[stack]

Newton's 3rd along with experiments/demonstrations of it, using various objects, bowling balls included, existed long before NASA existed. So it's not a NASA thing.

The closest I could get to perhaps your arrow analogy is the newton sled:



Full video here:


The single bar being half the mass of the double bar would probably mean your arrow would have to be of considerable mass as you mentioned. And I'm not sure how much energy a bow would absorb. But in any case, as you can see from the sled demonstration, think of the single bar as the mass flow leaving the rocket chamber, the double bar sled being the rocket. No air resistance to "push off of" is required nor is there enough "resistance" to push off of even if it wanted to.

I appreciate you taking the time to find these demonstrations, they are hard to find but interesting and I do enjoy seeing them. Don't get me wrong, I have a complete open mind about all of this, I will 100% hold my hands up if someone can show the fundamental principal that allows rockets to work in space.

While it's a convincing demonstration, it simply does not compare. As the driven component is in contact with the beads, the beads therefore are providing an external force as it is propelled forward. This is not comparable to the skateboard and bow analogy. It's equivalent to putting your foot down on the ground and pushing yourself off on the skateboard. If the driven component was not in contact with the beads underneath you would not get the same result.

How exactly are the beads providing a propelling force? All the beads are doing is providing a low friction means by which the sled can move across. Imagine if the beads were removed and the bottom of the pan had a thin layer of ice instead. Would you say the ice is providing the force that is pushing the sled in the two opposite directions? Further still, instead of beads or ice, put little tiny wheels on the bottom of the sled, just like a skateboard. And in doing so, you now have a tabletop version of the skateboard/medicine ball demonstration. Same exact concept. Would you say the wheels now are providing the propelling force?

As you can clearly see, there is nothing equivalent to putting your foot down on the ground and pushing yourself off as there is nothing touching the ground that is doing any pushing, in opposite directions, no less. The only energy/force is in the rubber bands transferred to the sled and bar and they, in turn, act accordingly as expected and predicted by Newton's Laws.

[james38]

While it's a convincing demonstration, it simply does not compare.

I still have a ton of catching up to do since this tread moves so fast. But I wanna jump in here real quick about a few things:

As the driven component is in contact with the beads, the beads therefore are providing an external force as it is propelled forward.

The beads only provide one force in this scenario, and it is friction. Friction is a force that resists the motion of objects sliding past one another. I'm not sure if this is the "external force" you are referring to. If not, could you clarify?

If the same demo were done without the beads, both sides would move less. This is because the friction between the objects and the surface below the beads is higher than the friction between the layer of beads and the objects. The video states that the beads are used to provide a surface with very little friction.

This is not comparable to the skateboard and bow analogy.

Again haven't fully caught up so sorry if this is redundant or I'm misunderstanding. But if your claim is that a skateboard doesn't move when an arrow is shot from the person on the skateboard, that could just be due to rolling friction. A bow and arrow might simply exert a lower force on both sides, too small to meet the threshold of the rolling friction.

Here's a similar example I found of a person throwing a ball on a skateboard, pushing him back. Skip to 4:00. In this example, the rolling friction was overcome by the force exerted by throwing the ball, which mechanically is similar to a bow and arrow.



Another way to understand this intuitively is the kickback of a gun. If you have ever shot a gun, and you imagine shooting a gun while on a skateboard, you know the skateboard will likely move due to the recoil (don't try this one at home). If you want to read more about why the kickback from a bow is less than from a gun, here's a source from an archery website: https://archeryandbow.com/do-crossbows-have-recoil/

It's equivalent to putting your foot down on the ground and pushing yourself off on the skateboard. If the driven component was not in contact with the beads underneath you would not get the same result.

The scenario of pushing your foot against the ground on a skateboard is kind of like the scenario of throwing the ball in the video above. In both cases, you are pushing an object away from you and experiencing an equal opposite reaction force. So why does throwing the ball only move you a little bit, just barely surpassing the rolling friction threshold, while pushing off the Earth with your foot moves you a lot?

