Fun for nerds

[soldar]

Degaussing battleships. More complicated than I thought.

[RoGeorge]

Trapping An Electron In a Box
The Action Lab



 

[RoGeorge]

Why 10,000 volts at altitude is a BAD IDEA
Strange Parts



 


Image from:  https://en.wikipedia.org/wiki/Paschen's_law

[soldar]

This Aussie woman explains HV DC power transmission but her videos do that thing they do now of taking the image from a second camera while she still looks at the first camera so she is not looking at the camera which is recording. I find that annoying and stupid.   Other than that the video is interesting.

Electricity Across Oceans: Is HVDC the Future?




Why is China Dominating Ultra High Voltage DC

[mendip_discovery]

... but her videos do that thing they do now of taking the image from a second camera while she still looks at the first camera so she is not looking at the camera which is recording. I find that annoying and stupid.

This goes back to when we would watch documentaries and they would interview an 'Expert'. Plus some find the staring eyes of a crazy Aussie just a little unnerving.

[soldar]

... but her videos do that thing they do now of taking the image from a second camera while she still looks at the first camera so she is not looking at the camera which is recording. I find that annoying and stupid.

This goes back to when we would watch documentaries and they would interview an 'Expert'. Plus some find the staring eyes of a crazy Aussie just a little unnerving.

I understand it when a person is interviewing another person and each one is being recorded by a dedicated camera so they are talking and looking at each other and not at the camera. Then I understand I am an onlooker, a spectator.

But if the video is recorded with the person addressing the camera directly then it should remain that way and if the camera location changes the person should look at the new camera and not keep talking to... nobody.

It irritates me to no end.  I feel like yelling "Hey!  I am HERE!"

[RoGeorge]

Franck Hertz Experiment
xofunkox-scientific experiments

This is a tube for the Frank-Hertz experiment. It can be used to determine the discrete energy level of the electrons. The tube is heated to approx. 180°C, which causes sufficient mercury to be present in the vapor phase. The accelerating voltage (cathode-grid anode) is then slowly increased from 0 to 60 volts. Approx. 1.3 volts counter voltage is applied between the grid electrode and the collecting electrode.
The electrons that emerge from the hot cathode are accelerated by the field. At a certain speed, they interact with the gas molecules and are slowed down. If they are accelerated again ... . If the highest speed before they interact with the gas is just before the grid, some fly through the grid, overcome the 1.3 volt opposing field and hit the catcher. This current flow, which generates several current maxima at the catcher with increasing acceleration voltage, can be represented graphically. The distance between the current maxima is typically 4.9 volts for mercury.

 

[BrianHG]

[RoGeorge]

Magnifying The World's Brightest Flashlight (200,000 Lumens)
The Action Lab



Conservation of Etendue 

[Sal Ammoniac]

Magnifying The World's Brightest Flashlight (200,000 Lumens)
The Action Lab




Conservation of Etendue 

Great! Now kids can burn ants with magnifying glasses at night.