as i understand things, an object has a particular colour because it absorbs the light and only reflects back a particular wave length. e.g. an
orange absorbs all wavelengths apart from orange wavelength light, which it reflect back making the object appear orange coloured
So does this mean that when there is no light, nothing has colour?
[Edited on 15/1/07 by liam.mccaffrey]
If there is no light you wont be able to see it so it cant, by your deffinition, have colour....
It will still be coloured though....
colour is a human perception. Hence in the absence of light, an object has properties that would give it the appearance of colour if it was
illuminated, however an object doesnt have 'colour' as such anyway.
quote:
Originally posted by tegwin
It will still be coloured though....
And the other question is - is the colour that I see as orange seen exactly the same way by other people?
Really colour has no meaning without light…
Why on earth are you asking this?????
Truly unanswerable.... bit like
-Schrodinger's cat?
or
-"If a tree falls in the forest and there is nobody around does it make a sound?"
or my girlfriend's favorite
"If a man is alone in a forest and says something, if there's no woman around to hear it is he still wrong?"
although I prefer Voltaire's
"all the reasoning of a man cannot outweigh a single feeling of a woman"
[Edited on 15/1/07 by BenB]
that is too simplistic.
there is no such fundamental thing as colour, it is not lying out there to be discovered but colour is something used by humans to describe what we
see around us.
we cannot ever know that what one person sees as orange is seen as another colour (again colour are arbitrary terms) or not. people who are colour
blind will get collurs wrong..
also there is more than visible light, IR, UV etc: and an object can do the same things, absrob ort not, light in those frequencies so has another
"colour" for those eyes or devices that can detect the frequencies.
but to answer your question using your terms, the object still has colour just that there is no light in which to see it.
A way to think about it, is your locost a diffefrent colour when you trun off the garage light? (I suppose you could claim it is since you cannot see
it). but it still has a cololur, unfortuanltey you don't know what that colour is. 
don't tell me you into quantum physics as well
Here is a good question...
How would you describe a colour to a blind person?
And you are right...chances are what you percieve as blue isnt what I see atall...
schrodingers cat is widely misunderstood. When he first proposed the idea, it was to illuminate a concept in quantum physics. He did it more to be
difficult. He never intended it to be taken seriously.
http://en.wikipedia.org/wiki/Schr%C3%B6dinger%27s_cat
as einstein wrote to schrodinger:
quote:
Nobody really doubts that the presence or absence of the cat is something independent of the act of observation.
Would there be any point. I doubt they could really grasp the concept in their head.
Real question is when a bind person thinks of something say an object, how does it appear in their head??
Quantum physics doesn't work. Neither do complex numbers 
Well, not in my brain anyway..... Nothing that can't be explained......
Young's double-slit experiment- just a fluke.....
Complementarity Principle- plain crazy......
I can feel my neurones oozing out of my ears already....
It does have some meaning regarding how partials behave when faced with a choice of outcomes like in the slit experiments. All comes down to the old wave particle duality problem.
Which to be honest isn’t a problem at all. Just a misinterpretation of what’s happening.
Forget particles, there's no such thing
[Edited on 15/1/07 by macnab]
Colour is a generic term for frequency we can see... hearing is a generic term for frequency we can hear.
Therefore, we cannot see or hear anything. We measure the comparible frequencies against each other using comparibly simple receptors. We dont just
sense sound using our ear canal and cavities, nor do we just see things through our eyes. We have rudimentary senses that combine all five (some say
six) senses. Therefore depending upon how good our receptors are gives us a different picture of what we are sensing, be it sound our vision.
Of course we all hear and see differently. So how do we compare smell...??
Steve
We don't actually 'smell' anything, we taste it.
Think about that next time you enter the sh#thouse 
Originally posted by Hellfire
Colour is a generic term for frequency we can see... hearing is a generic term for frequency we can hear.
Therefore, we cannot see or hear anything. We measure the comparible frequencies against each other using comparibly simple receptors. We dont just
sense sound using our ear canal and cavities, nor do we just see things through our eyes. We have rudimentary senses that combine all five (some say
six) senses. Therefore depending upon how good our receptors are gives us a different picture of what we are sensing, be it sound our vision.
Of course we all hear and see differently. So how do we compare smell...??
Steve
Or more importantly;
If a man says something in a forest, and there is no woman there to hear him, is he still wrong?
