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Bombs Bursting In Air...... Fireworks Photography

As I mentioned in a previous post, I have been trying new and different photo techniques.  And with the 4th of July upon us, I decided to give fireworks photography a whirl.  For those of you who don't know, I'm an avid amateur photographer with an eye on commercial photography someday.  My equipment is a step above point-and-shoot but is definitely not the stuff used by true professional photographers.  But I do the best I can with what I've got.

I was planning on going to our county park to shoot the fireworks display, but at the last minute wangled an invite to a party being held about a quarter mile away from the park.  This was great.  In addition to the food and beer, I was far enough away to be able to comfortably photograph the fireworks.  Any closer and I would have had to aim the camera much higher.  A little farther away turned out to be better.  Once the sky started to darken, I set my camera (a Nikon D300) on a tripod and aimed it toward the sky.  I chose a Nikon 18-200mm zoom lens. 

To begin with, I set the camera for manual operation, or manual mode.  I wasn't sure how long it would take to capture each shell exploding, but I knew that a fast shutter speed wouldn't work.  I wanted to be able to push the shutter button as soon as I heard the shell launch and then have the shutter stay open until it burst.  So I set the shutter for 5 seconds.  To allow for that long an exposure, I set the ISO, or camera sensitivity, at 200 (that's low).  After a few adjustments to my aim point and lens focal length, here's what I got. 

Because I shot the images a little wider than needed to make sure I had the explosion somewhere in the frame, this image is cropped.  But otherwise it's pretty much untouched.  I was pleasantly surprised with the result. 

So being the adventurous sole I am, I decided to try some other settings.

The fireworks crew were working in two groups.  And I wanted to try to capture two separate explosions in one image.  So I moved to get the two fireworks crew lined up one behind the other.  That way, if the shells launch in approximately the same direction (and that's a big if), the explosions will occur one behind the other.  Next I increased the shutter speed to 10 seconds.  By this time the sky had darkened quite a bit, so the exposure came out about the same.  And here's the result.  Again, I was surprised at the quality of the shot.

If you've never tried to shoot fireworks, I encourage you to try.  Even with a point-and-shoot digital, you might be surprised with the results.  And after all, if you don't try you'll never know what's possible.  So next 4th of July, you've got an assignment.  Good luck.

Exploding Car Windows?

Jenny asks:

I grew up in the South (Virginia and Georgia) where, as we all know, it gets really darn hot.  We were always told to crack the windows on the cars so they didn't crack.  Is that real?  Is is even possible?  I mean, I'm not sure how much extra pressure would result from heating a car from 70 to 100 degrees F.  Also, do you happen to know any real-life cases?  Thanks!

This sounds like a question for Mythbusters.  I actually submitted a question to those guys once about exploding bicycle tires.  My question generated no buzz.  So I'll work on your explosive question.  

You ask whether there are any real life cases of windows exploding for unknown reasons.  I found this thread in a simple Google search of "exploding car windows".  Jeeves says:

"If you Google 'exploding car window' or 'car window exploded' you find a lot of similar reports, even blog posts and Flickr sets, from drivers of a variety of vehicles. It appears at least at first glance that a lot of people did get it covered by insurance. I would personally let the dealer know because if it was a flaw caused during manufacturing, others could be affected by it as well.

There are a bunch of reasons people give for why the glass could have spontaneously "exploded," such as a defect in the glass, uneven stresses on the window from the frame, a defect in a rear defogger and/or a defogger inadvertently left on. I don't know much about this so I can't vouch for the accuracy."

The majority of these posts are anecdotal in nature and don't really go into the forces required for glass to shatter for no apparent reason. 

Modern car glass is actually a laminate.  A thin layer of flexible plastic is layered between two pieces of high-strength safety glass.  Safety glass is made so that it breaks into small, square pieces of glass.  Engineers found that these small pieces were much less likely to cause severe cuts and lacerations that the older forms of auto glass.  The plastic inter-layer was added to keep the shattered pieces of safety glass from flying all over the place once it did break.  The combination of safety glass with the plastic inter-layer has saved thousands of lives over the years.

