Measuring the altitude of ISS using the stars

Five stars Astro.

Imagine that, REAL mathematics and science without political bias or the need for a democratic "consensus" to decide what is a provable and repeatable numerical truth.

The basic answers depend on where the two different scientists are standing on the earth.

Here's why:

The difference in the angle varies with the difference between the two points ergo the larger the distance the greater the angle at a set time.

This is caused by the curvature of the earth.

That curvature determines the actual size of the earth because:

1) there is a set distance between two points on the curvature

2) that set distance and the measured angle determines the arc of the circumference of the globe.


Once you know the circumference you have the size of the earth within inches

of course there are other factors as well but they can be input into the equation to figure out the exact size of the earth.

The reason I am not throwing figures at you is that I have had to dumb this discussion down to the level of a math denier who is incapable of rational thought and logic.

Nope, it's apparent you don't understand how triangulation works. All I need to know is the baseline, my elevation and the parallax. The elevation over the horizon isn't changing so refraction is controlled for. Your complaints are invalid.

The whole point of measuring the parallax is to measure the distance. The stars are light years away, they can be regarded as infinitely distant for the purpose of these calculations.

We don’t know the size of the earth ? Are you serious ? We do know stupid when we see it displayed and that post is brighter than any star buddy

Hopefully they'll dictate some punctuation.

Wow, I don't want people to think I'm stupid! I better not even consider that we're lied to by NASA. It's not like there's money involved or anything.

And just what do you think I was doing in this video? The entire point, which you seem to have completely missed, is that I considered whether or not NASA was lying and unlike you I actually put in some real effort to test that claim. Turns out they weren't lying.

Gee... thanks for describing basic trigonometry for me. Not sure who your calling a math denier. Seems you have a real reading comprehension issue (user ignorance seems to be the issue).

Now... care to actually answer my questions, and not act like a condescending prick?

Do you know what a geodetic is and how they are defined?

Also, why do we have hundreds of them?

The answers to these questions reveal the fool that you are.

Keep avoiding the question dude, and expelling 2nd grade math as if you are some type of math genius.

Not sure why you are arguing with me. I'm not saying anything controversial here. I'm not saying the earth is flat.

Get off your high horse and read what I am saying.

I am saying, in as clear language as possible for you, THAT WE DON'T KNOW THE EXACT SIZE OF THE EARTH! It is a simple fact. We have various representative models that approximate it is all.

MEASURING (trigonometry) at different points of the Earth will give you different results, even with the same base assumptions (beyond that, there are quite a few different starting assumptions used, because we DON't KNOW)!

Go try it yourself if you don't believe me.

ANY calculation you make WILL be based on an ASSUMPTION, as the OP has done. Even if those assumptions, we think are pretty accurate, and can assume the numbers are about right... they are still, at their core, based on a range of assumptions (if you really want to get sown to it, heliocentricism is still an assumption, albeit a pretty dependable one).

Really very simple concepts here. We have a range of assumptive models that roughly stitch together to loosely describe the earth as an obloid ellipse shaped globe of somewhere around 40,000km circumference.

ALL APPROXIMATED!!!

You really can't be any more daft to keep arguing with this.

TL;DR my previous post?

Short version:
What is a geodetic and how are they defined?
Also, why do we have hundreds of official geodetic's?

Lucky bonus question: Why do we have less geodetic's for the Southern Hemisphere?

(hint: there's a few answers, the easy obvious ones, (land mass, population, etc) but then there are the less explainable reasons, that show the assumption for what it is... an approximation).

Answer these "not so simple questions", and you will understand that we don't know the EXACT size of the earth "down to inches", as you suggest.

Maybe we can have Astromut step in here to put the discussion to rest.

Astromut, in your opinion, do we know the EXACT size of the Earth, or is our knowledge (even if we think we're pretty accurate; for instance accurate enough to do the math and observations in the OP) still based on a set of approximations and assumptions?

