I didn't say that I didn't care. I will likely read and try to understand any experiment that you care to undertake. I just don't have the time and energy to spend on doing any similar experiments myself. I have too many unfinished experiments / projects of my own, audio related and otherwise. I still haven't built my 1KW tube amp!
I did maintain some rather wicked (by late 70's - early 80's standards) lasers used for cutting and drilling the ceramic substrates used in hybrid microelectronics. The same diffraction effects that make your bridge pictures look wavy will also de-collimate your laser beam.
The two foot long HeNe laser that I used to align the big CO2 cutting laser puts a 1/4 inch red dot on the wall nearby and a similar dot at the other end of the facility nearly 1/4 mile away. That dot becomes a slightly fuzzy red spot about a half inch in diameter on a stop sign about 2 miles down the road on a cool night with the beam travelling over grassy ground. On a hot humid night with the beam travelling over warm pavement, its a 1 inch fuzzier circle.
Yes, it's going to be a problem, but the green lasers pointers I've used have done surprisingly well for the cheap things they are. I've tested blue, but not enough to really know how well it works. Red might be the best, as least for scatter, but blue is nice because the scatter does show off the beam nicely.
I think I posted a laser pic or two a while back.
Some amateur rocket builders have flown high enough to see (or transmit/ record) the curvature. Not the whole earth, of course.
-Tim
There are several videos of rockets purportedly striking the "dome". In one case I also saw a video showing what looked like the same rocket at a higher altitude dropping it's booster stage.
Some of the videos are well done, but with technical issues in the way the interpretation is made.
Many of the videos are nonsense.
Some of the videos are well done, but with technical issues in the way the interpretation is made.
Many of the videos are nonsense.
That's actually pretty tight, better than anything I've got. Some of my little lasers are a foot or two wide at 5 miles. It isn't easy aiming them at that distance.
It was a special unit made for shooting a visible beam through the plasma tubes in the CO2 laser for the purpose of aligning it all. It was purchased around the time that I left the cal lab to become a development engineer.
I had performed a "Tubelab George" operation to extract almost 200 watts of laser light from an already worn out Photon Sources 100 watt laser. It only used two plasma tubes which were collinear so alignment was actually done by burning holes through a 1/4 inch thick asbestos sheet. We would look at the extremely hot white circle through a welding helmet and adjust for maximum roundness. OHSA....what's that? When the plant had to adopt some real safety procedures, the thick white sheet went away and the alignment laser was purchased. I still preferred to just tune the laser for the tallest "rooster tail" from the ceramic as it was being blasted. To fine tune, you look at the divots under a microscope and make sure they are round.
They got a new fancy Panasonic 500 watt laser that used five or six plasma tubes mounted on a single panel stacked vertically with a pair of front surface mirrors to reverse the beam direction for each tube. Alignment was not easy but not my problem.
The old Photon had a "regulated" 20 KV power supply and the current meter read about 250 mA when normally operating. There was a 4PR400 tube (a Pulse Rated 4-400) tube for each plasma tube. The HV was connected to one end of a glass tube, and the 4PR400's plate was connected to the other end. The tube was switched form cutoff to saturation to pulse the laser and blast a tiny divot in the substrate. A gas mixing panel metered CO2, Helium and Argon at less than 1 ATM. The mixture was unique for each target substrate until this machine became the only machine to do 30 mil alumina.
There was a unique "transformer" called a saturable core reactor" wired in series with the power transformer. A DC control voltage was used to cause a variable amount of core saturation causing the reactor's inductance to vary. This was a variable impediment to the flow of electricity, so I simply bypassed it. This caused the HV meter to remain firmly pegged on a 25 KV scale, and the current meter to read 400 to 450 mA when running at full boogie to cut 30 mil substrate for the MX-300 radios. We connected the cooling water up to the plant's chilled water loop used for HVAC instead of room temp water, but plasma tube life was now measured in weeks instead of months, and new ones were almost $2K a pop! That poor laser ran 24 / 7 like that for over a year, and I had to visit that thing almost every day, and once or twice a week I would get called in during the night, but there were actually more problems with the CNC table than the laser.
When the original 50 watt Photon hit the scrap heap, one of those 4PR400's and its socket became a wicked CB linear amp (over 1 KW), and the granite that held the plasma tube and all the hardware became another laser tech's mailbox post. Took 4 of us to drag that thing out of the trash.
Thanks for the story, George, as usual!
Decades ago I worked in a London theater that had saturable core reactor dimmers - they were tube driven! Big racks of the things with tons of space. I've never seen anything like it before or since. I had worked resistance dimmer boards, transformer dimmers, SCR and finally the triacs began to come it.
They got it cheap, it was unclaimed freight, apparently. No idea what the tubes, sorry - valves - were. Some day I need to build one of those things.
