This discussion is awesome. As an engineer, I know enough to be able to follow along, but I can’t really contribute much. Keep it going…
Protons aren’t “solid” to have a size either. They are made of quarks. Multiple waves of electromagnetic energy condensed in one space.
[quote]lothario1132 wrote:
swordthrower wrote:
Dr. Ryan wrote:
For anyone reading this thread looking for a practical application of any of this info, here it is:
From this day forward Planck Squats are the name of the exercise where the person loads the bar up with way too much weight than they can properly full squat and then proceeds to unlock/relock the knees and count that as a full-rep.
How to use it in a sentence, “This bozo at the gym loads four plates on each side, does a set of Planck squats and then struts off like a bad ass. What a tool.”
Nice…
Seconded. “Planck squats” has a nice ring to it. Does it count if it’s in a Smith Machine? :)[/quote]
You bet your quarks it counts! Actually, using a Smith machine further assures the Planck nature of the movement. Since the shortest distance between two points is a straight line, and the Smith machine locks you into a linear movement, that guarantees you the shortest distance versus a free squat which would allow 3-D movement.
[quote]brucevangeorge wrote:
Well, the thing is that photons don’t really have a size, like a particle, say, a proton does.
Protons aren’t “solid” to have a size either. They are made of quarks. Multiple waves of electromagnetic energy condensed in one space.[/quote]
Actually most of the mass of a proton doesn’t come from the quarks, but the energy of the gluons binding them together.
Lucasa, he’s right.
Mathematics can perform outside of physics, but physics must be described by mathematics.
Math is simply logic. It doesn’t require any physical basis. While the roots of math are physical, it has developed well beyond the point at which it requires a physical basis. To see a great example, look up “Abstract Algebra”, or something on infinite dimensional matrices.
Sure pi is incalculable, but it exists and the logic behind it is there. We could theoretically calculate pi to any degree of precision we need.
Also, no “true” circles exist. “Smoothness” or “circles” in a mathematical sense don’t exist in the universe. Sure we can well approximate most things as smooth, but in truth they are not.
You bring up the fact that “time is not invertible”. This is untrue, since given a function of time, we can easily invert to see how time relates to another quantity. Whether or not we can travel backwards in time is a completely unrelated issue. In addition, there are easily cases of uninvertible functions. Just Google it and see.
[quote]lucasa wrote:
Isn’t this a non-sequitir? You assert that mathematics can perform outside the bounds of physics. Must physics be bounded by mathematics? Just because math can’t deal with something divided by nothing doesn’t (necessarily) mean physics can’t do it. Pi is theoretically irrational and mathematically incalculable, but every circle in the universe contains pi. Math has yet to generate a truly random equation or an univertible function, but physics (thanks to time) does it in a myriad of ways every second of every day.
What I really want to know is if we’re a great big movie, when is intermission?[/quote]
[quote]lothario1132 wrote:
swordthrower wrote:
Ok kids, here comes the disgruntled physics graduate student…
First of all, the Planck time has nothing to do with the speed of light directly. It really has to do with reconciling gravity with quantum field theory. The fundamental “Planck” quantity is the Planck energy, which is the energy at which quantum field theory breaks down becuase gravity starts to have a non-negligible effect. A complete description of quantum gravity would be required, which we don’t have right now.
The reason this is an interesting quantity is becuase it really is a maximum energy that a photon can have, because if it had any more, it would create a particle massive enough to become a black hole. Therefore, bye-bye photon, and no observations can be made.
Using the uncertainty principle, you can derive the Planck scale, or Planck length, which corresponds to the Schwarzchild radius of a black hole of the Planck mass.
I think everyone also needs to be reminded that physics is a mathematical description of reality, and any non-mathematical speculation, while useful from a pedagagical or philosophical perspective, is not scientifically valid.
P.S. I just checked out the Wikipedia entry for the Planck scale, and it’s pretty good. Take a look.
Okay, hearing you. But what about my assertion that there is such a thing as the smallest unit of time? Isn’t the fact that there is such a thing as a “fastest speed” indicative of this?
Or is my caffeine buzz just making me even more full of shit than I normally am? :)[/quote]
Right, using the uncertainty principle, you could find a timescale which is the smallest timescale you could measure before all hell breaks loose and the photons you are using for your measurement create and get destroyed by black holes.
But again, this is a quantum gravity effect. It has nothing to do directly with the speed of light. (Obviously, since the speed of light is a fundamental constant, it is involved in the calculation of the Planck time, but not in the way you had suggested).