Acceleration increases speed over time. To reach a certain speed, you need to have a force exerted on you over time. The force exerted on you is very short when you throw the ball. When you throw a ball, its resistance to being thrown is negligibly small. Assuming your throwing arm moves with a constant velocity, the ball accelerates quickly to be at the same velocity as your throwing arm. By the time your arm is fully extended and about to let go of the ball, the amount of force you are exerting on it is much smaller than the moment you started to throw it. There was only a significant force applied for a short moment, and therefore only a short moment of acceleration, and therefore a small final speed.

If you stand on a skateboard and push a ball against a wall, you will meet constant resistance. The resistance is so high (assuming you are pushing off an immovable wall or the ground) that the force will only decrease when you and the skateboard start to move. Your arm will apply an equal force until you and the skateboard accelerate to a point where you start moving. Only at that point will the force and acceleration start to decrease. Because you and the skateboard are a much higher mass than the ball, the object being moved is much larger. F=MA, so more mass equals more force. This will be a longer duration of high force than the example when the ball is thrown, and therefore a longer duration of acceleration and a higher resulting speed of you on the skateboard. This is exactly the same as when your foot pushes off the ground.   

[Longtitube]

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.

[Mark Antony]

  I am lost for words at these responses...

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.

Your use of space being 1000 to 1000000+ times stronger than a high vacuum on Earth is over-dramatising it.  It's like somebody trying to get close to absolute zero, one group getting to within 0.0001K and another group getting to within 0.0000001K and then saying one is 1000 times colder than the other.  In principle it is, but in reality they are hardly any different to each other compared to the scale of what 293K represents, which is a comfy room temperature.  Same with such high vacuums.  Yes, one might be 1000000 times "stronger", but compared to 1 atmosphere they are as near as damnit the same as each other (I know they aren't the same, but hope you understand what I'm trying to say). 

Besides, in space it's not about absolute pressures, just relative pressures, and the suits are pressurised accordingly.

Rhesus, this is an outrageous comment, I can't believe you are standing over it



This table explicitly states that an "Extremely high vacuum" is 1000 to 1000 000 000 (1 billion) times stronger than a "High Vacuum". Are you saying that the figures in this image are wrong? If so, what are the true figures?

While it's a convincing demonstration, it simply does not compare. As the driven component is in contact with the beads, the beads therefore are providing an external force as it is propelled forward. This is not comparable to the skateboard and bow analogy. It's equivalent to putting your foot down on the ground and pushing yourself off on the skateboard. If the driven component was not in contact with the beads underneath you would not get the same result.

How is that the same as pushing off the ground?  The only thing providing any propulsion is the elastic.  All those beads do is offer resistance to motion.  If that experiment were carried out with things suspended in air from strings, would you believe the results or claim that they were pushing off the strings?  Until you can accept how Newton's laws actually work, the whole rocket debate is moot - and that's kinda' what I'm driving at.

How exactly are the beads providing a propelling force? All the beads are doing is providing a low friction means by which the sled can move across. Imagine if the beads were removed and the bottom of the pan had a thin layer of ice instead. Would you say the ice is providing the force that is pushing the sled in the two opposite directions? Further still, instead of beads or ice, put little tiny wheels on the bottom of the sled, just like a skateboard. And in doing so, you now have a tabletop version of the skateboard/medicine ball demonstration. Same exact concept. Would you say the wheels now are providing the propelling force?

As you can clearly see, there is nothing equivalent to putting your foot down on the ground and pushing yourself off as there is nothing touching the ground that is doing any pushing, in opposite directions, no less. The only energy/force is in the rubber bands transferred to the sled and bar and they, in turn, act accordingly as expected and predicted by Newton's Laws.

It's exactly the same as pushing off the ground. Whether it's beads or ice or water, it makes no difference as they are external to the system. The demonstration is no different to how a snow mobile works - you have the two static skis on the front and the conveyor belt at the back creating the forward movement, the snow underneath being the external reaction force. If the slider in the middle (the component driven by the rubber bands) was not in contact with the surface underneath then you would not get any motion of the heavier slider (neglecting air resistance of course)

Here's a similar example I found of a person throwing a ball on a skateboard, pushing him back. Skip to 4:00. In this example, the rolling friction was overcome by the force exerted by throwing the ball, which mechanically is similar to a bow and arrow.




