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/sci/ - Science & Math

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File: 151 KB, 300x300, Schwarzschild radius.png [View same] [iqdb] [saucenao] [google]
3207753 No.3207753 [Reply] [Original]

Is the schwarzschild radius of small objects computed the same way as large ones? For example, what is the schwarzschild radius of an electron?

>> No.3207764

probably not
nobody knows yet

>> No.3207770

>>3207753

We don't know, since we don't have a quantum theory of gravitation right now.

>> No.3207785

yes, if you know it's mass you can calculate it's schwarzchild radius, this is how we know the size of the smallest possible black hole, black holes with a radius smaller than that of a proton of neutron evaporate

>> No.3207808

>>3207785

Just because you have a formula and you put something in it doesn't mean the outcome is sensible.

I could also insert the mass of our sun into a wavefunction but i wouldn't have a wave-function of the sun then.

>> No.3207831

I don't think an electron has a schwarzschild radius. Anything on that small of a scale is dominated by the electric force. If you'd say, get two electrons close enough together (smaller than the predicted schwarzschild radius). It would just eventually blow itself apart.

>> No.3207837

>>3207808
The sun isn't a single particle.

>> No.3207840

>>3207837

Kinda like my point, y'know

>> No.3207848

>>3207808
It makes more sense to calculate the Schwarzschild radius of a point object than it does of the Sun or the Earth.

Because, you know, Schwarzschild's solution holds for space that is outside of the mass distribution. When you talk about the Schwarzschild radius of the Earth you actually mean the Schwarzschild radius of a point particle (or anyway an object smaller than the value you get as a result) with the same mass of Earth.

>> No.3207849

>>3207808
i'm not >>3207785
but it actually works
and you get a sensible answer

>> No.3207859
File: 45 KB, 500x380, lol1276858116734.jpg [View same] [iqdb] [saucenao] [google]
3207859

>>3207849

enjoy not knowing anything about physics

>> No.3207862

>>3207849

You probably also think that if you run towards a wall there is a slight chance you will tunnel through it, right?

>> No.3207865

>>3207837
It is when you look from a great distance at it.

>> No.3207868

<span class="math">R_s=1,35217468 \times 10^{-57}[/spoiler]

that is the schwarzschild radius for the electron, notice that it is almost the square of the planck radius thus meaningless and an electron has no schwarzschild radius, now a very high energy electron on the other hand..

>> No.3207874

>>3207868
>no units

>> No.3207881

>>3207868
>now a very high energy electron on the other hand..
http://en.wikipedia.org/wiki/Principle_of_relativity

>> No.3207884

>>3207862
but that's the way the universe works
it's a small chance but it is

>> No.3207890

>>3207874
SI obviously

>> No.3207896

>>3207753
It's based on information content.

1.Fdx=TdS from the first law of thermodynamics
2.T=(hbar(a))/((2pi)ck) from Unruh temperature
3.dS=((2pi)kmcdx)/hbar from Bekenstein bound
4.F=ma
5. Mc^2=kTN/2 from equipartition rule
6. N=(Ac^3)/(Ghbar) from holographic principle
7. T= (GM/R^2)(hbar/(2pi)kc)
8. F= G(mM/R^2)
9. Rs = 2GM/(c^2)

>> No.3207898

>>3207884

No, this is wrong.

lrn2physics

http://en.wikipedia.org/wiki/Quantum_decoherence

>> No.3207902

>>3207868
but the energy in it's own fame is the same

>> No.3207910
File: 115 KB, 469x428, trollface[1].jpg [View same] [iqdb] [saucenao] [google]
3207910

>>3207868
Why would an electron's energy affects its mass?

>> No.3207925

because energy is made of mass and mass is made of electrons

>> No.3207933

>>3207859
>>3207862
mass is not a wave

>> No.3207937

>>3207933

Why do you tell me?

>>3207910

Right. Mass is invariant. Why the troll pic?

>> No.3207938

>>3207890
Not obvious at all. This sort of calculations usually happen in natural units.

