lightning – Awesci – Science Everyday

Estimating the Distance of a Lightning Strike

By Anupum Pant

Everyone who’s studied basic science at school knows that light travels much much faster than sound. Light can travel about 300,000 km in a single second. Sound, in the same time would cover about 0.3 km. That’s a huge difference.

Considering that, it is fairly easy to calculate how far a lightning strike happens by measuring the time it takes the sound to reach you after you see the lightning. In that case, taking into account the enormous speed of light, you assume that the light instantly reaches you and you just count the seconds it takes for the sound to be heard at the place you are.

Then multiplying the seconds with 0.3 would give you, in kilometres, how far it happened – an estimation of, course.

So, if there isn’t a mess of lightning strikes happening somewhere, which usually isn’t the case, and if you can clearly tell which sound came from which lightning strike, which you can’t in most cases, you can actually estimate the distance of a strike very easily.

If you think that’s great. You might be interested in:
How to estimate the temperature.
and How to estimate the time to sunset.

Lightning Trapped Forever in a Box

By Anupum Pant

On a cloudy and stormy night (or almost all the time, in this part of Venezuela), dark clouds separate charges and are able to put together the right conditions to send off one of the nature’s most powerful forces from the heavens – lightning.

The air break downs and a great amount of static charge gets transferred through the path of least resistance. And a bolt of bright light is seen for a fraction of a second. It lasts for a very little time.

As it happens too quickly, the exact shape of a lightning bolt is difficult to see. However, a long time back, a German physicist, Georg Christoph Lichtenberg, figured something that could help make the lightning bolt last longer. Or in fact, it could trap the lightning tree-pattern forever in an insulator (eg acrylic or wood etc.). The tree-like figure is called the Litchenberg figure after the person’s name (Georg Christoph Lichtenberg) who first noticed this.

Isn’t it a nice sculpture to have – a block acrylic with a lightning bolt permanently trapped in it! Or may be it could be a great gift for your physicist friend. But, sometimes the litchenberg figure isn’t a desirable thing to have…

People who unfortunately end up getting hit by lightning, sometimes survive to this permanent tree-shaped scar mark (or tattoo) – A permanent litchenberg figure gets printed on their skin. It looks like this.

The Everlasting Lightning of Venezuela

By Anupum Pant

There’s a place in Venezuela which is the single greatest generator of tropospheric ozone – A basin in Venezuela where the Catatumbo River empties into Lake Maracaibo. The basin is surrounded on three sides by mountains and is home to a very unique phenomenon which produces more tropospheric ozone than anywhere else in the world. It’s called the Catatumbo everlasting lightning.

Almost every other day (more than 200 days a year), after dusk the largest lightning show on earth begins. The whole sky strobes blue light about 260 times every hour. This lasts for about ten hours. In that span lightning strikes about 20,000 times! Nowhere on earth is lightning as persistent as this place…

This happens because of the geography of the region. Since the basin is surrounded by mountains on three sides, it’s a perfect place for the equatorial warm and moist winds to crash. As they crash the moist air condenses water and forms clouds. These charged clouds create a lot of cloud to cloud lightning about 3 kilometers above in the sky.

This is better known among sailors as the Beacon of Maracaibo, as it serves a nice navigational aid for them.

Mysteriously, this lightning phenomenon which had lasted continually for 104 years disappeared in January 2010. Many thought it had gone for ever, but it started again in the month of April the same year. This was the longest disappearance ever. Scientists say it was the drought which made it stop for 4 months.

via [Slate]

Making Xrays Using a Sticky Tape

By Anupum Pant

It’s been known since the 1950s that peeling a sticky tape can produce great amounts of energy. But it wasn’t until recently (in the year 2009) a few scientists, who also didn’t quite believe what sticky tapes could do, decided to actually test this phenomenon.

Astoundingly, a simple act of peeling an adhesive tape, can produce enough xrays to make a Geiger counter cry like a cricket.

In fact, the xrays produced by peeling off sticky tape at the rate of about 5cm per second inside an evacuated chamber can produce enough xrays that can expose a photographic film – enabling you to take an xray of your finger – as demonstrated by the researchers in the video below.

The video is fairly old, was uploaded in the year 2009 and I somehow have never stumbled upon it. It seems relevant even today. Thanks to ScienceDump for showing me this today.

Imagine, you can take an xray picture of your finger using a simple adhesive tape (peeling off in vacuum of course). Scientists possibly couldn’t have discovered a cheaper source of producing xrays.

The vacuum is needed to let enough charge to accumulate before the medium in between the charges breaks. Had the peeling been done in atmospheric pressure, it would have just produced visible light (lower energy than xrays). You can even try doing that at home. Go to a dark room and try peeling off a sticky tape quickly. Thanks to the effect called triboluminescence, you’ll be able to see a spark of light coming out!