Last Edited by puzzlesphere on 11/12/2020 03:57 PM

For my purposes I approximated the Earth as a sphere with a radius of 6,371 km. It's a very simple approximation, but that wasn't really the point of the video. It wasn't to get down into the minutiae of the exact figure of the earth, I could easily approximate it much better than that but that starts to make the math too long to easily describe in a video with very simplistic diagrams. I'm trying to keep things as simple here as possible while still demonstrating a basic fact. The fact is that the space station is approximately as high as NASA says it is, as fast as NASA says it is and as large as NASA says it is. And it's way too high and way too fast to be some kind of plane, drone, or balloon that is simply floating or flying through the atmosphere. Even if I assume a flat earth, which is totally wrong, the answer in this case would have still been about 411 km over a flat earth.

Thanks for the answer Astromut.

While you didn't actually answer my question (Do we know the EXACT size of the EARTH?), your response does support what I am saying.

The 6,371km radius figure is the most commonly accepted approximation, but at best it is still complicated guess work.

Complicated enough to be self-related to other assumptions we have made over the centuries, so for instance, you can aim a telescope at the sky and predict (another guess) where something that we put into motion based on the very system we are using to measure it, will be at a given time. Then be able to observe said object based on those predictions... but it is ALL still assumptions.

The numbers you use are based on a set of assumption and approximation that confirm the same set of assumptions and approximations that NASA uses... so in a sense, of course you will confirm their "assumptions".

Yes, you can get "more accurate", but you are only increasing accuracy along the same line of assumptions, not actually proving any of the core underlying theories.

Not belittling your post, it is very impressive! Just pointing out the assumptive nature of it all.

So, just to confirm (for those wrongly claiming, with accompanying insults, that we DO know the exact size of the Earth)...

Do we know the exact size of the Earth?
Do we have a single algorithmic way of describing ALL observational geometry?

Last Edited by puzzlesphere on 11/12/2020 06:55 PM

If you observe it where it's expected to be then it's not just an assumption, it's observational evidence which can support one description of the earth over another. I feel like you are trying to belittle observational evidence and quibble about things that are irrelevant to the subject at hand. How "exact" is "exact" supposed to be? Your question is vague at best and pedantic at worst. Do we know it down to the atom over the entire surface of earth? No, of course not. Does that matter for this? No.

False. I didn't use NASA's numbers. It's not based on assumptions. It's observational evidence. We knew how far apart we were from each other, we knew the altitude of the telescope, and we measured the parallax of the space station. I don't even have to use the approximate radius of the earth (known since long before NASA) to determine that ISS would be over 400 km high even if I assume earth to be a flat plane.

Last Edited by Astromut on 11/12/2020 07:26 PM

Dude... settle down, and don't be so facetious.

Don't make assumptions about what I am saying and doing. I am actually supporting the very concept of observational evidence.

There are people insulting others in this thread for stating that science doesn't know the exact size of the Earth. Beyond being rude, they are wrong. Do you agree with this behaviour?

It's not about knowing down to the atom. We don't even have an agreed upon single way of approximating the earth's size, we have a collection of formula that loosely work together, to accurately (to our best approximations) describe small parts, or large averages.

Do you deny there are hundred's of geodetic's that ALL approximate the size and shape of the earth differently? Some quite extreme?

These geodetic's work for small (relatively) geographic areas, and get increasingly inaccurate as you get further from the "centre", hence why we have lots of them.

We don't even have a good single model, we have a lot of guesses and averages stitched together, is all.

That's just simple fact... I'm not sure why people get so angry at this? This doesn't deny the awesome scientific achievements we have made to date, and your ability to be able to track a satellite in realtime. It does, however, highlight that we can always get better.

Also, I didn't say you used NASA's numbers. I said you have used the same underlying set of assumption and approximations to achieve your observations. Which you did (you said yourself you used 6,371km as Earth's radius).

You didn't use some bizarre flat earth system, or some ancient measuring device, did you? No. You used the same underlying theories as NASA to "measure" things. So it is expected to get similar results. Our very measuring tools are built based on those assumptions.

Why do people get so defensive at a simple question? Do we know the exact size of the Earth? No. Get over it.

