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Messages - Longtitube

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1
Flat Earth Theory / Re: Let's start with "Burden of Proof"
« on: November 26, 2020, 09:05:21 PM »
The point I was making around 1psi and 0psi is that it is not a binary thing as NASA imply by saying there is a low pressure differential if you have 5psi inside the space suit and 0psi outside. The reality is that there is a massive pressure differential - we just don't have any experience of the strength of these vacuums on earth. We can get vacuums down very low but only on an extremely small scale (not infinite like in space). Or if we do scale it up in size we have to use very thick concrete walls or thick steel vessels. But why? Isn't it just a small pressure differential  ::)

Yes it is a small pressure differential, but applied over a large surface it amounts to a very large force. Let’s take a vacuum chamber with one flat wall 10 feet square and assume it’s air at 5psi outside and 0psi inside. That’s a wall of 14,400 square inches and it will be bearing a pressure load of 72,000 pounds force on that wall alone.

Both you and Jack refer to an infinite vacuum of space - but what are you talking about? Do you think there are pressures below zero?

......... (suggested investigation).........

Do try this at home!
I appreciate the mathematical demonstration but you are making the very assumption I am saying is flawed, that there is a 5psi pressure differential no matter how powerful the vacuum. This is an absurd assumption with no disrespect. You really can't talk about these vacuums without taking energy or even wall stresses into account.

Lets say you have a syringe like below:



For arguments sake, the barrel is 20miles long and the plunger is pushed in as far as it can go so only a very small amount of air is in the tip. You plug the tip and get someone to pull the plunger as hard as they can. That person is only going to get so far before the strength of the vacuum is just too much to go any further. Lets say you then get a horse to pull it further. At some point the barrel will collapse so you will have to replace it with steel to withstand the vacuum. The horse can go no further so you get a 16 wheeler truck to pull the plunger. The truck pulls the plunger further but now the steel tube collapses so you have to replace it and reinforce with outer ribs for support. You then get an army tank that pulls the plunger further. Each foot of distance the plunger gets pulled will require an exponentially higher amount of energy to do so. It will get to a point where no vehicle or combination of vehicles will be powerful enough to pull the plunger further. You are also getting closer to material limitations where there simply won't be materials strong enough to maintain the volume of vacuum. There is still only 1atm outside but the differential is growing immensely.

Unlike the confined volume inside the syringe, space is sold to us as being a vacuum of immense magnitude but also at an infinite scale. There are no materials that exist that could cope with this vacuum, be it at 5psi, 1psi or 0.001psi inside - makes no difference. The wikipedia scale above tells us that a vacuum in outer space is 1000 to 1 000 0000+ times stronger than a "high vacuum". We have only ever recreated a high vacuum on a large scale on earth. These are unimaginably powerful vacuums we're dealing with, yet we have astronauts dancing around on the moon? I think not.

Mark, can I just say how much I'm enjoying this conversation, learning how you think. I think I see where the vacuum logic comes from: take a cylinder of gas and a piston and apply increasing force to the piston, directed towards the gas, and the pressure will climb and as the volume of gas decreases and its pressure increases, it takes ever-increasing force to move the piston further into the cylinder in ever-decreasing amounts. This analogy is extended to pulling a piston out of a cylinder containing a vacuum, implying ever-increasing force is needed to pull the piston further out of the cylinder against the vacuum.

There's just one problem, a vacuum is nothing. Compressing a gas by reducing its volume does indeed take greater and greater effort, because there's a gas in the cylinder, but increasing the volume of a vacuum means increasing the volume of nothing. The outside pressure is still 1 atm and the internal pressure, the vacuum, is still nothing, nada, zero, so the differential is the same whether the piston is pulled out by 1cm or 500 yards. The piston is still being pulled against a pressure of 1 atm on the piston, however far it is pulled.

Have you any example of that experiment having been done to back up the idea? Gas compression is not a thought experiment like the vacuum in a piston example, it's an everyday occurrence; but I shall be astonished if you can point to even one successful attempt to prove pulling on a vacuum results in an ever-increasing resistance to being pulled. I'm not being frivolous by suggesting this would be a scientific revelation.