[quote]Dr. Ryan wrote:
You bet your quarks it counts! Actually, using a Smith machine further assures the Planck nature of the movement. Since the shortest distance between two points is a straight line, and the Smith machine locks you into a linear movement, that guarantees you the shortest distance versus a free squat which would allow 3-D movement.[/quote]
You see, this just makes total sense to me. Thank you for clarifying this, Doc.
[quote]swordthrower wrote:
Right, using the uncertainty principle, you could find a timescale which is the smallest timescale you could measure before all hell breaks loose and the photons you are using for your measurement create and get destroyed by black holes.
But again, this is a quantum gravity effect. It has nothing to do directly with the speed of light. (Obviously, since the speed of light is a fundamental constant, it is involved in the calculation of the Planck time, but not in the way you had suggested).[/quote]
You have a way better grasp of this than me… I’m an armchair physicist more than anybody in this thread.
But still…
Without invoking black holes and such, and just saying that there is a “speed limit” (as I like to call it) to the Universe, doesn’t that mean that there is a “smallest time unit” which cannot be infinitely small? Just looking at the rate equation and nothing else, and relying on the fact that c cannot be exceeded… that means there is a bottom limit to time. It is a discrete quantity, yes?
I understand your hesitation here… because gravity is fucked up. To put it succintly. 
[quote]PGA wrote:
jjblaze wrote:
If you’re bored at work and want to watch a great quantum movie and bend your mind a little, pop in a dvd of “What the bleep do we know?” Great flic.
And pretty much debunked by everyone! Even some associated with it![/quote]
Ok, so there’s one slight, tiny caveat there. Or maybe a big one. Still thought it was a good way to kill two hours, though. What the bleep do I know?
[quote]lothario1132 wrote:
swordthrower wrote:
Right, using the uncertainty principle, you could find a timescale which is the smallest timescale you could measure before all hell breaks loose and the photons you are using for your measurement create and get destroyed by black holes.
But again, this is a quantum gravity effect. It has nothing to do directly with the speed of light. (Obviously, since the speed of light is a fundamental constant, it is involved in the calculation of the Planck time, but not in the way you had suggested).
You have a way better grasp of this than me… I’m an armchair physicist more than anybody in this thread.
But still…
Without invoking black holes and such, and just saying that there is a “speed limit” (as I like to call it) to the Universe, doesn’t that mean that there is a “smallest time unit” which cannot be infinitely small? Just looking at the rate equation and nothing else, and relying on the fact that c cannot be exceeded… that means there is a bottom limit to time. It is a discrete quantity, yes?
I understand your hesitation here… because gravity is fucked up. To put it succintly. :)[/quote]
Sorry if I haven’t made it clear, but I am agreeing with you. Yes, there is such a unit of time. But I would caution you that it is not some absolute quantity. It is just the timescale at which physics according to our incomplete understanding breaks down. If we had a unified theory with quantum gravity, then we might be able to describe what happens on timescales smaller than that.
Also, please understand that I am by no means an expert. I specialize in astronomy, not theoretical physics, so my opinion shouldn’t be taken too seriously… I may very well be mistaken, and embarassing the physics community by writing pure jibberish.
[quote]lucasa wrote:
What I really want to know is if we’re a great big movie, when is intermission?[/quote]
This is a good question. How about these:
If we’re living in a computer game generated by the sickest, most ludicrously fast computer imaginable:
Do I get a saved game to revert back to after I die? Can somebody control-alt-delete us?
Even the most die-hard atheists (like me) have to admit that it’s spooky how the rules of the universe are meshed together so interchangeably and perfectly to give the possibility of life. If even the tiniest bit of the way the universe interacts with itself was changed, shit would be wayyy different (what if electrons didn’t react the way they do).
It’s almost like the way the universe is ordered almost guaranteed that something sentient like a human being would arise eventually. And by “almost guaranteed”, I mean “guaranteed”. We are living proof.
Is this a tremendous game of “Sims” we’re living in? We’ve already figured out the resolution of the 3d monitor we live in, and the speed at which we are animated in the program.
The laws of physics are constant, yes? Just like a set of defined variables and behaviors in a computer program. Could we write a computer program to desribe our observed reality? If it wasn’t for the quantum gravity problem, then the answer would be yes. We are this close:
| |
To being able to figure out just how quantum mechanics correlates with relativity.
PS I love diet mountain dew. Even if it makes me post stupid shit like this.
