QUESTION YOUR WORLD - How long is a light year?

So, how long is a light year...short answer: Long!!! long answer: about 5.9 trillion miles!!! That's how quickly light can traverse across space. So if you wanted to walk the distance of a light year you would need to be marching on your feet for about 168 million years!! For you to arrive at this moment, you would have had to start walking from the time when dinosaurs ruled the earth! Whew...better pack a few lunches for the calories you would have been using up! The speed at which light travels is still the fastest known speed in our universe.

On a related note, there sure are a lot of movies that make reference to this amazingly fast speed. Warp speed, Hyperspace, and Ludicrous speed are all references to the fastest known speed that we humans have been able to identify!

Check out more info on light year and big stellar distances here: Distance!


Also, Cool Cosmos has some pretty cool info about some of these huge distances and times!

Question Your World - How often does it thunder??

Thunder!! by ScienceMuseumofVA

How often does thunder happen on Earth?

A LOT!! 2,000 times per minute!! Also impressive is the amount of lightning that strikes the Earth every minute. 6,000 lightning strikes per minute! These bright flashes and loud rumbles of thunder are scary to some, but rain fall is a vital part of what makes Earth such a wonderful place for us to live on.

Here's an idea. Instead of being startled by the next thunder rumble you hear, you can use it to do a mini weather forecast.
Once you see lightning, just count the amount of seconds before you hear thunder. Then divide that number by 5.

Example:
(seconds between the lightning flash and hearing thunder) 10/ 5 = 2
The storm is 2 miles away from you!
That's enough time to grab an umbrella!

Thunder is pretty impressive stuff.

Question of the Week

In the wake of the devastating earthquake in Japan, tsunamis are on people's minds.  How much do you know about them? 

Take this brief tsunami quiz and find out:

1.  Name 4 geologic events that might cause a tsunami.

2.  Tsunamis are also called wave trains because they are a series of waves, not just one wave.  How far apart in time can they be?

3.  In deep ocean water, how fast can a tsunami travel?

4.  Suppose you are in a boat in the middle of the ocean and a tsunami approaches.  What would happen?

5.  What happens when the tsunami approaches land?

6.  Has Virginia ever experienced a devastating tsunami?

Answers:
1.  Tsunamis may be caused by earthquakes, landslides, volcanic eruptions or a meteor impact in the ocean.
2.  Tsunami waves can be as far as one hour apart.
3.  In deep ocean water, tsunamis can travel as fast as 500 miles per hour (800 kilometers per hour), as fast as a commercial jet.
4.  Not much.  In the open ocean, tsunamis are often less than a foot tall.  You probably wouldn't notice its passage.
5.  As a tsunami approaches land, the depth of the water decreases causing the bottom of the wave to slow while the top continues at the same speed.  The sea then begins to rise, either as a giant wave or as a rapidly rising tide.
6.  Yes, a meteor struck at the current mouth of the Chesapeake Bay about 35 million years ago, causing a huge tsunami which may have flowed over the Blue Ridge Mountains.

Question of the Week

Today in Richmond, we are experiencing a messy and somewhat hazardous mix of snow, sleet and freezing rain. 

Do you know what atmospheric conditions cause each kind of frozen precipitation?



Answer:  Winter precipitation types generally depend on the vertical temperature profile of the atmosphere.

• Snow falls when the temperature of the entire depth of the atmosphere from the cloud to the ground is below freezing (32 F or 0 C).
• Sleet falls when there is a fairly shallow layer of warmer air (above freezing) between the cloud and the ground but the temperature at the ground is below freezing.  Snow falls from the cloud, then partially melts in the warmer layer and then refreezes in the colder layer near the surface, forming pellets of ice.
• Freezing rain falls when there is a deep layer of warmer air (above freezing) but the temperature is below freezing at the ground.  Snow falls from the cloud, melts completely in the warm layer and then refreezes either just before hitting the ground or on contact with the cold surface.

Odd Science 2010

Besides highly publicized science stories of 2010 (Gulf oil spill, Chilean miner rescue, bedbugs, etc.), there were some intriguing and somewhat odd science stories:

1. You think like a worm – The human brain’s center of deep thought is curiously similar to a clump of neurons inside the head of the lowly ragworm. So similar, in fact, that ragworms, which evolved 600 million years ago, probably share a common ancestor with us humans. Hmmm…

2. The shrinking moon – Lunar geologists have found cliff-like scarps on the moon that they believe formed as the moon lost heat and contracted. But don’t panic – the moon’s radius has only shrunk a few hundred feet in the last billion years. Considering its small size, though (its diameter is less than the distance from Washington, DC to San Francisco), let’s hope it doesn’t shrink too much more…

3. Dinosaurs in color – Sinosauropteryx, a chicken-size dinosaur, and was covered with spiny hair, ate meat and walked on its hind legs. Scientists examining the hair bristles under a powerful microscope discovered its tail contained melanosomes, color-bearing cell parts found in modern birds. And what color was it? Sinosauropteryx sported a chestnut and white striped tail! Cool!