If you stand on a skateboard and push a ball against a wall, you will meet constant resistance. The resistance is so high (assuming you are pushing off an immovable wall or the ground) that the force will only decrease when you and the skateboard start to move. Your arm will apply an equal force until you and the skateboard accelerate to a point where you start moving. Only at that point will the force and acceleration start to decrease. Because you and the skateboard are a much higher mass than the ball, the object being moved is much larger. F=MA, so more mass equals more force. This will be a longer duration of high force than the example when the ball is thrown, and therefore a longer duration of acceleration and a higher resulting speed of you on the skateboard. This is exactly the same as when your foot pushes off the ground.

I appreciate you trying to explain this, but there is no need as I already understand it - it's no different to the NASA stance. But it's completely wrong! NASA and Newton are in disagreement - I trust Newton you trust NASA.

I'm sorry but that video you posted is farcical to an extraordinary level. Here is why:

His description of why he moves backwards is wrong as it violates Newton's 1st Law:


Here is the correct force analysis for why he moves backwards:

The green outline marks the system with green arrows showing the only force on the system (which is the air) and the velocity vector (Vsys)
The orange and blue outlines are between two internal components therefore they cannot influence the behaviour of the green system unless they have something external to work against (in this case the air) Note: I am missing an orange arrow working against the green air arrow.

This video actually made me laugh because the poor man, god bless him, was too heavy to get any real push back from the air so he had to put a sneaky pivot point underneath himself:



If you look at the video again, he's only getting enough push-back to teeter himself over this pivot point 

[Mark Antony]

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.

Longtitube, you are learning how the real world works, as opposed the the science-fiction that NASA create on a daily basis.

You are implying that there is a perfect vacuum in space. Perfect vacuums do not exist on earth nor in space.

[james38]

Interesting points Mark. Let me ask you this because I'm not sure I completely understand. According to your understanding of physics, the air is essential for two objects to move in opposite directions, right? For example, if a person in a hypothetical perfect vacuum threw a ball, the ball would move but not the person. Is this an accurate summary of your view?

[Longtitube]

I am lost for words at these responses...

......



This table explicitly states that an "Extremely high vacuum" is 1000 to 1000 000 000 (1 billion) times stronger than a "High Vacuum". Are you saying that the figures in this image are wrong? If so, what are the true figures?

You're not the only one lost for words, you don't understand what that table says, but the oil is on a slow rolling boil – just tell me who taught you scientific notation for numbers and I'll collect the person and drop them in it myself. 

Mark, that table lists pressures for various degrees of vacuum. Look at it again:–



"Pressure ranges of each quality of vacuum" is the title and you've selected the column of torr values for your case. The pressures are listed, not the "power of vacuum".

The number 1x10³ is 1 multiplied by 10³ which is 1x10x10x10 = 1,000. However, the number 1x10^-3 (don't miss the minus sign!)  means 1 divided by 10³ which is 1/1000 or 0.001 and we call that a thousandth. A thousandth of a torr is a pretty small pressure.

Another number like 9.87x10^-7 means 9.87 divided by 10⁷ which is 9.87/10,000,000 or 0.000000987 and is just smaller than a millionth. A millionth of a torr is much smaller than our last example.

The table is not telling us that this, that or the other vacuum is a thousand or a billion times "more powerful" than another, but that the pressure in one is a thousandth or a billionth that of another. The table explicitly tells you that the pressure in an Extremely High Vacuum is a thousandth to a billionth that in a High Vacuum.

Someone told you the work is done by the vacuum pulling on the piston, the vacuum chamber wall or the spacesuit, but it's not. The work of keeping the piston in the syringe, fracturing the vacuum chamber or bursting the spacesuit is done by the external pressure withstood or internal pressure contained. There is space for another person in the boiling oil...

If it's the vacuum pulling, then that would even work in a vacuum chamber. I'm serious: by your reckoning, pulling water into a syringe should be possible even in a vacuum chamber, because pulling that piston will increase the "strength of vacuum" in the syringe. So does it? Watch for yourself:–



I especially like the last bit of the demonstration when he lets the air back into the vacuum chamber. Air pressure does the work, not vacuum.

