The Flashing Light Prize is on right now, and that means all our favorite geeks and YouTubers are aspiring to what could be done with a 555. The rules are simple: turn a light bulb on and off somehow. [Sprite_tm] is answering the call, and he’s blinking lightbulbs at the speed of light.
[Sprite]’s method of blinking a light is simple: Use an ESP32 development board to turn on a relay. At the same time, send a packet out to the Internet and through four servers spread across the globe. When the packet goes through servers in Shanghai, the Netherlands, to Hong Kong, to Germany, and finally Japan — and back again — the light bulb turns off. It’s a physical demonstration of the speed of light and the quality of undersea optical fibers.
This route is quite long, and a reasonable estimate for the one-way, great circle path from Shanghai to the Netherlands to Hong Kong to Berlin and finally to somewhere near Osaka is about 36,000 km. A round trip for this light bulb packet is 72,000 km, or about 0.2 light-seconds. There are delays, of course, from fiber and cables not going directly over the Himalayas, delays in routers, and the difference between the speed of light in a vacuum and the speed of light in glass fiber. Still, light is quick, and the light blinks at about 1Hz.
You can check out [Sprite]’s entry video for the Flashing Light Prize below.
So who is going to make a reference to big bang theory?
I can only hope the venn diagram of hackaday readers and Big Bang Theory fans is two circles.
There’s an intersection of at least one, and I’m not ashamed to admit it. Chuck Lorre is brilliant.
I liked the older seasons, but the new stuff, meh.
The intersection is probably larger than anyone would wants to admit.
I watched an episode once.
That was one more than it deserved
First couple of years are great. https://www.youtube.com/watch?v=i5oc-70Fby4 Only 53 seconds.
Downside is the laugh track. In this clip it is so obviously fake. It follows camera cuts for crying out loud. But the clip takes me back to university.
Well, that was a waste of time.
I didn’t even bother to click that link.
I’ve heard enough ‘jokes’ that were actually just references in my life.
Sorry, but Penny deserves more than just one look ;)
*Opens a can of laughter*
/thread
World’s longest delay line oscillator?
Logically, the next step is to bounce a signal off the moon and use that as part of an oscillator…
Could it make the guinness world records?
Laser is too difficult without some friends at the Apache Point Observatory.
But bouncing radio signals would work!
Moon is about 1.3 light-seconds away, fits right into the .5 to 2 Hz limitation.
“Moon is about 1.3 light-seconds away…” Then doesn’t the total path equal 2.6 seconds? Logic–and arithmetic–is not my long suit; forget I said anything…
Shoot, you’re right.
Could still use the Moon, but not in the way I initially imagined.
Bounce it off the ISS instead?
ISS is only 400km up so the delay would be very short.
Maybe bounce it between a bunch of geostationary com stats and the ground.
Just add a PLL
Clearly more delay comes from routers processing the data/buffering it, than the light traversing cables.
This.
I wonder what the return packet order would be like.
(00.00) First packet received = Third packet sent (ON)
(00.52) Second packet received = Fifth packet sent (ON)
(00.55) Third packet received = First packet sent (ON)
(01.23) Fourth packet received = Second packet sent (OFF)
(01.26) Fifth packet received = Sixth packet sent (OFF)
(02.44) Sixth packet received = Ninth packet sent (ON)
(03.99) Seventh packet received = Fourth packet sent (OFF)
True so it’s not a good physical demonstration of the speed of light.
more than data buffering, the sorting algorithms used to find the route run on many different cpus, this is totally non-deterministic