True vacuum

[swansont]

10 minutes ago, Theredbarron said:

see what I mean by I suck at at this! I littlerally have a problem with reading and comprehending it even my own questions sound great at first. 

ok the reason why vacuum is important to what im doing is because the wheel that im using generates vacuum or a lower pressure differential in one spot. dont know if that makes sense. it moves pockets in a manner that generates the lower pressure area. I used planets as the original understanding of how to create this wheel. I dont want to explain all that again because you wont get it is what I see. Its not telepathy. its a physical object and its actually extremely simple to understand but very hard to explain to any of you here. everyone else on the other hand. 

My telepathy reference was in regard to you expecting people to know/understand things that you have not divulged. Not the operation of your device.

One thing that will be true is that pressure differentials will be limited by the pressure present, if you want air/wind to move anything. 

[Strange]

14 minutes ago, Theredbarron said:

ok the reason why vacuum is important to what im doing is because the wheel that im using generates vacuum or a lower pressure differential in one spot. dont know if that makes sense. it moves pockets in a manner that generates the lower pressure area.

If it works by moving pockets of air to create a partial vacuum (lowering the pressure in some places) then it will probably work less and less well when the air pressure is lowered - because there is less pressure for it to make lower.

3 minutes ago, Theredbarron said:

isn't that because the one side of each blade gets hotter creating a slight pressure on that side spinning the deal when its in a near vacuum?

Yes! (You often see it explained as the force of the light hitting it, but that is wrong and you are right)

18 minutes ago, Theredbarron said:

see what I mean by I suck at at this!

Good pun!

I know you are getting frustrated, but I think people are genuinely trying to help you. No one has said you are crazy or stupid. People have just tried to get a bit more information in order to ty and give you the answers you need.

I don[t really know what your "thing" is, what it does or what you think it might do. Most of that doesn't matter. People are only asking about details that seem to be relevant to answering the questions you are asking. (And trying to give some suggestions about other ways to think about things.)

[J.C.MacSwell]

One thing with regard to the "not a fan" air propulsor...if your set up manages (not necessarily a reasonable assumption but plausible) to put the same energy into the air it will (mostly) do so by increasing the air velocity. If say you reduced the air density to 1/4, the velocity would double...and this doubling of velocity would produce exactly the same lift/drag with 1/4 the air density (assuming the coefficient of lift or drag stayed the same...again not necessarily true...but reasonably possible)

With regards to your set up...it makes it harder to help if we don't know what it is but you may have a number of good reasons to prefer not to divulge it on a public forum, or for that matter, to anyone. No explanation needed if you prefer not to tell us or explain why you prefer not to...just helpful to indicate you prefer not to and have reasons.

6 hours ago, John Cuthber said:

If the atmospheric pressure is the so called "standard" of 760 mmHg it is impossible to get 30 inches of vacuum.

+1

[MigL]

3 hours ago, Strange said:

3 hours ago, Theredbarron said:

isn't that because the one side of each blade gets hotter creating a slight pressure on that side spinning the deal when its in a near vacuum?

Yes! (You often see it explained as the force of the light hitting it, but that is wrong and you are right)

Not to b a stickler...
But that is only accurate for partial pressures/vacuum.
Once you get to an appreciably good vacuum, heating ( on the dark side ) is no longer the driver, as there is no gas pressure due to heating.
It is radiation pressure on the silvered side ( if the spindle has low enough friction ) that forces the plates to act like solar sails would in space, and it will rotate in the opposite direction.

So this too, depends on what you are trying to accomplish, as the results would be opposite for differing vacuum.

[Strange]

6 hours ago, MigL said:

Not to b a stickler...
But that is only accurate for partial pressures/vacuum.

Which is the case for the Crookes radiometer in the illustration.

A much more sensitive device, operating at a much lower pressure, can show the effects of light pressure: https://en.wikipedia.org/wiki/Nichols_radiometer

[John Cuthber]

13 hours ago, Theredbarron said:

my original question is how important is the difference between 29 and 30! someone answered it and some just tried to ask about my setup.

