Help finding Long Distance Laser

[paul1598419]

Did some checking. It was not actually NOVA. There is a youtube video version called "Flat Earth Crushed by Discovery Chanel" It is from episode 6 of the seies called Genius.

Oh, that's better. I have watched NOVA for many years and this just didn't sound like something they would waste time and resources on. The Discovery Channel has changed hands over the years and I can see them doing this. I don't watch them any more, so I would have likely missed this.

 

[CurtisOliver]

You name it. It is "flattened". Both "round and flat". It is squashed "flat" by 63km/Pi = 20km or a whopping 0.17%

Just like a frisbee, but a little less.

And it lacks a hollow bottom, as our australian friends eventually might confirm. So the similarity with a frisbee is indeed limited.

But you might get a glimpse of Great A'Tuin if you climb on the equatorial rim, looking down the abyss.

If you looked over the rim, all you would see is many great a'tuins all the way down.
Need to bring Terry Pratchett into the 21st century with quantum turtles next.

 

[Encap]

What about the "four corners of the earth" ? LOL

 

[hakzaw1]

I have a 532nm Jetlasers PL-E Pro 600mW I would be willing to part with. Grab a 10x beam expander from them for $100 and you'll have yourself a divergence of at least <0.75mRad. Pm me if your interested.

XXXXXXX
JL Holiday sale 5% off anything... thusly the 10X 'grab' would be $133.00 (&38 to ship DHL Express ~72hrs)

Ok
two can play that game!!

I will 'see' your 600 and raise you a brand new BLACK JL Pro Pl-E 900-1000mW 520 w/ a 'not matching' 10X beam expander for only $90 extra. fits and works great just NOT a Black JL BE. free ship til new years eve. Full JL warranty. Just pay for return $hipping under warranty.

You pay JL for the 520 ..& I ship to you. (CONUS) FREE! Save $38 plus 5% Off SMRP

BTW I am from Canton where we say 'OHIO! round on the ends..HIGH in the middle!!'

 

[brendon7358]

XXXXXXX
JL Holiday sale 5% off anything... thusly the 10X 'grab' would be $133.00 (&38 to ship DHL Express ~72hrs)

Ok
two can play that game!!

I will 'see' your 600 and raise you a brand new BLACK JL Pro Pl-E 900-1000mW 520 w/ a 'not matching' 10X beam expander for only $90 extra. fits and works great just NOT a Black JL BE. free ship til new years eve. Full JL warranty. Just pay for return $hipping under warranty.

You pay JL for the 520 ..& I ship to you. (CONUS) FREE! Save $38 plus 5% Off SMRP

BTW I am from Canton where we say 'OHIO! round on the ends..HIGH in the middle!!'

532nm has better divergence than 520, also closer to the magic 555 which makes it equivalent to about 700mW of 520 brightness wise. In the daylight anyways.

Also beam expander is $100 not sure where you got $133 from.

 

[Encap]

Not to point out the obvious, you guys know there is a specific Buy, Sell, and Trade sub-forum where anything offered for sale is supposed to be posted , right?

In other sub-forums such as this, one nobody cares what or if anyone is selling anything , generally speaking, and stuff for sale in the middle of other discussions and topics just either plain boring or annoying, not to mention off topic.

 

[brendon7358]

He said he was looking for a laser, so pretty much a WTB thread so I offered him one, I don't see a problem with that.

 

[paul1598419]

532nm has better divergence than 520, also closer to the magic 555 which makes it equivalent to about 700mW of 520 brightness wise. In the daylight anyways.

Also beam expander is $100 not sure where you got $133 from.

Hakzaw1 is a distributor of JetLaser products. He has them in his stock for sale and can ship to anywhere from Texas.

 

[ruud]

So then it's a good way to prove it round. Should he.

But this doesn't need a Laser to do so. Light travels both ways. It's enough to point a telescope across a long lake and watch the visibility of lake shore features just at the water horizon. Daytime. This way we regulary demonstrate the spherical topography of the lake surface to our visitors when we hold a public observation "at the lake" with our astronomy club.

We have 22km lake distance to cross and it's easy to see.

That only proves that angular resolution (angles get to small because of perspective) is the cause we cannot see the shore anymore. No proof of a globe or a flat surface. You really need a laser to prove on way or the other.

 

[smallfreak]

That only proves that angular resolution (angles get to small because of perspective) is the cause we cannot see the shore anymore. No proof of a globe or a flat surface. You really need a laser to prove on way or the other.

Wrong. Even the ancient greek KNEW that the globe is round in every direction by a simple observation. Ships that come from behind the horizon are first spotted by their sails, later by the boat itself. So it must be travelling "a mountain". This also proves the horizon to be a certain distance due to the curvature of that "mountain" and not an endless distance.

AND it's the reason why the surrounding of the ship is always watched from the top of the mast - you can look further around that curvature.

This has nothing to do with diminishing angles. Using a Laser to prove the same is just one method to define one ray of light that can be distinguished among the others. It makes no difference whether you shine a Laser across the lake and watch its dot on the top of the sail or whether you just look at the boat from across the lake and only see this top of the sail, as the boat itself is below the horizon curvature.

Just make a graph and see for yourself. Or take the experiment in nature. You will see, it makes NO difference. Light travels both directions the same way.

People tend to think too complicated. Maybe that's one of the reasons why some dullheads nowadays think, that the spherical shape is not "proven". I't s simply because of the Dunning-Kruger effect. They wouldn't realize a proof even if it would hit them into their face.

 

[ruud]

Wrong. Even the ancient greek KNEW that the globe is round in every direction by a simple observation. Ships that come from behind the horizon are first spotted by their sails, later by the boat itself. So it must be travelling "a mountain". This also proves the horizon to be a certain distance due to the curvature of that "mountain" and not an endless distance.

