Recent content by Bernadette

Hello What experiment or observation shows that for atoms, molecules or masses of gas, there is attraction in the sense of Newton's law (universal attraction)? Bernadette

Thanks Sophie In the usual experience of the shadow of a disc, we look at this shadow (and its central point...). The question was: what do we see when looking towards the source of light hidden by the disc? In diffraction, light is considered to be a wave. This makes it possible to...

Hello Ibix Thank you for your interventions. I will go back to my reading. The arrival of RR and RG is quite simply a fascinating subject. When A Einstein was employed in the patent office in Zurich, Switzerland, he complained by post to a friend of his that he did not have access to many...

Hello Ibix (i must say that sometimes, i do not understand about what you write. When you write "serial of Fourier" in an other post. But i am sure you see the "things" in an other way than i. More with equations and mathematics. What is not easy for me) I try to resume. (And English is not my...

Hello Tech99. You are rigth. For the simulation... Some other pictures. (from wikipedia English. Arago spot. I have make some "trials" time ago (we don't have camera like now...). I think i will perform some and use a glass sheet (like Fresnel with Chinese ink) but with a small round...

Hello Tech99. Fresnel Spot: 1. Simulation The image above shows a numerical simulation of the Fresnel spot in the shadow of a disk (diaphragm) with a diameter of 2 mm, at a distance of 1 m from the disk. The light source is a helium-neon laser which emits in the red (λ = 633 nm) and is located...

In a "classical" diffraction experiment. The two holes of Young for example. There are particular points on the observation screen. Those for which the two optical paths have the same length. (and here the same duration). This is the center straight. The two "bright" lines (therefore in phase)...

Hello How Michelson does his experience. And what did he think before. At that time, it was thought that light needed a support to move. Ether. Assumed immobile (first assumption that MM (Michelson Morley) will hijack. By floating their interferometer on a bath of mercury to be able to turn it...

Hello Drakkith You write: "the light that forms the spot will not look as if it came from the edge of the sphere" Do you speak of the spot in the center of the shadow? If we follow Huyghens' theory (each point reached by the light wave can be considered as a source), each point in space in a...

I think so too

I think the video shows the experiment that Fresnel did around 1800. It's a shame the image isn't sharper when he points his camera at the light source.

Hello No more response? Can we say that when we apply the electric field (we approach the charge), the order increases? Have a nice day Bernadette

Hello Tech99 I read Fresnel quite a while ago. He meticulously describes the experiments he has carried out. But I don't remember him talking about those kinds of details. I did some diffraction experiments myself and found it to be a good way to make objects that intercept part of the light...

Hello Tech 99 and IbixThanks for the exchange. It's interesting. From what I know... In his treatise "optics" (1704 in English), Newton suggests that light is made up of material particles. Cautious, his name does not appear on the cover of his book... (sometimes added by hand) Huyghens...

(*): Founding texts of science analyzed by today's scientists. (bibnum). https://journals.openedition.org/bibnum/858 . In French, sorry... Bernadette