And the answer is that it depends what you are trying to do. How did you imagine that we could answer the question without knowing that?
 

 

12 hours ago, Strange said:

As I think others have said, trying to express a vacuum as 30 inches of Hg isn't terribly meaningful or useful. It is a bit like asking about the thickness of a piece of paper in miles

It's worse than that. It's like asking how thick a coin is by expressing is as "How much thinner than a thumb is it?".
 

 

15 hours ago, Theredbarron said:

So pretty much not going to get to 30 with standard equipment? or would digital be any benefit like sensors versus mechanical even if im not making it to 30?

Which part of "impossible" did you not understand?

[Strange]

15 hours ago, Theredbarron said:

So pretty much not going to get to 30 with standard equipment? or would digital be any benefit like sensors versus mechanical even if im not making it to 30?

Lets make this more explicit. Standard atmospheric pressure is 760 mm Hg (obviously, actual atmospheric pressure varies a lot around that). 

760 mm Hg is 29.9213 in Hg.

So the lowest pressure you could possibly achieve, on your gauge, from standard atmospheric pressure is 29.9213. But as your gauge is showing relative pressure (presumably, this is another bit of missing context) then the actual lowest pressure you could possibly achieve depends on your local air pressure at the time.

This is why you need to move to an absolute pressure gauge, showing the pressure in sensible units (e.g. torr or pascals).

 

By the way, you have asked a few times what people mean by "context". It is the extra information needed to fully understand the question being asked.

Quote

Definition of context

1: the parts of a discourse that surround a word or passage and can throw light on its meaning

2: the interrelated conditions in which something exists or occurs : ENVIRONMENT, SETTING

Quote

When we say that something is contextualized, we mean that it is placed in an appropriate setting, one in which it may be properly considered.

Quote

: the words that are used with a certain word or phrase and that help to explain its meaning

: the situation in which something happens : the group of conditions that exist where and when something happens

https://www.merriam-webster.com/dictionary/context

Hope that provides enough context to help you understand why people were asking for the context.

[Theredbarron]

13 hours ago, Strange said:

Lets make this more explicit. Standard atmospheric pressure is 760 mm Hg (obviously, actual atmospheric pressure varies a lot around that). 

760 mm Hg is 29.9213 in Hg.

So the lowest pressure you could possibly achieve, on your gauge, from standard atmospheric pressure is 29.9213. But as your gauge is showing relative pressure (presumably, this is another bit of missing context) then the actual lowest pressure you could possibly achieve depends on your local air pressure at the time.

This is why you need to move to an absolute pressure gauge, showing the pressure in sensible units (e.g. torr or pascals).

 

By the way, you have asked a few times what people mean by "context". It is the extra information needed to fully understand the question being asked.

https://www.merriam-webster.com/dictionary/context

Hope that provides enough context to help you understand why people were asking for the context.

ok I get that. Thanks. So it doesn't really matter that I reach 30 because its not even close to space is what I have understood so far? So if that is the most attainable then how are things tested against the forces of space other then a calculator?

or better yet is there any place in space that has is absent of matter? probably a dumb question but it is relevant to how my crap works

and another thing is there a chemical based smoke that creates without it pushing the smoke? im using smoke bombs and it forces the smoke around the chamber and makes it hard to see the effects that im trying to observe. something that oozes smoke

I also apologize for not being nice! Since I have been coming here people haven't exactly been awesome. I do come off arrogant. Its more of a defense thing. I understand that some of you deal with people that do the same crap as me but you should expect it. Your an open website for people who think they are scientist. im probably one of the worst. if I need to bring up a different subject to show you that im not playing then I can but I dont have property rights yet. im broke and it takes years for stuff to happen for some reason. I am very over qualified for power systems and electrical energy even if it doesn't seem that way. I ask questions not just to hear the answer but to also check the source.

now my chamber has a leak. This is the 3rd chamber I have imploded. 

this idea that im working on is just the one I know I cant prove to you here! I like the challenge. The very first topic I posted on here I request the challenge on this. I still want that. Im not here to convince anyone. I dont want a prize. I love reverse engineering! its extremely fun!

right now for me its like 2 different coding languages having the same result

You can think im crazy or an idiot. It doesn't matter to me.  I thought I was too. Then all the doctors later its still stands. How about that for context?

