389 reputation
27
bio website
location Israel
age 34
visits member for 2 years, 11 months
seen Oct 6 '13 at 9:59

Jun
5
comment What is a good read about Manning condensation?
Thanks. I have the article (I'm a Ph.D. student and our university is not that backward). I know this is a polyelectrolyte related stuff, but I don't know what are good reading in this field.
May
2
comment Solving Poisson-Boltzmann equation for flat surface without excess salt
@VijayMurthy Sorry I didn't post the source of this. I wasn't in my office (where I have the book) until now. Reading my question I have noticed that I have switched my notepad while typing in. Sorry
May
2
comment Solving Poisson-Boltzmann equation for flat surface without excess salt
@VijayMurthy: Thank you for your remark. Nevertheless, the solution I have posted, and my approach are derived under the right notations.
Nov
15
comment How do derive this result in stat-mech style
Thanks. Reading your answer I realized that I took the wrong derivative. It is bound to happen if you try and solve stuff when you are tired.
Oct
29
comment Depalma Free Energy fields
So, it could possibly exist some matter configuration in which some energy signatures could be measured. Unless there is some unexplained measurement that can only be explained by adding some other matter configuration, there is no reason for us to assume this. Who knows, maybe we are all, in effect on a back of a tortuous traveling through space, without any evidence, there is no reason to assume so. Button line, you think this is the case? Give us some evidence. This year Noble price in chemistry is exactly about that.
Oct
18
comment Can someone explain the color Pink to me?
You are right, what I should have explained is that our mind place each light we see on the appropriate position in it's red-green range and the blue-yellow range and this is why this are two kinds of color blind. The cell class I took was so long ago...
Oct
18
comment Why is the sun so dense?
I don't know enough about this for a complete answer but to my understanding, the sun is bright because it is dens. The high concentration of particles caused them to fall one toward the other releasing. The more matter there is, the stronger the gravity and the more dense the star will be. Most of the stars you see at night are suns which are very dense.
Oct
18
comment Can someone explain the color Pink to me?
Could you be referring to this? en.wikipedia.org/wiki/Technicolor
Oct
17
comment Does the speed of sand flow in a hourglass depend on a height of a sand column above the hourglass neck?
If there is one thing you can't do is compare the sand to fluid. Sand might get stuck in a sharp slopes which fluid will flow easily. There is a whole engineering field about this topic.
Oct
11
comment How to get distance when acceleration is not constant?
You add stuff to the equation until you reach a constant value
Oct
9
comment Could hydrogen liberated from water provide lifting energy which exceeds the energy it took to liberate it from water
@Phil: But what you are saying here is already done. Look for geothermal energy.
Oct
5
comment Why can I tell a flute from a trumpet?
To put it in plain words. The reason you can easily distinguish between instruments is mostly the difference in the imperfections in the generated waves.
Aug
8
comment How much solar energy hits a rooftop in Israel?
Those are the figures that sound more reasonable to me. Does that includes any loses (maintenance, excess heat, etc.)?
Aug
7
comment How much solar energy hits a rooftop in Israel?
What mostly bother me is the estimated loss. The numbers I know is that less than 15% of the light is converted to electrical energy. I was in a lecture lately which stated that due to a cycle which is much similar to Carnot cycle, the most efficient system will be transfer less than 30% of the light to usable energy. This is why I want to know the raw data, how much light hits the earth in my region and not the calculations...
Aug
7
comment How much solar energy hits a rooftop in Israel?
is this number for the amount of energy produced or arriving? What area are they relevant to square meter or square foot? Where did you got this number from?
Aug
7
comment Helmholtz Free Energy relation
I'm not sure about your question here. All I can tell you is that the pressure part comes out of the definition of work (consider the ideal gas case). As for the chemical potential ($\mu$), this is just a name. pressure and entropy where defined before the realization of of statistical mechanics so they are described in other, more commonly known equations.
Aug
4
comment How can a laser pointer have range of several kilometers in atmosphere?
I don't think that the test is carried in the atmosphere. I suspect it is carried in a clean and dry room (possibly, under vacuum) and use mirrors. This is much like the tests for batteries which are carried under ideal conditions (temperature, humidity etc.)
Jul
15
comment Electric field outside a capacitor
Why do we know that the electric field is 0? The intuition is clear but is there something more formal than that?
Jul
7
comment Circular equation of motion
I have forgotten to mention that everything is on the unit circle which force me to assume that $\alpha = 0$...
Jul
3
comment Are all electrons identical?
The idea is that we can't, using current technology, measure any differences between two electron in rest. I don't think there is even an experiment to distinguish between two electron (or more). Using your alien galaxy metaphor, that dude won't have any tool to tell if there is any difference between the planets (The same way as we can't tell if we are, in fact, only a small atom of a much larger galaxy). There might be a difference and once such a difference will be measures, theories will be updated (or thrown away).