The fact is, our BEST approximation of the Earth's radius is 6,371km, however, depending on the system you use, observational outliers put the radius of the Earth somewhere
between 3,980km and 9,550km.

These outliers disagree with many observations (so we can mostly, quickly discard them), but so does 6,371km not align with ALL observations. 6,371km just has the least number of disagreements with current observational techniques.

Do we know the EXACT size of the Earth? No.

Instead of arguing, you could have just been honest and said: "No, we don't know the exact size, but our guesses seem to be pretty good, as seen from the video in the OP".

Cheers

Last Edited by puzzlesphere on 11/12/2020 08:20 PM

We don't think you're stupid.

We know you're stupid.

Cool stuff, Astro.


Notice all the flatty shitroaches that have crawled out of their holes the in the past few weeks. Hmmm, wonder why?

Straight to insults and labels rather than having respectful discourse and addressing observation.

Hmmm, wonder why?

Quit whining, stupid Flatty pussy....

You are a hilarious dude that must have some real inner bitterness. All you can do is snarl.

How's your day going?

Care to provide a number, or a technique beyond elementary trigonometry (which provides a large average), for the exact size of the Earth?

You guys all have your heads so far up your own asses, that you don't even see I am not a flat earthier.

I literally use this math every day, and teach it to students that then use it create the infrastructure you live in and travel on.

I am not saying anything particularly controversial here (not to say there aren't some pretty big questions that still need answers).

You are conflating our current level of understanding, which is still largely assumptive in nature, with bizarre theories.

We don't know everything, and MANY of our current systems and assumptions could be improved... there is still a lot to figure out.

Have a bit of an open mind.

Last Edited by puzzlesphere on 11/12/2020 08:31 PM

What is the orbital decay rate of the ISS?

Well you were playing word games about the so-called exact size of Earth. We know the size of Earth to a very good accuracy. If you just want to play word games then go somewhere else. And if you want to claim that I used NASA's assumptions to verify NASA's assumptions then go somewhere else because that is not what I did and I will not tolerate you misconstruing what I did. using an approximate number for the radius of Earth that predates NASA is not using NASA. Furthermore I don't even need to use that number to prove that ISS is over 400 km in altitude. Even if you assume a flat Earth it's still over 400 km in altitude. And that in turn invalidates all the flat earthers who claim we live under a dome that is 100 km or less in altitude. 6371km is NOT some best estimate of Earth's radius, it's just an average value.

Citation needed.

Last Edited by Astromut on 11/12/2020 11:09 PM

Cool! Nice job.

when you get defensive about somebody attacking flat earthers specifically it's not so surprising that people start to assume you are a flat earther who just doesn't want to admit it.

He's definitely a Flatty. He's been stinking up threads for the past month or so as an AC with his same arguments from incredulity.

Wow this is impressive. I only made it up to advanced algebra and geometry so this trigonometry calculus? Is so out of my depth I don't even know what to call it but followed closed enough. Very interesting triangulating.

Also the capture of the ISS against the moon , from the ground even , is really nice! That poor thing is older than probably many GLP'ers who joined within the past 5 years and looks like it too , even in 4k.


And because I have to speculate , which I did anyways even before turning to Christ , that the ISS being only 220~ miles up still begs the question why the camera's on it all point down and we never see anything higher than a certain altitude.

There's no specification to the height of the firmament dome. Though trying to understand the perspective I think is the main point , among objectively too.

Plus here's a twist on par with 2020. ~

Plato was right: Earth is made, on average, of cubes

[link to phys.org (secure)]

Last Edited by This is my GLP on 11/12/2020 11:38 PM

Oh and NASA completely skipped sunspot number 2777.

Either they need you on their team or they really dislike 777.

Need Another Seven Astronauts. ~

Just saying! Don't be so quick to believe ET is friendly if showing up. ~

Last Edited by This is my GLP on 11/12/2020 11:45 PM

Fantastic. Thank you. I didnt read any responses but I did have a nerd epiphany.

Thanks for the fun.

play paintball.

-Echo

:cometrider:

:kahnkahn: