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Geology, Palaeontology & Archaeology / Is the Earth's core enriched for heavy dense elements, like gold?

« on: 15/06/2008 20:16:36 »

John Berger  asked the Naked Scientists:

If the Earth's core is made of heavy and dense metals, mostly iron, are the most dense metals at the centre of the core.

That is, if we could drill down 6,000 km, would we find large quantities of gold, uranium and osmium?

John Berger
Vancouver Island.


What do you think?

2

Physics, Astronomy & Cosmology / focus on reflection

« on: 23/09/2005 13:57:09 »

I would like to photograph a young lady standing on the other side of a bird bath, such that I would focus on her reflection in the water to get a shimmering image of her face.
Question, do I first focus on her head, then swing the camera to the water, or should I focus on the water instead. Any ideas? [?]

3

Physics, Astronomy & Cosmology / Global warming in solar system?

« on: 21/09/2005 14:59:58 »

Was just reading article on Martian polar caps at BBC news. The article mentioned the ice caps had been receding for three years now. Is this coincidence, or has global warming spread from Earth to Mars via solar winds carrying warm CO2 ... or is the sun increasing energy output and warming the entire solar system?
Any thoughts or observations on this?
 http://news.bbc.co.uk/2/hi/science/nature/4266474.stm

4

Chemistry / Jet exhaust analysis

« on: 30/05/2005 06:56:39 »

A class-mate told me she was convinced the engines of commercial jetliners emit toxic chemicals that cause people living in cities to get sick ... etc.
Although I responded with the view that the majority of jet exhaust is water vapour and carbon dioxide she was adamant.
Does anybody know of a simple test (perhaps analysis of the light reflected from the jet trails?) to prove the myth/theory right or wrong?

5

Chemistry / Invisible Ink formula anyone?

« on: 23/02/2005 03:41:16 »

One night over a bunch of red wine, I and two other students decided we would investigate the possibility of writing a message onto our class flag. Once the semester is over, that flag will hang over an indoor swimming pool ... so I was wondering if anyone knew of an invisible ink that would appear after the flag was hanging over the pool where the chlorine fumes would make it visible again.
If not chlorine, then how about time or some other factor.

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Chemistry / krypton gas in diving

« on: 18/02/2005 13:25:54 »

When a scuba diver works in cold water wearing a dry suit, we inflate the suit with a little bit of air to make it more comfortable and provide some insulation from cold water. In arctic diving, sometimes argon gas is used for its superior insulation properties (as opposed to  helium, which transfers too much heat from the diver to the water). Neon is not used as it causes narcosis in the diver. However, has anybody any idea why krypton is not used? I would think its insulation value is greater than argon's, but haven't found if it is a problem physiologically or if the cost of krypton is too great.

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Physiology & Medicine / Could we use krypton gas in scuba suit?

« on: 18/02/2005 13:28:01 »

When we dive in cold water wearing a dry suit, we inflate the dry-suit with a little bit of air to make it more comfortable and provide some insulation from cold water. In arctic diving, sometimes argon gas is used for its superior insulation properties (as opposed to  helium, which transfers too much heat from the diver to the water). Neon is not used as it causes narcosis in the diver. However, has anybody any idea why krypton is not used? I would think its insulation value is greater than argon's, but haven't found if it is a problem physiologically or if the cost of krypton is too great.