[Mark Antony]

Interesting points Mark. Let me ask you this because I'm not sure I completely understand. According to your understanding of physics, the air is essential for two objects to move in opposite directions, right? For example, if a person in a hypothetical perfect vacuum threw a ball, the ball would move but not the person. Is this an accurate summary of your view?

It's all relative - from the person's perspective the ball would move only, from the ball's perspective the person would move only.
From a third person's perspective the velocity of the system would remain unchanged but a displacement would be created between the person and the ball. How much the person moves and how much the ball moves depends on how the force acts around the respective centres of gravity and one other vital thing that I didn't even touch on yet and that is inertia (another thorn in NASA's side  ).

I especially like the last bit of the demonstration when he lets the air back into the vacuum chamber. Air pressure does the work, not vacuum.

I've acknowledged already that it's still 1 atm outside the vessel. You can't apply simple pressure vessel mechanics to vacuum chambers that we have no experience of on earth. If there is very little difference between them, then how come we haven't recreated these vacuums? In the 50-60 years of space travel, how come an astronaut didn't think of bringing a sample of this vacuum back to earth for analysis?

For all the money spent on the space program, they really have done a poor job answering lots of basic questions... 

[DuncanDoenitz]

You can't apply simple pressure vessel mechanics to vacuum chambers that we have no experience of on earth. If there is very little difference between them, then how come we haven't recreated these vacuums? In the 50-60 years of space travel, how come an astronaut didn't think of bringing a sample of this vacuum back to earth for analysis?

For all the money spent on the space program, they really have done a poor job answering lots of basic questions... 

 

So, bring back a sample of ...... Nothing?

[Longtitube]

I especially like the last bit of the demonstration when he lets the air back into the vacuum chamber. Air pressure does the work, not vacuum.

I've acknowledged already that it's still 1 atm outside the vessel. You can't apply simple pressure vessel mechanics to vacuum chambers that we have no experience of on earth. If there is very little difference between them, then how come we haven't recreated these vacuums? In the 50-60 years of space travel, how come an astronaut didn't think of bringing a sample of this vacuum back to earth for analysis?

For all the money spent on the space program, they really have done a poor job answering lots of basic questions... 

I don't think you have understood what has been written or demonstrated, possibly not even read or watched either. I have tried, but it seems oddly pointless. It has, however, been highly entertaining, especially the suggestion of "bringing a sample of this vacuum back to earth for analysis".    However, I don't want to break the strict conditions of these forums so I'm out.

Thank you for engaging. 

[Mark Antony]

I especially like the last bit of the demonstration when he lets the air back into the vacuum chamber. Air pressure does the work, not vacuum.

I've acknowledged already that it's still 1 atm outside the vessel. You can't apply simple pressure vessel mechanics to vacuum chambers that we have no experience of on earth. If there is very little difference between them, then how come we haven't recreated these vacuums? In the 50-60 years of space travel, how come an astronaut didn't think of bringing a sample of this vacuum back to earth for analysis?

For all the money spent on the space program, they really have done a poor job answering lots of basic questions... 

I don't think you have understood what has been written or demonstrated, possibly not even read or watched either. I have tried, but it seems oddly pointless. It has, however, been highly entertaining, especially the suggestion of "bringing a sample of this vacuum back to earth for analysis".    However, I don't want to break the strict conditions of these forums so I'm out.

Thank you for engaging. 

I watched the video and many of his videos in the past. The fact that he claims a "full vacuum" with his equipment is ridiculous. Boiling water does not prove a full vacuum as he implies.

Whats wrong with my suggestion about bringing back a sample of the vacuum? All they have to do is open a container in the vacuum of space, let the air out and close it again - bring it back to earth and we can now test a vacuum that we have never been able to recreate. What would be wrong with doing this?

[james38]

Whats wrong with my suggestion about bringing back a sample of the vacuum? All they have to do is open a container in the vacuum of space, let the air out and close it again - bring it back to earth and we can now test a vacuum that we have never been able to recreate. What would be wrong with doing this?

Nothing is wrong with this! I think Longitude liked it, as do I. Even if not for science, it would be an extremely cool item to have in a museum or something.

I will respond to everything else when I have more time.

