Planck Definition and 393 Threads

For my own edification. The Planck Function when integrated over all wavelengths will give the radiated power per unit area for a black body. Would I be right in thinking, that if I had a known temperature for the black body source or indeed a kT value for that source that by using the...

Quick question: Is Planck time the same in all reference frames? Is it different at, say, half the speed of light than at a relatively stationary point? What about in a severe gravitational field, like a black hole?

Locally, photons "blue-shift" when falling down a gravitational field. What happens when they arrive at the Planck frequency? Do they turn back into matter?

Although the title mentions biology the answers I need are from physics. If I have understood it correctly Argentinian Electroneurobiology assumes mind to take place at the actions of a force field overlapping the electromagnetic field of the brain. I think. An exposition...

Initially known theories: 1. General consensus: Planck length is smallest measurable unit of length 2. Objects approacing light speed contract in length Scenario: Some hypothetical mass measured to be a Planck length is accelerated infinitely close to light speed. Questions: Can a...

It is generally accepted that a star of sufficient mass collapsing in on itself will form a black hole (singularity) where density is infinite. I see a few problems arising with this, and I would like to have them clarified. 1.) Density=mass/area If the mass of any star is finite, how can an...

After reading more about Loop Quantum Gravity. I realized they tried to solve quantum gravity by literally sweeping Planck scale under the rug. That is. The smallest volume and area of the spin networks in LQG is Planck size. In String Theory, they make the string Planck size too. They are just...

A ways back, I seem to remember reading on the Planck Mission page that it's observations of the CMB could help foster support for M-theory cosmology and weaken support for Inflation, or vice-versa. I thought it had something to do with detection of Non-Gaussianity in the CMB. I could not...

It is said fundamental subatomic particles don't have size but just points. Yet particles can be modeled by strings that is Planck size. Does it mean particles like electrons and quarks are Planck size?? Or could they be bigger?? But in scattering, we can measure the particles. So it seems to...

Is the need for Quantum Gravity only related to understand what goes on in the Planck Scale between quantum fields and curvature of spacetime where they collide. Or is it a more general solution to how quantum object is connected to spacetime (or quantum spacetime)? Let's take the example of a...

If I'm correct Planck will publish its all-sky CMB map (foreground deducted) this year. What's to be expected from this? Is another revolution coming?

Lisa Randall's states in the book "Warped Passages" dealing with the Hierarchy Problem: "The Plank scale energy determines the strength of gravitational interactions...the strength is inversely proportional to the second power of that energy...A huge Plank scale mass is equivalent to...

http://arxiv.org/abs/1102.2784 New Limits on Planck Scale Lorentz Violation from Gamma-ray Burst Polarization Floyd W. Stecker 3 pages, submitted to Phys. Rev. Letters (Submitted on 14 Feb 2011) "Constraints on possible Lorentz invariance violation to first order in E/M_{Planck} for photons...

In early 2010 I attended this inaugural lecture by string theorist- Prof. Mavromatos entitled 'MAGIC strings'. In it he proposes that some string theory models may violate Lorentz symmetry at the Planck scale resulting in a kind-of foamy spacetime that could be observed by differing arrival...

Hi Everyone, Apologies if this is posted in the wrong place. I am trying to produce numerical solutions for the following initial value partial differential equations, namely the overdamped Schmoluchowski equation \frac{\partial p(x,t)}{\partial t}=-\frac{\partial}{\partial...

I have speculative question. What we would expect to see if Planck constant would become marginally smaller? My guess is that vacuum would start to produce black body radiation. Does it seems right?

why is it the highest temperature? what happens if it is exceeded? is there an experimental proof that it is the highest temperature? why the temperature at the time of just after the big bang higher or lower than it?

The coupling constant runs so the Planck scale changes. What is it at the AS point?

How much will the Planck mission resolve about the universe.

Hey guys I'm new here. I have a question about Planck lengths that has been bothering me lately. I'm not exactly well versed in the area of quantum physics, learning most of what I know from documentary shows and articles on the internet, so so this may seem like a stupid question, but...

Homework Statement Starting with the F.P. equation, where the probability has been defined in terms of the stationary probability and another probability function, Q(x,t), i am trying to derive the backward F.P. equation in terms of Q(x,t). Homework Equations The F.P. equation provided...

To solve the the blackbody radiation Planck had to solve the partition function or average energy for a harmonic oscillator. But where did he get the inspiration to change the energy of the harmonic oscillator from E = \frac{1}{2} m v^2 + \frac{1}{2} k x^2 to simply E = n h v This seems like...

Deck of Cards and Planck Time? This is truly unbelievable. I've checked my work multiple times, gotten it checked by others, and still the same answer remains. There are more ways to rearrange a single deck of cards than there have been Planck times since the Universe began. Number of...

Planck length -- Greene versus classics Brian Greene, in Chapter 10 of "The Elegant Universe", offers a sketch of string theory's version of why massive particles have a minimum size of the Planck length. I give my summary of the argument in the next paragraph, and the question in the following...

Expressing Planck's Law as a function of frequency, we have: I(\nu)=\frac{2h\nu^3}{c^2}\frac{1}{e^{\frac{h\nu}{kT}}-1} Expressing this in terms of wavelength, one should get I(\lambda)=\frac{2hc^2}{\lambda^5}\frac{1}{e^{\frac{hc}{\lambda kT}}-1} but I don't see how this is obvious by...