Surely explaining a colour to a blind person is not so difficult. You're only explaining your perception of the occurance to that person ie what
response that colour creates in you.
Perception is a bizarre one. One of the stumbling blocks with artificial retinas is that you have to use them early before the ability to learn new
perceptions finishes. Mice grown in cages with horizontal lines only loose the ability to perceive vertical lines etc etc.... Similarly giving a blind
person artifical retinas when they're 20-30 would be not so beneficial. They'd probably be good on faces (different perception centre- hence
newborns get quite handy with faces quickly) but for day to day stuff not much cop....
The other bizarre was is in people whose L hemisphere of the brain doesn't communicate with the R (usually surgically induced). Get them to close
their eyes and put something in their and though they'll describe it they won't be able to perceive it or name it, let them open their eyes
and they'll perceive and recognize it straight away)...
Humans have 9 defined senses by the way, can you guess them all?
Ie 9 difference cellular systems to gather information on our environment.
Sight, taste, smell, touch and hearing are only 5 of them.
Remember we're all based on the same ‘mechanics’ I therefore would not expect to much off a difference.
Things like preferences for certain tastes or colours are more subjective and not the same thing as how stimuli are first received.
More those are learnt or pre-programmed responses
[Edited on 15/1/07 by macnab]
quote:
Originally posted by Wadders
We don't actually 'smell' anything, we taste it.
he he Liams buggered off.
firestarter!
I stand corrected 
Originally posted by BenB
quote:
Originally posted by Wadders
We don't actually 'smell' anything, we taste it.
quote:
Originally posted by BenB
People who destroy their olfactory cranial nerve (sense of smell to you and me) have a lifetime of tasteless living... Good for chilli eating competitions though....
I trust you guys are all at "work" since you clearly have nothing better to do and obviously are unable t get into the garage to spend time
buildng your cars
[Edited on 15/1/07 by ayoungman]
quote:
Originally posted by jlparsons
Humans have 9 defined senses by the way, can you guess them all?
Aye, I read the same book! My dad had it for christmas. Was a new one on me, but makes sense.
There was one about little watchamacallits in your tendons. Means you can touch you nose with the tip of your finger with your eyes closed when
you're not pissed. So, obviously that one comes in handy.
quote:
Originally posted by Wadders
We don't actually 'smell' anything, we taste it.
Think about that next time you enter the sh#thouse
I have a cold so I cant taste anything? My mouth is not full of muces, my nose is!
Sh!t house? OMG - dont go there!!!
jollygreengiant - 15/1/07 at 06:26 PMOk 2 questions.
1, In Star Trek, when 2 vessels meet, why are they ALWAYS in the same orientaion. Is this a universal constant.
2, If space is infinate and a vaccuum then surely a vaccuum must exist within something. Therefore when/if you traveled to the end of the Vaccuum, what sort of barrier would you meet and WHAT would be on the other side.?
JoelP - 15/1/07 at 06:33 PMlol at question one, they never follow the physics through properly!
liam.mccaffrey - 15/1/07 at 06:52 PMi haven't buggered off i was at work
people have put some good arguments forward.
i think my original wording was not correct. i shall think and reiterate
GavBurns - 15/1/07 at 07:11 PMDEEP!
DIY Si - 15/1/07 at 07:33 PMquote:
1, In Star Trek, when 2 vessels meet, why are they ALWAYS in the same orientation. Is this a universal constant.
Star Trek, as with most sci fi programs are technically inaccurate, as it would just look silly having one ship upside down. Besides, up and down are meaningless descriptions in space, as they are all relative.
DIY Si - 15/1/07 at 07:35 PMquote:
2, If space is infinite and a vacuum then surely a vacuum must exist within something. Therefore when/if you travelled to the end of the Vacuum, what sort of barrier would you meet and WHAT would be on the other side.?
You're question is without an answer, as it creates an impossible scenario. You say the Universe is infinite, yet wish to know what is at the edge. This can not happen due to being infinite, thus having no edges.
jollygreengiant - 15/1/07 at 07:59 PMquote:
Originally posted by DIY Si
quote:
2, If space is infinite and a vacuum then surely a vacuum must exist within something. Therefore when/if you travelled to the end of the Vacuum, what sort of barrier would you meet and WHAT would be on the other side.?
