Recently i have wondered about how the moon and sun affect gravity here on earth. I was wondering wether the force of gravity would change during night or day due to the position of the sun and the moon and their gravitational pulls. But just as I sat down to work this out (being the cool 16 year old I am) I also remembered that the sun and moon would also pull on the earth. so the question is would the pull the on the earth be the same as that on you and therefore cancel out any effects or do you infact become magically (or marginally) lighter at night or day due to this affect?

What causes the distinct unpleasant sunbed-odour off my (and others') skin? Sunning myself in 'real' sun does not have the same effect, whatever the temperature or humidity.

Further: Why the pale spots on the skin  - shoulder bones and tailbone - if I stay immobile in the sunbed? Would wrapping myself tightly in clingfilm protect me from getting a tan/sunburn?

My limited understanding of science tells me that

a year is the period taken for the earth to orbit the sun, but

seasons are dictated by the tilt of the earth.

Why should there be a link between these?

One planet's year is defined by how long it takes the planet to complete one orbit around the Sun. So based on the distance from the Sun, one year on Earth is (of course) not the same as one year on Mercury (88 'Earth days') or Neptune (165 'Earth years').

But what if we theoretical were to move to the Sun? What would define one year on a star?

Anders, Norway

While out walking today, my son asked me another question I couldn't answer. He said that we're all told not to look directly at the sun, it's bad for our eyes; but what if a camera had filmed the sun, then we watched it on television - would that still be bad for our eyes?

Peter Finan

Haworth

West Yorkshire

On our approach to landing at Melbourne airport just after sunrise while aboard a commercial airplane I noted moving on the clouds at the same speed as the plane a circle of light with a rim of bright light and an outer rim of red light (see photo). On occasion I saw the shadow of the airplane within this circle of light.  It seems that this circle of light was from the rays of light from the rising sun and that they were being distorted by the airplane. What was happening?

I understand that on earth we feel the heat of the Sun because it radiates light to earth which then gets trapped within our atmosphere and gives out heat.  Space, being a vaccum, would contain no heat as there is no matter to conduct the heat of the Sun, so how close could you get to the sun before you would feel any heat from it?  Also would the sun not be able to radiate heat in the form of light to human skin in the same way as it radiates heat to the earth?

Many Thanks

James Stretton (Colchester)