Keeping a small dot over one mile distance

[RedCowboy]

The truth is the Earth is slightly OVAL, because it is spinning.
The circumference around the equator is slightly different that from north pole to south pole to north pole.

But for all practical purposes it is round.

On another note the fabric of space/time does bend around a gravity dense object, so much so that it has to be factored into the programming of our GPS devices.

Gravity forces LARGE celestial bodies to become round, only acting forces such as velocity can cause flex, but you would not see it if looking upon the earth from the surface of the moon.

As for projecting a spot, not a tiny dot, but a visible spot at 5680 feet, I have done it with a 200mw 532 module mounted in a heat sink and I replaced the final focus lens with a wider longer focal length sliding to focus lens, you can do it for 100 dollars.

 

[srow]

Unless the earth is like a pizza and has a crust/berm all the way around the edge. We would then be able to see that of course.

According to flat earth theory: You can see this pizza crust in the form of the Antarctic which has 200 foot high wall of ice entrapping all the oceans of the world.

Also, with over 10 billion humans that have ever lived, the edge would have been seen by now and we would have pictures of it or in the old days, an X on a map somewhere.

The edge of the earth is a little further inland from the Antarctic ice wall which is in perpetual darkness and impenetrable violent storms. Before the times of captain Cook the Antarctic was out of bounds to everyone because of the extremely harsh conditions. Nowadays nobody is allowed near the Antarctic because the UN will basically warn you off or Kill you.

Plus, if it were flat and we have sun rises and sunsets, that would mean that the earth is flipping like a piece of plywood which would create massive amounts of force near the far edges and none at the center.

We have never been taught the true consequences of perspective. The laws of perspective explain how the sun and moon rise and fall on a flat earth. Samuel Rowbotham explains this with many diagrams and examples in his book and it takes a lot to get your head around but it makes sense.

Sorry but there are so many laws of science, coriolis effect

The Coriolis effect! The direction in which water spins down a plug hole is dependent on the angle at which the water hits the hole and not it's location in the world. It is also supposed to affect a bullets trajectory but, conveniently is only noticeable at distances over 1Km. Who shoots targets at over 1Km to even verify this? There is also the Foucault pendulum which was used to convince people of the earth's rotation. The rotation of the pendulum was dependent on it's pivot ball joint and the angle at which the operator released it NOT anything to do with the Earth's rotation.

Reading comments from other users reminded me of this quote from the Matrix:

Morpheus: The Matrix is a system, Neo. That system is our enemy. But when you're inside, you look around, what do you see? Businessmen, teachers, lawyers, carpenters. The very minds of the people we are trying to save. But until we do, these people are still a part of that system and that makes them our enemy. You have to understand, most of these people are not ready to be unplugged. And many of them are so inured, so hopelessly dependent on the system, that they will fight to protect it.

Yes, they will fight to protect their Globe earth as you can see from this thread!

 

[srow]

As for projecting a spot, not a tiny dot, but a visible spot at 5680 feet, I have done it with a 200mw 532 module mounted in a heat sink and I replaced the final focus lens with a wider longer focal length sliding to focus lens, you can do it for 100 dollars.

Well, it looks like I'm going over kill because I negotiating a 520nm 1W laser with 3 element lens at the moment. Apparently 520nm is replacing 532nm as the new green. I'm hoping to use it on a 2 mile stretch of water if the 1mile stretch is successful.

 

[doubleone44]

Have you ever been in a plane? If you have, you can, on a clear day, clearly see the curvature of the earth. Also, if the earth was flat, how do you explain that we can travel westwards and end up east of our starting point?

Also, for non-derailing purposes:
The divergence of a 1W 520nm is way bigger than a 100mW 532nm, so get the latter. It's cheaper and better for what you are trying to prove (or disprove)

 

[Gabe]

Have you ever been in a plane? If you have, you can, on a clear day, clearly see the curvature of the earth. Also, if the earth was flat, how do you explain that we can travel westwards and end up east of our starting point?