[james38]

Ok, here we go. For anyone just tuning in, there are two conversations right now, one about rockets and newtons laws and one about spacesuits and pressure. There were a few more from before if Jack ever has a chance to continue them. This post will be about the spacesuits and pressure, and I'm going to start by reviewing the conversation a bit for those who might find it useful.

@Mark Antony, in my last big post I showed evidence that joints have always existed to allow bodily movements in spacesuits, but you still made the claim that "a pressure differential of 5-6psi would still render the suit impractically rigid". I will focus on this thesis of yours.

There are various other claims you have made, such as that "you would have an unusual chemical reaction as the protons strip the materials apart to create a more stable state" which even when asked about you did not further support with evidence. There are a bunch of unsupported claims. I will leave most of these other claims for which you did not provide supporting evidence for alone, but if you feel I'm missing anything essential please let me know.

I'll start where you are correct: you said that the vacuum of "space" has never been recreated on Earth. You are correct that we have never invented a vacuum chamber that recreates the level of vacuum found in space, although we do have ultra-high vacuum chambers. I agree with you that this would be an interesting experiment to take back some "space" from a space expedition. However, mathematically we can already predict what it would be like.

I've read through the conversation a couple of times now to try to understand your views as best I can. I think the highlight of your argument for all of us was the giant syringe example. It's pretty clear that your view is based on a sincere misunderstanding of the physics of pressure. And as any good scientist should do, I hope you can take a moment to critically analyze your thesis with an open mind. I'll give you both a mathematical and experimental approach with your syringe example.

First, the math. The fact that ultra high vacuums have extremely high negative exponents of pressures means that they are extremely close to zero pressure, i.e. the differences become negligible. If the pressure inside the spacesuit is 1atm (not sure what it really is, just a thought experiment) and you are in a ultra high vacuum chamber, the pressure outside the spacesuit is 9.87×10^−16 atm. So the final pressure differential is 0.999999999 ... and so on. When you now take it into space, the pressure inside the spacesuit is the same, but the pressure outside is now approx.  2.96×10^−20, so the final pressure differential is also 0.999999999 ... and so on, but negligibly larger. The only difference is that it is ever so slightly closer to 1atm in the case of being in space.

Now, maybe this math is problematic to you because you interpret the laws of physics differently. So let's take your syringe example, which is extremely helpful, for an experimental approach. You were mentioning how pulling the 20-mile syringe would require an exponentially greater force with distance. The exponential part is central and crucial to your thesis that the vacuum of space is so powerful we cannot comprehend it. I don't think you have any experimental evidence to support that claim, so let's test it. Modern science would predict that the force required to keep pulling the syringe would rise, but asymptotically, not exponentially. This means that while the force required to pull does increase over distance as you are pulling, the derivative of the function (Δforce required to pull)/distance is positive but trends towards zero. At a certain point the force will be very high, but the delta of (force over distance) will become negligible. Eventually, you will stop noticing the change in force as you are pulling. It will be a seemingly constant large force. The change in force as you are pulling will become unnoticeable to your senses or even measurement. If your tank can already surpass that force, you can keep going forever (in an ideal system). But because this is a rule, it can be tested with a normal-sized syringe.

If you are correct here, your findings would be groundbreaking. You would be making the greatest scientific discovery in hundreds of years. So you have no excuse not run the experiment You can purchase a syringe for 9 bucks here https://www.amazon.com/Frienda-Scientific-Dispensing-Multiple-Measuring/dp/B07MHMN3Y8/ref=sr_1_4?dchild=1&keywords=scientific+syringe&qid=1606773922&sr=8-4 , a spring scale for 13 bucks here https://www.amazon.com/Ajax-Scientific-Plastic-Tubular-Capacity/dp/B00EPQGQIA/ref=sr_1_2?dchild=1&keywords=scientific+pull+scale&qid=1606773980&sr=8-2, and you will need a ruler. Plug the syringe at the bottom with something, then pull it and measure the pulling force at regular intervals. Your hypothesis is it will rise exponentially, mine (and the rest of the scientific community) is that it will rise asymptotically. If you prove me wrong, you may have shocking news regarding a basic physics principle (Boyles Law). I'll buy the tools myself and verify your result if you prove me wrong.

*** (its also possible I've made a major blunder, because again, I'm not a physics guy, but maybe one or two other people can back me up on this?)