[quote]swordthrower wrote:
Sorry if I haven’t made it clear, but I am agreeing with you. Yes, there is such a unit of time. But I would caution you that it is not some absolute quantity. It is just the timescale at which physics according to our incomplete understanding breaks down. If we had a unified theory with quantum gravity, then we might be able to describe what happens on timescales smaller than that.
Also, please understand that I am by no means an expert. I specialize in astronomy, not theoretical physics, so my opinion shouldn’t be taken too seriously… I may very well be mistaken, and embarassing the physics community by writing pure jibberish.[/quote]
Dude, nobody here is Stephen Hawking. I am glad you showed up here to keep some kind of semblance to actual science in this thread.
So there IS a “smallest time”, but it may be less than a Planck time, we can’t be sure until the quantum gravity problem is solved. Wow.
Thanks, man. I just got smarter and lord knows I needed it.
Isn’t physics great? Particularly particle physics and nuclear physics. Where else do you get to say cool words like leptons, quarks, gravitrons, neutrinos, bosons, hadrons, photons, fermions and baryons. I love reading about this stuff (Discover Magazine, Stephen Hawking books, etc.) but I have to admit I can’t grasp much of it.
The only thing that gives me some solace is the fact that I have probably banged a few of those Physics geeks’ girlfriends when they were at the library studying. Okay, I made that up to appear cool.
One thing I can understand is Plank Squats in the Smith Machine. I bet that is how man will finally exceed the speed of light. Pile enough plates on and accelerate the load through a small enough range of motion and you could do it!
Serious question: Is the bulk of a physicist’s time at work spent thinking and pondering? Who hires physicists? Are they charged to work on certain projects? Do they have papers to submit to their bosses on what they came up with or what new mathematical proof they found?
[quote]bretc wrote:
Serious question: Is the bulk of a physicist’s time at work spent thinking and pondering? Who hires physicists? Are they charged to work on certain projects? Do they have papers to submit to their bosses on what they came up with or what new mathematical proof they found?[/quote]
LOL Actually I can answer this, as my younger brother was a double major in physics and math at FSU.
What happens is that if you come up with some crazy shit that you can apply due to your deeper understanding of the universe or whatever, then you get snatched up by the NSA.
Remember when the Predator unmanned aircraft took out that famous terrorist guy in Iraq? He was part of the design team that made that damn thing.
His next gig was with the Navy in designing and implementing visualization devices for submarines using crazy-ass processing computers and harmonics or whatever the hell it was to make the ocean our bitch in terms of guiding torpedoes and whatnot.
I can safely assert that no other nation will ever win a naval battle against the US. Ever. He didn’t give me any details of the technology, but the stuff he could tell me about… goddamn.
Let’s just say that my father saved his good sperm for three years after I was born, okay?
[quote]bretc wrote:
Serious question: Is the bulk of a physicist’s time at work spent thinking and pondering? Who hires physicists? Are they charged to work on certain projects? Do they have papers to submit to their bosses on what they came up with or what new mathematical proof they found?[/quote]
Depends on what field you are in. Thereotical/mathematical physicists from what I can tell are just mainly hired by universities. They basically submit papers of stuff they dreamt up.
Experimental high energy physicists are probably also mainly hired by universities. What they do is construct devices/write computer programs to test the crazy things theorists come up with.
As for the rest, it’s mostly applied. Stuff like superconductivity and quantum computing, you could probably be hired by any number of institutions/corporations that need to know about stuff like that. Then they try to figure shit out or do kind of “very high level” engineering.
[quote]pookie wrote:
Since there’s no way of registering those smaller/larger alien beings, then there’s no way to tell if they’re actually there or not. Correct me if I’m wrong.
If there’s no way of detecting the presence of those smaller/larger beings at all, why suppose that they exist? Why invent undetectable entities that have no interaction with this universe? What benefit does it bring? Is it simply because the concept of infinite regression towards smaller and smaller / larger and larger universes is somehow pleasing to you?[/quote]
I think you missed the point.
The point is that there are dimensions of scale too small or too large for humans to access. This is because our nervous systems are either too “grainy” or too “fine”, and our instruments themselves suffer from this same limitation, since they eventually have to connect to these limited senses.
Therefore, “microaliens” COULD abound. That they probably do abound is not so essential to this point, which defers “grainy time” to be mere perceptual limitation.
But - If there’s one thing that we can learn from observing nature, it’s that everything is somehow fractalline. A section of a tree resembles the entire tree. The tree resembles the forest. Even inorganically, the mountain side has rocks of similar slope and a gem is made of similarly shaped crystals, right on down to the molecular level.
And so you are likely considered a cluster of universes, to those in other (smaller) dimensions. And they can’t even see through, to each other, haha!