2
Flat Earth Theory / Re: Let's start with "Burden of Proof"
« on: November 26, 2020, 08:29:14 AM »
The point I was making around 1psi and 0psi is that it is not a binary thing as NASA imply by saying there is a low pressure differential if you have 5psi inside the space suit and 0psi outside. The reality is that there is a massive pressure differential - we just don't have any experience of the strength of these vacuums on earth. We can get vacuums down very low but only on an extremely small scale (not infinite like in space). Or if we do scale it up in size we have to use very thick concrete walls or thick steel vessels. But why? Isn't it just a small pressure differential  ::)

Yes it is a small pressure differential, but applied over a large surface it amounts to a very large force. Let’s take a vacuum chamber with one flat wall 10 feet square and assume it’s air at 5psi outside and 0psi inside. That’s a wall of 14,400 square inches and it will be bearing a pressure load of 72,000 pounds force on that wall alone.

Both you and Jack refer to an infinite vacuum of space - but what are you talking about? Do you think there are pressures below zero?

Here’s a simple investigation you can do into vacuums. Get a long length (more than 50 feet) of clear plastic hose, fill it with water and have it dunked in a large bucket of water. Seal one end to prevent air getting back in (use a bung or maybe a strong clamp) and lift the sealed end above the water, way up, 40 feet above the water in the bucket but make sure the other end stays under the water. Amazingly, the water in the hose will only rise about 34 feet above the water in the bucket and any hose above that height will be empty. What’s in that empty length of pipe between water and bung? A vacuum.

Think about that before trying the same investigation up in the mountains (if it’s within reach) at something like 10,000ft. Now the water will not rise higher in the pipe than about 23 feet. What has changed? The pipe, bung, bucket and water are the same, but the vacuum can only support a 23ft column of water. What has changed is the air pressure. The water in the pipe is not supported by the strength of the vacuum, but by the outside air pressure; 14.7psi at sea level and about 10psi at 10,000ft above sea level.

Do try this at home!

3
Flat Earth Theory / Re: Water is always level?
« on: November 25, 2020, 09:11:58 AM »

@longitube

Quote
Jack, I don’t mean to be rude and hope you won’t be offended

Excellent, I feel the same way! Rudeness is mostly about lack of courtesy/empathy.  In this case, the courtesy you are lacking is in properly understanding before criticizing and recommending diminutive remedial action/"coursework" of your enlightened choosing. 

I do not wish for you to misunderstand my tone, which is intended to be playful and somewhat scathingly sarcastic.  I am very difficult to offend, and encourage others (and myself) to speak their hearts and minds freely without censure.  I encourage the ruthless/vicious attack of all thoughts and though I do not condone ad hominem, I am most functionally impervious to it (as we all should be).

Quote
but air pollution where you live must be appalling.

Though air "quality" (composition, density, refractive index etc.) has everything to do with what we are discussing, you seem to be misunderstanding.  The reason we can't see beyond the few miles is to do with the air itself (and the intensity of the distant light source of course), and requires no added help from man made particulate/pollution.  When I say we can't see more than a few miles under normal weather conditions, I am talking about specifically towards the horizon - looking through the densest air.

Quote
Sorry to be blunt.

You spoke your heart and mind earnestly and to me that IS effective communication (or at least a necessary prerequisite).  No apologies necessary, though if you earnestly wish to avoid being rude (a worthy goal) you should try to make sure you fully understand what you are criticizing first before doing so and suggest courses of action / "coursework" earnestly (not for rhetorical ad hominem).

I don’t do ad hominem, I’m only interested in facts. I may be sharp with opinions I regard as nonsense, but never with the person - there’s far too much of that on the web already, people ridiculed and their convictions mocked without addressing whatever points are under discussion.

To return to how far we can see across level water: if the limit of our vision towards the horizon is just a few miles, how is it possible to see that mountain top on the horizon from the beach on a clear day, a mountain top which is 66 miles away across the water, through the densest air at the horizon?

4
Flat Earth Theory / Re: Let's start with "Burden of Proof"
« on: November 23, 2020, 02:05:36 PM »
Just think about it, the vacuum that is purportedly in space has never been recreated on earth.  Vacuums don't just go from 1psi to 0psi there is a huge scale of vacuum strength, each level being exponentially more difficult to achieve. Just look at the different types of vacuum given by the Wikipedia page:


@Mark Antony, I would like to take whoever taught you number systems and boil that person slowly in oil for doing such a rotten job. Vacuums don’t just go from 1psi to 0psi? Actually, that table from Wikipedia shows that vacuums do, but the numbers given could be easily misunderstood from the way they are expressed.