4. Bowerbirds exaggerate – Male bowerbirds lure their mates with large collections of stones, shells, bones and other trinkets, even some man-made ones. Their display is usually arranged from largest to smallest, creating an optical illusion. As the female approaches, the display area appears smaller, making the male in the center appear bigger. Clever guy!

5. Rubik’s Cube decoded – Have you ever tried to solve a Rubik’s Cube? How many moves did it take you? Mathematicians have discovered that out of the 43,252,003,274,489,856,000 possible starting positions, you should never have to make more than 20 moves to solve the puzzle. Can you do it?

These 5 are just a taste; Discover magazine's current issue includes the 100 Top Stories of 2010.

http://discovermagazine.com/photos/100-top-science-stories-of-2010

Is It Winter Yet? Maybe, Maybe Not…

Snow frozen onto a tree in Germany.
Photo courtesy of Wikipedia

Tuesday, December 21, is the Winter Solstice and usually considered the first day of winter. However, meteorological winter is already here! So what’s the deal? Well, the definition of winter depends on whom you ask.

A meteorologist defines winter as the three coldest months of the year: December, January and February. An astronomer defines winter as the three months between the Winter Solstice (December 21 or 22) and the Spring or Vernal Equinox (March 20 or 21). What’s the difference?

The definition of meteorological winter is fairly straightforward. Climatologically-speaking, the three coldest months of the year are December, January and February in the Northern Hemisphere. Therefore, meteorological winter begins on December 1 and ends on February 28 (or 29). In the Southern Hemisphere, the seasons are reversed, meaning if you lived in Rio or Buenos Aires, summer would begin in December and winter would begin in June.

Astronomical winter begins on the Winter Solstice, the shortest day of the year. The Earth has seasons and variable daylight hours because its axis is tilted 23.5° relative to its orbit around the sun. Winter in the Northern Hemisphere occurs when the northern half of the planet is tilted away from the sun. This tilt causes sun’s energy to be weaker on the Earth’s surface because:

• The sun shines on the Earth’s surface at an oblique angle.
• The sun’s energy is spread out over a larger area, diluting its strength. 
• The sun’s rays travel through more atmosphere before they reach the surface. 
• Days are shorter so there is less time for the sun to heat the surface. 

Less energy from the sun on the Earth’s surface means colder temperatures in the atmosphere – so winter arrives. For more information, check out last year’s blog about the Winter Solstice: http://sciencemuseumofvirginia.blogspot.com/2009/12/winter-solstice.html

Here are some questions for you to ponder:

• If the Earth’s axis had no tilt, would we have seasons? 
• If the tilt was at a greater angle, what would our seasons be like? 
• Do you think other planets in the solar system have seasons too? 
• How did Earth’s axis get tilted in the first place?

Question of the Week

It's snowing!  Snow showers are also predicted for Thursday and a winter storm might hit us this weekend.  Remember last December? 

Now for the Question of the Week:
What is the percent chance of a white Christmas in Richmond (in any given year)?

Answer:  In Richmond, there is a less than 10% chance that measurable snow will fall on Christmas Day.  There's about a 13% chance that at least a trace of snow will be on the ground and about a 7% chance that at least 1" will be on the ground.

Several inches of snow are predicted for today (Thursday, December 16), and a coastal storm this weekend has a 50-50 chance of bringing us more snow.  Will we see snow on the ground for Christmas?  We might...

Remember Hurricane Andrew?

As Hurricane Danielle churns far out in the Atlantic, I am reminded of another hurricane that made landfall on this day…

On August 24, 1992, a small but extremely intense Hurricane Andrew slammed into South Florida. Andrew made landfall as a Category 5 hurricane, the 3rd most intense landfalling US hurricane and the 1st in total estimated US property damage at the time. (Katrina eclipsed it in both intensity and damage in 2005.) Andrew hit the highly populated Miami area after a 27-year lull in hurricane activity in the Atlantic basin. During the period between 1965 and 1992, only 2 hurricanes of any significance made landfall in Florida, both in the panhandle. At the same time, the coast around Miami had experienced unprecedented development, populated largely by residents from the Northeast who had no experience with Florida’s history of violent hurricanes. As a result, South Florida was devastated. Damage was extensive, estimated at about $30 billion. Fifteen people lost their lives directly due to the hurricane and another 25 by more indirect means.

