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Physics, Astronomy & Cosmology / Re: A reported object travelling faster than the speed of light?

« on: 26/11/2019 18:00:36 »

You do not give us enough detail to identify precisely the report you talk about. 

However there are several cases of observations of  astronomical "objects" apparently moving faster than light.  The reason is that the moving source of light is not in fact moving but is a shell or layer that is illuminated by a pulse of light or a moving beam of light or particles that cause light emission.

Consider pointing a powerful continuous and steerable laser up at a low angle into the clear sky illuminating clouds in the distance and changing its angle by one radian  (around 60 degrees) in one millisecond.  Say there was a cloud 30 kilometres away  This is an experiment that can be done.

The spot of illumination by the laser on the cloud would move 30 kilometres in one millisecond  that is at an apparent speed of 30,000 kilometres per sec.  Now if this cloud was  300 kilometres away the spot would be moving at the speed of light.  Any further away and the spot will be moving faster than the speed of light.  Nothing is actually moving faster than light but it is possible to see a bright spot moving faster than the speed of light.

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Physics, Astronomy & Cosmology / Re: How does heat conduction in metals differ from non-metals?

« on: 29/01/2012 22:50:56 »

Metals are usually conductors of electricity and non metals insulators.  Electrical conductors have free electrons in their conduction bands and these are much more mobile than the atoms themselves and help with the transfer of heat energy through the material so electrical conductors are usually better conductors of heat than non metals.  That is not the whole story because the rigidity of the material and the availability of vibration bands in the crystal structure also plays a part in thermal conductivity.

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General Science / If Humans Were Wiped Out Would The World Survive ? (A nuclear power question)

« on: 06/04/2008 12:13:18 »

I am not suggesting any sort of active reduction of population.  We will have to learn to live with what we have got but governments and industry and general economic theory have a vested interest in young growing populations.  To reduce the population we will need totally innovative systems to cope with an aging and shrinking population or even a stable one. There are some hints as to how things might work but I would rather see a more active approach

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General Science / If Humans Were Wiped Out Would The World Survive ? (A nuclear power question)

« on: 06/04/2008 11:03:11 »

The world would get on just fine without humans.  It would also get on just fine if there were only one percent of the current human population and as long as the numbers stayed the same we could do what we liked with absolutely no problems and all live a very nice life.  The real problem is overpopulation not global warming but no one will admit the truth.

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That CAN'T be true! / Re: Motion sickness theory is a swindle

« on: 12/10/2006 09:19:45 »

As the human senses of hearing and motion detection both use the inner ear and similar sensors and low frequency motions will produce low frequency sounds it is not supprising that low frequency sound and motion sickness are linked.

Learn, create, test and tell
evolution rules in all things
God says so!

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Chemistry / Re: What is the least-viscous liquid (at room temperature) known?

« on: 03/08/2006 23:41:39 »

Google  (+viscocity  +water +ether +alcohol +mercury  ) produces some lists of viscocities of common substances

I just used a table of physical constans that I have had since I was a student.

Learn, create, test and tell
evolution rules in all things
God says so!