Discussion in 'Science & Society' started by Michael, Nov 2, 2010.
Analog, because you can't jump in time back and forth....
Log in or Sign up to hide all adverts.
Or neither. If we were going to liberally (very liberally) apply the concept then i would say, due to its organic nature, it can be perceived as analog. The comment above i can agree with and analog is more flexible. I'm just not seeing the digital aspect of the universe at all though. In the human world either digital or analog really depends on the application and they both have advantages and disadvantages.
Is the universe chunky or creamy? I don't know, is a particle a discrete unit or is it a blurry spot that probably has a particle in there somewhere?
Well lets see...is air digital or analog? The atmosphere? Not that i am aware of. Am i, a human, digital or analog? Where does this concept of it fit in? These are questions that need to be asked.
"Nevertheless, it is impossible, as Planck found out, to explain some phenomena without accepting that energy is quantized; that is, it exists only in integer multiples of some base value."
certianly does not mean the universe is digital but that the universe runs in intergrals and not in infinitely irrational numbers.
Our perception is analogous, even if the signal is digital.
The condition is that the digital signal frequency to be larger than a certain frequency.
On this is based cinema or television.
The images are displayed sequentially but at a frequency that we do not perceive them.
Please Register or Log in to view the hidden image! or Please Register or Log in to view the hidden image!
By digitizing can transmit several analog signals simultaneously.
Break between two digital signals can be much longer than the signal.
So during the break you can send another signal.
The receiver must be synchronized with the signal you want to receive.
Of course our reality includes digital and analog signals.
But I think the question refers to all our reality.
If our reality is digital then what is between two digital signals(Which are in sync with what we perceive as our world)?
Perhaps there is another world parallel to ours,with wich we are not synchronized?
Please Register or Log in to view the hidden image!
John99: Between time & a bacterium? There is a bit of semantic weirdness in this question. The following seem semantically better.
Between a non-living object & a bacterium? Answer: A virus.
Between a virus & a Bacterium? I cannot think of anything, but perhaps a biologist has an answer. Ditto for between a non-living object & a virus?
Between Philadelphia & New York City? Answer: New Jersey.
To me, time & a bacterium do not seem to belong in that sentence.
Others: It might be better to rephrase the question as: Is reality discrete or continuous?
Due to discreteness at the quantum level, it seems to me that the answer is that reality is discrete. The world of our senses seems continuous because the our perceptual mechanisms are not precise enough to observe the quantum level discontinuities.
There are those who propose that time is discrete rather than continuous.
There is a concept of minimum possible interaction. Id est: Consideration of (for example) billiard ball collisions would indicate that there is a discontinuity between the cue ball missing a ball completely & its not quite missing it.
When you view billiard ball collisions at the level of interactions between the fields associated with valence electrons, it is obvious that in practice, there is a discontinuity between a miss & the smallest measurable interaction. Is there a discontinuity in principle? I think that quantum theory indicates a discontinuity.
A note on Emil's post 46:
If the analogue signal has a finite number of Fourier components and you sample at twice the frequency of the highest frequency component (only twice in each cycle of that highest frequency component) your digital sample will EXACTLY reproduce the analog signal! This is for me a hard to believe, but true mathematical fact, which is not hard to prove, but I have forgotten how.
No and I just told why if the sampling frequency is high enough.
It is also interesting to note that photographs, even of the old film cameras, are digital. I.e. a 2D array of individual silver halide particles that were hit by at least two photons each.
I also hold a "crackpot" POV about perception. I.e. what we perceive is NOT, as the standard POV states, the "emergent" end product of many stages of neural computational transform of the signals our sensory nerve transducers acquired from environmental stimulation. Instead what we perceive is a creation of the parietal section of the brain, in what I call the Real Time Simulation, RTS.
To quickly understand the main flaws of the accepted theory of perception read short post at:
Read my longer RTS essay at: http://www.sciforums.com/showpost.php?p=905778&postcount=66 It explains dozens of neurological and psychological facts the accepted POV about perception cannot! (Doing that took about 8 pages if printed.)
As all nerves in the parietal brain either fire or don't*, the RTS is digital.
What you directly perceive has a stronger claim to being "reality" than what you can only infer may exist based on your direct perception. I.e. the "external world" is only INFERRED to exist. It may not exist but I, like almost** all others, do make the assumption that it does exist.
*There are a few optical nerves which don't have this fire or not nature -i.e. appear to be analogue, but not if you look closely at their activity - it is still just the movement of discrete Na+ ions across the axon sheath. I.e. for these nerves, the internal potential does not go quickly from -70mV to slightly positive as the nerve "fires" but can vary slowly up or down within this range.
** Bishop Berkeley did not so assume and has perfect logic in his defense of his position that the real world is only an illusion. (That logic has withstood 300 years of attacks!)