I dont know if you remember me posting this but I have a mild brain injury! of course it effects my reading cognition to which im sure you can see maybe!

So I dont have social media like snapchat or face book. I have a gmail account. So when I come here and ask stupid questions usually its because there is little human contact let alone with people that understand anything! Example how to change a light bulb. I think most people dont know how to in America. I was going to say the world but intellectual evolution has effected areas I have not been or understood yet!

your on the internet! you dont know who your talking to at all times!

23 hours ago, MigL said:

Not to b a stickler...
But that is only accurate for partial pressures/vacuum.
Once you get to an appreciably good vacuum, heating ( on the dark side ) is no longer the driver, as there is no gas pressure due to heating.
It is radiation pressure on the silvered side ( if the spindle has low enough friction ) that forces the plates to act like solar sails would in space, and it will rotate in the opposite direction.

So this too, depends on what you are trying to accomplish, as the results would be opposite for differing vacuum.

I just read this!. This is exactly what I need. What is meant by different vacuum?

[Theredbarron]

On 5/24/2020 at 1:13 PM, Phi for All said:

!

Moderator Note

You behave like an idiot. You see persecution in rigor. You cherry-pick what makes sense to you. You don't do science. So pretty soon, I imagine you'll break enough rules and we won't have to respond to your ungrateful crap. Have a great day!

 

So is this site for only mainstream science or are people allowed to get answers to questions that are relevant to what they are doing even if you dont believe in what they are doing? not trying to argue just you have only been negative! What is it that you have accomplished that you want me to respect? I would be its just not showing me on here and I cant find it!

On 5/23/2020 at 4:50 PM, 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 is important.

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

look I have come off as a dick! I know you have a 

phd! So you can understand that sometimes it takes someone to observe something to learn it. You definitely have what 30 inches hg means to you! im not talking about the actual measurement but the actual effects on our existence in every situation. Not every but most likely. It shows that water evaporates at a huge amount but only 1 inch for example or am I reading things wrong?

the last line is but only by one inch is what I understand in that area of pressure 29 inch to 30 inch is 1 inch but why doe that one inch have so much effect or is it the effort?

I tell you what I dont want a prize or reward, If I get a prize I will not accept! I will give it away. I dont care about being the first person to do something. I think a whole lot further then just what im doing! if I move too fast just answer what you can! im not going to hold it against you. I want to learn as much as possible! The way I learn is not the same as you!. I apply everything I learn and TEST it! I may not be able to tell you here on this site that I appreciate you but I have learned more from this site then everything else! I put myself in speculations because it is all speculation using physics that is understood to test. I want whats in your brain faster then what you think people can learn! state the obvious first!

so phil is not here?

[MigL]

1 hour ago, Theredbarron said:

What is meant by different vacuum?

Well, if you have a so-so vacuum, where you still have enough gas present, to create some pressure when heated, you have a Crookes radiometer, and the vanes spin away from the dark side ( gas pressure driven ).
If you have a really good vacuum ( and very low friction set-up ), you have a Nichols radiometer, and the vanes spin away from the light side ( light momentum driven ).

I  can't really give you values for the vacuum at which the 'switch' occurs as there would be a 'few' variables involved.
( thanks Strange, for supplying the name of the Nichols radiometer )

[Theredbarron]

35 minutes ago, MigL said:

Well, if you have a so-so vacuum, where you still have enough gas present, to create some pressure when heated, you have a Crookes radiometer, and the vanes spin away from the dark side ( gas pressure driven ).
If you have a really good vacuum ( and very low friction set-up ), you have a Nichols radiometer, and the vanes spin away from the light side ( light momentum driven ).

I  can't really give you values for the vacuum at which the 'switch' occurs as there would be a 'few' variables involved.
( thanks Strange, for supplying the name of the Nichols radiometer )

what switch? and tell me the varialbles? I will do my best on making in happen! 