>> No.3207953

>>3207898
this doesn't completely eliminate the chance of the tunneling
just makes it even more unprobable
the wavefunction is not really broken
quantum dechoherence only shows how the quantum effects create the classical view of the universe at larger scales

>> No.3207958

>>3207953
when a particle tunnels to a lower energy level outside of it's own event horizon you get vacuum metastability events.

>> No.3207973

>>3207953

Yes it does.

As said, you can't just put any numbers in a formula and get a sensible result, which is _certainly_ true in this case.

Quantum physics only works in isolated systems. Any interaction with classical systems (also called a measurement) instantly destroys the quantum effects.

>> No.3208011

>>3207973
http://www.nature.com/nature/journal/v406/n6791/abs/406043a0.html

It is my opinion that you are wildly uninformed about what you are talking about.

>> No.3208014

>>3207958
why would you need a particle tunneling for the vacuum fluctuations
and why do you think that particles are little black holes

maybe i haven't read abut that theory
but if you suggest that particles are little black holes
then what about the mass of the photons
and how could the particles react (electromagnetically for example) if they're inside a black hole

>> No.3208036

>>3207973
are you the same guy that argued with me and josef about this a while back? anyway, you are wrong, QM works on everything, being in an isolated system just makes it more apparent.

>> No.3208039

>>3208011

> a macroscopic object with many microscopic degrees of freedom could behave quantum mechanically, provided that it was sufficiently decoupled from its environment.

> decopupled from its environment

self-pwnage of the finest kind.

>> No.3208044

>>3208036

see >>3208011
and >>3208039
and maybe >>3207898

>> No.3208055

>>3208039
>sufficiently decoupled from its environment
>not completely isolated

Confirmed for retard.

>> No.3208061

>>3208055

> implying that doesn't mean you will never tunnel through a wall

ever herped so hard that you derped?

>> No.3208062

>>3208044
>sufficiently
asshat
a molecule in chlorophyll shows QM properties and its not isolated.

>> No.3208068

>>3208062

As said, it does mean that a human cannot tunnel through a wall at all.

> there has been no experimental demonstration of a quantum superposition of truly macroscopically distinct states

Also, sufficiently means that one can apply perturbation theory without it getting too classical. The perturbations have to be extremely small, which happens to not be the case for humans.

haha, moran

>> No.3208070

>>3208061
>implying that's the point

Look, you fucktard, you claimed QM has no bearing on macroscopic systems. You are completely wrong, and justa s retarded.

>> No.3208075

>>3208068
> there has been no experimental demonstration of a quantum superposition of truly macroscopically distinct states

its dated from 2000, in 2007 or 2008 we put a macroscopic object in a superposition, what now?

>> No.3208076

>>3208070

Your argument being?

derp there's an equation with a mass, i'll just put in mine and the result will mean i can tunnel through walls.

>> No.3208080

>>3208076
My argument is that you don't know shit about what you are talking about, and you need to shut your fucking mouth.

>> No.3208081

>>3208075

> sufficiently decoupled from its environment

I never said it wasn't possible. I said you won't ever tunnel through a wall, which will not happen because you are not decoupled from your environment at all.

what now?

>> No.3208082

>>3208039
the easiest way to see the quantum effects at larger scale is to cut a flat mirror at the places that cancel the probability of detecting a photon at a given distance from the mirror

the chameleon paint work in a very similar way

>> No.3208085

OP here. So if I understand correctly, the consensus seems to be that the laws of gravitation that we currently understand do not work correctly at microscopic scale?

>> No.3208089

>>3208080

same to you

go on spouting that bullshit into the world and confusing more and more people into this shit.

You people really need to learn some physics and not just applying formulae.

>> No.3208088
File: 187 KB, 450x450, movingthegoalpost.jpg [View same] [iqdb] [saucenao] [google]
3208088

>>3208081
>be proven completely wrong
>change your argument completely

Why do you act like a tripfag? You are pathetic.

>> No.3208093

>>3208089
Says the high schooler who only read about physics on wikipedia.

>> No.3208094

>>3208081
put the person and the wall in a vacuum with minimal light, define system as person + wall, now the system is sufficiently isolated. your move.

