 1500 feet elevation–the precipitation had turned to bona fide snow!

This is quite unusual for the Oakland Hills, of course. In the ten years I've worked here, this is the second, maybe third, dusting I've witnessed. I recall the great freeze of '74, when it actually snowed in Oakland close to sea level—that's the year all the eucalyptus in the hills froze and died.

My mind wandered—pretty far out in space (an occupational hazard at Chabot). I started thinking about all the recent news and discoveries from around the Solar System, my thoughts guided by the fat white flakes drifting down all around the observatory domes.

Last September, NASA's Mars Phoenix Lander detected snow falling high in the atmosphere–about 4 kilometers high. This Martian snow, however, quickly evaporated in Mars' thin, dry air, never reaching the ground. Phoenix used a laser probe to make the detection–so we don't actually have picture to look at!

Snows of the Solar System may also fall out of the plumes of "cryovolcanoes"–the frigid outer Solar System's version of volcanism (may it live long and prosper). On moons such as Saturn's Enceladus and Neptune's Triton, plumes of material have been detected spouting from fissures and cracks–probably fueled by heat generated by tidal forces from their parent planets.

On Enceladus, the geyser plumes contain water vapor and ice crystals, and are believed to come from subsurface lakes of "warm" water (32 degrees Fahrenheit–in other words, ice water… but that's a veritable hot spring, or magma chamber, on a cold moon like Enceladus!).

The ice crystals in the geysers' plumes mostly fall back to Enceladus–maybe in a diffuse fall of "snow" across the globe? I'm waiting for those pictures…

Saturn's large moon Titan is speculated to possibly have a form of cryvolcanism, though no direct detection has yet been made. Still, any water vapor that might erupt from a Titanian cryovolcano might be expected to fall in a form of snow….

Triton, much farther from the Sun than Saturn, is even colder than Enceladus. In fact, it's been called the coldest measured surface in the Solar System, at -391 degrees Fahrenheit. Here, nitrogen freezes solid. Triton cryovolcanoes, or geysers, may be partially solar-heated, but tidal heating within Triton is probably dominant. Triton's geysers spout nitrogen gas and dark material, which falls across the landscape in dark streaks and lighter deposits of frozen nitrogen–a form of extreme cryo-snow, to my imagination!

Now, are you as cold as I am just thinking about it? Time for a cup of cocoa…

By reporter Marjorie Sun.

I got interested in this story after hearing Silicon Valley venture capitalist Vinod Khosla speak at a conference this fall in Sausalito. He explained how he decides where to invest in green tech and it was fascinating. He and other top venture capitalists think they can help stop global warming and make a ton of money at the same time. You can listen to Khosla's talk on a webcast and listen to all sorts of entrepreneurs and v.c.'s talk about the latest renewable energy projects.

Khosla says to achieve a huge reduction in greenhouse gas emissions fast, we have to think about solutions that make big cuts in emissions and will be widely adopted. Buying a Prius is fine, he says, but it's really just "fashion." We need solutions that people in India and China will buy, Khosla says. To him, the key issues that guide his investments are cost, scale, and adoption. If a renewable solution isn't cheaper than coal, forget it, he says. Geothermal "is nice, but it doesn't scale."

Same with wind. It's "a great technology, but it's a toy." As for hydrogen fuel, the adoption risk is too high. Again, forget it, he says. The focus should be a war on coal, oil, and the manufacturing of cement and steel, which are huge emitters of carbon dioxide. (He's a major investor in Calera, an alternative cement maker in Silicon Valley.)

One more area for potentially huge gains is to improve energy efficiency, such as lighting. Another legendary venture capital company, Kleiner Perkins, is also racing to develop renewable energy solutions and make a fortune. (Khosla is a former partner there.) Kleiner's efforts were profiled in a cover story in The New York Times Sunday Magazine recently

With the Obama administration, it will be interesting to see what new federal policies– tax, economic and regulatory– will be adopted to accelerate solutions and spur more investment during a double whammy of crises: the economic meltdown and climate change.

Listen to the Building Blocks Go Green radio report online.

On the surface, geoengineering almost seems like science fiction. Could humans engineer a way to compensate for global warming by changing dynamics in the Earth's atmosphere? But it's one of the ideas being discussing at the American Geophysical Union conference in San Francisco. Each year, thousands of scientists descend on downtown San Francisco to hold a week of meetings and discussions.

Here's how the idea would work: Using planes or other high-altitude transport, we'd disburse millions of tons of sulfur dioxide (or hydrogen sulfide) into the stratosphere, 13 miles above the Earth. Those gases would create tiny particles, which would reflect sunlight. This process already goes on in the stratosphere - about a third of the energy from the sun is reflected back into space thanks to this dynamic. But by adding more reflecting particles, scientists think it might be possible to cool the planet - and compensate for human-induced warming.

No one has tried this idea yet - but it's something scientists have already observed — through volcanoes. In 1991, Mount Pinatubo erupted in the Philippines, spewing 20 million tons of sulfur dioxide into the atmosphere. As a result, global temperatures temporarily dropped about one degree Fahrenheit.

That doesn't necessarily mean a scheme like this would work. As UCLA Scientist Richard Turco said, it's not easy to predict how the particles would react and disburse. "If the particles are too large, that would actually create a warming effect, a greenhouse warming. Small particles are not useful because they don't reflect much radiation."

This plan isn't just a one time deal. As Turco continued, "we would need a huge monitoring system and can't afford to make any mistakes. Once you start this process, you have to maintain it for two to three centuries."

