# True vacuum

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How much does it matter if I can move matter in what appears to be 29 in hg on my gauge from 30 inches? only reason I ask is because I cant get the gauge to read lower.

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What is the context, and why is this speculation?

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What do you mean context? its in a jar and I can move the matter whatever it is like paper or smoke particles stuff that I can fit in the jar and not break the glass while its flung around in it. Speculations because its my own theory that im working on/

the problem is that I cant get the jar down to 30 on the mechanical gauge. Im not sure if its not getting to 30 or if the pump or gauge is off some way. I wanted to know how much of a difference is it really from 29 to 30 in hg

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15 hours ago, Theredbarron said:

What do you mean context? its in a jar and I can move the matter whatever it is like paper or smoke particles stuff that I can fit in the jar and not break the glass while its flung around in it. Speculations because its my own theory that im working on/

the problem is that I cant get the jar down to 30 on the mechanical gauge. Im not sure if its not getting to 30 or if the pump or gauge is off some way. I wanted to know how much of a difference is it really from 29 to 30 in hg

OK, there’s a pump. That’s a detail not originally included. You’re moving matter around. Gas is matter, so knowing details is important.

If it’s full of smoke that might be a problem, since particulates might be clogging the pump and/or gauge.

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23 minutes ago, swansont said:

OK, there’s a pump. That’s a detail not originally included. You’re moving matter around. Gas is matter, so knowing details us important.

If it’s full of smoke that might be a problem, since particulates might be clogging the pump and/or gauge.

True but I was using smoke as an example of what it can move. I have not used smoke yet because I have been trying to get to 30. Thats why im asking how much of a real difference does it make between 29 and 30? and you said it air is matter!

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9 hours ago, Theredbarron said:

True but I was using smoke as an example of what it can move. I have not used smoke yet because I have been trying to get to 30. Thats why im asking how much of a real difference does it make between 29 and 30? and you said it air is matter!

Air is matter, but it's not particulate matter. It's a gas.

Vacuum pumps don't work equally on all gases, but that's not likely the issue here. It could be the pump, it could be a leak, it could be the gauge. I've run into all three problems in vacuum systems where the indicated pressure did not fall very much.

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3 hours ago, swansont said:

Air is matter, but it's not particulate matter. It's a gas.

Vacuum pumps don't work equally on all gases, but that's not likely the issue here. It could be the pump, it could be a leak, it could be the gauge. I've run into all three problems in vacuum systems where the indicated pressure did not fall very much.

I think @Theredbarron wants to know what is pressure difference between when gauge shows 29 and when it shows 30 i.e. what means "1 inHg" on gauge expressed using other units.

(eventually change pascal to something else like bar mmHg etc.)

If your gauge has maximum -30 inHg and your reading is -29 inHg you should get better gauge with larger scale..

Like we can see on this gauge "in Hg" is shortcut from "inch Hg". Gauge has also second unit in "cm Hg".

This chart might be interesting to you. Inches Hg are in fourth column.

The get better vacuum scientists/engineers/people use two serial vacuum pumps. https://www.google.com/search?q=two+serial+vacuum+pumps

The get better vacuum you can fill container the first by pure Oxygen (e.g. from electrolysis) and place there (before filling) piece of metal or metal wire. Hermetically close it. Then pass current (large one) through wire, and Oxygen will react with wire, taking even more gas from the chamber. This technique was used to make vacuum tubes, light bulbs etc.

If you turn off pump, and leave it this way for a while how fast pressure is returning to normal? You could make video on YouTube (but please place camera on tripod). If it is slowly returning (not within seconds), use timelapse. It will be interesting project for you. It will tell how hermetic is your entire chamber and connections.

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14 hours ago, Theredbarron said:

What do you mean context? its in a jar and I can move the matter whatever it is like paper or smoke particles stuff that I can fit in the jar and not break the glass while its flung around in it.

What is in the jar?

Is the jar sealed?

What is the jar made of?

How do you move the matter?

What does this have to do with measuring pressure?

How are you measuring the pressure?

Why does the pressure in the jar matter?

That is the sot of context required.

Quote

Speculations because its my own theory that im working on/

I would keep asking questions separate from presenting a "theory" if I were you.