I will apply everything learn from this site and I have! 

[Strange]

2 hours ago, Theredbarron said:

So it doesn't really matter that I reach 30 because its not even close to space is what I have understood so far? So if that is the most attainable then how are things tested against the forces of space other then a calculator?

No, that's not what I said. You seem to think that "30" is a vacuum, presumably because it is the last number on your gauge.

There are three problems with your constant references to "30"

1. A pressure of 30 would be more than a perfect vacuum; it would be a negative pressure. (Which is obviously impossible).

2) You are not measuring the pressure of your vacuum, you are measuring how far below air pressure it is. Air pressure varies. It is like saying that you are building a wall and you want it 4 feet below head height. But that depends on the person (everyone's head height is different) and even the time of day (we get shorter throughout the day).

3) It is not accurate enough. I have no idea what your meter is like, but presumably it is similar to the image posted by Sensei on the first page of this thread. That has divisions of 0.5 in Hg. So the lowest pressure it can measure is 29.5 in Hg. That is many thousands of times larger than the pressure you need to achieve. A "perfect vacuum" would be somewhere between the 29.5 and 30 marks. It is like trying measure the thickness of a human hair by comparing it with a brick.

When people create good quality vacuum (or measure the vacuum of space) then they measure how much greater than zero the pressure is. And they measure it in the right units. 

3 hours ago, Theredbarron said:

or better yet is there any place in space that has is absent of matter?

Not completely absent of matter.

The space between galaxies is the emptiest, with roughly 10 atoms per cubic metre. 

The space between stars (inside our galaxy) there may be 1,000 times more than that.

And the space between planets there will be roughly 1,000 times more again.

For comparison, a high quality laboratory vacuum (which would be impossible for you to achieve) will have something 10 quadrillion (10¹⁶)  molecules per cubic meter.

So even a really good vacuum does not approach that of deep space.

3 hours ago, Theredbarron said:

now my chamber has a leak. This is the 3rd chamber I have imploded. 

If you described what your "chamber" is (it was a "jar" earlier) then maybe people would be able to help.

Also, if you are not using the right sort of equipment, it could be dangerous. If you are causing this sort of accident, I don't think we should give you any advice other than: stop until you have the right equipment (including a safety cage around the vacuum chamber).

3 hours ago, Theredbarron said:

How about that for context?

Not relevant. 

Useful context would be what type of meter you are using. Why you are not using the right sort of meter. What your vacuum chamber/jar is made of. How large it is. Why you can't just put a barrier between the "spinning thing" and the paper, smoke, whatever.

 

 

[Theredbarron]

4 minutes ago, Strange said:

No, that's not what I said. You seem to think that "30" is a vacuum, presumably because it is the last number on your gauge.

There are three problems with your constant references to "30"

1. A pressure of 30 would be more than a perfect vacuum; it would be a negative pressure. (Which is obviously impossible).

2) You are not measuring the pressure of your vacuum, you are measuring how far below air pressure it is. Air pressure varies. It is like saying that you are building a wall and you want it 4 feet below head height. But that depends on the person (everyone's head height is different) and even the time of day (we get shorter throughout the day).

3) It is not accurate enough. I have no idea what your meter is like, but presumably it is similar to the image posted by Sensei on the first page of this thread. That has divisions of 0.5 in Hg. So the lowest pressure it can measure is 29.5 in Hg. That is many thousands of times larger than the pressure you need to achieve. A "perfect vacuum" would be somewhere between the 29.5 and 30 marks. It is like trying measure the thickness of a human hair by comparing it with a brick.

When people create good quality vacuum (or measure the vacuum of space) then they measure how much greater than zero the pressure is. And they measure it in the right units. 

Not completely absent of matter.

The space between galaxies is the emptiest, with roughly 10 atoms per cubic metre. 

The space between stars (inside our galaxy) there may be 1,000 times more than that.

And the space between planets there will be roughly 1,000 times more again.

For comparison, a high quality laboratory vacuum (which would be impossible for you to achieve) will have something 10 quadrillion (10¹⁶)  molecules per cubic meter.

