Welcome to The Deep science and technology column where we cover topics from the deep sea to deep space and beyond.
Although many of the files are bulging, this week’s column will be a little different. Many of you know that I’m the Star Lady at the UOG Planetarium and we’ve got something happening in the sky tonight that will be worth looking for. So we’ll talk a little about that first.
CHRISTMAS ORNAMENT RISING
We’ve got something interesting happening in the sky this evening and you certainly don’t need a telescope to see it. We’re having a total eclipse of the Moon. It’s being touted in the mainland US as the ‘solstice eclipse’ but it won’t happen on winter solstice for us as we celebrate winter solstice tomorrow at 9:39 a.m. More on the solstices and the strangeness of sunrise-sunset times here later.
A lunar eclipse occurs when the Earth, the Sun and the Moon line up exactly with the Earth in the middle. We don’t have a lunar eclipse at every full Moon and a solar eclipse at every new Moon because the Moon’s orbit is tilted about five degrees to the Earth’s orbit around the Sun. This means that typically the Moon passes either above or below the Earth’s shadow and doesn’t enter it.
But tonight the Moon will pass into the darker part of the Earth’s shadow and we’ll be having a total lunar eclipse. Now we all know that in a total solar eclipse that the Moon blocks the Sun’s light entirely and there is a brief period of darkness. But strangely enough, when there’s an eclipse of the Moon, you can still see the Moon, even though the Earth is between the Moon and the Sun.
The difference occurs because the Earth has air and the Moon doesn’t. The Earth’s air bends the Sun’s light around the Earth to shine on the Moon. Now, if you think about it, it’s always sunrise or sunset somewhere on the earth. That area is called the sunrise-sunset ring and it’s a permanent feature. Twice a day, your spinning spaceship rotates you through it.
The typical colors of a sunrise or a sunset are red or orange. That’s because the Earth’s air absorbs light and turns it to heat. When the Sun’s light is traveling through a lot of air as it does at the sunrise-sunset ring, more of the shorter wavelengths are absorbed and the light that emerges is red or orange.
So if the light that shines on the Moon passes through the sunrise-sunset ring, you’d expect the Moon to be red in color and in a typical lunar eclipse, that’s exactly what happens. The Moon is a lovely coppery red, the color of a sunset.
But how a lunar eclipse actually looks depends on something very important, the quality of the air you have to breathe. If the air is clean, the Moon is red. If the air is dirty, particularly at the higher altitudes, the Moon can be very dark. We had a lunar eclipse here on Guam shortly after the eruption of Mt. Pinatubo in 1991 and the Moon was so dark, you could barely see it unless you knew exactly where to look.
So what will the Moon look like tonight? Well, there are a couple more factors that make this eclipse unique. A typical total lunar eclipse lasts about four hours. The Moon orbits the Earth at 2300 mph, but the Earth is big and it takes a while for the Moon to transit through the Earth’s shadow.
And that’s what makes this eclipse unique. I tell my Planetarium patrons that actually watching a lunar eclipse is sort of like watching paint dry. In a ‘clean-air eclipse, there’s first a little color on the limb and the color can take up to an hour to transit across the Moon’s face. I usually tell people to make watching a lunar eclipse a “commercial eclipse”. In other words, watch TV and at every commercial go outside and see what’s happened to the Moon.
But tonight’s eclipse won’t be like that. When the Moon rises out of the eastern ocean tonight it will already be completely eclipsed. This eclipse starts at 4:30 this afternoon and totality begins at 5:47 p.m. Moonrise begins at 5:55 p.m. and sunset will be at 5:59 p.m. This means that if this is a typical eclipse, the Moon will rise from the eastern ocean and it will be a beautiful red Christmas ornament.
Maximum eclipse will be at 6:17 p.m. and totality will end at 6:42 p.m. The whole show will be over at 8:01 p.m. So, what will this eclipse look like? Well, we have had a few volcanic eruptions in our area recently and there’s really no telling how dark the Moon will be. You just need to go out and have a look for yourself. Here’s hoping it won’t be totally overcast!!
THE LONGEST NIGHT?
So I mentioned earlier in the article that they’re calling this the solstice eclipse in the states because it happens on the 21st of December, which is winter solstice for them. Since we’re where America’s Day Begins, solstice doesn’t happen for us until tomorrow. And of course, winter solstice is the shortest day of the year, right? Well, yes and no.