AND it's the reason why the surrounding of the ship is always watched from the top of the mast - you can look further around that curvature.

This has nothing to do with diminishing angles. Using a Laser to prove the same is just one method to define one ray of light that can be distinguished among the others. It makes no difference whether you shine a Laser across the lake and watch its dot on the top of the sail or whether you just look at the boat from across the lake and only see this top of the sail, as the boat itself is below the horizon curvature.

Just make a graph and see for yourself. Or take the experiment in nature. You will see, it makes NO difference. Light travels both directions the same way.

People tend to think too complicated. Maybe that's one of the reasons why some dullheads nowadays think, that the spherical shape is not "proven". I't s simply because of the Dunning-Kruger effect. They wouldn't realize a proof even if it would hit them into their face.

Wrong. They

Wrong. Even the ancient greek KNEW that the globe is round in every direction by a simple observation. Ships that come from behind the horizon are first spotted by their sails, later by the boat itself. So it must be travelling "a mountain". This also proves the horizon to be a certain distance due to the curvature of that "mountain" and not an endless distance.

AND it's the reason why the surrounding of the ship is always watched from the top of the mast - you can look further around that curvature.

This has nothing to do with diminishing angles. Using a Laser to prove the same is just one method to define one ray of light that can be distinguished among the others. It makes no difference whether you shine a Laser across the lake and watch its dot on the top of the sail or whether you just look at the boat from across the lake and only see this top of the sail, as the boat itself is below the horizon curvature.

Just make a graph and see for yourself. Or take the experiment in nature. You will see, it makes NO difference. Light travels both directions the same way.

People tend to think too complicated. Maybe that's one of the reasons why some dullheads nowadays think, that the spherical shape is not "proven". I't s simply because of the Dunning-Kruger effect. They wouldn't realize a proof even if it would hit them into their face.

Look into perspective . Even physicists admit that on a flat plane one can look further just because perspective also works on a flat plane. Its simple but easily overlooked. I did not say earth is flat but the ancients just had no good equipment like for instance the p 900 superzoom camera of Nikon. I mean , people nowadays dont know what they are talking about . They think they can see curvature from a plane window while that is way too low for the curvature to be seen.

 

[smallfreak]

Look into perspective . Even physicists admit that on a flat plane one can look further just because perspective also works on a flat plane. Its simple but easily overlooked. I did not say earth is flat but the ancients just had no good equipment like for instance the p 900 superzoom camera of Nikon. I mean , people nowadays dont know what they are talking about . They think they can see curvature from a plane window while that is way too low for the curvature to be seen.

As I said: Dunning-Kruger.

Yes, on a flat plane you can "look further because of perspective". Since it is not curved, objects do not vanish behind the bulge. Everything is "visible" even at "astronomical" distances. It just gets smaller alltogether. Perspective on a flat plane can NEVER show the effect that the lower end of an object becomes invisible whereas the top is still visible - but lower to the horizon. It's simple geometry that children at school can calculate. "Could" in some countries, I suspect. You don't need a degree in Math or Physics to understand that.

The ancient greek did not have sophisticated equipment, but they had a sharp brain. Starting 1608, when Hans Lipperhey invented the telescope, one could easily prove this observation, even to otherwise uneducated people.

Regarding your idea, that one cannot see the "curvature" from a plane, becaus it's "too low" - would you mind to throw in some math for that assertion? I assume you are talking about the horizon "looking curved" instead of flat, whereas I am talking about the curvature along the sight that makes objects vanishing "behind the hill". Even considered that it might be pretty hard to calculate what "curvature" is necessary that one might recognize as "curved", I'm interested to see what causes you to believe that.

In fact, the horizon can be seen "curved" even from sea level. This might not be obvious, unless you ar an artist, finding that drawing a flat horizon with a ruler looks "hanging" to the observer. To "look straight" one has to apply a slight curvature to it. But that is not a prove of anything, just an interesting fact about perception. However you can simply apply a ruler on the real horizon in front of you and watch, whether it aligns - it does not.

So take a heart and throw in some numbers that support your claim. Or just do as the scientists of NASA wold do: Go out and look for yourself. There is nothing hidden. Just go and see. No need to argue for or against it. It can be SEEN quite easily. Arguing with someone about math or geometry require both parties to have about a comparable level of knowledge. It's not enough to "believe". Oh yes, I'm bad in math, but when I carefully listen inside, I FEEL that all those educated bigheads must be wrong, as it does not sound reasonable to me.

 

[Immo1282]

Ruud, did you make an account to be argumentative about Flat Earth? Really shining start, gotta say /s.

There is no argument. There is no conspiracy. There is only ignorance.

If I were in your shoes now, I'd get educated about forum etiquette from the sticky threads, then make a fresh start. Nobody's going to see your profile post, so you're better off posting your question as a proper thread, and your introduction thread (with location in the title!!).

 

[ruud]

Ruud, did you make an account to be argumentative about Flat Earth? Really shining start, gotta say /s.

There is no argument. There is no conspiracy. There is only ignorance.

If I were in your shoes now, I'd get educated about forum etiquette from the sticky threads, then make a fresh start. Nobody's going to see your profile post, so you're better off posting your question as a proper thread, and your introduction thread (with location in the title!!).

Who cares ? I am not a flatearther anyway : )

 

[Immo1282]

Who cares ? I am not a flatearther anyway : )

You fooled me...

Second bit of my post still applies though - you'll get help more effectively if you introduce yourself & ask your separate question in the right places.

 

[Nordhavn]

If the earth was flat a map would be accurate and you would not need different projections to avoid distortion. They taught this in fifth grade social studies in the day. Along with algebra.