So even a really good vacuum does not approach that of deep space.

If you described what your "chamber" is (it was a "jar" earlier) then maybe people would be able to help.

Also, if you are not using the right sort of equipment, it could be dangerous. If you are causing this sort of accident, I don't think we should give you any advice other than: stop until you have the right equipment (including a safety cage around the vacuum chamber).

Not relevant. 

Useful context would be what type of meter you are using. Why you are not using the right sort of meter. What your vacuum chamber/jar is made of. How large it is. Why you can't just put a barrier between the "spinning thing" and the paper, smoke, whatever.

 

 

holy crap!

where is the end then? look I have always been the end but maybe where is the end of vacuum?

where is the end if we cant get there?

[Endy0816]

40 minutes ago, Theredbarron said:

holy crap!

where is the end then? look I have always been the end but maybe where is the end of vacuum?

where is the end if we cant get there?

Pressure is force exerted over some area. Fewer or simply less energetic(lower temperature) atoms bouncing around and you get a lower pressure.

Closer you get to zero and the more difficult achieving an accurate reading becomes. There's vacuum energy too ,which I think would prevent you from getting all the way to zero in any case.

Can you upload a picture of the gage? You have probably drawn a decent enough vacuum for most things though never hurts to check.

[Strange]

6 hours ago, Theredbarron said:

holy crap!

where is the end then? look I have always been the end but maybe where is the end of vacuum?

where is the end if we cant get there?

The"end" is a pressure of zero (not 30).

You can get as close as you want to zero. But the closer you get the more difficult and expensive it is (because of leaks, outgassing and all the other issues mentioned in this thread).

Here:

On 5/24/2020 at 9:10 PM, Strange said:

To give you some more specific figures on the level of vacuum you would need to achieve if you want to reproduce the conditions in space:

• Low vacuum: 760 Torr to 1 x 10^-3 Torr
  • Vacuum cleaner: to 600 Torr
  • Thermos bottle 10^-3 Torr
• High vacuum: 10^-3 to 10^-9 Torr
  • Electron microscope
  • Ion Implanter – Evaporator – Sputterer
• Ultra high vacuum: 10^-9 to 10^-12 Torr
  • CERN LHC: 1 x 10^-10 Torr
  • Moon’s surface: 1 x 10^-11 Torr
  • Deep Space 1 x 10^-17 Torr = 0.000,000,000,000,000,01 Torr

You are currently in that "low vacuum" range.

From: https://www.raclub.org/Documents/Programs/VACUUM.pdf (there is a lot of other useful information in there; looks like a pretty good tutorial)

Read the article at that link. It is useful

 

[swansont]

9 hours ago, Theredbarron said:

So is this site for only mainstream science or are people allowed to get answers to questions that are relevant to what they are doing even if you dont believe in what they are doing? not trying to argue just you have only been negative! What is it that you have accomplished that you want me to respect? I would be its just not showing me on here and I cant find it!

Your question is a mainstream science question.

 

Quote

look I have come off as a dick! I know you have a 

phd! So you can understand that sometimes it takes someone to observe something to learn it. You definitely have what 30 inches hg means to you! im not talking about the actual measurement but the actual effects on our existence in every situation. Not every but most likely. It shows that water evaporates at a huge amount but only 1 inch for example or am I reading things wrong?

Yes, I have. PhD in experimental atomic physics, so I have used vacuum equipment for a long time. I've been through multiple iterations of having to fix vacuum problems. And so I know that you hadn't given enough information to diagnose the problem. (also, being a scientist, I wouldn't be using inches of Hg) 

Like I said, it could be the gauge, it could be the pump, it could be a leak.

You didn't tell me what kind of gauge you were using - it matters. You didn't say anything about the setup - it matters. 

 

It gets harder and harder to lower pressure the lower the pressure gets. A mechanical pump will only get you so far (a good one gets you to the low end of "low vacuum" in the list Strange presented). All systems leak; the question is how much. Outgassing and virtual leaks will limit you as well. For good vacuum one bakes the system to speed up the outgassing, but that's usually not an issue for just a mechanical pump. 