Will the results from the PLanck satellite shed any light on Loop Quantum Cosmology or any other form of matter bounce?

I was wondering if the speed of light (c) can be derived from Planck's constant (h) or the opposite way. I know that they are both fundamental constants, but I'm sure they are connected somehow. Saying it on a different way: if Planck's constant would be different, would the speed of light...

Why? Some measurements confirm this statement? Or this is a theoretical conclusion?

I've heard of Stephen Hawking talking about the Planck Length and how nothing could exist at a level smaller than that length. I'd like to know how we know this to be certain. It seems that history has always repeated itself in that when humans see as far as we possibly see we simply just...

Stephen Hawking's recent book The Grand Design uses M-theory to predict a multiverse, which then does away God via the anthropic principle. A common criticism that string theory makes no experimentally falsifiable predictions which is countered that experiments do not have enough energy to...

In his nobel laureate speech. I thought "small values of energy" <=> "long wavelengths"? And for a body of a low temperature T, the maximum is for long wavelengths, so it can't be that either. What did he maen?

I've been trying to graph an idea I had, but frankly I don't understand SR well enough to ensure my assumptions are correct, and that I'm using the correct formulas. I would appreciate any input/corrections you folks could give. Here's the idea, which I'll follow with my assumptions: Idea...

out of "The Origin and Development of the Quantum Theory" given somewhere in the 1920's. If you type the title in google, you can read a html copy As a fun historical sidenote, the following quote seems amusing in hindsight:

I have a long standing belief the Planck density is the ultimate limit on mass density in the universe - including black hole 'singularities'. Am I hopelessly out of touch with mainstream science? Any input would be appreciated.

In the PBS documentary on Einstein's E=MC^2, the story makes it seem as if Planck called on Einstein in response to Einstein's paper on E=MC^2 which was published in 1905. But Einstein wrote an earlier paper on the photoelectric effect and the quantization of energy, also in 1905. Was it for...

It there a smallest possible wavelength? And if there is, what is that wavelength?

If I'm not mistaken he explained it with the theory that light energy can be released only in integer multiples of a constant times the frequency of the light. How did he come to this conclusion? Was it to do with the fact that the higher the temperature, the higher the frequencies of the light...

Can an extra dimension of empty space be smaller than a Planck length? Is that why string theory allows those extra dimensions to be smaller than a Planck length? Because they are empty? I remember reading posters on these forums say that space itself can expand faster than the speed...

Hi all, I've just started reading upon quantum physics and came across Max Planck. I believe he was the one to state that the oscillating atoms or molecules that emit radiation could only occupy quantum states, whereby photons with energy according to E=hf are emitted when an atom changes...

Learning a bit more about Planck units, it looks like a number of arguably arbitrary, or at least pragmatic, choices had to be made, regarding using G versus 4piG, using 1/4piEpsiolon0 versus Epsilon0, and so on, but in the reading I don't see any question that h/2pi, rather than h, is the best...

Hi all -- I had a question about the Planck black body / Johnson-Nyquist resistor temperature formula: \[ E_{\nu}^{2}d\nu=\frac{4R_{\nu}hd\nu}{e^{h\nu/kT}-1}\] I'm just wondering why the formula has $ exp(h\nu/kT)-1$ in the denominator? I would have expected $ exp(h\nu/kT)+1$ as...

Homework Statement Starting with the Planck distribution R(\lambda,T) for blackbody radiation. (a) Derive the blackbody Stefan-Boltzmann law (ie total flux is proportional to T4) by integrating the above expression over all wavelengths. Thus show that R(T) =...

I am considering PhD positions in Physics. Can you guys tell me how reputable Max Planck institute (Heidelberg) is compared to top universities? Thank you.

Homework Statement Find a set of 3 exponents a, b, g such that the quantity [G]^a [h]^b [c]^g has dimensions of time. In other words: [T] = [G]^a [h]^b [c]^g (hint: you should get 3 algebraic equations in the 3 unknowns a, b, g which are not that hard to solve. Now determine the socalled...

Amateur so go easy on me. Let's say you're traveling so close to c that you are only 1 Planck length/planck time slower. Seems like you have to increase speed in increments of Planck lengths/planck times (correct me if I'm wrong). Presumably to go any faster, you'd have to skip right to c...

Planck energy: E_P = m_P c^2 = \sqrt{\frac{\hbar c^5}{G}} Gravitational radius: r_G = \frac{r_s}{2} = \frac{G m_P}{c^2} Gravitational radius is equivalent to Compton wavelength: r_G = \overline{\lambda}_C \frac{G m_P}{c^2} = \frac{\hbar}{m_P c} Planck force is a constant in the Einstein...

How can the Planck length and the speed of light both be universal constants? Will the Planck length change depending on your frame of reference? :)

Did Planck think that light was a particle or a wave?

Could someone explain the relationship between the FSC and the Planck Scale? What are they in relation to each other. I know what the Planck Scale is, and I even have a loose understanding of the FSC, but what of them in contrast and comparison? And how does the FSC affect QM, if at all...

Homework Statement I am checking some equations for my simulation and are looking at the Planck function. My question involves the constant used for the Planck function expressed in Wavenumbers. I have found this expression for the function...