Safety glass is manufactured to have built-in stresses.  When broken, safety glass shatters into small, square-shaped pieces.  Normally, safety glass breaks only when sudden outside forces deform the glass, such as when a rock or a passenger's face strike the glass.  Ouch!  But is possible to introduce the same kinds of stresses in a gradual way.  For example, if a car has been driven around town for an hour or two with the air conditioner on full blast, the car interior (including the window glass) will have cooled down.  Accidentally turn on the defroster and the window glass will be cooled even more (with the AC on, the defroster blows cold air onto the windshield). If that car is then parked in full noonday sun (lets say 100 degrees plus), the windshield will begin to heat from the outside first.  Now let's assume that one of the two layers of glass was manufactured with a little too much stress.  Keep in mind, this glass is in two layers with a plastic laminate in between acting as a tiny insulator.  Differential heating will cause the two layers of glass to change dimensions at different rates.  The outside, hotter layer will be slightly larger than the cooler, inside layer.  And since they are attached to each other by the plastic inter-layer, stresses will build up.  The windshield will actually start to bulge out slightly.  If the glass is placed under too much stress, it will shatter.

In the vast majority of cases, auto glass is capable of withstanding all of the stresses placed on it by normal daily wear and tear.  But occasionally, unusual situation do occur and broken glass will be the result.  The fact that many insurance companies pay to replace glass that breaks for unexplained reasons suggests that they also understand that manufacturing defects can cause this kind of breakage.

To Heat or Not to Heat? Ask the Thermostat.

Cory Bowles writes:

"I have a great question for you, one that's been a raging debate in my family for YEARS.  However, living down in sunny Texas, this is probably not a problem you run into much. Anyway, here goes:
 
"When the temperatures are cold (I live in the far-north suburbs of Chicago) and you go out to warm up your car, is it best to let the car run for a few minutes with the heater off so you are just letting the engine warm up? Or, to turn the heater on, so that when the engine does warm up, it starts pumping warm air into the car.   Perhaps down south you do the opposite with the air-conditioning?"

So, you guys really have "raging debates" about this stuff, huh?  Here in Texas, the only thing that generates really heated debates is what camoflage pattern to wear on the next hunting trip.  Not really!!  I'm just kidding.  We don't debate camoflage patterns.  Fashion is, after all, a personal choice.

Turn on the heater or don't turn on the heater.  I'll give you my best take on the subject, but it probably won't end the debate once and for all.  Let's start with how car heaters work.  Once a car engine starts, regardless of the outside weather, it begins to generate heat.  This heat is removed from the engine by circulating water through the engine block and then out to the radiator where the heat is transfered to the outside air.  I admit, this is a simplified description, but for this situation, it works.  In order to help the engine warm up more quickly, the water circulation system is fitted with a temperature sensitive valve called a thermostat.  By remaining closed when water temperatures are cold, this valve prevents water from circulating through the engine block and radiator, allowing the water temperature inside the engine to rise more rapidly. 

So if you turn the heater on when you start the engine, the thermostat will remain closed until the water in the engine block is nice and toasty.  Then the thermostat opens, heated water begins to flow, and the heater starts to warm the car's interior.  Consequently, you are better off turning both the engine and the heater on at the same time.  After all, who wants to sit in a freezing car anyway?  

Here in Texas heat is the problem.  Our solution is to turn the AC on full blast, roll down the windows and drive fast.  I don't know if that's the most effecient way to do it but who cares?  It feels good!

Jefferson Davis, Fort Davis, Jeff Davis County... A Common Thread

Melissa Dowdy asks:

I found the link to your blog on Julia's page.  I have what I think is an interesting question and hope it is within the scope of the questions you answer on your blog. 

Yesterday I was driving in Kentucky and saw the Jefferson Davis Monument.  I have seen it many times but it never fails to amaze me that in the middle of the tobacco, corn and soybean fields that this giant monument to the president of the CSA just pops up.  It is in the middle of extremely rural western Kentucky (lots of Amish people still travel by horse and buggy in the area).

So... can you tell me how it compares in size to the Washington Monument?  Any random bits of trivia (about JD, his monument or the Washington Monument) would also be appreciated.

When I read your question, I initially wondered if Melissa knew something about my hometown, Fort Davis, Tx., because there are some interesting coincidences here.  The Jefferson Davis Monument is located in southern Kentucky near the town of Fairview and near the birthplace of Jefferson Davis.  Construction on this impressive obelisk was begun in 1917.  Work was halted in 1917 because of a shortage of construction materials during World War I.  Work resumed in 1922 and the monument was completed in 1924.  

