What is Macroscopic: Definition and 126 Discussions

My first thread here. Please bear with my lack of knowledge. I talked to a physics grad student about whether it's fair to describe QM as a theory applied only to microscopic objects. Although the definition of "fair" is ambiguous, at least he told me that, from his understanding, he wouldn't...

I'm learning about Schrodinger's equation in my general chem class right now, so obviously I'm doing a little background reading on quantum theory. The following is an excerpt from a supplement on basic (very basic) quantum theory: The answer is that quantization is only noticeable when...

Hello all Has anybody use HELIOS code yet? I need that in order to preparing macroscopic XS to PARCS.

In this thread I would like to start a debate on realism at the macroscopic level. To some of you this may be an issue that looks so trivial that it doesn't make any sense to try to talk about it. It is my hope that you still may be interested in making some comment, especially if someone else...

I don't quite understand why macroscopic objects we encounter in everyday life don't exhibit quantum probabilistic behavior. For example, the car standing in front of my house has a definite position and definite boundaries rather than being dissolved in some cloud where it's not clear whether...

In the beginning there were only probabilities. The universe could only come into existence if someone observed it. It does not matter that the observers turned up several billion years later. The universe exists because we are aware of it. — Martin Rees Professor of Cosmology and...

Thermodynamics makes good predictions for macroscopic experiments, but the actual physics is going on in the microscopic particular level. The second law of thermo is often thrown around, usually by people who couldn't explain F=ma back to you. My question is the way the second law...

I read often that the transition from quantum to classical, the fact that there normally no macroscopic quantum objects are observed, has only become clear with the proper understanding of the decoherence mechanism. But what about Broglie wavelength!? Physicists knew before, that macroscopic...

Homework Statement Two cars each of mass 1410 kg traveling at 91 km/h in opposite directions collide head-on and come to a disastrous halt; see Figure P.38. Assume that the surrounding air and ground temperature remains fixed at 18°C. Calculate the total entropy change of the cars and...

In some discussions here about quantum effects in the macro world, ZapperZ will only admit that things like superconductivity, Bose Einstein condensates etc. are good examples. But these are just macroscpic quantum coherent phenomena. Of course, if you have a flux qubit, you can directly...

The compositions of nuclear reactors are often stated in volume fractions. i.e the fractions of the volume of some region that are composed of particular materials. Show that the macroscopic cross section for the equivalent homogeneous mixture of materials is given by ∑a = f1 ∑a1 + f2∑a2 +...

So first off, Ill admit I've forgotten most of the finer details of the bell inequality so I apologize if I've gotten something wrong. From how I remember it, the bell inequality is a test of any local hidden variable theory vs. QM. It uses the fact that the inequality measured if a classical...

I have heard many times that's quantum mechanics doesn't apply at the macroscopic level. But I am not sure if I fully understood what was meant. Surely quantum mechanics applies even to macroscopic objects, its just that the wavefunction of such objects is so highly localized that we in effect...

Dont know if this is the right place to post this... Physicist often say classical mechanics can't explain things at subatomic levels. So, can quantum mechanics ever explain things at the macroscopic level ?

[SOLVED] Macroscopic quantum model Hi! I'm supposed to calculate the quantum number of a macroscopic system (The Earth and a satellite). I should assume that the satellite is moving in a circular motion around earth, and that it fulfills the same quantization conditions as the Bohr model...

Hi to all, I have a quantum question to post here. In the discussion on atomic theory, we know that electrons in different orbital levels have different quantum energy, say n=1 and n=2 have different energy levels. When one electron 'jumps' to another energy level, say from n=2 to n=1, the...

Homework Statement what is meant by the term macroscopic as used in the phrase macroscopic variable (4 marks) Homework Equations The Attempt at a Solution larger scale... dont know what else to add..

http://www.physorg.com/news78650511.html One millimeter oil droplets interfering with themselves... cool. :biggrin: It looks like there doesn't seem to be an upper boundary size for quantum mechanical phenomenom.

Hi; I'm new to the forum and I hope my question is not out of line. Has anyone ever done double slit experiments with macroscopic objects such as grains of sand, for instance. It seems to me that with appropriately sized and spaced slits in a mask of appropriate thickness, one should be able...

In the cosmological realm there seem to be no exact symmetries as with the quantum realm. Microscopic axes of symmetry appear to randomize on the large scale. Might even quanta be shown of complex structure? Can you think of any examples where outer space exhibits what would be considered...

I understand most implications of Quantum mechanics on the microscopic world, at least in a non-mathematical sense. However, why is the macroscopic world any different? I understand that there is a change in mass, which affects the Heisenburg Uncertainty Principal to make the uncertainties in...

Several times I've listened to Brian Greene talk about string theory and say that General Relativity is a macroscopic theory but Quantum Mechanics is a microscopic theory. Do you think it could be otherwise? I know that this is an accepted "dogma" that is often repeated by others but I...

If I have heard correctly, models of the early universe predict the existence of macroscopic strings brought about by the enormous initial expansion of the universe. A way of proving string theory correct - among others - would be observing such macroscopic strings. My question lies with how one...

Hello Physics Geniuses, Can any of you explain the physics of nonlocality as it applies to macroscopic systems - such as a human being and human consciousness? We have an increasingly apparent anomaly in psychology/psychiatry which is an apparent singularity: realtime networks of real people...

Quantum (number) configurations, but not classical configurations, repeat within the limits of spacetime. Would you entertain such a definition? I believe it to be a fundamental concept hereto overlooked.

People were explaining things fine with other systems (EG the olde four-element idea) until we started looking through enourmous microscopes. So what's to say those other systems aren't TRUE for the parts of the world they represent (in this case the macroscopic universe)? What really defines...