Category Archives: Science

Driving While Stoned

I was recently in a conversation with a friend about the effects of driving while stoned versus driving while drunk.  He was of the opinion that they were equally bad while I was of the opinion that marijuana had little to no effect on driving.  Well, the National Highway Traffic Safety Administration is here to tell me that I was right. *does the “I was right” victory dance*

Yep, there is a negligible effect on the rates of getting into an accident while under the effects of THC.  Of course, this doesn’t mean that you’re safe to smoke up before getting behind the wheel.  The problem is that, unlike alcohol, ingesting a certain amount of THC has unpredictable outcomes.  What it does for one person can be radically different from what it does for others.  That means that while people with the same blood-alcohol level tend to be impaired at the same level, people with the same THC levels in their blood stream have varying levels of impairment.

What we need is more science!  Sadly, since marijuana is still considered a schedule one substance, there is little research that can be done at this point.  How marijuana is considered as dangerous as heroin is beyond comprehension and common sense.  Hopefully, that will soon change.

Crash Course Astronomy

Ever wanted to know a bit more about astronomy?  Well, astronomer Phil Plait is here to teach you more!  It’s a great series so far at three episodes and well worth your time if you want to get some basic astronomy under your belt.  I wish they’d do it more like Netflix does and just release them all at once.

Phun With Photons

During Neil deGrasse Tyson’s talk on Tuesday, he talked about firing photons one at a time to produce a result.  During almost any talk about physics experiments you will eventually hear about physicists shooting individual photons.  Despite its near ubiquity and my hundreds of hours of physics classes I’ve never really heard an explanation of how physicists manage to produce a single photon.  None of my friends had either.  So I decided to hit the interwebs and find an answer.  It is so simple, I am almost ashamed that I didn’t come up with an explanation on my own.  More proof that my brain is slowly turning to mush from lack of exercise.

Think about a flashlight.  Turn it on and light goes beaming out.  That light is composed of untold schmillions of photons.  Electricity is running through the filament causing the (usually) tungsten filament to heat up and produce light.  The electrons passing through the tungsten will collide with an individual atom temporarily causing the individual atom’s outer shell electron to jump to a higher energy level.  This is an unstable condition for the atom so the electron will eventually fall back down and photons will be produced.

“But that doesn’t help us, we still have multiple photons being produced!”, you might exclaim.  And you’d be right.  Here’s where a little ingenuity is involved.  We need a source which produces a known number of photons at known wavelengths.  Enter the spectrometer!  Thanks to that lovely invention, we know the wavelengths of the photons produced for just about everything.  Prior to that, I assume it was mostly trial and error.

Now it’s just a matter of choosing a substance, isolating it, and running just enough electricity through it to produce a reaction on a single atom.  But what shall we choose?  It turns out there are plenty, but the easiest example I could find is sodium.  A single sodium atom produces two distinct wavelengths of light at 588.9950 nm and 589.5924 nm.  Oops, but that’s still two photons, what do we do now?  Filters!  We just place a filter across the path of the photons that blocks one of the wavelengths and voila, a single photon source!

Obviously, creating a device capable of firing a controlled amount of electricity across a controlled number of atoms is non-trivial, but that’s the basic concept.  You just take your basic light source and winnow it down to its atomic level.

All The Leaves Are Brown And The Sky Is Grey

I looked outside my window yesterday and was greeted by two trees already showing their spectacular yellow color.  Yep, autumn is here already.  It seems a bit early for the colors to change, but I seem to recall thinking in previous years that the leaves were turning later than usual so maybe this is the actual normal.  Remembrances of specific events that happen once a year is a tricky thing to do.  This is partly why it’s so difficult to get people to believe that climate change is happening.  Things happen in gradations instead of all at once.

But that’s not what I want to talk about.  I want to talk about colors!  Or colours for the one person in the U.K. that reads my blog.  Leaves change color in the fall.  Duh.  But why do they change different colors?  The answer is science!

Green – You all know this from your basic biology course, I’m sure, but leaves turn green because they’re filled with chlorophyll (a word that I’m sure has denied many a student a spelling bee championship).  Chlorophyll is what plants use to help them absorb light which they use to perform photosynthesis which converts light to energy.  Yes, plants eat light for breakfast, lunch, and dinner.  Yum!  But chlorophyll is kind of like a mask that hides the true color of the leaves.  In the fall, as trees prepare to hibernate for the winter, the chlorophyll slowly drains away and the plant’s true colors shine through.

Yellow – The “true” color of most tree leaves. Year round, most trees produce carotenoid which is responsible for the vast array of yellow colors you see in trees during the autumn.  During the spring and summer, the yellow color is just overridden by the green of the chlorophyll.  What color of yellow a leaf appears in the fall is a result of differing amounts of carotenoid in the leaf.

Red – Some of the most beautiful trees are those that turn a brilliant red (or purple) color.  Like chlorophyll, though, the red color is due to a special production of the chemical anthocyanin.  Scientists don’t know for sure why anthocyanin is produced in some trees.  One theory is that anthocyanin is produced in because it helps protect the leaves from the light so they can continue producing food for the plant a little while longer.  Another is that it’s a warning sign for insects to let them know that they probably don’t want to choose this tree to live in for the winter.  Many trees that turn red will turn another color after the anthocyanin production stops.