Who was Jefferson Davis, and why would someone build a monument to honor him?  Good question, Steve.  Jefferson Davis was born in what is now Todd County, Kentucky in 1808.  He graduated from West Point, served valiantly under Zachery Taylor in the Mexican-American War, married Taylor's daughter, Sally Knox Taylor (who died of malaria three month's after their marriage), and was appointed Secretary of War by President Franklin Pierce.  And I'm just getting started here.  This guy's biography reads like a Tom Clancy novel.  Davis served in the United States Congress both as a representative and a senator.  In 1861, he resigned his seat as senator and was named President of the Confederate States of America.  It is this post for which he is most well known.  And it is probably also the post which he least desired.  I believe he was very conflicted about his role in the Civil War.

Nevertheless, regarding the monument's dimensions:

1)  The monument is the tallest un-reinforced concrete structure in the world. No steel was used to reinforce the concrete. As one pour was completed, large chunks of limestone were left projecting up to connect it to the next pour above.

2)  The monument is the tallest concrete obelisk in the world. (All of the taller obelisks are constructed with blocks of stone.)

3)  It is the third tallest obelisk in the world (behind the San Jacinto Monument and the Washington Monument). (Because its cross section is octagonal and doesn't have a pyramidal top, the San Jacinto Monument could be considered a column instead of an obelisk.)

4)  It is the fifth tallest monument in the United States (behind the Gateway Arch, San Jacinto Monument, Washington Monument, and Perry's Victory and International Peace Memorial). (The Crazy Horse Memoriall, with a planned height of 563 feet (172 m), will become the second tallest monument upon completion.)

The information above comes from Wikipedia.com.

And to top it all off, I live in Jeff Davis County Texas, in a small town called Fort Davis.  The town of Fort Davis is named after the pre Civil War era cavalry fort of the same name (founded in 1854) located about 400 yards from my home.  The fort and county were named after, guess who, the then Secretary of War, Jefferson Davis.  Like I said, interesting coincidences.

 

Attack of the Giant Bees!! Save the Playscape!!

Tracy Becker writes:

"Is there some non-toxic (kids & dogs) way to keep the nasty carpenter bees off a wood play scape? Hubby just finished a gigantic play scape for the boy, and within one day (!!!) there was a carpenter bee making a home in it. Grrrrr...."

Don't you just hate it when you finish a big job, and all you want to do is sit back in a comfortable chair, drink a cold beer, and admire your handiwork, and then a big, black Carpenter Bee comes along and eats it.  I'll bet it really bugs you.............  Get it?..........."bugs" you.  Never mind.

Fortunately for me, we don't seem to have many problems with Carpenter Bees here in West Texas.  We've got lots of other nasty critters, like scorpions and vinagaroons.  But that's another story.  Carpenter Bees are large (larger than a bumble bee) bees with hairy a hairy head and thorax, and a shiny black abdomen.  They bore holes into soft wood where they lay eggs and raise young Carpenter Bees.  I've looked at several sites for information on controlling these beasts and a very helpful site can be found at UC Davis' website.  It describes several methods for controlling these bees, with emphasis on non-chemical solutions.

One method to prevent Carpenter Bees in the first place (a little too late for Tracy and her hubby) is to avoid soft woods like pine, spruce, or fir.  If you can afford the cost, use oak or maple instead.  If you have to use soft woods, fill all depressions or cracks with wood fillers or caulk.  These openings are invitations for Carpenter Bees to start digging.  If you already have a problem, try filling the holes with steel wool and then capping it with caulk.  There appears to be some disagreement as to whether to do this during the day while the bee is still in the hole, or to wait till early evening when the bee should be out.  The  UC Davis site suggests the latter.  Another non-chemical approach is to dust the holes with a desiccant powder containing boric acid or diatomaceous earth.  These powders are natural and work by abrading the hard surface of the bee's body, causing it to leak water and drying the bee to death.  Pretty cool.  Read all the information on the UC Davis site.  I think you'll find it helpful.