[Longtitube]

Whether you’re a physicist or not, @james38, that’s very close to the points I was making, but more elegantly put. @MarkAntony, the water boiling at room temperature in that vacuum chamber is not going to begin until about 17 torr of pressure is reached - a medium vacuum, by the standards of the table from Wikipedia we both have referred to. The water boiling freely implies the pressure is reduced to and sustained at a vacuum of at least that degree. The syringe still doesn’t suck any water up when activated in that regime.

[james38]

that’s very close to the points I was making

Ok there was some mild plagiarism  . I should have mentioned that a lot of what i said was a reiteration of what you and others have said.

[Mark Antony]

Ok, here we go. For anyone just tuning in, there are two conversations right now, one about rockets and newtons laws and one about spacesuits and pressure. There were a few more from before if Jack ever has a chance to continue them. This post will be about the spacesuits and pressure, and I'm going to start by reviewing the conversation a bit for those who might find it useful.

@Mark Antony, in my last big post I showed evidence that joints have always existed to allow bodily movements in spacesuits, but you still made the claim that "a pressure differential of 5-6psi would still render the suit impractically rigid". I will focus on this thesis of yours.

There are various other claims you have made, such as that "you would have an unusual chemical reaction as the protons strip the materials apart to create a more stable state" which even when asked about you did not further support with evidence. There are a bunch of unsupported claims. I will leave most of these other claims for which you did not provide supporting evidence for alone, but if you feel I'm missing anything essential please let me know.

I'll start where you are correct: you said that the vacuum of "space" has never been recreated on Earth. You are correct that we have never invented a vacuum chamber that recreates the level of vacuum found in space, although we do have ultra-high vacuum chambers. I agree with you that this would be an interesting experiment to take back some "space" from a space expedition. However, mathematically we can already predict what it would be like.

I've read through the conversation a couple of times now to try to understand your views as best I can. I think the highlight of your argument for all of us was the giant syringe example. It's pretty clear that your view is based on a sincere misunderstanding of the physics of pressure. And as any good scientist should do, I hope you can take a moment to critically analyze your thesis with an open mind. I'll give you both a mathematical and experimental approach with your syringe example.

First, the math. The fact that ultra high vacuums have extremely high negative exponents of pressures means that they are extremely close to zero pressure, i.e. the differences become negligible. If the pressure inside the spacesuit is 1atm (not sure what it really is, just a thought experiment) and you are in a ultra high vacuum chamber, the pressure outside the spacesuit is 9.87×10^−16 atm. So the final pressure differential is 0.999999999 ... and so on. When you now take it into space, the pressure inside the spacesuit is the same, but the pressure outside is now approx.  2.96×10^−20, so the final pressure differential is also 0.999999999 ... and so on, but negligibly larger. The only difference is that it is ever so slightly closer to 1atm in the case of being in space.

Now, maybe this math is problematic to you because you interpret the laws of physics differently. So let's take your syringe example, which is extremely helpful, for an experimental approach. You were mentioning how pulling the 20-mile syringe would require an exponentially greater force with distance. The exponential part is central and crucial to your thesis that the vacuum of space is so powerful we cannot comprehend it. I don't think you have any experimental evidence to support that claim, so let's test it. Modern science would predict that the force required to keep pulling the syringe would rise, but asymptotically, not exponentially. This means that while the force required to pull does increase over distance as you are pulling, the derivative of the function (Δforce required to pull)/distance is positive but trends towards zero. At a certain point the force will be very high, but the delta of (force over distance) will become negligible. Eventually, you will stop noticing the change in force as you are pulling. It will be a seemingly constant large force. The change in force as you are pulling will become unnoticeable to your senses or even measurement. If your tank can already surpass that force, you can keep going forever (in an ideal system). But because this is a rule, it can be tested with a normal-sized syringe.