Yes, hurricanes can be devastating and deadly; however, I have always been fascinated by them. (I confess - I am a weather nut.) Don’t get me wrong – I do not want them to come ashore and destroy homes and lives; however, watching them develop from a messy disorganized cluster of clouds into a perfect spiral inspires me to wonder at the beauty and power of nature. But I do prefer that all this beauty and power stay well off-shore…

Happy Birthday, Voyager 2!

For an incredible 33 years, Voyager 2 has been our eyes of discovery in the outer solar system and beyond. This venerable spacecraft has been in continuous operation more than 12,000 days, sending us compelling photos and information about the gas giants of the solar system: Jupiter, Saturn, Uranus and Neptune. Now headed into interstellar space beyond the solar system, the spacecraft is still transmitting invaluable data about the solar wind and deep space beyond the planets.

On August 20, 1977, Voyager 2 blasted off from Cape Canaveral, FL on a mission to the giant planets of the solar system. Its sister spacecraft, Voyager 1, was launched a few days later on September 5. Both original missions were intended to study just Jupiter and Saturn. However, both continued sending data beyond those planets, and thanks to these intrepid spacecraft, we have now had a close encounter with every planet in the solar system. (Pluto is now called a “plutoid” and is no longer considered a planet.)

(Just think, the computers on these spacecraft were made in the 1970’s and they are still working! Pretty remarkable, huh?)

Here are a few fast facts about the Voyager mission:

• Explored all giant planets of the outer solar system
• Explored their 48 moons and unique ring systems
• Closest approach to Jupiter - 1979
• Closest approach to Saturn - 1980 (Voyager 1); 1981 (Voyager 2)
• Closest approach to Uranus – 1986 (Voyager 2)
• Closest approach to Neptune – 1989 (Voyager 2)
• Carry a golden record with a greeting from Earth
• Now the most distant human-made object in space (Voyager 1)
• Distance from sun - 17 billion km (Voyager 1); 14 billion km (Voyager 2)
• Signal from Earth takes over 12 hours to reach spacecraft
• Crossed termination shock, where solar wind slows abruptly, in 2004 (Voyager 1); 2007 (Voyager 2)
• May have reached or will soon reach Heliopause or entry into interstellar space
• Currently, 5 teams investigating: Magnetic fields, Low energy charged particles, Cosmic rays, Plasma (Voyager 2), Plasma waves
• May continue to operate and send data until around 2020

Long-lived Voyager has been documented often in fiction and pop culture (remember “V’ger” in the Star Trek movie?). So Happy Birthday, Voyager! May you live long and prosper!

East Coasters Roasted by Heat Wave

By Ben Remo

Science Museum of Virginia intern

Residents of the east coast may have noticed an increase in heat lately. This increase has led to scorching temperatures of over 100 degrees. Most might be asking, how can this possibly happen? Why should we be subjected to such a hot summer? These dangerous, record breaking temperatures are caused by a heat wave currently hovering along the Atlantic coast. Last week, the northeast region experienced the worst heat wave in years.
At times temperatures have been above 100 degrees in some areas. New York City has opened over 100 cooling centers around the city providing relief from the heat for those who do not have access to air conditioning. Here in Central Virginia we have been subjected to temperatures around 100 degrees for days at a time.

How Heat Waves Work
Heat waves occur when temperatures are 10 degrees or above the normal averages in a region for a substantial period of time.
Ironically, heat waves do not mean that the earth is closer to the sun, a common misconception. According to National Geographic News, the week after 4th of July weekend, the earth was farther away from the sun than it will be at any other time this year. This is because the distance between us and the nearest star has little to do with the surface temperature here on earth.
The tilt of the earth on its axis has more to do with the occurrence of a heat wave. This is what makes for seasonal change. It is currently summer in the Northern Hemisphere because we are pointed towards the sun on the axis.
The formation of heat waves can be attributed to ridges of high pressure in the atmosphere that hang around the sky for some period of time. These ridges make the air hot and move clouds away, making the surface hotter. Clouds are a lot like oven mitts for the earth’s surface. The clouds act as a buffer between the surface and the sun just like oven mitts are a buffer between our hands and a hot object in the kitchen. When those “oven mitts” are not around, it makes for some hot days.

