# The Flat Earth Society

## Flat Earth Discussion Boards => Flat Earth Debate => Topic started by: Ozymandias74 on November 15, 2019, 06:01:47 PM

Title: Gravity and the equivalence principle
Post by: Ozymandias74 on November 15, 2019, 06:01:47 PM
The equivalence principle simply puts says that you cannot tell the difference between gravity and acceleration.
keep in mind that acceleration is a constant change in speed, not a constant speed.
Given that, why is gravity so hard to understand or believe its real.
Also why is it so hard to believe that gravity can hold the atmosphere in place.   Even though space is a vacuum, gravity can hold the air in place.
There is a pressure gradient, as evidenced by the thinner atmosphere in the mountains.  Why is it so hard to believe that the air gets thinner and thinner the higher you go and the line between 'space' and our atmosphere is tenuous.

something else to think about, you have an unopened soda bottle.   you shake it up and open it, obviously it will spew out everywhere.
Now consider this, if the soda bottle is accelerating, is there an acceleration that will prevent that bottle from spewing everywhere.   Can you accelerate that bottle so fast even if you shake it up and open it, all the liquid and gas just stays in the bottle.
a typical car goes zero to 60 in 10-12 seconds, supercars can do it in 4 seconds or less.
now lets pretend we can accelerate that bottle super fast, say zero to 500 mph in 10 seconds.   Do you think the liquid might stay in the bottle?
now lets think about even faster, say zero to 10,000 mph in 10 seconds (for the sake of the thought experiment, dont worry about HOW such acceleration would be achieved, just imagine the pressures that such acceleration would cause on the bottle). In such circumstances its not too difficult to imagine that even if you shake a soda bottle and open it, the bottle will remain full, all the gas and liquid will remain inside the bottle, even if the bottle is in a total vacuum.
Also note that once you reached your end speed (whether 500 mph or 10,000 mph), then the acceleration stops and now the liquid and gas would be free to leave the bottle. This also helps to demonstrate the difference between a constant speed and a constant acceleration.
Title: Re: Gravity and the equivalence principle
Post by: MouseWalker on November 15, 2019, 07:29:51 PM
The equivalence principle simply puts says that you cannot tell the difference between gravity and acceleration.
keep in mind that acceleration is a constant change in speed, not a constant speed.
Given that, why is gravity so hard to understand or believe its real.
Also why is it so hard to believe that gravity can hold the atmosphere in place.   Even though space is a vacuum, gravity can hold the air in place.
There is a pressure gradient, as evidenced by the thinner atmosphere in the mountains.  Why is it so hard to believe that the air gets thinner and thinner the higher you go and the line between 'space' and our atmosphere is tenuous.

something else to think about, you have an unopened soda bottle.   you shake it up and open it, obviously it will spew out everywhere.
Now consider this, if the soda bottle is accelerating, is there an acceleration that will prevent that bottle from spewing everywhere.   Can you accelerate that bottle so fast even if you shake it up and open it, all the liquid and gas just stays in the bottle.
a typical car goes zero to 60 in 10-12 seconds, supercars can do it in 4 seconds or less.
now lets pretend we can accelerate that bottle super fast, say zero to 500 mph in 10 seconds.   Do you think the liquid might stay in the bottle?
now lets think about even faster, say zero to 10,000 mph in 10 seconds (for the sake of the thought experiment, dont worry about HOW such acceleration would be achieved, just imagine the pressures that such acceleration would cause on the bottle). In such circumstances its not too difficult to imagine that even if you shake a soda bottle and open it, the bottle will remain full, all the gas and liquid will remain inside the bottle, even if the bottle is in a total vacuum.
Also note that once you reached your end speed (whether 500 mph or 10,000 mph), then the acceleration stops and now the liquid and gas would be free to leave the bottle. This also helps to demonstrate the difference between a constant speed and a constant acceleration.
and Denpressure
Title: Re: Gravity and the equivalence principle
Post by: Wanderer on November 29, 2019, 10:45:11 PM
Not all FEs subscribe to 'no gravity' but those who do should be aware that as one goes deeper into the earth a dropped object's rate of acceleration will change from what it experiences on the surface. Indeed at the centre of a global earth it will float.
If FE'ers are sincere in their beliefs they can test that by going into a deep well, or maybe the Grand Canyon and measure how long it takes for an object to drop, say 10 metres  1) at the top of the canyon, 2 ) at the  bottom.
If the time to drop is the same in both  cases, then they have (some) supporting evidence.