Isn’t shit grand?
[quote]lothario1132 wrote:
lucasa wrote:
Even the most die-hard atheists (like me) have to admit that it’s spooky how the rules of the universe are meshed together so interchangeably and perfectly to give the possibility of life. If even the tiniest bit of the way the universe interacts with itself was changed, shit would be wayyy different (what if electrons didn’t react the way they do).
It’s almost like the way the universe is ordered almost guaranteed that something sentient like a human being would arise eventually. And by “almost guaranteed”, I mean “guaranteed”. We are living proof.
Is this a tremendous game of “Sims” we’re living in? We’ve already figured out the resolution of the 3d monitor we live in, and the speed at which we are animated in the program.
The laws of physics are constant, yes? Just like a set of defined variables and behaviors in a computer program. Could we write a computer program to desribe our observed reality? If it wasn’t for the quantum gravity problem, then the answer would be yes. We are this close:
| |
To being able to figure out just how quantum mechanics correlates with relativity.
PS I love diet mountain dew. Even if it makes me post stupid shit like this. :)[/quote]
Well there are some catches here:
Supposing there are an infinite number of universes, it’s no surprise that ours exists. It is only one in a continuum of possibilities, and the only reason we are in THIS one is the fact that it allows us to exist.
Of course my initial supposition is up in the air.
As far as how close we are to writing a computer program to simulate it all?
The mathematics is much too complicated to be able to do everything analytically. You would have to make many many approximations.
When physics comes across an intractable mathematical problem, it just says “ok, let’s approximate this by this”.
[quote]boomerlu wrote:
When physics comes across an intractable mathematical problem, it just says “ok, let’s approximate this by this”.[/quote]
True.
But what is the most precise and frighteningly predictable part of physics?
Quantum physics.
It is my guess that we will tack on relativity to this instead of the other way around.
Which actually makes sense in a way. We start from the ground up, and then extrapolate from there.
But still, this is me conjecturing and nothing more.
PS “Intractable” is another word for “gimme some more time to figure this out, dammit!”
Given our track record, I would bet on us figuring this out sometime. Maybe not soon, but sometime.
[quote]lothario1132 wrote:
boomerlu wrote:
When physics comes across an intractable mathematical problem, it just says “ok, let’s approximate this by this”.
True.
But what is the most precise and frighteningly predictable part of physics?
Quantum physics.
It is my guess that we will tack on relativity to this instead of the other way around.
Which actually makes sense in a way. We start from the ground up, and then extrapolate from there.
But still, this is me conjecturing and nothing more.
PS “Intractable” is another word for “gimme some more time to figure this out, dammit!”
Given our track record, I would bet on us figuring this out sometime. Maybe not soon, but sometime. :)[/quote]
Hey, don’t forget about cosmology. The early universe was a VERY strange place…
[quote]Kailash wrote:
pookie wrote:
Since there’s no way of registering those smaller/larger alien beings, then there’s no way to tell if they’re actually there or not. Correct me if I’m wrong.
If there’s no way of detecting the presence of those smaller/larger beings at all, why suppose that they exist? Why invent undetectable entities that have no interaction with this universe? What benefit does it bring? Is it simply because the concept of infinite regression towards smaller and smaller / larger and larger universes is somehow pleasing to you?
I think you missed the point.
The point is that there are dimensions of scale too small or too large for humans to access. This is because our nervous systems are either too “grainy” or too “fine”, and our instruments themselves suffer from this same limitation, since they eventually have to connect to these limited senses.
Therefore, “microaliens” COULD abound. That they probably do abound is not so essential to this point, which defers “grainy time” to be mere perceptual limitation.
But - If there’s one thing that we can learn from observing nature, it’s that everything is somehow fractalline. A section of a tree resembles the entire tree. The tree resembles the forest. Even inorganically, the mountain side has rocks of similar slope and a gem is made of similarly shaped crystals, right on down to the molecular level.
And so you are likely considered a cluster of universes, to those in other (smaller) dimensions. And they can’t even see through, to each other, haha!
Isn’t shit grand?[/quote]
Whatever you’re smoking, I’d love to try it!
I have no idea what you mean by a grainy nervous system… Are you referring to our role as observers, and the limitations of our senses, or something more fundamental?
As for the pretty picture you paint of our belovd mother nature, the problem begins, as you said, “right on down to the molecular level.” Things stop being fractalline and just get whacky. Why the mass difference between protons and electrons? Why the proton decay time? Why the matter anti-matter asymmetry?
Oh, and how does a forest resemble the tree?