I’ve Been Thunderstruck

In magical lore and mysticism, all numbers are ascribed certain properties and energies. Seven is a number of great power, a magical number, a lucky number, a number of psychic and mystical powers, of secrecy and the search for inner truth. The origin of belief in seven’s powers lies in the lunar cycle. Each of the moon’s four phases lasts about seven days. The Summerians, who based their calendar on the moon, gave the week seven days and declared the seventh and last day of each week to be uncanny. Life cycles on Earth also have phases demarcated by seven, there are said to be seven years to each stage of human growth, and there are seven colors to the rainbow, seven notes in the musical scale, seven petitions to the Lord’s Prayer, and seven deadly sins. The seventh son of a seventh son is said to be born with formidable magical and psychic powers. The number seven is widely held to be a lucky number, especially in matters of love and money.

[Source : The Handy Science Answer Book]

Want to go somewhere in North America and weigh less than you do at home? Head over to the Hudson Bay area region of Canada, and, due to lower levels of gravity that has stumped scientists for over 40 years, you’ll actually weigh less than at home! The reason is that weight is a product of mass times gravity. If your mass remains the same, but the effect of gravity decreases, you’ll produce less of a force on the scale, and thus will weigh less. Similar to what would happen if you weighed yourself on the moon!

The mystery started in the 1960’s when a detailed study of the earth’s gravity fields were being charted. It was noted that gravity levels in the Hudson Bay region were less than at other places on the earth. Two theories about what’s going on have been postulated, and are reported in this article at howstuffworks.com :

One theory centers on a process known as convection occurring in the Earth’s mantle. The mantle is a layer of molten rock called magma and exists between 60 and 124 miles (100 to 200 km) below the surface of the Earth . Magma is extremely hot and constantly whirling and shifting, rising and falling, to create convection currents. Convection drags the Earth’s continental plates down, which decreases the mass in that area and decreases the gravity.

A new theory to account for the Hudson Bay area’s missing gravity concerns the Laurentide Ice Sheet, which covered much of present-day Canada and the northern United States. This ice sheet was almost 2 miles (3.2 km) thick in most sections, and in two areas of Hudson Bay, it was 2.3 miles (3.7 km) thick. It was also very heavy and weighed down the Earth. Over a period of 10,000 years, the Laurentide Ice Sheet melted, finally disappearing 10,000 years ago. It left a deep indentation in the Earth.

The second theory is particularly amazing. What it suggests is that the ice sheets that occupied the area so long ago were actually so heavy that they depressed the earth itself, effectively reducing the mass of the earth in those areas. Less mass means less gravity. It turns out that both of the theories are correct, and are both explained in more depth in the article, which I encourage you to read.

The Hudson Bay area is going to have less gravity for a long time. It’s estimated that the Earth has to rebound more than 650 feet to get back to its original position, which should take about 5,000 years. But the rebound effect is still visible. Although sea levels are rising around the world, the sea level along Hudson Bay’s coast is dropping as the land continues to recover from the weight of the Laurentide Ice Sheet.

So, if you have a weigh in that you need to weigh a specific weight at, head over to the Hudson Bay region and get weighed in there. But hurry, you only have about 5,000 years until gravity levels return to normal!

I was doing some research today to come up with a new post, and came across this article that has a long list of strange facts about the moon. Here is a sample:

1. Water Vapor: On March 7, 1971, lunar instruments placed by the astronauts recorded a vapor cloud of water passing across the surface of the moon. The cloud lasted 14 hours and covered an area of about 100 square miles.
2. Magnetic Rocks: Moon rocks were magnetized. This is odd because there is no magnetic field on the moon itself. This could not have originated from a “close call” with Earth—such an encounter would have ripped the moon apart.
3. No Volcanoes: Some of the moon’s craters originated internally, yet there is no indication that the moon was ever hot enough to produce volcanic eruptions.
4. Moon’s Age: The moon is far older than previously expected. Maybe even older than the Earth or the Sun. The oldest age for the Earth is estimated to be 4.6 billion years old; moon rocks were dated at 5.3 billion years old, and the dust upon which they were resting was at least another billion years older.

There are quite a few more interesting facts about that lunar landscape we see almost every night. Give the article a read and you might find something interesting to share at your next party!

If you have a few extra moments, check out the root web site where these facts came from…Informant News. I’m sure the articles here will lead to quite a few more blog posts!

Reading through the September 2006 issue of Astronomy magazine recently, I came across a two-page spread discussing the speeds of objects in space. Here’s a little list I’ve put together for your consideration:

1. Person (brisk walk) : 4 mph
2. Automobile (interstate speed) : 65 mph
3. Commercial Jet (cruising speed) : 600 mph
4. Venus Rotational Speed : 4.1 mph
5. Mercury Rotational Speed : 6.8 mph
6. Pluto Rotational Speed : 30.4 mph
7. Earth Rotational Speed : 1,040 mph
8. Sun Rotational Speed : 2,231 mph
9. Neptune Rotational Speed : 6,001 mph
10. Saturn Rotational Speed : 22,994 mph

Some things that strike me as amazing here : Venus’ rotational speed is so slow that you could run around the circumference of Venus before it has a chance to make one full rotation; Saturn is rotating on its axis at a very, very fast pace! I wonder what it would be like to be on the surface of Saturn as it whips around so quickly…is that what accounts for the nasty storms on the surface?

In the big scheme of things these don’t amount to much, but I thought them amazing just the same. We, or at least me, tend to take think in terms of the Earth so often. But, the fact is, there is quite a bit of disparity out in space!

Wrapping up my series of posts about the moon, here are ten things you probably didn’t know about the round orb that we only notice at night:

1. When Neil Armstrong took that historical step of “one small step for man one giant step for mankind” it would not have occurred to anyone that the step he took in the dust of the moon was there to stay. It will be there for at least 10 million years.
2. In a survey conducted in 1988, 13% of those surveyed believe that the moon is made of cheese.
3. How close can you get without completely running out of gas? Apollo 11 had only 20 seconds of fuel left when they landed on the moon.
4. In China, the dark shadows that are on the moon are called “the toad in the moon”.
5. The moon is not a planet, but a satellite of the Earth.
6. The moon rotates at 10 miles per hour compared to the earth’s rotation of 1000 miles per hour.
7. One side of the moon is always facing the Earth.
8. The moon is the only extraterrestrial body that has ever been visited by humans it is also the only body that had samples taken from it.
9. The moon has no global magnetic field.
10. On the moon, there is no wind or water.

These facts, and more, can be found at MoonConnection.com.

Following up on my post from the other day, where I talked about mirrors left on the moon for earth-based experiments, it seems that’s not the only thing that has been left on the moon through the years of our interaction with it. For example, if you landed in the Sea of Tranquility right now, you’d find:

1. Apollo 11 Lunar Module Descent Stage
2. Neil Armstrong’s Apollo Space Boots, Model A7L
3. Empty Food Bags
4. Tongs
5. Bulk Sample Scoop
6. Camera (Hasselblad El Data)
7. Medals Commemorating Two Dead Cosmonauts
8. Film Magazines
9. Food Assembly, LM (4 man days)
10. Urine collection assembly, large
11. Bag, Emisis
12. Footprint

This is just a small list of the items that are currently on the moon, awaiting pickup by a 21st century garbage truck! I can understand the reason those items needed to be left behind, lest the space capsule weigh too much to escape the moon’s gravity, but it sure seems a shame that we leave junk on the place outside of the earth we visit!

A more complete list of junk on the moon can be at the Lunar Legacy Project.