And then there's the "get out of jail free" aspect. If the focus of climate change policy becomes geoengineering, what happens to simply cutting emissions? As Professor Alan Robock of Rutgers University acknowledged, the costs and technology of geoengineering are uncertain — and it wouldn't curb other climate change impacts, like ocean acidification. "We have to focus on mitigation and keep this in our back pocket for emergencies."

According to Professor David Keith of the University of Calagry, it's worth studying geoengineering — just in case. Our greenhouse gas emissions will continue to grow. "We're not going to stop today, and even if we stopped today, there's enormous inertia," Keith said. In the event that climate change becomes catastrophic, Keith says we may need a last resort. "Whether you like or don't like this, it can be done quickly."

For more on what's new at the AGU, check out KQED's Climate Watch blog.

The pilot project at UC Berkeley called Mobile Millennium uses cell phones as data points to show traffic patterns in real time.

To become an early adopter of the technology, you must have an unlimited data plan on a mobile phone with a GPS system. If you have that, you can sign up here.

Project leader Alex Bayen says that it's not just a breakthrough in how we can gauge traffic, but also a scientific breakthrough – that is, it was a challenge to take random data points, some in motion, some not, and to turn them into usable traffic information. This is how Alex Bayen put it.

And he adds that, as cell phones get more memory and more devices on them, they will become more central in our lives.

The science of place-based reporting is a burgeoning field. A program at UCLA, for example, uses cell phone information to create a personal environmental risk assessment and a UC Berkeley study monitors currents in the Sacramento River.

Listen to the Dialing in on Traffic radio report online.

Watts in your kitchen?
Do you remember the last time you felt that the Federal Government was on your side? I know; it's been a while. One function of government, to protect consumers from fraudulent claims by manufacturers, may be making a comeback.

The U.S. Department of Energy (DOE), which develops product testing for the Energy Star program, recently reached an agreement with LG, one of the world's largest manufacturer's of appliances and consumer electronics, over some LG refrigerators that failed to live up to the Energy Star label.

DOE allows manufacturers to test their own products. Some LG refrigerators were tested with their icemakers turned off and earned the Energy Star label, meaning that they are among the most energy efficient refrigerators on the market. But consumers don't generally turn their icemakers off. The LG refrigerators in question, with French doors and through-the-wall ice and water dispensers, can use up to twice as much energy than is reported on the refrigerator labels.

If you own one of the notorious refrigerators–go to the LG special web site to find out–then LG will send someone out to make some modifications, and hand you a check to cover all the hidden energy charges for the life of the refrigerator. Home Energy's Senior Executive Editor Alan Meier estimates that LG will be spending around $150 million on home visits and energy rebates.

Is LG the only manufacturer to circumvent performance standards? Probably not, so we are watching the news for more DOE settlements.

Do you know how to spot hidden energy guzzlers in your house? If you get your gas and/or electricity from PG&E, you can compare your home energy use over time and spot those peaks and valleys that indicate something is wrong, or something is right. If your electric bills shoot up soon after buying a new refrigerator, TV, or other appliance, and it isn't due to a change in the weather, you can easily spot the culprit.

If you have an online account, login, click on the "Billing" link, and then click on "Usage History". What's really cool, at least for energy geeks like me, is that you can pull up graphs showing two years of electricity use, gas use, and electricity and gas charges. And you can pull up a graph that superimposes your gas and electricity use with a graph of "heating degree-days" and "cooling degree-days". The degree-days give you a snapshot of the load on your heating and air conditioning systems–more on that later.

Should their ACTN3 gene version exclude some of these folks
from marathons? Photo by Monica Darby.
Should I sign Johnny up for football or cross country running? Let me take a quick look at his ACTN3 gene to find out.

This scenario is not as far fetched as it sounds. A genetic test is available that claims to be able to help parents predict what sports their kids will be good at. The idea is that the parents can then funnel their kids into the sports at which they are most likely to succeed. How scary is that!

As I said, the test looks at the ACTN3 gene. Some work has been done that shows that elite athletes with one version are good at sports like football or sprinting. And that elite athletes with another version are good at sports like marathons.

But this gene is just one of many involved in determining how good someone will be at a certain sport. One of the key researchers who identified this gene has written that it can only really account for 2-3% of muscle variation in the general population. In other words, it is just one of many factors involved in making a star athlete.

So this genetic test might be able to distinguish an Olympic athlete from one who doesn't quite make the team. But how many kids does this really apply to?

Even if a genetic test could tell everything about a person's muscles, I would still think it is awful to restrict a child's choices of sports based on that sort of genetic test. Let me give you a hypothetical for why I find this sort of testing so troubling.

Imagine that instead of this test, there is a reliable one that will accurately predict someone's height*. Let's say a family has the test done on their son and they find that he will grow to be 5′3″.

The family steers the boy away from basketball because height is so important in that game. If this actually happened, then the NBA may never have had former pro Mugsy Bogues.

A genetic test that looks at a single trait to determine a person's future is dangerous. Should someone not be introduced into a sport because of their genes? Really?

A genetic test for height won't look at determination. Or speed or ball handling or all of the other traits that made Mugsy such a great player for 16 years.

And the ACTN3 gene test doesn't look at lots of other important traits too. In fact, it won't predict whether your child will be a super athlete or necessarily even good at football vs. a marathon.

Even if a test were developed that looked at all of these traits, should parents use it to control the sports their kids can play? What about their child's interests? Should Mugsy's parents have taken the basketball away from him even though he obviously loved the game?

Just let the kids play! Genes are not destiny.

*This sort of test is a long way off. Scientists only recently found the first "height" gene.