"Acceleration Equivelance" as an alternative to Gravity would result in no change in the time to drop.
Because (obviously) all objects, no matter where they are willl all be accelerating upwards at the same rate.

If the time changes then indeed they need to accept that gravity is the true force.

[ you can do better in Peru, where G is just 9.7639 m/s/s compared to 9.818m/s/s in the average  case]
Title: Re: Gravity and the equivalence principle
Post by: JackBlack on November 29, 2019, 11:40:12 PM
Not all FEs subscribe to 'no gravity' but those who do should be aware that as one goes deeper into the earth a dropped object's rate of acceleration will change from what it experiences on the surface. Indeed at the centre of a global earth it will float.
For the distances we can go down it is actually fairly constant.
Yes, there is less matter below you, but you are closer to it, and it is denser.

It looks something like this:

However I'm not sure if that takes the centrifugal force into account.

It floating at the centre is entirely theoretical, and thus can't really be used as an argument.

It would be better/easier to measure the time taken to fall at various locations on the surface of Earth, especially between high latitudes and the equator. But it needs to be done fairly accurately and air can mess it up.

But they will still come up with excuses as for why it changes.
Title: Re: Gravity and the equivalence principle
Post by: Macarios on November 30, 2019, 02:59:29 AM
Thin long thread and a small heavy ball at the end of it will make pendulum that can be used to measure g more accurately than by free fall timing. Measure time of several full oscillations and then divide to get more precise time of a singe one. With low amplitude of the pendulum's oscillations the air influence is much lower than during free fall.

This might help:
http://www.pstcc.edu/departments/natural_behavioral_sciences/Web%20Physics/Experiment%2004web.htm (http://www.pstcc.edu/departments/natural_behavioral_sciences/Web%20Physics/Experiment%2004web.htm)
Title: Re: Gravity and the equivalence principle
Post by: MouseWalker on November 30, 2019, 09:56:47 AM
Or you could follow travels of
kern the gnome

Title: Re: Gravity and the equivalence principle
Post by: Alpha2Omega on December 01, 2019, 09:19:06 AM
Thin long thread and a small heavy ball at the end of it will make pendulum that can be used to measure g more accurately than by free fall timing. Measure time of several full oscillations and then divide to get more precise time of a singe one. With low amplitude of the pendulum's oscillations the air influence is much lower than during free fall.

This might help:
http://www.pstcc.edu/departments/natural_behavioral_sciences/Web%20Physics/Experiment%2004web.htm (http://www.pstcc.edu/departments/natural_behavioral_sciences/Web%20Physics/Experiment%2004web.htm)

That's the principle used by some gravimeters (gravity meters). These devices can be extremely sensitive to very small changes in the acceleration of gravity, to the point that they can give good estimates of the height of 3-story buildings. Measuring the height of the geology building (or some other on-campus structure) based on measured changes in the acceleration of gravity is often an experiment in introductory geophysics labs - or was 40 years ago.

Gravity surveys were so effective in locating salt domes, which are often associated with very large petroleum reserves and accompanies by telltale gravity anomalies, that most or all of those in oil-producing regions were quickly located by the end of the 1950s.
Title: Re: Gravity and the equivalence principle
Post by: Tom Bishop on December 01, 2019, 11:20:02 AM
Actually, gravimeters are seismometers. They are not measuring gravity directly, but vibrations from "gravity waves" and "infra-gravity waves".