14 hours ago, Theredbarron said:

the problem is that I cant get the jar down to 30 on the mechanical gauge. Im not sure if its not getting to 30 or if the pump or gauge is off some way. I wanted to know how much of a difference is it really from 29 to 30 in hg

I know from practical experience with properly maintained lab equipment that it can still be really hard to create a good seal to pump the air of of something. If you are doing this with homemade equipment (a "jar" - what sort of jar? a jam jar with a screw top?) then I am not surprised if you can't get just below air pressure.

How much difference is it? It is 1 in Hg (about 0.5 psi).

14 hours ago, Theredbarron said:

Thats why im asking how much of a real difference does it make between 29 and 30?

How much difference does it make to what?

It is roughly equivalent to being 1,000 feet above sea level. It will reduce the boiling point of water by about 1º. Does that help?

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We are on a planet made of matter. It is in a universe full (largely) of vacuum.

What observations were you hoping to make about the jar that you can't make much more simply about the Earth?

1 hour ago, Strange said:

How much difference does it make to what?

It is roughly equivalent to being 1,000 feet above sea level. It will reduce the boiling point of water by about 1º. Does that help?

Except it's the other way round.
This is one reason why inches of vacuum is a stupid unit.

He has removed roughy 29/30 of the air.

So the pressure is roughly 1/30 *750 mm Hg
Water will boil in that jar at about 27C

The other reason why it's a lousy unit is that it literally depends on the weather.

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15 minutes ago, John Cuthber said:

Except it's the other way round.
This is one reason why inches of vacuum is a stupid unit.

He has removed roughy 29/30 of the air.

Are you sure. If the the pressure has gone from 30 to 29 inches of Hg then surely he has only removed 1/30 of the air?

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Look at pressure conversion table picture from my post..

57 minutes ago, Strange said:

If the the pressure has gone from 30 to 29 inches of Hg then surely he has only removed 1/30 of the air?

1 atm is 0 inHg.. (..on vacuum gauge scale)

Edited by Sensei

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15 minutes ago, Sensei said:

1 atm is 0 inHg.

What?

Quote

1 atmosphere = 29.9213 in Hg

It is also contradicted by the definition of "in Hg"

Quote

1) One inch of mercury (in Hg) is defined as that pressure exerted by a 1-in. column of  mercury at standard gravity and a temperature of 0°C:

I guess you are confusing relative and absolute pressure (meters).

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9 minutes ago, Strange said:

It is also contradicted by the definition of "in Hg"

On vacuum gauges scale is reversed. i.e. 0 is shown when there is normal air pressure, and -30 is shown when there are near vacuum conditions. Look at any photo of vacuum gauge.

12 minutes ago, Strange said:

I guess you are confusing relative and absolute pressure (meters).

Look at conversion pressure table picture that I gave in previous post.. Look at any vacuum gauge photography..

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So what im getting is that if I were to move pieces of paper in a jar without actually contacting the paper, How much does that 1 inch of vacuum truly matter in a grand scale of things? It doesn't leak down at all. I pump it for about an hour or more depending on if I remember that its on. there is a motor built into the chamber that spins a wheel thats not connected to anything except by air. It moves the paper pieces the same way in 15 in or 29 in. Im just not seeing how getting to 30 is going to make a difference. I use paper just because it light and easy to get. I can do smoke by igniting one in the chamber after vacuum is applied so that the smoke is not pumped out. Im not sure what other stuff I can put in the jar thats light enough for this to move.

2 hours ago, Strange said:

What is in the jar?

Is the jar sealed?

What is the jar made of?

How do you move the matter?

What does this have to do with measuring pressure?

How are you measuring the pressure?

Why does the pressure in the jar matter?

That is the sot of context required.

I would keep asking questions separate from presenting a "theory" if I were you.

I know from practical experience with properly maintained lab equipment that it can still be really hard to create a good seal to pump the air of of something. If you are doing this with homemade equipment (a "jar" - what sort of jar? a jam jar with a screw top?) then I am not surprised if you can't get just below air pressure.

How much difference is it? It is 1 in Hg (about 0.5 psi).

How much difference does it make to what?

It is roughly equivalent to being 1,000 feet above sea level. It will reduce the boiling point of water by about 1º. Does that help?

dont worry im not trying to prove anything here. Im looking for the fine details.