Also, for non-derailing purposes:
The divergence of a 1W 520nm is way bigger than a 100mW 532nm, so get the latter. It's cheaper and better for what you are trying to prove (or disprove)

This.

Sorry for the large photo. This is a photo I took myself, on a trip to Mexico in an airplane, at about 35,000 feet I believe. No editing, no fisheye lens, no window distortion. Take a ruler or a pencil or something, move it along the horizon, you can clearly see it's not flat. But it's always good for snew to conduct his/her own experiments if they want, for their own evidence.
BTW doubleone, would you happen to know the divergence for the NDG7475 and the NUGM01T diodes? I know they're very similar, and less than 2mRad usually, but that's all I got. Thanks

 

[doubleone44]

BTW doubleone, would you happen to know the divergence for the NDG7475 and the NUGM01T diodes? I know they're very similar, and less than 2mRad usually, but that's all I got. Thanks

I'm not sure, but I think it's about the same as the NDB7875 diodes, as they (presumably) have the same emitter size (gotten from max. Amp ratings). Divergence would (as usual) depend on the lens, but this should atleast give some information.

 

[RedCowboy]

A 1 watt 520 is MULTI MODE and highly divergent. :banghead:

Enjoy your bright green laser flashlight.

 

[Gabe]

I'm not sure, but I think it's about the same as the NDB7875 diodes, as they (presumably) have the same emitter size (gotten from max. Amp ratings). Divergence would (as usual) depend on the lens, but this should atleast give some information.

A 1 watt 520 is MULTI MODE and highly divergent. :banghead:

Enjoy your bright green laser flashlight.

Oh, yuck. Thanks guys. For some reason I had in mind the idea that these 1W greens had good divergence. Gonna need some additional optics if I ever use it.

 

[Laser Chick]

-Nope, there are many other seas and oceans than just at Antarctic.
-You are very wrong on The Coriolis effect. Marine snipers can attest to that.
-There have been many around the world flights. They were able to see the Earth as a round globe the whole time. There was not a flat spot with big lettering saying "other side up". Jeepers Creepers ...smh .. shakes head.
-Plus there are the magnetic fields that are based on a round shape, not flat.
-Seismograph research stations all over the world that support a round earth.
-There have been some massive tsunamis lately. They would have pushed water over your so called edge and the ocean levels would have dropped. Instead they are rising.
-A flat earth would not hold the oceans for millions of years. There would be a leak, erosion or melting somewhere along the edge and the oceans would go bye-bye.
- Tectonic plates would rip a flat earth apart.

Of course we are fighting for the "almost" round/globe earth because it is correct.
If you came up to me and said that you were going to plunge your thumbs into both of my eyes and it will not hurt or harm my eyesight. I will fight you tooth and claw because I know for a fact that you are wrong, plain and simple.
Start walking, riding and floating due East at the equator. Sooner or later you are going to end up in the same spot srow.
Believe what you want because it does not have any effect on my life but good luck with your research.
If you find firm factual evidence. Would love to see it.
BTW, 1 or 2 miles per the whole surface of the whole earth does not give you much room for error for your data to be off. Remember that the atmosphere is very heavy pressing down on the land and water so a change in barometric pressure can skew all your data.

 

[VisibleGreen]

I would suggest that sellers do not sell to Srow as the intended use could be unsafe. We have someone that won't listen to reason when it comes to statistical data so I have reason to believe that he will ignore safety precautions when using a high powered laser.
I worry about the other guy at the receiving end of the laser and anyone in the lake or near any reflections.

 

[Gabe]

I don't think we should beat on the guy, so long as he/she isn't a troll. They stated they'd rather not talk about flat earth suchandsuch, only about the use. Their viewpoint on the earth being flat is very similar to believing in a religion. They were raised with that belief, it's in the core of their minds so they'll strongly believe in it. In spite of overwhelming evidence, they will often stick with the he belief they grew up with, maybe unless they do some exploring and searching for proof themselves. Very similar in both cases. Yet, we don't beat on others simply for their beliefs, now do we? That's what the religion read is for . So I say leave snew alone, help him/her with whatever they need help with, and let us all be on our merry ways.