You're question is without an answer, as it creates an impossible scenario. You say the Universe is infinite, yet wish to know what is at the edge. This can not happen due to being infinite, thus having no edges.
There was a time when man said the world was flat and we all believed it. General opinion I believe currently says that the universe is infinite. HOW do they know, have they been there. Who knows what is at the edge of the universe.
The universe is expanding, so we are told. If so what is it expanding into.?
Once again he kicks the beehive and then retires to a safe distance to watch.
DIY Si - 15/1/07 at 08:09 PMSee, that's cheating. You've gone and changed the question!
The answer depends partly upon what you believe to be true. As you say, no real, confirmable answer can be given, as if the Universe is expanding at the speed of light, there is no possible way to reach the edge, as you would have to travel at much greater than light speeds. This may be possible with worm holes, but would be "fiddly" at best!
steve m - 15/1/07 at 08:40 PMLiam
have you still got that very very big adjustable spanner you bought at stoneliegh a few years ago ??
if so smack you head with it !
You may recover and come back to our world
liam.mccaffrey - 15/1/07 at 08:42 PMive never been to stonleigh steve m. have you been hitting yourself with adjustable spanners perhaps?
steve m - 15/1/07 at 08:45 PMoooppps
could be the wrong Liam !!
Me thinks it was newark then ?
[Edited on 15/1/07 by steve m]
[Edited on 15/1/07 by steve m]
liam.mccaffrey - 15/1/07 at 08:56 PMwrong Liam, never been to newark either
you must stop smashing your head with adjustable spanners
steve m - 15/1/07 at 08:57 PMi will
JoelP - 15/1/07 at 09:37 PMsome areas of space are apparently retreating faster than light. Cant tell you off the top of my head how this is possible, but it was explained once. The 'edge of the universe' is technically the boundary of spacetime, flying outwards ever since the beginning. There is nothing beyond. Indeed, there is no beyond. However, i reserve the right to change this reply at the first sign of trouble
Anyway, two questions im sure no one can answer, are these:
- why is the charge on a proton precisely equal and opposite to that of an electron, when they are completely different particles?
- Why is there more matter than antimatter in the universe, when technically there should be equal amounts of each?
[Edited on 15/1/07 by JoelP]
jollygreengiant - 15/1/07 at 10:11 PMquote:
Originally posted by JoelP
- Why is there more matter than antimatter in the universe, when technically there should be equal amounts of each?
[Edited on 15/1/07 by JoelP]
If there was a perfect balance to the universe then it not be expanding or contracting.
In fact all would be in perfect balance. Ergo Tony Blair would have the same brain power as a single celled organism.
Bugger he has. There goes my explanation.
rusty nuts - 15/1/07 at 10:13 PMBut Blair has an answer for everything, even if it's the wrong answer
macnab - 16/1/07 at 09:54 AMI'm hoping that he gets hanged in this new program thats coming. I'll PMSL.
trogdor - 16/1/07 at 10:09 AMphysics is full of these kinda questions that haven't been answered,
for isntance within an atom, why do the protons all stick together in the middle? shouldn't they repel each other?
when you get this small conventional physics just goes out of the window
macnab - 16/1/07 at 10:47 AMIts the strong force that’s holding them together, basically a very short distance field capable of overcoming this repulsion also referred to as the colour force. The distance apart being a balance between the two forces. Once the strong force is overcome (by quantum tunnelling or a smack from an incoming high speed partial) the protons get fired out by the electro static force as an alpha partial (a type of radiation)
02GF74 - 16/1/07 at 11:02 AMquote:
Originally posted by JoelP
- Why is there more matter than antimatter in the universe, when technically there should be equal amounts of each?
[Edited on 15/1/07 by JoelP]
is it the case we haven't found where the anti-matter is? Come everyone, have a good look in your garden shed.
macnab - 16/1/07 at 11:08 AMReckoned to be due to a slight imbalance (there are some new theories that predict this occurring), so what’s here is only a tiny fraction of the initial amount of material.
Another theory is that the big bang had an axis of symmetry (research in to the microwave back ground should reveal this), which caused the matter and anti-mater to go in opposite directions. Which means that it would be outside the visual horizon by now.
[Edited on 16/1/07 by macnab]
trogdor - 16/1/07 at 01:56 PMI find it amusing in physics that they find it embrassing how much they don't know,
its the same in my degree, the oceans are so unknown yet we know so much about them. is ironic really
[Edited on 16/1/07 by trogdor]
macnab - 16/1/07 at 04:24 PMThat sounds an interesting degree.