BTW, for John99 only: A piron I think fits between a virus, which must invade and use a cell to reproduce and and a bacteria, which is alive and needs only to eat to reproduce. Like a virus, the piron is not alive, but it can reproduce outside of cells, I think, or at least doesn't need that biological machinery of the cell to reproduce. Some years ago, man had no idea how pirons reproduce. That may not still be true -far out of my field of physics. Pirons cause diseases, including "Mad Cow disease."
Math demonstration is not my forte,but I understand the practical significance of the Fourier transformation.
It is mostly used in dynamic systems to establish and optimize these systems.Answer as quickly as possible, without override and without oscillation.
Any signal can be decomposed into sinusoidal oscillations,which has a base frequency and harmonics with different amplitude.(Fourier decomposition)
A harmonic is a sinusoidal oscillation with a frequency an integer multiple of the frequency from the base.
Please Register or Log in to view the hidden image! ...................................................... Please Register or Log in to view the hidden image!
The Fourier transformation is applied to the periodic signals,taking into account a period of time equal to the period of repetition.These have a finite number of harmonics.This signals may be reproduced by repeating the same signal again and again.(digital)
Usually, in nature the signals are not periodic.In this case it is considered a time period that you want analyzed and is assumed to be repetitive on that period of time.Fourier transformation of these signals has an infinite number of harmonics.These signals can not be reproduced by repeating the same signal again and again.
Another application is to understand the sounds.
The same musical note (hence the same frequency) is played differently by different instruments.
Fourier decomposition of these signals have the same basic frequency and the same harmonic frequencies but the amplitude of these harmonics varies from instrument to another.
Therefore even if the human ear not perceive the sounds that have basic frequency greater than 20kHz
but we perceive them as harmonic frequencies and they contribute to the tone.
That is why "Hi-Fi " play frequencies even greater than 20kHz.
Reality is a very complex and difficult concept to grasp. Who's reality? Mine, yours; someone else's? Or, do they mean by reality the general state of things on earth and in the cosmos? Can there actually be a 'general state' of things in the cosmos; is it actually definable?
The question itself seems flawed as reality is so difficult to define.
Anyway, the way I see it is that 'reality' is analogue superimposed on a digital matrix. Think of it like a digital amplifier with a couple of tubes added to it. The digital keeps the amp working nice and steady, clinical and defined, while the tubes add warmth and slight wobblyness, a potential for error.
It's Two.....Two......Two Realities in one!
Send the money to my paypal account.
In my opinion, reality is inherently connected to time and time only travels in one direction - forward. In saying that, time does not oscillate around a set point, does not slow down or speed up (but only in OUR perception), or is detectable in discrete amounts - those discrete amounts are only designated by us humans as units of time.
My life experiences have never been in little bits and pieces - has always been continuous in nature. Otherwise, I would be leading a very staggered and disjoint life.
In reality (no pun intended), the question borders on that of abstract thinking and comes down to one's opinion.
And I've just stated mine!
You don't sleep?
But don't synapses either fire or not? there's no "partial" firing is there?
You're thinking of the nerve's axon, not the interconnections between two nerves. Various neurotransmitters do diffuse (in both ways as they are reused) across those gaps (called synapses) between nerves.
If you want to be pedantic, yeah.. but the point is is the firing digital or analog. I believe it is digital, but the synapse can be influenced by multiple firings (summing/integrating the combination) or not and the receptor will either respond or not (again in a digital manner)
Linky: http://books.google.com/books?id=dS...ge&q=synapse firing analog or digital&f=false
I am not being pedantic. Just correcting your term. Nor is it pedantic to note that receptors don't "respond" as most would understand that term.
They are special shape structures mainly on the dendrites of nerves, although a few do exist on the cell body also. Each is like a lock in that it will accept a particular (shape) neurotransmitter, like its "key." When the receptor is occupied by its "key" the conditions internal in the nerve are changed, so you could call that a "response," but it is very local and nothing one can observe.
Yes you are. Did you even read the info at the link?
You, and probably everyone else understands exactly what I'm saying. There is a gap, a synapse between neurons, there is a "firing" that takes place across that synapse. It involves multiple neurons in most cases, but ...
You still didn't answer the question. Please Register or Log in to view the hidden image!
Digital or analog?
You know exactly what I'm talking about, just answer it.
So we look further into how we operate on an elementary level. This would be the firing of neurons, which is dependent of changes in electrical potential due to the passage of K and Na ions across a cell membrane.
These potentials are responsible for the release of neurotransmitters which give rise to the processes mentioned above. I suppose this is where reality all starts.
The further you look at things, on an atomic level, the closer continuous and discrete processes become. Infinitely smaller and smaller discrete processes become increasing more like a continuous process.
But where do we draw the line?
Separate names with a comma.