How to Stay Cool
OK. We know what causes heat waves; the next step is learning how to stay cool in the middle of one.
First, dress appropriately for the heat. With work that may be easier said than done. But on the weekends or after work, try to wear open toed shoes (no socks!) and loose, breathable clothes. When running the air conditioner, turn on all the fans in the house. It helps the cool air spread throughout the house. Next, go to the local pool or water park. While keeping you cool, a day at the pool is also good family fun. Drink cold water to stay hydrated. If you’re hydrated, you’re cool. Lastly, according to http://www.greenlivingonline.com/ ingredients in spicy foods actually cool you down after awhile. Add a marginal amount of peppers to any meal to cool you down on a hot day.

Global Warming?
Can a heat wave be attributed to global warming? That’s a sticky question. Global warming is climate; a heat wave is weather. The basic difference is time. Climate is long-term averages of weather, while weather is what’s outside right now. Some scientists believe global warming will change prevailing weather patterns to cause events such as heat waves, stronger hurricanes and even an extra snowy winter like the one just past. So the answer is maybe and maybe not. Scientists are studying both climate and weather trying to find answers. In the meantime, stay cool!

The Chesapeake Bay “Ouch” Forecast

Have you met Chrysaora quinquecirrha? If you’ve spent time in the Chesapeake Bay in the summertime, you probably have. His more familiar name is sea nettle, and he is not one of the most pleasant fellows you will ever meet. The sea nettle is a large sea jelly, a semi-transparent bell-shaped invertebrate with long stinging tentacles. Chrysaora quinquecirrha lives along the Atlantic Coast south of Cape Cod. Like many of us, he loves the Chesapeake Bay and its tributaries and can be seen in greater abundance here than anywhere else on the East Coast.
Getting tangled up with a sea nettle is not a fun experience. Those long tentacles contain thousands of microscopic nematocysts; upon contact the nematocysts fire a stinging filament into the victim. Sea nettle stings are not fatal but do cause a burning sensation and a painful rash. People often carry a bottle of meat tenderizer in their beach bags to counteract the sting, but plain vinegar works just as well. Vinegar prevents unfired nematocysts from firing thus preventing further discomfort.
Want to know how to avoid this unpleasant fellow? This summer NOAA is experimenting with sea nettle forecasting. Their website (http://chesapeakebay.noaa.gov/forecasting-sea-nettles) includes a map predicting the probability of encountering one, based primarily on water temperature and salinity. Sea nettles prefer water temperatures between 25° and 30°C (77° - 86°F) and salinity between 10 and 20 parts per thousand. Unfortunately for those of us who love it, the Chesapeake Bay is an ideal sea nettle habitat. So next time you head to the bay or the “Rivah” to swim or water ski, check out NOAA’s sea nettle prediction map. That way, you will know whether or not to pack the meat tenderizer.

Could the oil spill reach Virginia?

As officials make another attempt to cap the well spilling oil into the Gulf of Mexico, Virginians might be asking, “Could oil show up here?” As of now, it appears a large oil slick on Virginia waterways is unlikely, but oil residue in the form of tar balls could wash up on local beaches. How could oil that’s currently in the Gulf of Mexico end up in Virginia?
The Earth’s oceans are always on the move, their motion influenced by atmospheric circulation patterns, water temperature and salinity, ocean floor topography, and the Earth’s rotation. These ocean currents can occur both at the surface and deep in the ocean; they often travel great distances and have an enormous effect on regional climates.
As far as the oil spill goes, the Loop Current is the first culprit that could carry oil toward the East Coast. This current flows north between the Yucatan Peninsula and Cuba into the Gulf of Mexico, loops east and then south along the west coast of Florida. The Florida Current would take up where the Loop Current left off, carrying the oil around Florida. Then the Gulf Stream would take over and carry it up the southeast coast.
The Gulf Stream is an enormous river of warm water averaging 60 miles in width and 3000 feet in depth. At Cape Hatteras, the current’s flow rate is an incredible 85 million cubic meters per second, equivalent to over 1 billion fire hoses! (By comparison, the Mississippi River moves water at roughly 0.6 million cubic meters per second.) A major influence on East Coast weather, the Gulf Stream sometimes breeds Nor’easters in the winter and intensifies hurricanes in the summer, as happened with Hurricane Hugo off the coast of South Carolina in 1989.
At present, disruptions in the Loop Current appear to be keeping oil away from Florida and the Gulf Stream. Eddies often form and then break off from the main body of the current; the majority of the oil that had drifted into the Loop Current in recent weeks appears to be caught in an eddy and cut off from the main body of the current. Satellite pictures even suggest that the current itself may soon sever entirely, lessening the imminent threat of oil coming ashore in Florida and beyond.
This afternoon BP began an attempt to plug the leak with a method called top kill, an ambitious procedure intended to clog the well with thousands of pounds of heavy fluids pumped through extremely long pipes. This procedure has never been attempted so far beneath the surface; it could take several days to determine if it was successful. For everyone’s sake, let’s hope they succeed.