Orange – If you know your colors, you know what’s coming here.  The orange of leaves is a mix of both anthocyanin and carotenoid.  So when you see an orange leaf, you know that there’s a bit of anthocyanin being produced but not enough to override the yellow of the carotenoid.  As with the red leaves, you will often see orange leaves change to yellow before falling off the tree.

There you have it, science!

Bad Joke Of The Day

What kind of comedy do eyes like?

Vitreous humor!

I thought up this (totally original, I’m sure!) joke while reading about those strange floaty things that some people have in their vision.

You’re welcome.

The Speed Of Light Slows Down

Once upon a time, there was a blast of neutrinos detected on Earth, followed three hours later by another blast of neutrinos.  7.7 hours after the initial blast, a star brightened in the tell-tale signs of a supernova in the Large Magellanic Cloud.  This is highly unusual because neutrinos and photons both travel at the speed of light and while it is known that photons spend the first 3 or so hours bouncing around inside a supernova, there’s still 4.7 hours unaccounted for.  Since scientists couldn’t explain the arrival time difference, they dismissed it as two separate occurrences even though the probability of them being related is quite high.

Now, scientists have a mathematical solution for the time difference.  Basically, it goes like this.  Neutrinos for the most part do not interact with matter at all.  They can go right through the Earth as if it were empty space.  Photons are not so lucky.  They can be bent by gravity, they can run into matter, and they can cease to be photons for miniscule moments of time to form an electron-positron pair.  The latter is where things get interesting.  An electron-positron pair suddenly has mass that can be much more affected by gravity than a lone photon.  It last for no time at all before going back to a photon, but scientists found that this new gravitational potential of the electron-positron pair corresponds to the missing 4.7 hours.

This is fascinating because a quantum mechanical effect has been combined with a relativistic effect to produce a result.  If this explanation for the missing 4.7 hours is correct, could this discovery lead us down the path of other discoveries that will lead to a unified field theory?  I also wonder what this means for our calculations of distances of objects.  If the Large Magellanic Cloud is 4.7 light hours farther away than previously thought at 160,000 light years distance, how much farther away is UDFj-39546284 at 13,370,000,000 distance?  What if the effect isn’t linear?

You Are Still Just A Rat In A Cage

You ever wonder why pet mice and gerbils and such seem to enjoy those little exercise wheels so much?  Probably because they are in this little cage and there’s not much else to do, right?

Wrong.

Scientists decided to take exercise wheels out of the cages and put them in places outside and see what would happen.  One they put in a green urban center and another they put in a remote dune area.  Much to their chagrin, they found that wild mice and rats and even some snails, slugs, and frogs enjoyed using the exercise wheel.  Over three years, they recorded over 1,200 uses of the exercise wheel.  They originally used food to lure the animals to the exercise wheel site, but on the chance that they were using the wheel because of the food, they removed it and still were recording wheel usage.

This is the kind of experiment that gets mocked by people who don’t have a basic understanding of how science works.  I have no idea if there are any useful scientific conclusions to draw from this experimeint or not.  The authors suggest that there may be something to gleen about the habits of sedentary versus more active humans, but who know.  They did an experiment that was never attempted before and reached a conclusion that is at least somewhat unexpected.  Basic science like this is how big discoveries are made.  There is a quote that I remember, but can’t find the source and it goes something like this: Great discoveries are often thought to come from someone burning the midnight oil and coming across some new discovery and shouting “Eureka!”, but more often than not it comes from someone looking at a bit of gathered data and thinking to herself, “That’s odd”.

Pyroclastic Whoah!

You know how Pompeii was destroyed in an instant from the eruption of Mt. Vesuvius?  What did all of the damage and the amazing preservation is what’s called a pyroclastic flow.  It’s a very fast-moving conglomeration of ash and gasses and lava that has immense destructive powers.  It’s one of those things that happens so quickly, you don’t have much time to document it.  Luckily, scientists are getting a lot better at predicting volcanic explosion so there’s usually a camera or ten around to capture the awesomeness.  Here is an example of said awesomeness:

[youtube http://youtu.be/95bYATFIOxs]

Global Warming Is Easy To Understand

How long do you think it would take you to understand the mechanism that leads to global warming?  Years?  Months? Days?  Nope.  Fifty-two seconds:

[youtube http://youtu.be/R-qtr9xKwow]

If you want more information, How Global Warming Works has one, three, four, and five minute versions that go into greater detail.  I love examples of elegant learning like this.

Algae To Oil In About An Hour

There is some more promising great news in the quest for cheap, renewable fuel front.  The Pacific Northwest National Laboratory is licensing a process that can create oil from an algae slurry in an hour and the company, Genifuel, is starting production on an industrial scale machine to produce it.  Even better, the byproducts of this process are all recyclable.  Unfortunately, the produced oil then needs to go through the normal refining process to create gasoline, etc. which is horribly polluting, but that environmental damage can at least be limited to a small geographic area as opposed to the drilling for oil which all to often has vast implications on large swaths of land.

Of course, this still leaves us in the same boat of burning gasoline to power our cars and I’m not sure that’s a tenable solution for the long run.  It also still remains to be seen if this process can be expanded to the scale of our voracious appetite for oil.  Regardless, it’s a tantalizing look into what could be our solution to our dependence on foreign oil.