See: https://wiki.tfes.org/Gravimetry
Title: Re: Gravity and the equivalence principle
Post by: JackBlack on December 01, 2019, 11:53:12 AM
Actually, gravimeters are seismometers. They are not measuring gravity directly, but vibrations from "gravity waves" and "infra-gravity waves".
No, plenty of gravimeters measure the rate of free fall acceleration, i.e. gravity.
Title: Re: Gravity and the equivalence principle
Post by: Tom Bishop on December 01, 2019, 12:01:32 PM
Actually, gravimeters are seismometers. They are not measuring gravity directly, but vibrations from "gravity waves" and "infra-gravity waves".
No, plenty of gravimeters measure the rate of free fall acceleration, i.e. gravity.

False. Write an article, paper, or make a YouTube video to contradict the content in the TFES Wiki link.

Title: Re: Gravity and the equivalence principle
Post by: sokarul on December 01, 2019, 12:13:06 PM
Actually, gravimeters are seismometers. They are not measuring gravity directly, but vibrations from "gravity waves" and "infra-gravity waves".
No, plenty of gravimeters measure the rate of free fall acceleration, i.e. gravity.

False. Write an article, paper, or make a YouTube video to contradict the content in the TFES Wiki link.

No he was right.

https://en.m.wikipedia.org/wiki/Gravimeter

They were mentioned on the discovery channel or history channel years and years ago.
Title: Re: Gravity and the equivalence principle
Post by: Tom Bishop on December 01, 2019, 12:29:31 PM
Actually, gravimeters are seismometers. They are not measuring gravity directly, but vibrations from "gravity waves" and "infra-gravity waves".
No, plenty of gravimeters measure the rate of free fall acceleration, i.e. gravity.

False. Write an article, paper, or make a YouTube video to contradict the content in the TFES Wiki link.

No he was right.

https://en.m.wikipedia.org/wiki/Gravimeter

They were mentioned on the discovery channel or history channel years and years ago.

Umm...  The TFES wiki article quotes directly form that page.

Quote
Many broadband, three axis, seismometers in common use are sensitive enough to track the sun and moon. When operated to report acceleration, they are useful gravimeters. Because they have three axes, it is possible to solve for their position and orientation, by either tracking the arrival time and pattern of seismic waves from earthquakes, or by referencing them to the sun and moon tidal gravity.

Recently, the SGs, and broadband three axis seismometers operated in gravimeter mode, have begun to detect and characterize the small gravity signals from earthquakes. These signals arrive at the gravimeter at the speed of light, so have the potential to improve earthquake early warning methods. There is some activity to design purpose-built gravimeters of sufficient sensitivity and bandwidth to detect these prompt gravity signals from earthquakes. Not just the magnitude 7+ events, but also the smaller, much more frequent, events.

Seismometers have a gravimeter mode. How is that possible? It's because the devices are the same.

The TFES.org wiki article contains several quotes from PhD's who describe that gravimeters are seismometers.

You have provided nothing except for a failure to read and address the content material.
Title: Re: Gravity and the equivalence principle
Post by: JackBlack on December 01, 2019, 12:42:17 PM
Good job describing yourself, like normal.

Your wiki article is not evidence.
If you think you have actual evidence, feel free to provide it.

Rather than trying to pretend all gravimeters are seismometers you should ask yourself just what is a seismometer and how do they function.
Title: Re: Gravity and the equivalence principle
Post by: Stash on December 01, 2019, 12:48:37 PM
Actually, gravimeters are seismometers. They are not measuring gravity directly, but vibrations from "gravity waves" and "infra-gravity waves".
No, plenty of gravimeters measure the rate of free fall acceleration, i.e. gravity.

False. Write an article, paper, or make a YouTube video to contradict the content in the TFES Wiki link.

No he was right.

https://en.m.wikipedia.org/wiki/Gravimeter

They were mentioned on the discovery channel or history channel years and years ago.

