/sci/ - Science & Math

>>5362686
bump pls

It affects the state of the particle. That horsefeathers about "when you measure the position of the particle, you bump it so the speed changes hurrrr" is nothing but a comforting story to make quantum mechanics sound like nothing more than a collection of instrumentation errors.

>the less accurately you are able to measure its velocity, and vice versa.

actually, its momentum.

Everything statement you've made is incorrect. Because you're obviously a 15 year old popsci retard, I'm not even going to bother correcting you.

To answer your questions: the inequality exists independently of both "the state of the particle" and "measurement". Locality, causality, and Lorentz invariance prohibit FTL signalling.

Every statement you've made is incorrect. Because you're obviously a 15 year old popsci retard, I'm not even going to bother correcting you.

To answer your questions: the inequality exists independently of both "the state of the particle" and "measurement". Locality, causality, and Lorentz invariance prohibit FTL signalling.

>>5362695
I was also told that the "observation" that causes a quantum state to collapse is simply interaction on a large enough scale to be properly described by some form of classical mechanics (I'm almost certain this isn't correct, but I'll go off of it). Does this sort of interaction cause a certainty in momentum and uncertainty in position (or vice versa)? How does this work?

>>5362712
the part about Hawking radiation was paraphrased directly from the transcript of one of his lectures. sorry duder

but thanks for answering my questions anyway

OP, Heisenberg may have been uncertain about how to measure the speed and position of a particle simultaneously but today using modern technology like SEMs we are able o learn a lot more about the atomic structure of matter and in general have developed models of the quantum universe with far better predictive capability.

>>5362752

O U!

>>5362728
> transcript of one of his lectures
Whose "lectures"? "Velocity" has absolutely fuck-all to do with the Hawking radiation. I doubt you even know how to calculate Bekenstein-Hawking entropy or get microstate density matrices from there either semi-classically or with string theory. You have absolutely no idea what you're talking about, popsci retard, and you have to be 18 to browse 4chan. Fuck off.

damn Heisenberg looks like Billy Herrington.

>>5362766
http://www.hawking.org.uk/into-a-black-hole.html

>This is summed up in the uncertainty relation, discovered by Werner Heisenberg in 1923, which says that the more precisely you know the position of a particle, the less precisely you can know its speed, and vice versa. This means that if a particle is in a small black hole, you know its position fairly accurately. Its speed therefore will be rather uncertain, and can be more than the peed of light, which would allow the particle to escape from the black hole. The larger the black hole, the less accurately the position of a particle in it is defined, so the more precisely the speed is defined, and the less chance there is that it will be more than the speed of light,.

But by all means, keep getting inordinately angry at someone on the internet who has done nothing to provoke you. Didn't they teach you in your communication studies classes that it's not OK to call someone a popsci retard and tell them to fuck off?

>>5362802
There comes a point where you dumb science down so much that it becomes pseudoscience. This accurately portrays such a thing. That is so wrong it's not even funny.

>>5362766
>>5362802
lol nerd fight


nerds

>>5362819
take it up with mr. hawking

>>5362802
I'm pretty sure this notion of Hawking Radiation was discredited. The modern explanation of it involves the gravitational field of the black hole losing energy through pair production.

>>5362866
It was never, ever like this. Not even in Hawking's original paper written on the matter in the 70's. Whoever wrote that is an idiot. I doubt it was Hawking himself.

>>5362802
this seems to make a faulty assumption like actually describing a volume inside a blackhole...the math breaks down after the event horizon. we cannot say that a particle that falls into it exist at a definite location...also spin states of particles may also be broken inside it since it at least seems to me matter behaves like bosons inside black holes. for fuck sake a whole supernova implodes and all that matter now resides at a mathematical point. well now i don't know if their wave functions are superpositioned of they moved to a higher dimension or smth but trying to apply heisenberg here at this extreme point should be handled with caution.

Any two variables that are inverses of each other have the mathematical property that the more you know about one, the less you can know about the other. Frequency and time, momentum and position: they are problems with the mathematics, not the reality. The uncertainty principle in quantum mechanics is a realization that we have to use probability to understand the behavior of tiny things, Don't go adding any more weirdness than you have to.

>>5362891
Explain how momentum and position are inverses of each other. Trust me, it's the reality and not just the math.

>>5362874
>>5362819
I don't even know what people are talking about in this thread, but you would probably do a great service to the world by editing that article right now and fixing it.

