Prematurely overcome by the holiday spirit, we failed to send a round-up last week. Apologies for that. One of the most popular questions from that week – also with a holiday flavour – was what to do during a lightning storm at the beach. Are you safer on the beach or in the water? The discussion contains a fair bit of disagreement, but some great tips for optimum lightning-avoidance behaviour.

This week's questions started with whether the wind affects sound waves (it does, but not in the way you might expect), and whether the foods we crave are the ones our bodies actually need (let's hope so).

Here's one for the physics-minded: ever wondered why most rocket launch pads are sited near the equator? It's to make the most of the rotational velocity of the Earth's surface, which is greatest at the equator. But can you think of any other ways we exploit this tremendous energy source? So far, not many readers can.

If you've ever been caught by brambles while walking in the countryside, you might be curious why the thorns of roses and blackberries are designed to catch animals rather than repel them. Could it be that roses are actually carnivorous?

Finally, August is the month for… meteor-hunting. The Perseid meteor shower is at its height on 12 August. One of our readers reckons he can hear meteors. Is that possible?

Enjoy your weekend.

Michael (acting for Kat)

I know it would be best to go home and have a beer--but that's not my question. Given a choice: wet, sitting or standing on the beach or just barely sticking your head out of the water, close to shore: which is the safer choice and why?

We took the single span cable car from Lake Skalnaté, at 1751m above sea level, to Lomnický štít which, at 2634m above seal level, is the second highest peak in the Tatra mountains.

The peak was covered in cloud with little wind. The air was highly charged with static, I could feel what hair I have standing up and my wife got shocks from the metal handrails that surround the narrow ridge.

Suddenly I felt a slight but definite slap on my head. I was taken by surprise and was wondering if I had been hit by a bird when, perhaps two seconds later, there was a crack of thunder. I had seen no flash when I felt the slap, but had been looking down at the time.

My wife did not notice the effect but felt it prior to a second thunder clap, I did not feel the effect the second time, the lightning was again unseen.

The sensation definitely felt like a physical contact and I firmly link it to the lightning.

What was it we experienced and how could it precede the sound?

I avoided holding the handrails, which were earthed, after hearing the thunder. Was I correct in assuming this would be safer than holding them?

Would the steel cable  to the ground over 883m below not have been very attractive to lightening and how would this have been protected against at the winding gear?

Regards

Hal

Hello,

Inquiry:

From my ancestors, story goes, that after a lightning storm, they would search for rocks from lightning strikes up in the mountains. These rocks, almost completely round, would be used as a health benefit. That is, they would be put in a glass of water, the rock would supposedly "fizz", and they would drink this as a health tonic.

Is there any substance to this, or is it an "old wives tale"?

Thank you,

Stergios Vlioras

P.O. Box 43055,

Burnaby, B.C.

V5G 4S2

ph# 778-837-3405

Last week me & my family were down the beach in Suffolk, UK and as soons as we packed up a storm appeared. As we got soaked walking back we saw a fork of lightning strike the sea (North Sea).

My question is what happens when lighting strikes the sea? Or more to the point; how much of the sea is affected by the strike? Will it kill the fish? What would have happened if a human was in the sea? 

I am guessing that it would affect the wildlife but I am not sure if the large mass of water would disperse the energy and affect it less.

And if so, would the lightning strike cause any harm to the bird.