Nature Definition and 730 Threads

if the Plasma membrane is amphipathic (hydrophobic and hydrophilic), why does it only allow hydrophobic stuff to pass thru?

We are discussing the Demystifier's paper "Quantum mechanics: myths and facts". http://xxx.lanl.gov/abs/quant-ph/0609163 Previously: Myth 1 https://www.physicsforums.com/showthread.php?t=229497 Myth 2 https://www.physicsforums.com/showthread.php?t=230693 QM implies that nature is...

The hunt for superheavy elements has focused banging various heavy nuclei together and hoping they’ll stick. In this way, physicists have extended the periodic table by manufacturing elements 111, 112, 114, 116 and 118, albeit for vanishingly small instants. Although none of these elements is...

Homework Statement (a) What is the minimum energy (in electron volts) that is required to remove the electron from the ground state of an ionized atom (Z=2)? (b) What is the ionization energy for this ion? Homework Equations After doing what I got the answer for part (b)... but I don't...

Are we no more than animals, I know we separate our selves from the animals because we can manipulate our environment, shape and mold things out of steal. I think we are a truly violent race; if you would put 30 people in a room with no way out, the people would divide themselves and invertible...

Flattening of a planet Hi all, Does anyone know how to calculate the flattening of a planet, say a gaseous one for simplicity, simply from it's radius and rotational period? Natski

I just wonder to the doubters after so many experiments proving nonlocality, what type of "Proof" would be "proof" enough for the people out there who still think a local interpretation could ever describe reality?

This may be obvious to some, but have you ever looked at yourself and went, "woah"? Self replicating strands of molecules have come an EXTREMELY long way. Does anyone wonder, "why?" Its like there's some form of driving force. (I don't mean evolution, that is the "how") I mean, why do these...

Fossil fuels was created by nature. Dose that mean as we speak the processes continues and fossil fuel is continually being made if not why?

Time-gravity relativity is based on the fact that the anything that can effect the speed of light can also effect time. Blackholes have enough mass to suck light, so light must traval in the form of matter( and matter has to have mass) not radiation/energy, so what is light? P.S. Sorry if...

two closely spaced slits are cut into a piece of cardboard. A green light is used to illuminate the slits. a) what would be observed on a screen placed L, meters behind the cardboard? does the observation you described in a) support the wave theory or the particle theory of light? justify your...

1. Homework Statement A single slit is illuminated with a helium-neon laser whose wavelength is 633 nm. If the slit width is 2.2 x 10 e-5 m, calculate the position of the third maximum in degrees 2. Homework Equations Sin Theta(m) = (m + 0.5) Lambda/w 3. The Attempt at a Solution...

Why should time be considered as a 4th dimension?

Raw foods and other "nature" stuff A friend of mine rejects boiled vegetables, as he sais all the nutrients are destroyed. I hold that only some of the nutrients are destroyed and there isn't much difference between eating boiled and unboiled stuff. What's lost in the process can be...

hello all, i am new to this forum and to physics itself. I am a high school student who has studied physics for about two weeks. Regardless of this, while studying a question arose. it is this; according to the theory of superposition, two waves moving in opposite directions, one positive...

What is the accepted view of spacetime? Do we think we really live in a four-dimensional spacetime, or is it accepted that we live in a three-dimensional space but where four-dimensional spacetime is the correct way to model causality?

Can anyone tell me the true nature of a photon? One physicist tells me they don´t exist, another says they vary in size and now I am told they are paired masses. When I originally asked if one could split the photon, I thought it was partially material, i.e. consisting of colour with an...

The Presidential candidates have largely ignored science and technology so far. Nonetheless, Nature magazine took itself to task to compare and contrast the various candidates stands on three science and technology issues: climate, stem cell research, and space. Their assessment is...

http://www.nature.com/news/2007/071220/full/news.2007.389.html this just came out in Nature News, comment? To be sure, they are talking about how many DIMENSIONAL fundamental constants you need. The main bunch of constants that people always want to measure and to explain are the...

Hello all Just a simple question that intrigue me recently. Some body could explain about how scientists exactly know that transuranium elements cannot be produced naturally in the Universe? JPAM

Homework Statement The sun's average surface temperature is 6000K. An incandescent light has a temperature of 2500K, and a flouresent light can be considered to have an average temperature of 3500K. Why do neither of these artificial sources of light provide proper light when exposing a...

what is the best estimates on the number of neutrinos in nature?

hi there, i've read books and some web sites and I'm wondering this electric charge? Is it something physical (compose of matter)? some say its the one causing the electric field, by analogy, is it like mass has something to do with gravity? thank you

I had a look at a simulation of galactic populations in the universe from the Max Plank university and realized it looked a lot like a population of neurons. The same branching and clustering occurs in both cases... in fact I found this comparison of the two images on the net... here they are...

but I am confused how do you proof that the dirac field describes spin half quanta when quantized? please refer me to a link on the net where this derivation is shown if possible i can't find it in any of the books on quantized field theory

what is the nature of gravity constant? i just ask that? and if we can know the nature of it can we understand the meaning of gravity?