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1 minute ago, Theredbarron said:

So what im getting is that if I were to move pieces of paper in a jar without actually contacting the paper, How much does that 1 inch of vacuum truly matter in a grand scale of things?

It is impossible to say. I'm not sure why the pressure would be relevant at all. What is moving the paper and why would pressure affect that?

3 minutes ago, Theredbarron said:

there is a motor built into the chamber that spins a wheel thats not connected to anything except by air. It moves the paper pieces the same way in 15 in or 29 in.

So you have some sort of fan (mechanical system for moving air) and you want to determine at what pressure it will stop working?

I doubt there is an easy answer to that. Only experiment or a detailed finite-element fluid simulation will tell you.

20 minutes ago, Sensei said:

On vacuum gauges scale is reversed. i.e. 0 is shown when there is normal air pressure, and -30 is shown when there are near vacuum conditions. Look at any photo of vacuum gauge.

So a relative pressure gauge.

This is just yet more "context" that the OP needs to provide.

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2 minutes ago, Strange said:

It is impossible to say. I'm not sure why the pressure would be relevant at all. What is moving the paper and why would pressure affect that?

So you have some sort of fan (mechanical system for moving air) and you want to determine at what pressure it will stop working?

I doubt there is an easy answer to that. Only experiment or a detailed finite-element fluid simulation will tell you.

So a relative pressure gauge.

This is just yet more "context" that the OP needs to provide.

not a fan. The pressure matters because in space there not a lot there. Does it really matter that its 1 inch on a gauge difference is what I want. Not stall testing a fan or anything like that. If I can move matter without touching it in a vacuum then I can move matter without touching it in space. Then im going to add a feature to make it more powerful within a vacuum just like pretty much all planets do. Im not sure what context your looking for but im not a scientist!

2 hours ago, Sensei said:

I think @Theredbarron wants to know what is pressure difference between when gauge shows 29 and when it shows 30 i.e. what means "1 inHg" on gauge expressed using other units.

(eventually change pascal to something else like bar mmHg etc.)

If your gauge has maximum -30 inHg and your reading is -29 inHg you should get better gauge with larger scale..

Like we can see on this gauge "in Hg" is shortcut from "inch Hg". Gauge has also second unit in "cm Hg".

This chart might be interesting to you. Inches Hg are in fourth column.

The get better vacuum scientists/engineers/people use two serial vacuum pumps. https://www.google.com/search?q=two+serial+vacuum+pumps

The get better vacuum you can fill container the first by pure Oxygen (e.g. from electrolysis) and place there (before filling) piece of metal or metal wire. Hermetically close it. Then pass current (large one) through wire, and Oxygen will react with wire, taking even more gas from the chamber. This technique was used to make vacuum tubes, light bulbs etc.

If you turn off pump, and leave it this way for a while how fast pressure is returning to normal? You could make video on YouTube (but please place camera on tripod). If it is slowly returning (not within seconds), use timelapse. It will be interesting project for you. It will tell how hermetic is your entire chamber and connections.

thank you.

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16 minutes ago, Theredbarron said:

Does it really matter that its 1 inch on a gauge difference is what I want.

No way of knowing.

17 minutes ago, Theredbarron said:

If I can move matter without touching it in a vacuum

Well, not by moving the air obviously. A build up of electric charge would do it.

17 minutes ago, Theredbarron said:

Then im going to add a feature to make it more powerful within a vacuum just like pretty much all planets do.

How are planets relevant to this?

18 minutes ago, Theredbarron said:

Im not sure what context your looking for but im not a scientist!

Being a scientist has nothing to do with it.

Some of the context has been dragged out of your slowly and painfully. Some was clever guesses by members here. Some is still not clear.

Here is a summary of some of the context missing from your original post:

• What is the "jar"? (Size, construction, seal, etc)
• Why are you trying to create a vacuum?
• There is a vacuum pump - what is the spec of the pump? What pressure does it claim to achieve? Do you know about other techniques, such as "getters" to reduce the pressure?
• What doe 30 in Hg and? Seems it is from a vacuum gauge (so is relative pressure, not air pressure) although you still haven't admitted that.
• How the jar sealed?
• How are you measuring the pressure?
• How do you move the matter? Apparently some sort of spinning object that moves the air (the "not a fan")
• How large is this spinning object (the "not a fan")?
• What shape is it?
• What is it made of?
• How fast is it spinning?
• What are you trying to achieve?