Here on Guam, we’re so close to the equator that the Sun’s angle doesn’t change much and it’s the angle of the Sun that affects the number of hours it spends above the horizon. The Sun actually started setting later last month, but it will continue to rise later here on Guam until the end of January. The longest day in December was on the first when we had 11 hours and 24 minutes of daylight. The shortest day contains 11 hours and 20 minutes of daylight, only four minutes less than December’s longest day.
So what day is the shortest day? This year it’s really strange. I’m used to all the even numbered days or all the odd numbered days being the ‘shortest day’ but this year, the 15th, the 17th and the 19th last week were all 11 hours and 20 minutes long. And this week, every day from Monday the 20th to Christmas Day on Saturday, they’re all 11 hours and 20 minutes long as is the 27th. All the rest of the days next week are 11 hours and 21 minutes long.
I think it’s pretty safe to say that here on Guam, we don’t have a shortest day, we have a shortest month. Of course, 11 hours and 20 minutes of daylight is a vast improvement over the 8 hours and 20 minutes of daylight they’ll have in Seattle on Wednesday! So use our long December nights to do a little Moon and star gazing and don’t forget to watch the lunar eclipse tonight!
And now for a little story about a subject that all of us are interested in at this time of year!
HOW HE REALLY DOES IT!
Santa skeptics have long considered St. Nick’s ability to deliver toys to the world’s good girls and boys on Christmas Eve a scientific impossibility. But new research shows that Santa is able to make his appointed rounds through the pioneering use of cutting-edge science and technology.
"Santa is using technologies that we are not yet able to recreate in our own labs," explains North Carolina State University’s Dr. Larry Silverberg, a professor of mechanical and aerospace engineering who just completed a six month visiting-scholar program at Santa’s Workshop-North Pole Labs (SW-NPL). "As the first scholar to participate in the SW-NPL program, I learned that we have a long way to go to catch up with Santa in fields ranging from aerodynamics and thermodynamics to materials science."
For example, Silverberg says that Santa’s sleigh is far more advanced than any modern form of air transportation. "The truss of the sleigh, including the runners, are made of a honeycombed titanium alloy that is very lightweight and 10 to 20 times stronger than anything we can make today," Silverberg says.
The sleigh is also equipped with state of the art electronics, including laser sensors that can detect upcoming thermals and wind conditions to find the optimal path. The focus on efficiency and a smooth ride has also led to the development of a nanostructured "skin" for the sleigh that is porous and contains its own low-pressure system, which holds the air flowing around the airborne sled onto the body, reducing drag by as much as 90 percent.
A key finding from Silverberg’s visit to the North Pole is that Santa uses a reversible thermodynamic processor — a sort of nano-toymaker known as the "magic sack" — that creates toys for good girls and boys on site, significantly cutting down on the overall weight of the sleigh. The magic sack uses carbon-based soot from chimneys, together with other local materials, to make the toys. The magic sack works by applying high-precision electromagnetic fields to reverse thermodynamic processes previously thought to be irreversible.
The sleigh is driven by Santa’s well-known team of reindeer, which is equipped with side-mounted jetpacks. The reindeer and jetpacks, which are powered by cold fusion, "are arrayed in such a way as to create a stable reindeer-sleigh system," Silverberg says. "The sleigh’s reins are used to not only direct the heads of the reindeer, but to direct the orientation of the jetpacks for precision flight."
Silverberg explains that the sleigh is also equipped to make use of so-called "relativity clouds" to help ensure Santa and his reindeer can travel approximately 200 million square miles, making stops in some 80 million homes, in one night. "Based on his advanced knowledge of the theory of relativity, Santa recognizes that time can be stretched like a rubber band, space can be squeezed like an orange and light can be bent," Silverberg says. "Relativity clouds are controllable domains — rips in time — that allow him months to deliver presents while only a few minutes pass on Earth. The presents are truly delivered in a wink of an eye."
Silverberg says the experience was "an eye-opener. I appreciate the opportunity Santa has given me to visit his sleighport and work alongside the elves at SW-NPL. It was a unique learning experience and a tremendous honor." He notes that the principles of cold fusion are still a closely guarded secret.
I hope you enjoyed our excursions into fact and fantasy. MERRY CHRISTMAS to all!!