Z Decimal (formally Dr Zack)

Z Decimal (formally Dr Zack)

Jan 12, 2019, 11:08 PM

Dear Dr. John D,

Thanks for asking me for opinion and thank you very much for the invitation. I had plans to go to England before February 1st but it turns out that I will go South tomorrow morning and I will come back to Madrid in 18 days or so. There might be a chance for me to go to London but I cannot assure you that, not right now.

But I would really love to attend the experiment.

Not sure if you have done any experiment like this before, but you may face a few problems.

I am going to mention all the problems that I remember and I hope they will be helpful.

Aiming the laser to a specific point is not simple through distance as you know. 15KM may look like a short distance, but it is not that short. Using powerful flashlights will definitely help especially if you use different colors and put one above another with a separation of at least 50cm between each flashlight. Your friends from the other side will see the flashlights above each other and they will quickly recognize it. Just make sure they are high enough, once they see them you can lower the alititude as much as you can to see if they can still be visible from 1 meter or less. The signals will help as well. But the problem here is that even if they locate their friends in the other side, aiming the laser with a Tripod will be hard. Because if you move it 1 degree, the beam in the other side will move 260 meters.

So to point it to a specific place may not be easy but not impossible. It may take you some time to get it done. But if you are doing this in a very cold weather, people may not be so patient and wait till it’s done. So I suggest taking something really really warm to warm up everyone. And if it’s possible, you can create a device to help you move the laser slowly. Mike (a member of our team FECORE) created a great device and named it SALAD. with that device, we can point the laser accurately to anywhere we want. So that is a very important thing that will save everyone’s time and effort. You don’t have to make the same thing, but you can create something cheap and does the same job. A smart carpenter can do it, you just need to give him an idea. So instead of a tripod I would suggest a better aiming device that  can go up and down and also pan left or right.

1 meter above water surface is something that I have been dreaming to achieve for a long time. It may work for you if there is no refraction. As you know, depending on the temperature, an invisible layer above the water surface may get created and that will make seeing the laser from that distance impossible.

So just in case, be prepared to take something with you to raise the laser higher. This is just to make sure you are not going back home without doing anything.

You should know the divergence of your lasers in mRad, to make sure that the laser will not contact the water´s surface, I think 1 meter is too low for the lasers you are using but maybe the copper pipe will reduce the divergence as you said, I am not sure. But I have to tell you that if the lasers contact the water´s surface, the beam may not reach the other side, and if it does, it may look higher or you may get a weird shape. It happened to us a few times. We had one of your lasers and in 7km, it lit up the entire place. Maybe the divergence in 7km was about 3.5 meters. Not sure though. But I am sure it was more than 1 meter, so for this reason, you need to find a way to reduce the divergence, maybe a collimated lens is the best option. But they are usually expensive. A friend of mine, used a telescope´s lens and it worked pretty fine for him, he just put the laser pointer inside the telescope. So maybe that may help.

I am not sure what the experiment is meant to prove, but if you are willing to measure the height of the beam from the target location, then it’s better to have a big building as a target, because the beam may literally light it all up.

I was gonna suggest taking fireworks or flare guns with you to show your positions but they may not be heard or seen from that distance, we already tried fireworks but in vain. I think you can use compasses to know where you are pointing the laser to. If the place you are pointing the laser to can be seen during the day, then, take the compass and measure the azimuth of it carefully, and do the same thing from the other side, so when it’s night, you can just follow the compass. Because when it’s totally dark, it gets really hard to remember where you should look.

Start the experiment a few hours before sunset. Your team should be in the other side before sunset,

You will need one camera to record a non-stop video for the entire experiment (not a time-lapse) from the target location, and it will be better if you have another one from your position. Why a camera and why not a time-lapse? Because cameras do not blink, and believe me, in the dark you may miss the signal because all city lights will act like they are doing signals. and if you blink you may miss it. But when you watch the video, you may see the source of the light. Cameras are slower than the human eye so it may capture a fast light that your eyes missed. because to the camera the light passes slower. A cellphone camera can capture the remote control light but we cannot see it with our naked eye. And it’s better not to use a timelapse because timelapse mode takes a picture every 5 seconds or so and put them all together to look like a video. but that is like blinking, and the point is not to blink 🙂

Please take someone to film everything professionally. If I go, I will do it all for you. Because this is history. It has to be well documented.

This may sound stupid but please take enough food with you. You may think the experiment will take two or three hours but it may take the entire night. and hunger will make everyone wanna go back home.  You don’t wanna go back in the middle of the experiment. 🙂

That’s it I guess, these are all the things I could think of right now. I have to sleep now cuz I have to travel in the morning. If I remember anything else, I will let you know.


Best regards,


Jan 13, 2019, 5:48 PM

Hi Zack

Thanks for your reply and numerous points – very much appreciated, we are discussing them – especially the food one!!  Cake sounds good.

I need to “publish” on youtube and the website your agreement or disagreement with the method in achieving the aim.

I am keeping this as simple and clear as possible, so people who are unsure can understand how these experiments are carried out.  After we all agree on the method, then we will engage in the scientific princciples – one step at a time, to keep it scientific, sequential and logical for the whole community.

Could you send me a brief email simply stating that you agree or disagree with the method in acheving the aim.

If no, please could you say why and suggest a modification.

Kind Regards


Jan 15, 2019, 2:32 PM

Of course I agree if it is done correctly.

I still do not know what it is about but I can assume that the main idea is to measure the curvature of earth. If yes, then seeing the source of the beam from the altitude you mentioned in the experiment should be impossible in the globe model, so to me, there is no need to have the beam shining on a board or on a buildng because measuring that will be hard if not impossible because of the divergence, and because it is not needed as long as you can see the source of the beam that should be behind a curve, however, there will still be an argument about whether the source of the light is a mirage or not. So you may wanna answer this question before ending the experiment and I think that the best possible way to answer that is to use a boat to go from the target location to where the laser is at, with a camera that films the source of the light all the time, because if that is a mirage then the image will change the more you get close to it. Either it will disappear, or go down a bit until it reaches the real image or something. This is something that everyone may wanna see. This is like another experiment to answer a debatable argument 🙂

To do this may require more money that you guys have. It will be a good idea to let people help with what they can 🙂

Thanks for the message and if you need anything, let me know and I will see if I can help.

Have a great  day 🙂

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