So people have answered some of these by guesswork. And you have given away a tiny bit more information. Do you see why it is hard to answer your questions when you keep so many important details a secret?

Anyway, I don't know what you are trying to do. If the purpose of the vacuum is to prevent the motion of the air caused by your spinning object ("not a fan") form moving the paper, then why not just put a barrier between the "not a fan" and the paper? Then the air movement caused by the "not a fan" cannot move the paper. That would seem a lot simpler.

You could then go another step and use an earthed metal barrier to eliminate the possibility of static buildup on the "not a fan" (which could be made worse by the vacuum) moving the paper.

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2 minutes ago, Strange said:

No way of knowing.

Well, not by moving the air obviously. A build up of electric charge would do it.

How are planets relevant to this?

Being a scientist has nothing to do with it.

Some of the context has been dragged out of your slowly and painfully. Some was clever guesses by members here. Some is still not clear.

Here is a summary of some of the context missing from your original post:

• What is the "jar"? (Size, construction, seal, etc)
• Why are you trying to create a vacuum?
• There is a vacuum pump - what is the spec of the pump? What pressure does it claim to achieve? Do you know about other techniques, such as "getters" to reduce the pressure?
• What doe 30 in Hg and? Seems it is from a vacuum gauge (so is relative pressure, not air pressure) although you still haven't admitted that.
• How the jar sealed?
• How are you measuring the pressure?
• How do you move the matter? Apparently some sort of spinning object that moves the air (the "not a fan")
• How large is this spinning object (the "not a fan")?
• What shape is it?
• What is it made of?
• How fast is it spinning?
• What are you trying to achieve?

So people have answered some of these by guesswork. And you have given away a tiny bit more information. Do you see why it is hard to answer your questions when you keep so many important details a secret?

Anyway, I don't know what you are trying to do. If the purpose of the vacuum is to prevent the motion of the air caused by your spinning object ("not a fan") form moving the paper, then why not just put a barrier between the "not a fan" and the paper? Then the air movement caused by the "not a fan" cannot move the paper. That would seem a lot simpler.

You could then go another step and use an earthed metal barrier to eliminate the possibility of static buildup on the "not a fan" (which could be made worse by the vacuum) moving the paper.

whats your deal? I only asked a question and you act like your under attack. You dont need to know anything about what im doing. I asked what is the real difference not what do you think of my setup. I get that my gauges are relative to the atmosphere and I dont need to admit anything. Get over yourself. all you have been is insulting. I dont need your help in understanding because all you want to do is pretend to know more then me.

Sorry the type of gauge im using is an ac system gauges. Im guessing that its not true vacuum and I would need an absolute gauge or something like that or is the vacuum read on a gauge relative no matter what? maybe im not good at asking the right questions. like I said not a scientist.

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25 minutes ago, Theredbarron said:

You asked what context was missing. I am trying to be helpful by pointing out some of the extra information (context) that you could have provided.

25 minutes ago, Theredbarron said:

You dont need to know anything about what im doing.

Context can be vital. There clearly wasn't enough information in your first post to answer your question.

25 minutes ago, Theredbarron said:

I get that my gauges are relative to the atmosphere

Yes, that's the point. YOU know that. No one else does. Unless you tell them. (Someone cleverly guessed it. I wouldn't have.)

25 minutes ago, Theredbarron said:

all you have been is insulting.

I can't see where I have been insulting. But feel free to report my post(s) to the moderators.

25 minutes ago, Theredbarron said:

I dont need your help in understanding because all you want to do is pretend to know more then me.

I also tried to make some helpful suggestions about alternative approaches to the problem. (Based on the assumption that the problem is to be solved is to eliminate air movement as the reason for the paper moving.)

But have it your own way.

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OK Thredbarron,

It's going to work better if you start at the beginning.
I doubt that you woke up one morning and thought "Just for kicks, I will hook a vacuum pump and gauge to a jar".

What are you trying to do or find out?

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4 minutes ago, Strange said:

You asked what context was missing. I am trying to be helpful by pointing out some of the extra information (context) that you could have provided.