However, if snew is simply a troll, then I'll eat my hat and just go back to whatever I was doing before.

 

[VisibleGreen]

I don't think we should beat on the guy, so long as he/she isn't a troll. They stated they'd rather not talk about flat earth suchandsuch, only about the use. Their viewpoint on the earth being flat is very similar to believing in a religion. They were raised with that belief, it's in the core of their minds so they'll strongly believe in it. In spite of overwhelming evidence, they will often stick with the he belief they grew up with, maybe unless they do some exploring and searching for proof themselves. Very similar in both cases. Yet, we don't beat on others simply for their beliefs, now do we? That's what the religion read is for . So I say leave snew alone, help him/her with whatever they need help with, and let us all be on our merry ways.



However, if snew is simply a troll, then I'll eat my hat and just go back to whatever I was doing before.

I guess you're right. We already helped him but upon learning a few things I'd still reconsider helping him making a dangerously powerful laser.
I believe in sharing knowledge with people but we should also be careful who we share this knowledge with.

 

[Chrisbee]

Even if you think that you can accomplish a reasonable sized dot at 1+ miles in order to be able to take accurate measurements from, you still have to worry about precise leveling of the laser. At the least, some sort setup like surveyors use. And that won't be 15mm above the ground.

BTW FE'ers don't believe in a "pancake" like flat earth. More of a cylindrical type earth. And we're on one of the flat ends.
So there's that...

 

[srow]

The photo out the plane window. I'm struggling to get reference points to tell either way if it's flat or curved.

Safety! I'm new to lasers and if it hadn't been for you lot I would have never known. The three lasers I previously purchased were over the net with no real warnings I can remember and I've already done some things that I wouldn't have done had I have known. I do quite a bit of welding and I know full well the dangers of looking at the arc. Ok, I'll have a look at the 100mW(less dangerous). Someone believing in something is no reason for them to be banned from owning a laser.

Laser Chick: I have a control in the place to verify my results. If I see the laser at the other side at 15mm elevation(confirming no arc) I will then place a 50mm thick float in the middle lake to mimic the arc to see if the dot is only visible above 150mm elevation.

As for the coriolis effect and snipers. Read this sniper manual and tell me where the coriolis effect is mentioned. https://archive.org/stream/milmanual-fmfm-1-3b-sniping-u.s.-marine-corps/fmfm_1-3b_sniping_u.s._marine_corps#page/n0/mode/2up

This video is so funny but does highlight the problems a sniper would encounter if he had to take the coriolis effect into account. https://youtu.be/95jPqnnfwoA When has anyone ever seen or heard of a sniper having to take into account which direction he is pointing in with a compass? I've never seen a sniper having to take out his compass to make corrections for the coriolis effect. And he wouldn't just need a compass, he would need to know what latitude he was at because every degree of latitude has a different surface velocity eg, the equator has the fastest surface velocity and the poles have the least. He would need some form of gadget to compute the corrections or a book of tables where he could look up the corrections, neither of which I have ever seen or heard about. Can anyone show me any proof that a sniper has to take into account the coriolis effect or show me the math involved?

 

[srow]

Even if you think that you can accomplish a reasonable sized dot at 1+ miles in order to be able to take accurate measurements from, you still have to worry about precise leveling of the laser. At the least, some sort setup like surveyors use. And that won't be 15mm above the ground.

I've already taken into account refraction of 1/7. Please show me proof of why 15mm isn't a suitable height?

 

[RedCowboy]

I've already taken into account refraction of 1/7. Please show me proof of why 15mm isn't a suitable height?

Over a mile or two your beam will expand and you would measure from center to center, a round spot is more important than the size, as for 15mm, just try it, you will see that your beam bottoms out.

But for a moment think about time zones and if you placed a stick into the ground and then another 100 miles away and had your assistant take a pic at the same moment, not the same time of day because you may be in the next time zone, but with you each facing north take a pic while in communication at the same moment and notice the angle of the shadow in relation to the stick.
Be at the same latitude.

This will be the same results all around the earth if you stay on the same line/latitude all the way around the globe.