My daughter dived underwater in the swimming pool and screamed as loud as she could. I was right next to her with my head out of the water, but I could only detect the tiniest sound, at the end of the scream. But when I was underwater with her, I could hear most of the scream. Why?

Why is it people sound different, what has caused it to happen

Why does banging on metal produce a reverberating echo-type sound instead of say, a thick knock-like sound when hitting wood? My assumption is that the space of atoms and vibrations change the intensity, volume, frequency, pitch, and effect. But what about the sound of blowing wind? Or the long booming rumble of thunder? or the sound of a motercycle down the road? What makes these types of sounds what they are, with precise magnitude, frequency, pitch, and intensity?

As I know there is no environment things like (sphere) in space, so how do we catch astronauts talking from earth to moon and in future mars to earth ? how signal travels in space? like sound waves!

I  have little fantasy about space ! Can we hear sound in space?

 Why does going faster create a higher pitched sound?

Is it possible for a human to visit that place? Or would their mere presence cause the sound to increase to the point where it is no longer the quietest place on Earth?

If I play an old mono song on my stereo and reverse the wires (phase) of one speaker, I can find a spot where a mono microphone will fail to pick up any sound (as long as the speakers are angled correctly and the room isn't too reflective).

My daughter dived underwater in the swimming pool and screamed as loud as she could. I was right next to her with my head out of the water, but I could only detect the tiniest sound, at the end of the scream. But when I was underwater with her, I could hear most of the scream. Why?

Linda Simpson Katonah, New York, US

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)