Geyser Plumbing

Christa asks:

"I've always wondered how geyers work and how old faithful can be old faithful.
Thanks."

You know, I was wondering about that too.  Last year My wife and I went to Yellowstone National Park, the land of geysers.  Having never been before, I found the steaming vents, bubbling mud, and spewing geysers absolutely fascinating.  We went in September, after all of the big crowds had left and were really blessed to be able to wander through the geyser field near Old Faithful early in the morning surrounded by billowing steam and frost covered trees.  It was really beautiful.  The photo below is one I took of Grand Geyser, one of largest in Yellowstone. 

Christa, you wanted to know how geysers work.  The best explaination I found was in Geology.com.  The information below is taken directly from their site. 

"A geyser is a vent in Earth’s surface that periodically ejects a column of hot water and steam. Even a small geyser is an amazing phenomenon; however some geysers have eruptions that blast thousands of gallons of boiling hot water up to a few hundred feet in the air. 

"To understand how a geyser works, you must first understand the relationship between water and steam. Steam is a gaseous form of water. Steam is produced when water is heated to its boiling point. When water converts into steam at surface conditions it undergoes an enormous expansion because steam occupies 1600 times as much space as the original volume of original water. The eruption of a geyser is powered by a "steam explosion" when boiling hot water suddenly expands into the much more voluminous steam. 

If you have a fissure or hole in the earth that contains water from top to bottom, all you have to do is add heat, lots of heat, to the water at the bottom of the column of water.  When the deep water reaches the boiling point and suddenly converts to steam, the sudden expansion forces the cooler water above it up to the surface with amazing speed and force.  It's kind of like shooting off a cannon, except geysers use water suddenly converted to steam as the gunpowder, the cooler water above the steam as the "bullet", and the fissure in the earth as the barrel.

As to why Old Faithful is so faithful, it all depends on the physical geology of Old Faithful's vent and underground plumbing and the available supply of water.  The Yellowstone.net website reports that the time of the next eruption is dependent on the length of the last eruption.  Follow the link and look at "Predicting Old Faithful" to see the method park rangers use to post the time of the next eruption.

If you haven't been to Yellowstone, I highly recommend going.  It's a great place to visit.
 

 

Dim Bulb....... Good or Bad?

Lisa writes:

"Your daughter sent me ... but I have an actual question! It's been bugging me for ages! Here you go: if you have a light on a dimmer, does it use less energy if it is dimmed? (One of our bathroom lights is on a dimmer and I leave it on as a nightlight, but I turn it way down - and every night I wonder if it is still sucking up electrticity as if it was on full bright ... )"
"Cheers!"

Thanks for checking out my blog.  And thanks for supporting Julie and Uncommon Misconceptions.   Up until a few years ago, I was absolutely convinced that electricity worked because little imp-like fairies ran back and forth in the wires.  Now that I've spent some time studying the matter, I know that it really works because of leprechauns.  

Dimmer switches.  There are two basic types of dimmer switches found in our homes these days.  The older of these is the rheostat-type dimmer.  They went out of common use about 20 years ago.  These dimmers worked by reducing the voltage that runs to a light fixture.  However, the voltage that wasn't needed to light the bulb was converted to heat.  Bottom line, the dim bulb still uses the same amount of electricity as the bright bulb.  If you're living in an older home or apartment you may still have this type of dimmer switch.  One way to find out if you've got the older rheostat dimmer is to turn the light fixture on, turn the light level way low, wait about 10 minutes or so, and then put your hand on the plastic cover plate.  If you've got the old type, the cover plate will be warm.  Not hot, just noticeably warm. 

The rheostat dimmers have been replaced by electronic dimmer switches.  These switches operate by rapidly turning the electricity on and off inside the switch. The on-off cycle happens so fast that our eyes can't perceive the changes and the light coming from the bulb appears dimmer.  I'm really convinced that those leprechauns are involved in this somehow.  The end result is that less electricity flows to the light and you actually do use less electricity.  Cool, huh?  A thorough and informative discussion of dimmer switches can be found here.

One other thing to keep in mind, though.  If you are like me and use CFL's (compact flourescent lights) wherever you can, dimmer switches may cause other problems, even with electronic dimmer switches.    However, if you put a CFL on a dimmer switch, after the light has been turned on for a while (20 minutes or so) you may notice the light level pulsating, rapidly going from bright to slightly dimmer and back.  If you have this problem, you should go to a simple on/off light switch.  These new fangled devices are changing almost daily, so they may have a solution to this problem that I don't know about.

