Just a couple of quick questions,

  wolfie3000 12:40 27 Jun 2008

Been talking to a friend and we came up with two questions we cant answer,

So can anyone answer these?

1 Can the speed of light be slowed down when passed through solid materials or is the speed of light constant??

2 why is it that on coins the person on the coin is always in profile and on paper money the people always face front?

  Legolas 12:49 27 Jun 2008

On your first question click here On your second question sorry I haven't a clue

  day2strike 12:52 27 Jun 2008


  wolfie3000 12:53 27 Jun 2008

Thanks Legolas,
Will give it a good read, interesting stuff.

So when people say "the only thing that's constant in this universe is the speed of light" there wrong.

  barca1 13:27 27 Jun 2008

wolfie3000 i sent you a message via this forum two weeks ago,i resent it a few days later & you didnt have the decency to reply..? yet you ask us for questions..?

no harm done eh..

  iambeavis 13:29 27 Jun 2008

Perhaps it's because coins are cast with a cameo, or positive relief image, so having to allow for the profile of the nose would render the coin rather thick?

  Seth Haniel 13:47 27 Jun 2008

Silhouette is always side on.

what is the Speed of light on Jupiter with a much denser atmosphere to escape from??

  interzone55 14:01 27 Jun 2008

1) Light can be slowed down by passing through very dense objects, one scientist has slowed it down to 15mph
click here

When people talk about the speed of light, as in Einstein's theory of relativity, they mean the speed of light in a vacuum.

2) not all faces on coins are in profile. The face of Sacegewea on the US $1 coin is semi-profile, you can see both eyes but she isn't filly face on. click here
As for why they're (mostly) in profile, I would imagine that it is much easier to create a recognisable profile on a coin than it is to create a face on image.

  Weskit 14:28 27 Jun 2008

Read somewhere that light originating from the centre of the sun takes a million years to reach it's surface, presumably because of the density of the sun's mass...

  S5W 14:35 27 Jun 2008

Recently some phycicists have postulated that the speed of light has been slowing down since the beginning of the universe. When measuring the red shift of some apparently very distant galaxies they appeared to be mature which was thought to be unlikely. If we are seeing them at about 11 billion years ago they should be young and blue with much dust and rapid star formation because there had been insufficient time for galaxies to mature. Interesting hypothesis and no doubt more to come.

  S5W 14:49 27 Jun 2008

phycicists = physicists. Apologies.

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