 

 

[John Cuthber]

It might be worth explaining the bizarre unit- the "inch of vacuum".

It is, as I said, like trying to describe the thickness of a coin by measuring the difference between that thickness and the width of your thumb.

The original idea was fairly simple.
You got a mercury filled barometer.
http://www-mdp.eng.cam.ac.uk/web/library/enginfo/aerothermal_dvd_only/aero/fprops/statics/node15.html,

Then you connected the top of it to your apparatus.

The better your pump was, the more it pulled the mercury up.

And if your use for a pump was pulling water out of a mine shaft, that's probably as good as it needed to be. You could pull water roughly 13 times further , because it's 13 )or so) times denser than water.

The problem is that the pump doesn't pull the mercury up- the atmosphere pushes it up- and the atmosphere is variable..
Well, that's still OK if you need to know if your pump is pulling water out of a mine, because the head of water is also affected by the atmosphere.

 

But, if you want to get a reasonably accurate measurement, you can't use the atmosphere as a reference point. (OK, technically, you can- if you measure it accurately).

 

If the actual atmospheric pressure varies by an inch of mercury, that isn't going to make much difference to the mine pump. A change between 20 inches and 21 isn't worth worrying about.
But, if you are actually working with a pressure  that's less than an inch of mercury, your "reference" point varies so much that you can't tell if your pressure is positive or negative (well- it' can't really be negative, but that';s what the gauge.would show).

None of that will actually help answer the OP's question.

 

Because the question is like saying "my antique clock keeps time to +/- 30 minutes a day. IS that good enough?"

Good enough for what?

If the OP ever actually tells us what question they want to answer, we might be able to answer it.

 

[Strange]

12 hours ago, Theredbarron said:

and another thing is there a chemical based smoke that creates without it pushing the smoke? im using smoke bombs and it forces the smoke around the chamber and makes it hard to see the effects that im trying to observe. something that oozes smoke

I'm not sure what a smoke bomb is, but it sounds incompatible with the idea of trying to create a vacuum. 

Smoke is just fine material suspended in air. In a vacuum there is no air so you cannot have smoke. But you can have dust. So any fine material would do. It won't float about (if you have a good vacuum) but I assume that is the point: you want to know that your device is exerting a force on it, not just random air movements.

One problem you might have is eliminating any static charge to avoid clumping.

Lycopodium was the classic inventor's material for this sort of thing. There may well be modern alternatives. https://en.wikipedia.org/wiki/Lycopodium_powder#Other_uses

[swansont]

17 hours ago, Theredbarron said:

 and another thing is there a chemical based smoke that creates without it pushing the smoke? im using smoke bombs and it forces the smoke around the chamber and makes it hard to see the effects that im trying to observe. something that oozes smoke

There are chemicals used in smoke/fog machines. 

[Ghideon]

@Theredbarron here is an idea how I think you could have formulated the initial question with lower risk of being dragged in an (unwanted) detailed discussion about the specific experiments.  Hopefully this post helps OP in future topics and increase the odds for fruitful discussions*. 

I have an idea about doing some experiments in vacuum. Not just low pressure as on a mountain top or high up in the atmosphere, but vacuum. More specifically I wish to create, or get as close as possible, to the vacuum of space. Right now I have a meter. The best I manage to get to using my current equipment is a reading of 29 inch hg on the meter. How does my current meter reading compare to the vacuum of space? What difference would it make if I could reach a reading of 30; how much closer to the vacuum of space would a reading of 30 be? 

The above question is not intended to be the perfect vacuum question from engineering or scientific point of view, it’s just a variant on the initial question intended to help the formulation of future questions. The question intentionally still contains issues from OP regarding units, measurement relative to local atmospheric pressure etc, written from OPs point of view with the information available at that point. From this point there would still be lots of questions about the meter, units, issues with equipment and others but maybe less focus on the actual experiments.

 

*) I've learnt some new things about vacuum measurements and units from this thread. 

[John Cuthber]

A fog in a vacuum is impossible. There's nothing to hold it up.