A extremely high vacuum, from that table, is < 1x10-12 torr meaning less than a millionth of a millionth of a torr. But that’s still a higher pressure than zero. If it were < -1x10-12 then that would be less than minus a millionth of a millionth of a torr - a negative pressure, less than zero - which doesn’t exist!

The very low pressures listed in that table are indeed extremely difficult to achieve on Earth, but all are larger, however slightly, than the bottom row of the table, the perfect vacuum, which is precisely zero pressure. If you already know and understand this, please feel free to ignore it and forgive my misunderstanding you.

5
We do? Please explain, since I missed that first time around. (I know, I know)
The video is shown to us in a 16:9 aspect ratio, without apparent squashing. The frame of the camera is not 16:9. Therefore, cropping likely occurred, either in a way transparent to the user, or by the user's choice.

This, combined with the countless observations we've made above, brings the obvious conclusion. The exact nature of the cropping, and how it was performed, will probably remain unknown.

I don't think I've heard a lamer excuse, at least this week. If the original video footage was shot in 4:3 (4K) instead of 16:9 (1080p), it would lose a little at the top of frame and an equal amount at the bottom of frame in conversion, but the centre of the 4:3 footage would still be the centre of the 16:9 conversion shown on the YouTube footage. If the person setting up the camera to make the video selected a resolution less than the highest the camera is capable of, there is currently no camera around which does that by cropping off, say, much of the top left, bottom left and top right to record in 1080p instead of 4K and therefore needs the camera repositioned to frame the footage correctly at the lower resolution and thus not properly use the centre of the lens. "Hey, we got a really cool feature on this camera: change resolution and ya gotta reframe! Much cooler than these squares who don't have to!!" That would sell like cold offal.

Here's a video of the different resolutions available on a GoPro Hero4 Black, shot from a tripod. Notice how the camera does not change its direction of view for each different resolution.


6
Flat Earth Community / Re: A Question From a Round-Earther
« on: November 22, 2020, 03:17:24 PM »
Boats at the horizon disappearing bottom up They're not really disappearing over the curve as you might think. Even if the earth was a globe and the size we're told it is, the curve wouldn't be noticeable only a few miles out to sea which is more or less the furthest our eyes can see looking across a large body of water. What is happening is the atmosphere is acting like a lens. This short video explains it:



Watch the whole thing if you've got the time, it's quite interesting. If you haven't the time the demonstration begins at around the 1:45 mark.

Okay, I watched the whole thing. So, if I dig a hole in the beach to get my eye below beach level, I won't be able to see the shoreline of the opposite coast. Did I get that right? And the unzoomed photo of Toronto, if I use a magnifying glass it should be possible to see kids playing on the Toronto shore and people sunbathing? Possibly there's something missing in the instructions, 'cos I'm not seeing them like in the Bishop experiment.

7
Flat Earth Theory / Re: Questions regarding gravity
« on: November 22, 2020, 10:13:02 AM »
https://forum.tfes.org/index.php?topic=16913.0

You might find this recent discussion interesting.

8
If this really is just "distortion" shouldn't the curve remain above the line?
Once again - you assume that the centre of the video is the centre of the camera's frame. We know that this isn't the case.

We do? Please explain, since I missed that first time around. (I know, I know)

9
Flat Earth Theory / Re: Water is always level?
« on: November 20, 2020, 06:42:24 PM »
@longitube

Quote
I meant an observer standing on the ground, not lying on the ground, sees just a few miles?

Yes.  That is, laterally towards the horizon through the densest air you can typically only see a few miles.

The top of everest is still the ground though!  I just think it is very interesting, and misunderstood by so many, that from the highest point on earth, under the best visibility conditions possible, you can only see a couple hundred miles (laterally, towards the horizon).  That is the max, though at sea level (the min) it's only a few miles directly through the densest air.

Jack, I don’t mean to be rude and hope you won’t be offended, but air pollution where you live must be appalling. I live by the ocean and can see cliffs and headlands twenty miles away while standing on the beach. I can see large hills inland more than thirty miles away from a roadside viewpoint that’s perhaps 150 ft above sea level. From the same beach on a clear day I can see on the horizon the top of a mountain which is 66 miles away. I know this because I’ve seen these things often with my own eyes, without using binoculars, a powerful zoom camera or Google Earth. Furthermore, at night I can watch the moon and stars setting on the horizon, and how far away are these? A few miles?