>>5362766
How to be mad as fuck
Step 1.
Be this guy

>>5362885
the article isn't saying that the exact position of the particle is known, it's just saying that a particle that has been pulled beyond the event horizon of a black hole must be somewhere within the event horizon of the black hole

If you know ecavtly where something is it isn't moving; How can you tell its momentum? If you know its velocity, not by its change of position, but by knowing its mass and energy, how do you know where it is? I will confess, I haven't looked at this stuff for years - we use the uncertainty principle in Wavelet analysis all the time - but I remember the epiphany I had when I realized the math can be reduced to a simple inverse which shows the uncertainty principle in action. Just look up the mathematical definition; you'll see a simple inverse,,,something like h/v

>>5362928
and therefore its (very) approximate position is known

>>5362928
that still isn't a safe bet imho
a black hole is where space-time is curved so much that light cannot escape and we really are trying to define the volume inside this place like a conventional "space"? no sir, i don't believe this

>>5362766

Nice to see that all that scientific education has had zero effect on plebeian boorishness

Here, I looked it up for you
sigma sub x times sigma sub p is greater than or equal to Planck's constant divided by two
xy+constant implies x=constant /y.........inverse!

>>5362936
a black hole with a rotation of 0 is perfectly round (those with a rotation of 1 or 2 bulge a little at the center, like the earth), so
V=(4/3)(pi)(r)^3
r equals the schwarzchild radius

simple geometry

>>5362952
I understand the math of the principle, just not the reality. thx tho

>>5362952
that's xy=constant...sorry

>>5362955
but the space it occupies isn't, is it?
Einstein tries to illustrate that by dropping an apple and introducing a curve on a table cloth on 2-dimensions...you try to imagine the 3d curve that gravitation causes. it really isn't a simple geometric shape

>>5362959
I don't either... I don't think anyone does. But you can engineer with it,
http://arstechnica.com/science/2012/09/demolishing-heisenberg-with-clever-math-and-experiments/
Here's a cool article that shows a way around the math limitations.

>>5362955

The radius of a black hole is way way bigger than it looks.

>>5362891

Probability really has no place in quantum mechanics. It's purely about the 100% deterministic evolution of hilbert spaces. When you force these hilbert spaces to fit into the macroscale world, then probability comes in, and no one knows for sure why it is.

>>5362899

>editing Stephen Hawking's personal webpage

That's a federal offense.

>>5363122
Which government?

>>5363126

The one that can get you extradited from anywhere in the world to face charges that are not crimes in the country of origin.

>>5362959

There are uncertainty principles in any sort of signal analysis. No one is particularly perplexed by the issues in time-frequency filter resolution.

The interesting bit isn't the uncertainty principle, but the fact that position and time are related by the FT in such a way that the uncertainty principle is of maximal interest, that is, the position is described as a probability which can be constructed in a fourier series. That's where the physics is.

>>5362959

There are uncertainty principles in any sort of signal analysis. No one is particularly perplexed by the issues in time-frequency filter resolution.

The interesting bit isn't the uncertainty principle, but the fact that position and MOMENTUM are related by the FT in such a way that the uncertainty principle is of maximal interest, that is, the position is described as a probability which can be constructed in a fourier series. That's where the physics is.

Particles exist not as points but as probability density functions. That is, every particle (such as an electron) can be described as a function of three variables P(x,y,z), such that when you integrate P over all of space you get 1, and to calculate the probability of finding the electron in a certain region, you integrate P over its volume. Actually, the more fundamental quantity is the wavefunction Psi(x,y,z), which you square to get the probability function.

Particles also have a probability density function for momentum, which can be calculated exactly if you know the wavefunction for position.

Heisenberg's uncertainty relates the product of the standard deviations for both the position and momentum wavefunctions, specifically that it must be greater than the constant hbar / 2. If a wavefunction is "more accurate" it has a more sharply peaked wavefunction, and thus a smaller standard deviation. The more sharply peaked position, the more spread out momentum, and vice versa.

Hawking radiation has to do with virtual particles which pop into existence then destroy themselves. If an electron and positron form spontaneously, normally they destroy each other and nothing happens. But if they form at the edge of a black hole, one can fall in while the other escapes, thus the black hole "radiates".

No information can travel faster than light.

The Heisenberg uncertainty principle is true by definition in QM, and can be used as an axiom to derive everything in QM.

>>5363168
Information "leaked" from a black hole retains the rotation of the particles that originally fell in

if Hawking radiation is due to virtual particles, wouldn't the seemingly "leaked' particles just have random rotations

>>5363168
Not OP, but thanks man, this is the first time I ever got it. If you aren't full of shit I really learned something today.

>>5363168
told people earlier today. hawking is a retard.

more so what about a partical withing the singularity of a blackhole? you now have its postion and velocity accuratly measured by the speed of the black hole.

information leaving black holes.
>information

>herp, information=faster than light thus able to surpass the extreme density not only at the center of the continuously asorbing field of mass but also the mass itself.

>even as a 16yo, i knew that cripple was truely just a retard that liked to troll the science community.