Umm...  The TFES wiki article quotes directly form that page.

Quote
Many broadband, three axis, seismometers in common use are sensitive enough to track the sun and moon. When operated to report acceleration, they are useful gravimeters. Because they have three axes, it is possible to solve for their position and orientation, by either tracking the arrival time and pattern of seismic waves from earthquakes, or by referencing them to the sun and moon tidal gravity.

Recently, the SGs, and broadband three axis seismometers operated in gravimeter mode, have begun to detect and characterize the small gravity signals from earthquakes. These signals arrive at the gravimeter at the speed of light, so have the potential to improve earthquake early warning methods. There is some activity to design purpose-built gravimeters of sufficient sensitivity and bandwidth to detect these prompt gravity signals from earthquakes. Not just the magnitude 7+ events, but also the smaller, much more frequent, events.

Seismometers have a gravimeter mode. How is that possible? It's because the devices are the same.

The TFES.org wiki article contains several quotes from PhD's who describe that gravimeters are seismometers.

You have provided nothing except for a failure to read and address the content material.

If the devices are the same why is a "mode" needed?
Title: Re: Gravity and the equivalence principle
Post by: Macarios on December 01, 2019, 01:30:52 PM
You can learn about gravimeters and seismometers here:
https://en.wikipedia.org/wiki/Gravimeter (https://en.wikipedia.org/wiki/Gravimeter)

For example: seismometers follow 3-axis data, gravimeters just 1-axis, but seismometer can operate in gravimeter mode.
Title: Re: Gravity and the equivalence principle
Post by: Tom Bishop on December 01, 2019, 02:24:19 PM
Actually, gravimeters are seismometers. They are not measuring gravity directly, but vibrations from "gravity waves" and "infra-gravity waves".
No, plenty of gravimeters measure the rate of free fall acceleration, i.e. gravity.

False. Write an article, paper, or make a YouTube video to contradict the content in the TFES Wiki link.

No he was right.

https://en.m.wikipedia.org/wiki/Gravimeter

They were mentioned on the discovery channel or history channel years and years ago.

Umm...  The TFES wiki article quotes directly form that page.

Quote
Many broadband, three axis, seismometers in common use are sensitive enough to track the sun and moon. When operated to report acceleration, they are useful gravimeters. Because they have three axes, it is possible to solve for their position and orientation, by either tracking the arrival time and pattern of seismic waves from earthquakes, or by referencing them to the sun and moon tidal gravity.

Recently, the SGs, and broadband three axis seismometers operated in gravimeter mode, have begun to detect and characterize the small gravity signals from earthquakes. These signals arrive at the gravimeter at the speed of light, so have the potential to improve earthquake early warning methods. There is some activity to design purpose-built gravimeters of sufficient sensitivity and bandwidth to detect these prompt gravity signals from earthquakes. Not just the magnitude 7+ events, but also the smaller, much more frequent, events.

Seismometers have a gravimeter mode. How is that possible? It's because the devices are the same.

The TFES.org wiki article contains several quotes from PhD's who describe that gravimeters are seismometers.

You have provided nothing except for a failure to read and address the content material.

If the devices are the same why is a "mode" needed?

Gravimeters are low frequency seismometers with infinity long period response. Read: https://wiki.tfes.org/Gravimetry
Title: Re: Gravity and the equivalence principle
Post by: Stash on December 01, 2019, 02:35:44 PM
Actually, gravimeters are seismometers. They are not measuring gravity directly, but vibrations from "gravity waves" and "infra-gravity waves".
No, plenty of gravimeters measure the rate of free fall acceleration, i.e. gravity.

False. Write an article, paper, or make a YouTube video to contradict the content in the TFES Wiki link.

No he was right.

https://en.m.wikipedia.org/wiki/Gravimeter

They were mentioned on the discovery channel or history channel years and years ago.

Umm...  The TFES wiki article quotes directly form that page.