If you are correct here, your findings would be groundbreaking. You would be making the greatest scientific discovery in hundreds of years. So you have no excuse not run the experiment You can purchase a syringe for 9 bucks here https://www.amazon.com/Frienda-Scientific-Dispensing-Multiple-Measuring/dp/B07MHMN3Y8/ref=sr_1_4?dchild=1&keywords=scientific+syringe&qid=1606773922&sr=8-4 , a spring scale for 13 bucks here https://www.amazon.com/Ajax-Scientific-Plastic-Tubular-Capacity/dp/B00EPQGQIA/ref=sr_1_2?dchild=1&keywords=scientific+pull+scale&qid=1606773980&sr=8-2, and you will need a ruler. Plug the syringe at the bottom with something, then pull it and measure the pulling force at regular intervals. Your hypothesis is it will rise exponentially, mine (and the rest of the scientific community) is that it will rise asymptotically. If you prove me wrong, you may have shocking news regarding a basic physics principle (Boyles Law). I'll buy the tools myself and verify your result if you prove me wrong.

*** (its also possible I've made a major blunder, because again, I'm not a physics guy, but maybe one or two other people can back me up on this?)

You are applying extremely basic physics principles to a vacuum condition that we have no experience of. It's like saying things fall to earth because of gravity. 'Gravity' is just the name of a phenomenon that we have no scientific explanation for.

Scientific vacuum chambers on earth require extremely complex processes to create. They need mechanical displacement pumps, ion pumps and often the chamber needs to be baked to 600+ degrees to remove any contaminants or moisture in the chamber.

And even after doing all this, the vacuums are so powerful that leaks through seals aren't the only problem, you have diffusion leaks through the steel itself! This is a quantum physics problem, not a school mechanics problem. You have to take molecular bonding and vibration into account. In the lowest vacuums in space you have 1 hydrogen atom per cubic meter but even this can become more unstable depending on the excitation/vibration of the proton.

And yet all of these problems have been miraculously solved in the ISS, lunar modules, space suits but not on earth? In 2018 there was a 2 mm hole in the ISS that they covered with duct tape  . In an incredibly embarrassing gaffe, Chris Hadfield posts an SEM image of the hole which turned out to be the album cover for the band Remedy Drive!






It was at this point I knew NASA were taking the piss out of everyone. It's not a conspiracy, it's a joke on a global level.

[DuncanDoenitz]

It was a file image to illustrate the type of damage caused by micrometeorites.  It was taken in 1984 and published by NASA in 2006.  Remedy Drive subsequently used the image for their album artwork.  I don't know if they had the copyright holders permission. 

And the force applied by the ISS atmosphere to the approx 2mm hole and its subsequent "duct tape & a gob of epoxy" is about 50 grammes.  You do the math. 

NASA is apparently pouring millions of dollars into fooling you; please try and give them some credit. 

[stack]

In an incredibly embarrassing gaffe, Chris Hadfield posts an SEM image of the hole which turned out to be the album cover for the band Remedy Drive!






It was at this point I knew NASA were taking the piss out of everyone. It's not a conspiracy, it's a joke on a global level.

You might want to dig a little deeper and orient yourself toward facts, not just something that seems dazzling to your belief system.



Timeline:

1984: The photo was taken.
2006: The photo was first published by NASA.
2006: The photo was uploaded to Wikipedia.
2014: Remedy Drive released “Commodity” using the photo as the album’s artwork.
2018: Chris Hadfield tweeted the original photo, but misinterpreted by flat-Earthers as stolen from the album “Commodity”.

Chris Hadfield’s Tweets:

[GreatATuin]

It was a file image to illustrate the type of damage caused by micrometeorites.  It was taken in 1984 and published by NASA in 2006.  Remedy Drive subsequently used the image for their album artwork.  I don't know if they had the copyright holders permission. 

NASA content are generally not copyrighted. So as long as they didn't make it look like NASA endorsed their album, they're fine.

[Tom Bishop]

Timeline:

1984: The photo was taken.
2006: The photo was first published by NASA.
2006: The photo was uploaded to Wikipedia.
2014: Remedy Drive released “Commodity” using the photo as the album’s artwork.
2018: Chris Hadfield tweeted the original photo, but misinterpreted by flat-Earthers as stolen from the album “Commodity”.

Chris Hadfield’s Tweets:

The problem appears to be that Chris Hadfield implied in his post that it was a recent photo from the space station incident. The previous album art from years prior still shows Hadfield to be a liar, even if the album appropriated it from a prior NASA source.

Hadfield days later posting that it's an example doesn't absolve him of being deceptive.