Guest Bigyin Posted July 2, 2004 Share Posted July 2, 2004 1. we know the speed of sound/light but do we know why it is that speed? 2. is the speed of light allways the same anywere? i know there cant be any sound in space so why does it not affect light? 3. speed of sound and light is found out by D=V*T (as in time 60s in a min 60 mins in a hr etc) but what if we are wrong what if there is 64s in a min cause our time scale is not right well i dont think it is cause every year is not allways the same cause of a leap year if so would that not **** up a few things? im a science newb so thats why im asking these questions so i might be talking a lot of shit please say to me "u dum ****" if needed Link to comment Share on other sites More sharing options...
TheProphet Posted July 2, 2004 Share Posted July 2, 2004 1. Sound is the moving of atoms, hence it's varied speed in different materials! Light on the other hand is eletromagnetic and consist of photons which always travels in a constant speed of 300km/s (if my memory serves me right) No mather form which Refernce plane u messuare! 2. read answer on 1. 3. Well we have defined time this way.. 1 sec i 1 sec. no more no less... but acording too Special relativity that clock measures time differenlty in different speeds.. so u got a point.. but light still travels att C when u travel at 0,8C for exampel, so for light the only affect is that u notice time to go faster on earth when traveling at 0,8c There are meny threads with the same or alike questions so please go and read them to for more answers =) Link to comment Share on other sites More sharing options...
JaKiri Posted July 5, 2004 Share Posted July 5, 2004 2. is the speed of light allways the same anywere? i know there cant be any sound in space so why does it not affect light? Light doesn't depend on any medium for transmission, however its speed can be affected by the medium it is travelling in; for example, light bending in a prism (or entering/exiting water, or any other medium transition) is due to its changing speed. 2. read answer on 1. Incorrect in some places (and you rather overcomplicate q3) but what if we are wrong what if there is 64s in a min All units (a meter, time, whatever) aren't universal. They were created by man, and exist as a comparison to eachother. There will always be 60 seconds in a minute, because that's how we've defined a minute; to be 60 seconds long. Link to comment Share on other sites More sharing options...
TheProphet Posted July 5, 2004 Share Posted July 5, 2004 JaKiri: So true! Light can also alter speed in different Materials... Like the Experiment by Hau where she slows so much... that it HALTS =) Even more interesting is a team of other researchers that have been able to read out single photons spin (i belive) by sending light into a very cold "cigar" of rubidium athoms! Indicate that they didn't alter the photons spin in this reading neither! i shall get back with the correct names from Scientific America (don't remeber which issue either)! Link to comment Share on other sites More sharing options...
JaKiri Posted July 6, 2004 Share Posted July 6, 2004 The most famous thing where light slows to a crawl is the Einstein-Bose condensate. Link to comment Share on other sites More sharing options...
QuarkQuarkQuark2001 Posted July 6, 2004 Share Posted July 6, 2004 Light doesn't depend on any medium for transmission' date=' however its speed can be affected by the medium it is travelling in; for example, light bending in a prism (or entering/exiting water, or any other medium transition) is due to its changing speed. Incorrect in some places (and you rather overcomplicate q3) All units (a meter, time, whatever) aren't universal. They were created by man, and exist as a comparison to eachother. There will always be 60 seconds in a minute, because that's how we've defined a minute; to be 60 seconds long.[/quote'] Let me talk some more about the refraction. Refraction occur when light travels from one medium to another medium. In other words, the speed of light in one medium is faster than another. It is right that the speed in vacuum is the fastest and the speed in diamond (a pure carbon product) is the slowest. Moreover, scientist define the refraction index as " The faster speed /the slower speed in another medium" Where the ratio of sine of the angle of incidence to the sine of the angle of refraction, where it's still true when the i is 90 degree. FOR REFRACTION, ONE OF THE MEDIUM MUCH BE OPTICALly DENSER WHILE THE OTHER IS OPTICALly LESS DENSER. Please be reminded of the optically THIS word. As the density of hot air is less dense( or denser "wanna to know this grammar item)than cold air, so air passes hot air with a higher speed and thus mirage occurs when the difference is too large. Maybe then you think all denser object is optically denser, but it's not true. Therefore, you need to be careful when you answer long questions and writing essays. Link to comment Share on other sites More sharing options...
Radical Edward Posted July 6, 2004 Share Posted July 6, 2004 The most famous thing where light slows to a crawl is the Einstein-Bose condensate. why EBC and not BEC? Link to comment Share on other sites More sharing options...
swansont Posted July 6, 2004 Share Posted July 6, 2004 The most famous thing where light slows to a crawl is the Einstein-Bose condensate. IIRC They've also done this in room-temperature vapor using electromagnetically-induced transparency (EIT) to make the linewidth really narrow, so there's a really big dispersion right near the resonance. Link to comment Share on other sites More sharing options...
JaKiri Posted July 6, 2004 Share Posted July 6, 2004 Maybe then you think all denser object is optically denser, but it's not true. I never suggested this, and your post is unbelieveably badly worded for an 'addition'. why EBC and not BEC? I think it sounds better. Link to comment Share on other sites More sharing options...
QuarkQuarkQuark2001 Posted July 8, 2004 Share Posted July 8, 2004 I never thought you but just remind bigyin. I know you are good. Link to comment Share on other sites More sharing options...
Sayonara Posted July 8, 2004 Share Posted July 8, 2004 your post is unbelieveably badly worded for an 'addition'. I believe HK = Hong Kong. Link to comment Share on other sites More sharing options...
JaKiri Posted July 8, 2004 Share Posted July 8, 2004 I believe HK = Hong Kong. We should have never given them back to china. Link to comment Share on other sites More sharing options...
QuarkQuarkQuark2001 Posted July 8, 2004 Share Posted July 8, 2004 ?What do you mean ? Link to comment Share on other sites More sharing options...
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