# All Questions

393 views

### Combined Translation and Rotation of a disk possible? material and references?

I am considering building a robot that can rotate and move at the same time. Since it's just a theoretical idea at the time and I need read up material, I thought I would ask here. I am thinking of a ...
541 views

### Using supersymmetry outside high energy/particle physics

Are there applications of supersymmetry in other branches of physics other than high energy/particle physics?
210 views

### Majorana-like representation for mixed symmetric states?

Is there a generalization of the Majorana representation of pure symmetric $n$-qubit states to mixed states (made of pure symmetric $n$-qubit)? By Majorana representation I mean the decomposition of ...
845 views

### Is mass-energy conversion in chemical reactions experimentally observable

This is a common point of argument on internet forums. I think it is fairly well established theoretically that there is a very small amount of mass converted to energy in an exothermic chemical ...
483 views

982 views

### Critics of Mannheim's Conformal Gravity Theory?

I'm looking for more articles/reactions/critiques/support for Philip Mannheim's recent conformal gravity theory. See here: http://arxiv.org/abs/1101.2186v1 Any ideas on where to start?
240 views

### what is the probability distribution for the angle of an approximate laserbeam

I'm trying to simulate the light distribution characteristics from a Gaussian laser beam, but having difficulty with the angular distribution. I need to generate a large number of points on an x/y ...
200 views

### What does this infinitesimal Eulerian change describe?

This is a question I originally posted in math.se which received an answer that was far too mathematically sophisticated for what I wanted; given that basic multivariable calculus was used through out ...
1k views

### Is the E-cat by Andrea Rossi et al. for real?

Does this thing really do what they say? http://www.youtube.com/watch?v=EhvD4KuAEmo If it does, it looks like this will probably be the biggest breakthrough in science ever :)
586 views

### Are there 'higher order moments' in physics?

This may be a rather noob question but please let me clarify: I'm struggling to understand the use of the word 'moments' w.r.t., probability distributions. It seems after some research and poking ...
267 views

### Is the pressure at the outer hole on a pitot static tube equal to atmospheric pressure?

I'm looking at a pitot static tube question right now and I just need some clarification. There is the outer hole on the pitot static tube, not the hole that the air stream goes through, but the other ...
114 views

### Why do clusters of stars eventually dissipate?

Why don't the stars in a star cluster attract each other gravitationally, forming one big star? What causes a cluster to disperse the stars in it?
147 views

### How do I determine where the maximum air velocity around an object is?

I have a freestream of air directed at an object. Is there a way to find where the maximum air velcoty occurs with only having initial air speed and static pressure at the object?
890 views

### Why does a ping pong ball change direction when I spin it on a table?

When I spin a ping pong ball on the table, it rolls forward in the opposite direction of the spin, and then eventually changes direction and rolls backward. Here's a video demonstrating the effect. ...
219 views

### Atmospheric interference and ground based stellar observations

Stellar spectra captured from ground based equipment needs corrections to remove atmospheric spectral noise. Is there an Internet site that shows specific amplitude and wavelength differences between ...
97 views

### Is it possible to transform chemical energy in electrical energy by modifying the equilibrium constant?

Considering a Daniell cell, is it possible to create endlessly electrical energy by using atmospheric temperature (for exemple) variations to modify the reaction's eqilibrium constant ? I apologize if ...