echi, light energy is quantized into photons. also, the dimensions of time and space can be thought of as being quantized in terms of the planck length. however, this is just the level at which our science breaks down -- at which point things are governed by different laws which we cannot observe. but that does not mean that things dont necessarily happen at that level.
Thanks, stuh505.
Is it correct to think of the quantum as a sort of unit of measurement? I've never been clear on this. Is a photon equivalent in size to the planck length?
Saying that something is quantized means that it only takes on integer values like 1,2,3 instead of 1.2345... The only things that take on integer values are things that can be counted, so saying that light is quantized implies that light is composed of a stream of individual particles (called photons) which can be counted. Similarly, you could say that water is quantized by molecules of H20. Light is not quite as simple as water, though, because although light is composed of particles those particles do not move in the way that conventional particles do. They are subject to wave properties, meaning that the density of particles in space can be reduced or increased similarly to a wave of water...but unlike a water wave which is a transverse, mechanical wave, photons are actually traveling in the direction of the wave and there is no obvious logical explanation for how a stream of particles would be subject to these wave properties. This paradox is the wave-particle duality.
Photons cannot be thought of as having a size. They have no size and no mass, they are just pure energy...and they do not even exist in exact locations. The planck length is the minimum distance that the position of a photon can be measured to. It is impossible to measure the position more accurately than this because it does not HAVE an exact position! So the planck length can be thought of as a quantization of space. Similarly, the amount of time it takes for a photon to travel the planck length can be thought of as a quantization of time.
As we look deeper, we discover that fundamental particles like this do not behave in the same way that we think of particles at the human scale like marbles or grains of sand (newtonian). This is what leads people to believe that perhaps our concept of a particle as being a "thing" at all is not even correct...that perhaps instead a particle is just a representation of a vibration and our entire universe is just a strange interpretation of vibrations in some ethereal plane...
stuh505, You're the man.
I need some time to think about this, but I'm sure I will return with ever more (hopefully, less-dumb) questions.
Can anyone explain the significance of the Mandelbrot Set? (Sorry, I don't know how to better ask that question.)
It has no significance, it is just an interesting mathematical formulation that makes pretty pictures.
So, time is relative... right? I know the old example about person A traveling through space at close to light speed and person B remaining on Earth-- then, when person A returns to Earth he/she will have aged only slightly, while person B will have aged considerably more. This idea I am somewhat comfortable with... that Time and Energy are somehow relative.
But I have been wondering about the relative nature of time as it might apply to a person's thought processes. Why is it that, sometimes, an hour can feel like twenty minutes? It's probably just that we are not very good time keepers, I guess. Our thoughts can wander off and cause us to lose track.
Okay... Here's the really dumb question that I want to ask:
We assume that everyone experiences the passage of time in almost exactly the same way. (A minute feels about the same for me as it does for you.) Is this a safe assumption?
Specifically, what about when a person is experiencing an altered state of awareness, like someone who is dying? If it takes a person only a minute or so to die (suppose you saw someone get shot), is it safe to assume that the dying person would have a similar experience of time to that of an onlooker? Is there any scientific reason to think that a dying person might experience time on a totally different scale?
Your perception of time is far different from your physical rate of change through time. But perception is governed by your brain, a machine...your brain also must follow the laws of physics but it is not the laws of physics that result in an altered perception of time for you.
That said, have you ever ridden the 200 foot free-fall drop ride at the fair? You wait in line and watch and it looks like they are in the air for about a second from the ground. But when I got in the char and fell, it felt like a hell of a lot longer!
This means Star Trek and warp drive engines are all bullshit! All my childhood dreams shot to hell!
stuh505 wrote:Your perception of time is far different from your physical rate of change through time. But perception is governed by your brain, a machine...your brain also must follow the laws of physics but it is not the laws of physics that result in an altered perception of time for you.
Would it seem too unreasonable to think that a person who, from the perspective of an onlooker, dies instantly might not experience an instant death?
Might someone who, perhaps, dies "instantly" from a shotgun blast to the brain, for example, experience the process as taking much longer than it would appear to witnesses?
NickFun wrote:This means Star Trek and warp drive engines are all bullshit! All my childhood dreams shot to hell!
No, on the contrary...we do not understand enough about the fundamentals of our universe to say if that technology will become possible someday or not. However, the theory of GR predicts that it may be possible:
Quote:The Alcubierre Metric defines the so-called warp drive spacetime. This is a Lorentzian manifold which, if interpreted in the context of general relativity, exhibits features reminiscent of the warp drive from Star Trek: a warp bubble appears in previously flat spacetime and moves off at effectively superluminal speed. Even more striking, inhabitants of the bubble feel no inertial effects. The object(s)within the bubble are not moving (locally) faster than light, instead, the space around them shifts so that the object(s) arrives at its destination faster than light would in normal space
http://en.wikipedia.org/wiki/Alcubierre_drive
Quote:Would it seem too unreasonable to think that a person who, from the perspective of an onlooker, dies instantly might not experience an instant death?
Might someone who, perhaps, dies "instantly" from a shotgun blast to the brain, for example, experience the process as taking much longer than it would appear to witnesses?
No, because perception of time is a brain function. If the brain is not functioning, time cannot be perceived. If moment your brain explodes, your consciousness will cease to exist. There is no delay whatsoever.
I understand that there can be no consciousness if there is no brain. I am only asking about the small amount of time it would take for the brain to explode. Wouldn't the person still have a subjective experience of time in such a case?
In the situation of a shotgun blast, absolutely not. Action potentials in the brain travel at a rate of 10-20 meters/s, whereas the shot from a shotgun will be traveling through your brain at upwards of 300 meters/s, meaning it will take only 0.00067733 seconds for your brain to be completely destroyed. This would allow an action potential (which is a brain signal) to travel a distance of only 0.01016 meters, or 1 cm. In other words, if you were staring at the shotgun at the time it was fired, it would be impossible for the message to pass from your eyes to your brain before you were dead, so you wouldn't even know that you were shot.
However, if you were shot from a handgun that only grazed a portion of your brain while not completely destroying it, you might very well have a few seconds of consciousness...and I do not find it hard to believe that your perception of time during that period would be askew, especially since it would disrupt blood and oxygen flow which is a notorious cause for strange out of body and near death emotions.
Wow. Thanks, stuh505. I had an idea about what the dying experience might be like, but you seem to have just destroyed it. Now I have to reconsider everything. This totally blows my mind! (sorry)
Seriously, this is not at all what I had guessed. I actually have looked for information on this subject (the speed at which the brain functions, and such) but I never could find anything that was useful to me-- probably because I didn't know what terminology to use in my search. Anyway...
Thanks, again. You rock!
If you are interested in what a shotgun shell will do to your head, take a look at this photograph. Not for the faint of heart...
http://poetry.rotten.com/shot-au/0001/shotau1.jpg
I guess that oughtta' do it. Looks like he ate a stick of dynamite. F#ck!
damn work filters, i always wanted to see a shotgun blast to the head, i hope that doesnt sound, bad? lOL!
Does light really slow down when it travels through a substance (non-vacuum)? Or does light just seem to travel slower due to its being redirected or channelled through a substance? IOW, does the light simply have a greater distance to travel through a substance (vs through a vacuum), making it appear to slow down even though its speed remains constant?
Keep em coming.