Hope this helps.

Mom, Dad, 3 kids, and Grandma........ on a Plane!

Jacqueline writes:

"is there a place in texas that a family coming from northern california (say, Oakland airport) could meet grandparents coming from Washington DC (say Dulles airport) and fly one leg each (ie not changing planes) and meet up at a resort with a pool, good weather and good food and have fun? with kids ages 1, 4, and up to 7....without doing too much driving....Or, if not Texas, Colorado? Somewhere else I am missing?"

A travel question.  I love to travel.  Planes, trains, or automobiles, it doesn't matter.  Fancy hotel, beach resort, dirt camping.....I've done it all.  So I'll give this question my best shot.  The first, and probably most difficult requirement is an airport accessible by direct flights from both the San Francisco area and Washington DC.  The only airports in Texas that fill that bill are Houston (George Bush International Airport) and Dallas-Fort Worth (DFW International Airport).  Getting both sets of travelers to either of these airports would be fairly easy.  Unfortunately, there aren't any resort-type properties in either of those locations that I family would find very fun.  I'm familiar with both; born in Houston and raised in the Dallas-Fort Worth area.  So....let's look at other possibilities.

Colorado?  Denver airport would be a good possibility.  I found four airlines that offered non-stop flights from San Francisco and three to Denver from Washington, DC (expedia.com).  Several nice year-round resorts operate west of Denver in places like Breckenridge, Aspen, and Vail/Beaver Creek.

How about Phoenix/Tuscon?  Or Salt Lake City, Utah?  These should also offer the same kinds of flights and tourism opportunities nearby.  Hope you and your family find something that works and that wherever you guys end up, that you have a great time.

Hot Car in Seattle

Amy Bresslour writes:

"I live in Seattle where it is rarely HOT in the summer.  Generally it is in the mid-70's with a light coastal wind - perfection.  Unfortunately, we had a MAJOR heat snap a few weeks ago and I thought I was going to lose my mind.  See, no one in Seattle has AC at home or really knows how to deal with heat of any kind."
 
"I'm wondering if you can give me some tips to keep my car cool(er) in what is shaping up to be this HOTT summer in the City!  Other than parking under a tree - what can I do?"

So.....you think it gets HOTT in Seattle.  Let's see.  I live in far West Texas, near the Mexican border, where the official plant is the cactus.  I think I know a few things about dealing with heat.  I'll share a few ideas.

First, jump in the car and start the engine really quickly, put the car in gear, roll all the windows down, and drive really, really fast.  This works best when the driver is dressed in skimpy attire.  The skimpier, the better.  I realize you live in Seattle, but I don't recommend driving around in the nude.  Although I remember once in 1968, I was............ uh, nevermind. 

Second option.  Car window sun shades.  These things are designed to be folded up flat and stored under the car seat.  When you park your car, pop the shade out and open it up.  Then shove the bottom edge up where the windshield meets the dashboard and the top up under the rearview mirror.  Then fold the visors down and you're set.  The aluminized surface reflects a lot of the sun's energy back through the glass and out of the car.  It won't totally solve the heat problem, but it does help a lot.

There are other solutions that are a bit more expensive, like hiring a full-time driver and having him keep the car running all day with the air conditioner on.  You might find that a bit over the top.  Hope that helps.

Q&A: Fort Davis Indians Football Future?

Jo Tucker asks:

Do you think the Fort Davis Indians will be in a play-off game on December 4, 2009?

Interesting question.  This past year's Indian team really looked good.  And I'm sure they would have gone much further in the playoffs if Adrian Hernandez hadn't gotten injured in the state semi-final game.  But that's ancient history already. 

This fall's Indian team will be losing two starters to graduation, including Adrian.  So two thirds of the 6-man starting lineup will be returning.  And given the overall strength of the Fort Davis program compared to others in the district, I don't think they will have problems making it back to the playoffs next year.  So, yes, I predict that the Fort Davis Indians will be in the play-offs in December of 2009.  Whether the exact date will be December 4th or not, I just don't know.