Quote
Many broadband, three axis, seismometers in common use are sensitive enough to track the sun and moon. When operated to report acceleration, they are useful gravimeters. Because they have three axes, it is possible to solve for their position and orientation, by either tracking the arrival time and pattern of seismic waves from earthquakes, or by referencing them to the sun and moon tidal gravity.

Recently, the SGs, and broadband three axis seismometers operated in gravimeter mode, have begun to detect and characterize the small gravity signals from earthquakes. These signals arrive at the gravimeter at the speed of light, so have the potential to improve earthquake early warning methods. There is some activity to design purpose-built gravimeters of sufficient sensitivity and bandwidth to detect these prompt gravity signals from earthquakes. Not just the magnitude 7+ events, but also the smaller, much more frequent, events.

Seismometers have a gravimeter mode. How is that possible? It's because the devices are the same.

The TFES.org wiki article contains several quotes from PhD's who describe that gravimeters are seismometers.

You have provided nothing except for a failure to read and address the content material.

If the devices are the same why is a "mode" needed?

Gravimeters are low frequency seismometers with infinity long period response. Read: https://wiki.tfes.org/Gravimetry

I did read the wiki. Conversely, perhaps seismometers are high frequency Gravimeters with very short period response.

If one were to really say that Gravimeters & Seismometers are measuring the same thing, then a "mode" wouldn't be required. There's nothing in the wiki that says that Gravimeters don't measure gravitation.
Title: Re: Gravity and the equivalence principle
Post by: JackBlack on December 01, 2019, 02:43:29 PM
Gravimeters are low frequency seismometers with infinity long period response.
i.e. the 2 devices can function in similar ways were seismography relies upon changing measurements while gravimeter does not.
i.e. the observed acceleration of gravimeters is gravity, not seismography.

Again, do you actually understand what these devices are?
Title: Re: Gravity and the equivalence principle
Post by: Tom Bishop on December 01, 2019, 02:58:59 PM
I did read the wiki. Conversely, perhaps seismometers are high frequency Gravimeters with very short period response.

If one were to really say that Gravimeters & Seismometers are measuring the same thing, then a "mode" wouldn't be required. There's nothing in the wiki that says that Gravimeters don't measure gravitation.

Seismometers don't drop projectiles like the claims here. So how can it have a gravimeter mode?

Gravimeters look for the density variations of "gravity waves" in the subseismic band. It's nothing like the device erroneously imagined. Full gravity is not being measured directly.

The fact that the gravity anomalies are indistinguishable from the seismic zones and that gravimeters show more negative readings over the mountains and continents shows us everything we need to know.
Title: Re: Gravity and the equivalence principle
Post by: Stash on December 01, 2019, 03:23:22 PM
I did read the wiki. Conversely, perhaps seismometers are high frequency Gravimeters with very short period response.

If one were to really say that Gravimeters & Seismometers are measuring the same thing, then a "mode" wouldn't be required. There's nothing in the wiki that says that Gravimeters don't measure gravitation.

Seismometers don't drop projectiles like the claims here. So how can it have a gravimeter mode?

Gravimeters look for the density variations of "gravity waves" in the subseismic band. It's nothing like the device erroneously imagined. Full gravity is not being measured directly.

The fact that the gravity anomalies are indistinguishable from the seismic zones and that gravimeters show more negative readings over the mountains and continents shows us everything we need to know.

How are gravity anomalies indistinguishable from the seismic zones? You have a bunch of maps in the wiki, but I would hardly say "indistinguishable". I'm afraid you would need more exacting data than just your maps to use such a term.
Title: Re: Gravity and the equivalence principle
Post by: markjo on December 01, 2019, 03:28:06 PM
Seismometers don't drop projectiles like the claims here.
No, but some gravimeters, like this one (http://www.microglacoste.com/pdf/A-10Manual.pdf), do.  I don't think that it has a seismometer mode, however.
Title: Re: Gravity and the equivalence principle
Post by: sokarul on December 01, 2019, 07:23:16 PM
Actually, gravimeters are seismometers. They are not measuring gravity directly, but vibrations from "gravity waves" and "infra-gravity waves".
No, plenty of gravimeters measure the rate of free fall acceleration, i.e. gravity.

