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.

Calculating Sunset Time With Your Fingers

Did you know, estimating sunset time with the help of your fingers is really very easy. This is one thing every person going for a trek should remember. I know you have smartphones which tell you the exact sunset time these days. In that case, learn it to show it off to your friends. By the time their smartphones come out of their pockets, and get unlocked, you’ll have an estimate ready.

Here’s what you do…

Stretch your arm as much as you can and count the number of fingers that can come in between the sun and the horizon. That’s it.

Each finger is about 15 minutes of remaining sun time. If four of your fingers, or one hand fits there, you can directly say that it’s one hour to sunset.

Another thing to note is – where you are on Earth roughly. Good news for people near the equator. The estimate near the equator is very close to 15 minutes per finger. However, for people trekking nearer to the poles, you might have more time than what you just estimated using this technique. Very near to poles, it is a completely different story.

When pros have 2 hands (8 fingers or 2 hours) of time left for sunset, they start searching for a shelter to spend the night.

But again, smartphones can give you really an accurate time. This simple farm trick, like the one  I shared a few days back – telling temperature with cricket sound. It is just a rough estimate. So make sure you don’t completely rely on this to get back home before it gets dark.

via [Groovy Matter] and [Lifehacker]

Crickets – Nature’s Weather Reporters

Background

An annoying Cricket’s treet-treet-treet noise is really unbearable sometimes, especially when a house cricket ends up under your bed and treets all night long. To others, it’s pleasing, they associate it with the night time, and it makes them go to sleep.

Whatever it is for you, there’s one interesting thing universal about that noise they make. If you can count the number of chirps, you can almost accurately estimate the atmospheric temperature using a simple formula! Good ‘ol farmers used to do this.

I know all of us have smartphones these days, so counting cricket chirps to estimate temperature probably makes no sense to you. Still, I’ve said it back then and I say it again, it’s never bad to know anything.

Here’s how you do it

For doing it, you somehow should be able to measure 14 seconds. In those 14 seconds, count the number of times a single cricket chirps. Suppose there are 35 chirps heard, you save that number and add it to 40 (always 40). And this gives you the present temperature in Fahrenheit.

35 chirps + 40 = 75 degrees Fahrenheit

Now, since only a handful of countries use Fahrenheit to measure temperature, you might want to convert it into Celsius scale. I personally am comfortable with only the Celsius scale. But you don’t have to go through the trouble of converting because, to measure the temperature in Celsius scale using the cricket’s treet, this is what you have to do.

Simply count the number of chirps it makes in 25 seconds. Now divide the number by 3 and add 4 to it. There you have your ambient temperature in Celsius scale. Suppose the cricket chirps 50 times…

(50 chirps/3) + 4 = 20.67 degrees Celsius

Why it works

To know that it is first important to understand how a cricket makes that sound. Remember only male crickets of a few species make this sound. They do this by a process called stridulation – rubbing 2 body parts to make a sound. Rubbing the underside of one wing with the upper side of the other wing does this trick – as they have rough and hard structures over there.

To move these wings it requires a particular chemical reaction to happen in their muscles. The speed of this chemical reaction is dependent on how hot or cold it is. The hotter it is, the faster the reaction happens and the faster it is able to move its muscles to produce more sounds in those 14/25 seconds…

via [Scientific American] and  [Howstuffworks] and [Farmer’s Almanac]