Why did textbooks (when I was in high school 5 1/2 years ago) always associate photons with the visible light part of the EM spectrum. Wouldn't the radio, x-ray, gamma, etc. areas of the spectrum exist as photons too? What about the transverse waves; would it not form a helix shape instead of...

can someone explain me why single-slit diffraction occurs in terms of the electromagnetic interpretaition of light

The current (18 October) issue of Nature http://www.nature.com/nature/journal/v449/n7164/index.html in the "News and Views" section has this piece by Hermann Nicolai String theory: Back to basics p797 Hermann Nicolai Summary: "Long touted as a theory of everything, it seems that string theory...

Hi and thank you for viewing this post. I'll begin with the question from the textbook; Q: An electromagnetic radiation has a frequency of 5.00 x 10^14 Hz. a) Calculate its wavelength in a vacuum, in meters and nanometers. b) Calculate its wavelength in water. c) Is this radiation visible? If...

The wikipedia article on Bose-Einstein condensates mentions that helium-4 is, or can be, a boson. It says that a condensate is made by putting many bosons, such as helium-4, into the lowest energy state. How can an atom be a boson? I figured that an atom, composed of fermions, would have to...

Were we better off in a state of nature? How credible was the concept of the Noble Savage? The thing is that society is constantly changing. How can we create a stable society within such a dynamic world culture? We need an ideal as a North Star. An ideal does not depend upon what is or...

Hopefully this isn't a foolish question but, I am up to CalcII and am anxious to apply what I've learned but have found nature fails to provide functions for it's behaviour like textbooks do. Is there a book or something I can read to develop this skill?

"Are there certain acts, like torturing children, which are always wrong? If so, what are they?" [taken from a list of stimulus questions] I believe this question invokes one huge look into evil/morality as a whole [questioning the value of moral absolution, moral relativism, universalism...

I once heard a very interesting thought through a zen story, that said "Nature reflects the true self." So simple, yet I had felt that before, but didn't know how to explain so crispe and clear. Now, the problem for me comes with the question not doubting this thought, since we have our own...

First of all; Howdy all hope everyone is well. Second; Everything seems to be energy it's everywhere in every form cause nothing exists that isn't energy if i am wrong don't bother reading any further but please tell me why and proof please. So assuming I'm correct from what I've...

Ok, the following problem I've tried several times to solve, although I suspect that somewhere along the line I'm just approaching what appears to be a simple problem in the wrong way: ------------------------------- A two-point source operates at a frequency of 1.0 Hz to produce an...

Is evil primarily a product of mankind or nature? It seems that mankind is unique in identifying, defining, and reciprocating evil. Evil, however, with its seeming connection to dying, disease and disaster, might be considered a natural outgrowth of suffering. Survival may depend in part upon...

Perhaps some consensus can be arrived at in regard to what infinity is. After that, perhaps its nature can then be discussed. One approach to defining infinity is to first define what finite means and then say something is infinite if it is not finite. Rather than define infinity by what it...

There is a discussion on the nature of time in the General Physics forum, originally titled "What is time?" I know that physicists have no firm conclusions on this issue, but I want to read about the various views that are taken seriously by physicists. Can anyone comment on the books/authors...

I think this is a recurring theme in many other threads, but haven't seen a poll. If we can get a large enough number of participants, would suggest to publish the results.

http://arxiv.org/abs/0707.2593 he argues that if you believe QM is "universally applicable" (whatever special thing that means for him) then you should believe in manyworld branching of reality. I don't, and I don't even consider it empirical science--so I guess I have to accept that QM is NOT...

maybe somebody out there has some thoughts on this... is it maybe possible that some mechanism is in place such that the fabric of spacetime, reduced to 'cells' of dimensions in keeping with Planck length, is itself expanding? such an effect would lead to each 'cell' being capable of being...

This thread is distinct from discussion of the mainstream media coverage of the letter that just appeared in Nature Physics. I just want to get more precise about the actual issues. So far, not having a subscription, I don't have access to the advance online publication in Nature Physics...

Here is the Penn State press release http://www.eurekalert.org/pub_releases/2007-07/ps-whb062907.php called "What happened before the big bang" the press release evidently covers much of what you need a subscription to read in Nature Physics magazine, or else have to get it at your university...

MEASURE To measure nature with absolute certainty, one would need a tool of absolute certainty. Unfortunately for science, there is no such thing! Measure? MJA

On wikipedia they give a fairly simply explanation of inductance But on http://www.electronics-tutorials.com/ they give a different definition I don't understand the latter there. Theyre saying any solenoid resists current and the higher the inductance the higher the resistance...

:rolleyes: Most of the animals along with Homo sapiens are divided into two sex, i.e male and female. What is the advantage of two sex? Is it has anything more to do than increasing genetic diversity? Is there any possibility of occurring more sexual discrimination among animals of the...

Is destructive behavior and benefiting psychologically as well as materially from other people's misfortune a part of human nature or an endless chain of role models that have been passed down from generation to generation to us today? Is our predisposition to compete (like in sports) and to...

I have a lot of quesitons relating to Photons and the Wave/Particle Nature of light. Answers to anyone of my questions would be appreciated! =] Thanks in advance. -Can you define photons as particles of EM radiation? or "wave bundles of EM radiation?" Are photons "matter waves," wave...