Satellite image courtesy of NASA. Colors indicate water temperature: darker colors = cooler temperatures, lighter colors = warmer temperatures.

Eyjafjallajökull: “the little volcano that could”

Eyjafjallajökull? Can you pronounce it? Apparently, it’s: “AY-uh-fyat-luh-YOE-kuutl(-uh).” If that helps, good for you! Even after hearing an Iceland native pronounce it, I still can’t manage to wrap my tongue around that many syllables.
First, a little geography – Iceland, sometimes called the land of fire and ice, is an island in the North Atlantic Ocean between Greenland and northern Europe. It’s about the size of Virginia with a population slightly less than that of Virginia Beach. At 65°N latitude, the subpolar climate would be brutally cold if the Gulf Stream ocean current did not moderate temperatures somewhat; Iceland's average July high is around 57°F and its average January high is around 34°F.
So why does Iceland have so many active volcanoes? Two factors. First, the island is bisected by the Mid-Atlantic Ridge, the boundary between the North American plate and the Eurasian plate. The two plates diverge along this boundary, forming new crust along the ridge; therefore, Iceland is continually getting bigger. In addition, geologists believe Iceland is over a hot spot, an area of rising lava below the earth’s crust. Hot spots often breed volcanoes and sometimes new islands; the islands of Hawaii were formed over a hot spot in the Pacific. However, the Hawaiian Islands are in the middle of a drifting tectonic plate, rather than between plates, so an island in the Hawaiian chain will eventually drift away from the hot spot and a new island will begin to form over the hot spot. As long as Iceland straddles the mid-ocean ridge and the hot spot remains under the ridge, Iceland will remain one of the most active volcanic regions on earth.
Eyjafjallajökull may have cooled slightly, but today’s strong tremors indicate that the eruption is not over yet. Also scientists are concerned that Katla, a much bigger and more active volcano, may erupt next. Past evidence indicates that when Eyjafjallajökull erupts, Katla follows. Katla’s eruption could be much more explosive, and Katla is overdue. Explosive eruptions often send ash and other matter into the upper atmosphere where they stay for long periods often causing dramatic global climate change.
Now that Eyjafjallajökull has calmed somewhat, we can take a look at the impact and subsequent ripple effect this eruption caused around the globe. The most obvious: Eyjafjallajökull’s ash cloud grounded planes all over Europe, inconveniencing travelers who were stranded in airports for days and costing the airline industry over $1 billion in lost revenue. In addition, the eruption affected the economy and citizens of countries near and not-so-near the island of Iceland.
Kenya - thousands of laborers are out of work; flowers and produce cannot be shipped to Europe. 10 million flowers, mostly roses, have been thrown away.
Ghana – pineapple and pawpaw farmers’ incomes are suffering due to lack of refrigeration at Ghana’s capital airport.
Japan – Nissan stopped production at two of its plants on Wednesday because they ran out of tire pressure sensors due in from Ireland.
Australia – a family from Britain saved for two years to make a trip to Australia, then the hotel more than doubled the rates (because they could). The frustrated family moved to a hostel.
Iraq and Afghanistan – medical evacuation flights are taking up to 8 hours longer than usual because they cannot fly back to the US out of Germany but instead must fly out of Spain.
United States – the airline slowdown cost the US economy $650 million and affected about 6000 American jobs. BMW reduced production at its Spartanburg, SC plant due to lack of supplies from Germany. Brides in New York had no Dutch flowers (tulips, peonies, or daffodils) for their weddings. Marathoner David Gray missed his second consecutive Boston marathon while stuck in a hotel in Brussels (the first was due to injury).
If Katla erupts, the impacts could be even greater…

Thanks to CBS News for the international anecdotes and to the Associated Press for the photo.
For more info, go to http://www.guardian.co.uk/environment/blog/2010/apr/20/iceland-volcano-your-questions-answered
And for great volcano pix, go to - http://www.boston.com/bigpicture/2010/04/icelands_disruptive_volcano.html