Lots of new thing’s been discovered recently. Good chance of getting on board a submersible as well, I’d love that.
[Edited on 16/1/07 by macnab]
DIY Si - 16/1/07 at 06:14 PMDon't know about anti matter much, but protons and electrons are made up of three quarks (up and down in this case), giving the electron -1 and the proton +1. The component parts are, however, totally different in weight.
As said there is much about physics that can only be guessed at present, due to not having any way of measuring/viewing/detecting it at all. Bit like the deep ocean stuff. We know roughly what's going on, but the details are a little blurry.
JoelP - 16/1/07 at 08:28 PMelectrons are not made of quarks, they are in the lepton family, and are nothing to do with quarks. Neutrons and protons are made from 3 quarks each, with the charges balancing to zero and +1 respectively.
The usual answer is that it is chance, that if the charges were not equal we wouldnt be here discussing it as the universe wouldnt 'work'! I suspect that this answer will be replaced with a more fundamental explanation, ie string etc.
http://en.wikipedia.org/wiki/Lepton
DIY Si - 16/1/07 at 11:49 PMOoops. Been a while since I did stuff like this, so may have missed a few "minor" details!
Peteff - 17/1/07 at 12:07 AMWorks like a charm.
trogdor - 17/1/07 at 09:52 AMyeah oceanography can be pretty interesting! unfortunatly i never work with any thing pretty or really weird i was a chemical and physical oceanographer but am now doing a dissertation in geophysics, looking at volcanic processes along the Mid Atlantic Ridge, near the Ascension Islands is kinda cool i am using images noone has really looked at before!
Wish i could get time on a submerisible, but they are almost impossible to get on! would of liked to go on a cruise though, there is a brand new research ship! is sat outside the building right now.
macnab - 20/1/07 at 09:00 PMStow away…
omega 24 v6 - 20/1/07 at 09:31 PMJeez what a deep and disturbing topic this is. Obviously science has a long way to go yet.
If I was in court for assault and argued my own case that in no way could I have hit the guy would the following theory get me off.
Basically before my fist can contact the guy's fizzog then it has to travel half the distance from the clenched position to his face. It then has to travel half the remain distance to get to his face etc etc. And since half of something can never be nothing then I rest my case I never laid a finger on the guy.
Would I be a free man or could the law prove differently?????
martyn_16v - 20/1/07 at 11:52 PMSounds very like the tortoise and arrow paradox: if you shoot an arrow at a tortoise that is walking away, by the time the arrow reaches where the tortoise was, it's moved away a bit. So now the arrow has to travel that bit further, but in that time the tortoise has also moved just a wee bit further away, so the arrow has to travel just a little bit farther, but now the tortoise is a gnats nads further, etc etc. Utter rubbish of course, you'll just end up with tortoise kebabs if you actually try it.
iank - 21/1/07 at 02:49 AMZeno's paradox (tortoise and arrow) make my head hurt.
"Still hotly contested by philosophers" which proves a lot more about philosophers than tortoises if you ask me.
http://en.wikipedia.org/wiki/Zeno's_paradoxes
(reminds me of a rather crude but funny joke about mathematicians vs engineers)
Schrodinger - 21/1/07 at 10:28 AMquote:
Originally posted by JoelP
schrodingers cat is widely misunderstood. When he first proposed the idea, it was to illuminate a concept in quantum physics. He did it more to be difficult. He never intended it to be taken seriously.
http://en.wikipedia.org/wiki/Schr%C3%B6dinger%27s_cat
as einstein wrote to schrodinger:
quote:
Nobody really doubts that the presence or absence of the cat is something independent of the act of observation.
[Edited on 15/1/07 by JoelP]
Er' leave my cat out of this
Peteff - 21/1/07 at 11:47 AMIt'll not pass MOT if you leave the cat out
I'm glad I'm not a philosopher, don't they have to think of some sh!te to justify the title. I want to know the answer to some complex problems like where does all the stuff I put in the compost bin disappear to? It was full two days ago and now there's only half in it, and archaeology, all that stuff they dig up who buries it ?
Didn't Schrodinger like cats, wouldn't the theory have worked with a mouse or something?
[Edited on 21/1/07 by Peteff]