Decades ago I worked in a London theater that had saturable core reactor dimmers - they were tube driven! Big racks of the things with tons of space. I've never seen anything like it before or since. I had worked resistance dimmer boards, transformer dimmers, SCR and finally the triacs began to come it.
They got it cheap, it was unclaimed freight, apparently. No idea what the tubes, sorry - valves - were. Some day I need to build one of those things.
The control board for the reactor used discrete transistor circuits. We had spares for every board in the thing. Needed them too....Spare tubes too, but none were ever changed. They didn't die. Ceramic dust is a very good abrasive. it made life difficult for the CNC table. We fixed it a lot.
The big ceramic tube in the plasma etcher / vapor deposition system....That one died several times and it took me a couple of hours to change it. I think that thing put out 3 kilowatts on either 27 or 40 MHz. That monster machine ran on 3 phase power. It was used for depositing metal on thin film ceramics. And removing the top layer of some metals for better adherence of the next metal. It was the goto machine for making gold plated razor blades for the coke heads. It was the late 70's, gold was far cheaper than coke!
It was always blowing the cartridge fuses on the power panel.....Florida during a summer thunderstorm. When it blew a fuse the whole machine shut down, even the vacuum system. There was a panel with 10 or 12 big cartridge fuses. I would take a handheld meter set on AC volts, and run down the panel quickly with both probes in one hand to find the fuse with voltage across it.
The setup tech and others often watched me work on things, because sometimes it could get "interesting." I got a panicked phone call at about 3 AM one night and the only words I could make out were "it exploded" so I hopped in my car and zoomed to the plant (a 5 minute drive at that time). I found the setup tech rather shaken with a toasted Kontron meter in his hand. It seems that some of the meter's internal parts came through the case and passed right by his head on it's way to the wall behind him. He had tested the fuses with the meter on OHMS.......The panel was 480 volts 3 phase. He wouldn't go near that machine again!
The big ceramic tube in the plasma etcher / vapor deposition system....That one died several times and it took me a couple of hours to change it. I think that thing put out 3 kilowatts on either 27 or 40 MHz. That monster machine ran on 3 phase power. It was used for depositing metal on thin film ceramics. And removing the top layer of some metals for better adherence of the next metal. It was the goto machine for making gold plated razor blades for the coke heads. It was the late 70's, gold was far cheaper than coke!
It was always blowing the cartridge fuses on the power panel.....Florida during a summer thunderstorm. When it blew a fuse the whole machine shut down, even the vacuum system. There was a panel with 10 or 12 big cartridge fuses. I would take a handheld meter set on AC volts, and run down the panel quickly with both probes in one hand to find the fuse with voltage across it.
The setup tech and others often watched me work on things, because sometimes it could get "interesting." I got a panicked phone call at about 3 AM one night and the only words I could make out were "it exploded" so I hopped in my car and zoomed to the plant (a 5 minute drive at that time). I found the setup tech rather shaken with a toasted Kontron meter in his hand. It seems that some of the meter's internal parts came through the case and passed right by his head on it's way to the wall behind him. He had tested the fuses with the meter on OHMS.......The panel was 480 volts 3 phase. He wouldn't go near that machine again!
I had a HeNe laser in highschool for a sicence fair project.At 300 yards the beam would spread probably two inches.
I have one of the cheap green lasers and about 20' it already has a primary beam of 2mm with splatter around it forming an oval 4mm x 6mm. for less thatn $10 what can one expect.
Looking at the construction, it might be possible to get the glue off it and try to get a better spot focus.
I have one of the cheap green lasers and about 20' it already has a primary beam of 2mm with splatter around it forming an oval 4mm x 6mm. for less thatn $10 what can one expect.
Looking at the construction, it might be possible to get the glue off it and try to get a better spot focus.
Thanks this makes a lot of sense with regards to the air density especially as we adjust altimeters along the way. Except of course jet levels all use the same setting. Thanks again I was actually serious I hadn't thought of this before.
I have not read all of the posts, so it may have been mentioned already.
Do these flat earth folks have reliable friends they can call when on a continent opposite to see if the sun is up when it is dark where they are? Would they just say the sun is at the far opposite end and the light doesn't cover the entire area regardless of being flat?
Do these flat earth folks have reliable friends they can call when on a continent opposite to see if the sun is up when it is dark where they are? Would they just say the sun is at the far opposite end and the light doesn't cover the entire area regardless of being flat?
@Object52. Yes; not all of the flat earth is illuminated at the same time, so no problem having friends in different places seeing different times of day. Not really a big problem on the flat earth model.
If there are enough of these flat earth folks, seems that there's some money to be made offering bus and boat rides to the edge of the earth. The edge should be easy to find, just go straight in any direction and the magical ice wall at the edge will eventually stop you. I don't know how you convince these folks we're going 'straight' if GPS is fake and the stars are what ever they believe and the sun is blah blah blah ... oh it could be some fun. Maybe sell some DIY gear on the boat. Maybe one of these clowns can draw on a map where the edge is. Ha
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