>> No.3208103

>>3208085
they do work
but are negligible because the electromagnetic and strong force are so much stronger

that's why we can't see its effects at that scale
in other words when we predict what 2 particles do we can completely ignore gravity and still get a very good result
at least at small distances

>> No.3208107

>>3208088

> implying it wasn't you who changed the subject.

Just look at it. I said humans don't tunnel, then you post a source supporting my view, then you use strawman of there have been macroscopic systems in superposition states (still under sufficient shielding from environment) and claim i changed the subject.

moron.

>> No.3208116

>>3208093

> implying i'm not a PhD and you are just reiterating the phrases burned into you by your teachers without thinking about it

This is called pop-sci. You take concepts and apply them to situations where they yield apparently fantastic results, like a human tunneling through a wall.

"It's so beautiful it must work"

>> No.3208118

>>3208103
>but are negligible because the electromagnetic and strong force are so much stronger

Not all the time: http://www.sciencedirect.com/science/article/pii/S0921452606010787

>> No.3208121

>>3208094

humans can't survive that. Who will throw the body against the wall?

your move

>> No.3208126

>>3208093
what i can't understand is why are you wasting your energy by arguing with an obvious troll

>> No.3208127

i hate how high schoolers think they know everything and they're the shit just because they're taking AP classes at high school and reading wikipedia

>> No.3208131

>>3208116
>implying you even have a bachelor's

So, if you actually know this stuff, tell me. What mathematical construct is used to describe a statistical quantum state and evaluate its coherence it has?

>> No.3208137

>>3208107
its like arguing with a fucking creationist or something:
>get proven wrong, change subject
>claim our proof supports your claim
>ignore posts that prove you wrong
>formulate vague replies that are impossible to accurately respond to

im out, you win, im out.

>> No.3208144

>>3208103
gravity as we know it doesn't work at small scales, it fuckes everything up.

>> No.3208154

>>3208137

troll


I said humans don't tunnel

I said that is because of decoherence

You said "but they have macroscopic states in a superposition"

I said yes, but under sufficient shielding form environment, which is not the case for humans

you: you troll, changed the subject etc.


You are butthurt because i proved you wrong. It is fucking retarded calling me a troll when you are the one changing the discussion to ad hominems and strawmen.


It is not even hard to understand. I just said humans do not fulfill the requirements for tunneling to happen, which you had said yourself here >>3208011

pathetic

>> No.3208160

>>3207898

The probability of a macroscopic object spontaneously tunneling through a wall is still non-zero. Quantum decoherence just illustrates how ridiculously unlikely such an event is as the frequency of interactions between particles in such an object scales up. You could very well sit and watch a billion random iterations of the universe go through their entire existence without ever seeing such an event. Yet the probability is not zero.

>> No.3208164

>>3208131

not sure what you mean with statistical quantum state.

A mixed state?

>> No.3208169

>>3208160

see
>>3208011

It only works if > sufficiently decoupled from its environment

>> No.3208174

>>3208164
The quantum equivalent of a state extracted from some statistical ensemble.

>> No.3208183

>>3208169
you seem to be unable see see the word sufficiently

>> No.3208189

>>3208183

> implying a human is sufficiently shielded from its environment

what the fuck man? Have i been mega-trolled?

>> No.3208192

>>3208154
read what quantum decoherence really means
quantum wavefunctions can never collapse
the act of measuring means that you're interacting thus contributing to the wavefunction of a latter experiment on the same particle

>> No.3208194

>>3208192

sigh, it doesn't really matter. All that matters is that that a human is not sufficiently shielded from its environment to be subject to quantum effects.

>> No.3208196

>>3208169

Electrons and even sizable molecules are already known to tunnel without being decoupled from their environment. It is not a requirement at all.

Decoupling is supposed to increase the probability in a noticeable way at macroscopic scales, but as we've no way to test that yet it remains hypothetical.

>> No.3208205

>>3208196

> Electrons and even sizable molecules are already known to tunnel without being decoupled from their environment

The double slit experiment doesn't work if not performed in a vacuum.