You need to do some real research, Jack, do some real investigations, before declaring how little we can see. Sorry to be blunt.

10
Flat Earth Theory / Re: Water is always level?
« on: November 20, 2020, 10:33:48 AM »
@longitube

Theoretical max, around 200 miles from the top of everest under perfect visibility.

At sea level (where the air is densest) it is typically only a few miles, but it varies with weather.

I’m not concerned with standing on Everest (where most folk wouldn’t survive without an oxygen supply) so much as normal observational height. I should have been clearer, I meant an observer standing on the ground, not lying on the ground, sees just a few miles?

11
Flat Earth Theory / Re: Water is always level?
« on: November 20, 2020, 06:50:56 AM »
@WTF_seriously

Quote
So the limit of our vision is variable depending upon altitude.

Correct!

There are two main reasons for that.  One is the angular resolution limits of the human eye, and the other is the "standard"/"normal" density gradient within our air.

So how far can we see at ground level?

12
Flat Earth Investigations / Re: Thork's Jack Russell challenge
« on: November 19, 2020, 12:59:32 PM »
No contest! Lovely dogs, whippets, and very soft natured. Thanks for sharing.

13
Flat Earth Investigations / Re: PLASMA MOON SCIENTIST 1965
« on: November 19, 2020, 06:58:32 AM »
If you look at it from another perspective, from that of the claims he makes, they are basically bunk. I mean how would a plasma moon have craters?

And furthermore, these craters and other surface features are unchanged from day to day, year to year and have been recorded in charts for decades as continuing features. A plasma moon would not preserve these features. Jupiter is reckoned to be a gas giant and its features visibly change daily in telescope films of its surface, but the moon only changes how much of its visible surface is lit by the sun in a predictable, repeatable cycle. Plasma, schmasma.

14
Flat Earth Investigations / Re: PLASMA MOON SCIENTIST 1965
« on: November 18, 2020, 07:06:07 AM »
Um. The guy in that 1965 video wouldn't be a day under 50 years old, so by 2002 he would be 97 or older. I don't think the guy mentioned as a Royal Society Edinburgh donor is likely to be the same person

We did verify his name is Roy Foster, and he was a Professor of Earth science and Chemistry at the university of Dundee Scotland, he is the only R. Foster from Mitchel and Longman 1983 directory "Materials Research Centres: A World Directory of Organizations and Programmes in Materials Science" as the head of the Chemistry department at Dundee alongside Professor J. S Brimacombe. They were researching absorbtion spectra in the Ultra Violet, wavemechanical studies, mechanism of oxidation of Gaseous fuels etc he is the only recorded R Foster from RSE with his earliest recorded association with RSE dating to 1926. Its the same person, and im not here to speculate, im looking for hard data on his publications. Saying move on nothing to see is the exact thought terminating praxis that gets one nowhere. When there is clearly something to unpack. Also, alot of people make donations posthumously. What im looking for is his research refrenced in this 1965 interview.

That’s more info than we first had to go on, good digging, but you’ll need more to identify the video guy. How do you know his actual name? It’s not given in the video. What is the actual Professor Foster’s background? Was he Scottish or UK born? The video guy’s accent is continental, not British, and certainly not Dundonian. I’m not trying to ridicule you, just pointing out the identifying of the “professor” is far from complete yet.

15
Flat Earth Investigations / Re: PLASMA MOON SCIENTIST 1965
« on: November 17, 2020, 09:07:43 PM »
Um. The guy in that 1965 video wouldn't be a day under 50 years old, so by 2002 he would be 97 or older. I don't think the guy mentioned as a Royal Society Edinburgh donor is likely to be the same person, especially since the thickly-accented Tasmanian (allegedly) gentleman in the video is really difficult to find traces of apart from the video and there are a number of real Professor R Foster individuals to be found, including professors of Irish history, mathematics, circadian neuroscience, Quaker theology and English. They all have published work, the video guy doesn't appear to have any.