Context can be vital. There clearly wasn't enough information in your first post to answer your question.

Yes, that's the point. YOU know that. No one else does. Unless you tell them. (Someone cleverly guessed it. I wouldn't have.)

I can't see where I have been insulting. But feel free to report my post(s) to the moderators.

I also tried to make some helpful suggestions about alternative approaches to the problem.

But have it your own way.

How much does it matter from 29 to 30 in reality not in my chamber? so the context would be space since thats where most the vacuum is! How much in relation to that does that 1 inch specifically from 29 to 30 hg (hg because thats what im used to). planets might be involved in space so thats why thats there. Im using what I have observed about vacuum and pressure relationships but I wanted to know more of the finer details about the difference in that specific range and if what im doing requires me to get to that. Maybe my pump is bad or my gauges but if I needed the 30 then I would pursue that but if not then my questions have been answered either way. I didnt think it was that hard of a question. If I showed you my setup all you will do is tell me how jacked up you think it is. Good thing thats not my question so my setup is irrelevant. Sensei Gave me something useful so maybe I can look at it from a different perspective at least.

How about from 15 to 30 in relation to earth?

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If you are an insect in the jar  it matters very little- you are dead either way. Both are far too low..

If you are trying to do things that need a good vacuum- like build a mass spectrometer, there's no meaningful difference between 29 inches of vacuum and atmospheric pressure.

Both are millions of  times too high

4 minutes ago, Theredbarron said:

. I didnt think it was that hard of a question.

Well, do you now realise that you were wrong?

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2 minutes ago, John Cuthber said:

OK Thredbarron,

It's going to work better if you start at the beginning.
I doubt that you woke up one morning and thought "Just for kicks, I will hook a vacuum pump and gauge to a jar".

What are you trying to do or find out?

No one listens to what I type about what im doing and some tend to simply pretend that im not doing this in speculations. So I would but moving matter without touching it is what im describing it as and I wanted to do it in a vacuum as far as I can with what resources I have. What I want to know is how much does it really in space or anywhere matter that one inch. only because my setup wont pull that on my guage and if I need to upgrade it would be because that one inch difference has more importance then lets say 15 to 30.

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1 hour ago, Theredbarron said:

there is a motor built into the chamber that spins a wheel thats not connected to anything except by air.

My best guess is that the vacuum required depends on what kind of physical force that is going to move the matter in the jar and what claims you are looking to support. You need "enough vacuum" to remove any doubts regarding the effect. You want to reduce the possibility that the matter is indeed moved by remaining air (=fan) instead of the effect you are looking for. One way of initial testing might be to run the experiment at lower and lower pressure and see how it affect the outcome and how it matches your prediction and expectations. Does something special happen when you get close to 30 that makes you expect a significantly improved result at for instance 29?

Are you looking for some radiation pressure effect? Static electricity? Other?

1 hour ago, Theredbarron said:

If I can move matter without touching it in a vacuum then I can move matter without touching it in space. Then im going to add a feature to make it more powerful within a vacuum just like pretty much all planets do. Im not sure what context your looking for but im not a scientist!

At the scale of planetary systems I guess gravity is the dominant force.

Edited by Ghideon
Grammar, missing words

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1 minute ago, Ghideon said:

My best guess is that the vacuum required depends on what kind of physical force that is going to move the matter in the jar and what claims you are looking to support. You need "enough vacuum" to remove any doubts that the matter is indeed moved by remaining air (=fan) instead of the effect you are looking for. One way of initial testing might be to run the experiment at lower and lower pressure and see how it affect the outcome and how it matches your expectations. Does something special happen when you get close to 30 that makes you expect a significantly improved result at 29?

Are you looking for some radiation pressure effect? Static electricity?

At the scale of planetary systems I guess gravity is the dominant force.

Yes to the first but more about the feature that I want to add and if i need 30 inches for an important reason or not.

As for gravity im not saying thats what im doing but there is a feature of all planets that I noticed that I may have been able to harness or whatever. It does the same thing repeatedly on every test. Its not a fan or representing a fan in any way. It is specifically designed to do what it is doing. 30 inches is the only one I haven't been able to get too for a while now!

and its not hand made its 3d printed.

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