> we've no way to test that yet it remains hypothetical

agree

>> No.3208208

>>3208192 samefag
the experiment doesn't have a wavefunction lol
i mean the particle's wavefunction for the latter experiment*

>> No.3208234

>>3208194
yes something as big as a human would not tunnel through a wall even if we had to wait till the end of the universe (the big rip)
just as it is improbable that all the molecules of air would gather in just 1 corner of the room..
even though you can think of them only in the classical way
the same analogy is that the wind won't build a cattle in the middle of the desert

but tunneling does happen and the sun is a living proof
it just does not have enough mass to sustain hydrogen fusion without quantum tunneling

>> No.3208244

>>3208205

Flash memory chips require no vacuum for their tunneling writes to function.

You're missing the forest for the trees again. Air in the vacuum chamber does not prevent quantum effects from occurring, but it will make them too unlikely to be detected by our instruments in quantity. There must still be an interference pattern, but for any instruments we can make in the foreseeable future it will be drowned out by the scattering caused by interfering air molecules.

>> No.3208255

>>3208205
http://www.youtube.com/watch?v=OUj0gt3h9Tk
home made double slit experiment
i don't know why you'd think that it has to be in vacuum but you're wrong AGAIN

>> No.3208258

>>3208255

lrn2context fucktard

for electrons and molecules

jesus why are there only trolls in here.

>> No.3208263

>>3208258
yes, because photons magically isolate themselves and electrons dont.

>> No.3208266

>>3208258
when everybody else is going the wrong way, maybe -you- are driving on the wrong side of the road.

>> No.3208270

>>3208258
>implying light doesn't interact with air

>> No.3208271
File: 119 KB, 696x468, troll-senses.jpg [View same] [iqdb] [saucenao] [google]
3208271

>>3208258
are you aether?

>> No.3208274

>>3208266

> implying that dude didn't just put words out of context and reversed them.

>> No.3208276

>>3208263
>>3208270
You do know that electrons are charged particles and photons are neutral?

>> No.3208279

>>3208276
you do know that both photons and electrons interact mainly through the electromagnetic force? having or not having a charge makes no difference.

>> No.3208281

>>3208276
>photons are neutral

So are air molecules. Photons slam into them and get absorbed/re-emitted anyway.

>> No.3208285

>>3208276
you do know that we detect the position of an electron by shining light on it which in turn "collapses" it's wavefunction?

>> No.3208290

>>3208285

> collapse

Oh boy this got funny. First you said collapses never happen, then suddenly it does happen. Just as you need it, right?

>>3208279

So you're implying light is heavily influenced by air molecules? That must surely be the case as the laser i shoot through the air right now makes a giant decoherent spot on my wall.

> implying electrons aren't different than light because of their mass and charge and are therefore way more likely to participate in interaction with air.

>> No.3208291

>>3208276
You do know that protons are charged particles and neutrons are neutral?

ya,... this is just as relevant

>> No.3208292
File: 36 KB, 600x750, point1307692285232.jpg [View same] [iqdb] [saucenao] [google]
3208292

>>3208291

ITT

>> No.3208302

>>3208290

The problem isn't the likelihood. We already know how likelihood of interactions affects the probability of tunneling.

The problem is that you think this probability can ever be zero, and that it is somehow "unlocked" to a non-zero value by a certain level of decoherence.

Also for future reference, lab vacuum chambers do not produce anywhere near a total vacuum.

>> No.3208307

>>3208302

It doesn't have to be a total vacuum, just vacuum enough so that most of the electrons/buckyballs will still be coherent.

> somehow "unlocked" to a non-zero value by a certain level of decoherence

of coherence.

My first post was saying that if you take a formula that was shown to be correct in certain realsm of reality, does not necessarily lead to meaningful results when used somewhere completely different, the example being a human tunneling through a wall.

There are infinitley many interactions that cause total decoherence, which makes the probability zero, or in other words, quantum mechanics must contain classical physics as a limiting case, which does indeed mean that on these scales quantum effects do not occur at all.

>> No.3208339
File: 28 KB, 442x330, 1301527335366.jpg [View same] [iqdb] [saucenao] [google]
3208339

>>3208307

>> No.3208345

>>3208339

lame, dude, lame

not even him