Just a video clip of an "interesting" individual who may or may not have been a professor, but turned out to be wrong. Nothing to see; move along, people

16
Flat Earth Theory / Re: Let's start with "Burden of Proof"
« on: November 16, 2020, 07:50:08 AM »
I think MarkAntony’s problem with physics is there’s no consideration of momentum, so there “has” to be “something” to push against.

17
Flat Earth Theory / Re: Let's start with "Burden of Proof"
« on: November 15, 2020, 10:12:21 PM »
Your analogy with the boat is incomparable as there is no vacuum present and, unlike the rockets in space, it conforms to all of Newtons laws of motion. Your example with the rocket at the start is exactly what you think should happen but definitely not in theory or practice

Think about it this way: You are in your spacesuit with a bowling ball travelling at 60m/s away from the earth. You think to yourself "I'll need to throw this bowling ball hard enough to propel myself back towards the earth again". The problem here is that both you and the bowling ball are all part of one system. You can throw the bowling ball as hard as you want (let say 10m/s) - the bowling ball will travel at 10m/s away relative to your position and 70m/s away from earth for a time until it runs out of energy but at the end both you and the ball will still be travelling at 60m/s away from the earth. The net result force is, has and always will be zero as both you and the bowling ball were contained within the one system. You can't create your own external force. A rocket in a vacuum would simply exhaust all the burnt fuel and matter but the net force would be zero and there is no change in velocity.

I'm sorry, but I don't agree with this, your definition of a system seems wrong: once the ball has been thrown, unless it is somehow tethered to the astronaut, it is no longer part of a system with him. Thank you for responding nevertheless.

If anyone else is interested in this kind of problem, this might help illustrate it, including discussion of whether the ball remains part of the system or not:-


18
Flat Earth Theory / Re: Let's start with "Burden of Proof"
« on: November 15, 2020, 04:58:24 PM »
I appreciate MarkAntony doesn't want to post any more on rockets in space, but the insistence rockets don't work in space because there's nothing to push on is wrong. Simply put, the rocket is pushed by expelling its fuel out the back at extreme speed (speed generated by burning the stuff). Take the third stage of a Saturn V, which weighed around ten metric tonnes when empty and carried over a hundred metric tonnes of fuel, and operated only in space. Expel those hundred tonnes as a single mass backwards at 10ms-1 from a stationary rocket and reaction to the necessary force will push the now empty 10 tonne rocket forwards at 100ms-1 in accord with Newton's 3rd Law. Since the tonnes of fuel have left the rocket, the rocket continues on its way until another force acts on it. Of course the real rocket exhaust roars out of the engine at much higher speed, supersonic speed in fact (and not all the fuel at once.)

There is an earthbound comparison I find useful: swing your open hand through the air and feel how much resistance from the air you can detect, then try swinging your open hand through a bath of water at the same speed and feel how much more resistance to movement from the water you can feel. There's lots more resistance from the water, isn't there? Yet here's a conundrum: boats that use water jet propulsion don't direct that jet into the water, they direct it above the water into the air, which has much less resistance to push against. The difference in propulsion is dramatic, so here's a 1000hp+ gas turbine-powered jet boat doing its stuff on a Canadian river. (look at the enormous rooster tail from the water jet; these guys are nuts...)



Now if the water jet works much better pushing the water jet into air with much, much less resistance to push against than water, then the efficiency of a water jet has nothing to do with pushing against a resistance. Its efficiency is all to do with directing as much water backwards in as short a time as possible to drive the boat forwards at as high a speed as possible in accordance with Newton's Third Law. The boat above manages 100mph+ speeds. Rocket engines do the same, and are in fact more efficient in a vacuum than in the atmosphere.

19
Flat Earth Theory / Re: Disappearing Stars as you walk North/South
« on: November 14, 2020, 03:00:16 PM »
The refraction coefficient of our atmosphere has an average of k=0.17.

Are you sure about this? I was under the impression k represents the extinction coefficient of the medium, not its refractive index which is represented by n and is 1.0003 for air at 0 deg C and 1 atmosphere pressure.

20
Flat Earth Theory / Re: Disappearing Stars as you walk North/South
« on: November 13, 2020, 08:40:51 PM »
If you want the wiki's answer, you'll find it in the entry Shifting Constellations. Perspective, allegedly.  ::)

https://wiki.tfes.org/Shifting_Constellations

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