Recent content by jumpjack

Found a very good, free and online tool to play with rays reflections: https://phydemo.app/ray-optics/simulator/ I am currently using a couple of parabolic dishes for satellite TV, covered with small mirrors, to succesfully reflect sunlight to my north-facing window for 4-5 hours per day...

I live in a flat at ground floor, roof is 3 floors above...

Around 150$ + shipping. But this was the price for "backers" at the time of first prototypes, I don't know which will be the final retail price. Anyway any other heliostat project I found was in the order of thousands of dollars, it was enormous (1 m2 or more) and you had to build it by...

"Caia" heliostat from Solenica is eventually on delivery all around the world! (after 6 years awaiting since its presentation at MakerFaire Rome). Mine should be shipped around April, I'll report about it here. Did anybody here purchase it?

Point is: is it just cylindrical, or something else? Continuing my simulation I found the possibly it is cylindrical, but also that a discrete mirror would work better than a continuous one, because each mirror would reflect into the window a "box of light" as large as the mirror itself, without...

This is what I want. Or at least, if not a point, an user defined area 1x1 meter sized. I think I found a gemetric method with geogebra, using 4 mirrors with 5° difference orientation one w.r.t the adiacent one; once I refine the model I'll post it.

I am studying this topic since a long time... and didn't find a solution yet; not a static one, anyway; for a moving mirror I created a program which calculates the needed orientation of a mirror, given a position in the world, to constantly reflect the sun into a static point...

nobody can help?

To the SUN field, I am talking about Sun EMF.

I eventually found some equations to work with: https://ocw.mit.edu/courses/aeronautics-and-astronautics/16-522-space-propulsion-spring-2015/lecture-notes/MIT16_522S15_Lecture25.pdf http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?2001ESASP.476...61I&defaultprint=YES&filetype=.pdf...

I cannot find precise values for solar EM on Earth, only a couple of clues: The magnetic field at an average place on the Sun is around 1 Gauss, about twice as strong as the average field on the surface of Earth (around 0.5 Gauss). https://www.windows2universe.org/sun/sun_magnetic_field.html...

I think you completely misunderstood my post. Forget Mars. Just replace "Moon/Mars" by "Moon" in the post above. Look at the picture: Will electrons in the wire be moved along it by Lorentz force? If I connect a second wire parallel to the first one, but completely isolated shielded from...

Moon and Mars have no magnetic field, but that they are immersed into solar magnetic field. If I place a long wire along north pole, perpendicular to Sun, while Moon/Mars moves along its orbit, the wire cuts magnetic field lines; this should produce a difference of potential between fare edges...

The equation I know for calculating air drag force is: F = 0.5 * rho * Cd *A * v^2 rho = air DENSITY Cd = coefficient of drag A = cross section v = speed in m/s From this I get for Cd: Cd = F / (0.5 * rho * A * v^2) Comparing to your equation: CD = FL/ (0.5 * Air viscosity * V^2 * Area) So I...

What do you think? RU2563511 MICROBIOLOGICAL METHOD OF TRANSMUTATION OF CHEMICAL ELEMENTS AND CONVERSION OF ISOTOPES OF CHEMICAL ELEMENTS Viktor Kurashov, Tamara Sakhno SUBSTANCE: radioactive raw materials containing radioactive chemical elements or their isotopes, are treated with an aqueous...