False. Write an article, paper, or make a YouTube video to contradict the content in the TFES Wiki link.

No he was right.

https://en.m.wikipedia.org/wiki/Gravimeter

They were mentioned on the discovery channel or history channel years and years ago.

Umm...  The TFES wiki article quotes directly form that page.

Quote
Many broadband, three axis, seismometers in common use are sensitive enough to track the sun and moon. When operated to report acceleration, they are useful gravimeters. Because they have three axes, it is possible to solve for their position and orientation, by either tracking the arrival time and pattern of seismic waves from earthquakes, or by referencing them to the sun and moon tidal gravity.

Recently, the SGs, and broadband three axis seismometers operated in gravimeter mode, have begun to detect and characterize the small gravity signals from earthquakes. These signals arrive at the gravimeter at the speed of light, so have the potential to improve earthquake early warning methods. There is some activity to design purpose-built gravimeters of sufficient sensitivity and bandwidth to detect these prompt gravity signals from earthquakes. Not just the magnitude 7+ events, but also the smaller, much more frequent, events.

Seismometers have a gravimeter mode. How is that possible? It's because the devices are the same.

The TFES.org wiki article contains several quotes from PhD's who describe that gravimeters are seismometers.

You have provided nothing except for a failure to read and address the content material.

Title: Re: Gravity and the equivalence principle
Post by: rabinoz on December 01, 2019, 09:18:26 PM
Gravimeters are low frequency seismometers with infinity long period response. Read: https://wiki.tfes.org/Gravimetry
Precision absolute gravimeters are not seismometers!
Gravimeters are seismometers. Gravimeters and gravity maps are discussed here: https://wiki.tfes.org/Gravimetry
Absolute gravimeters are not seismometers but are precision absolute reading accelerometers.
Quote
Absolute gravimeters
(https://ipfs.io/ipfs/QmXoypizjW3WknFiJnKLwHCnL72vedxjQkDDP1mXWo6uco/wiki/Gravimeter.html)
Absolute gravimeters, which nowadays are made compact so they too can be used in the field, work by directly measuring the acceleration of a mass during free fall in a vacuum, when the accelerometer is rigidly attached to the ground.

The mass includes a retroreflector and terminates one arm of a Michelson interferometer. By counting and timing the interference fringes, the acceleration of the mass can be measured. A more recent development is a "rise and fall" version that tosses the mass upward and measures both upward and downward motion. This allows cancellation of some measurement errors, however "rise and fall" gravimeters are not in common use. Absolute gravimeters are used in the calibration of relative gravimeters, surveying for gravity anomalies (voids), and for establishing the vertical control network

Typical absolute gravimeter:
Quote
Scintrex A10 Portable Absolute Gravimeter (https://scintrexltd.com/product/a10-outdoor-absolute-gravimeter/)
PRODUCT DESCRIPTION

The A10 is an absolute gravimeter optimized for fast data acquisition and portability in outdoor applications. The instrument allows operation in harsh field conditions on open outdoor sites in the sun, snow, and wind.

Automated leveling, Battery operated, Temperature controlled sensor, Ideal roadside operation from a vehicle.

Performance Specifications
 Accuracy: 10µGal (Absolute) Precision: 10µGal in 10 minutes at a quiet site Operating temperature -18˚C to +38˚C continuous operation

From: A10 portable absolute gravity meter (https://scintrexltd.com/wp-content/uploads/2017/03/MgL_A10-Brochure.pdf).
This includes a description of the method of operation.
The is essentially a free-fall measurement in a vacuum chamber using a laser interferometer for precise velocity measurement.
This time read A10 portable absolute gravity meter (https://scintrexltd.com/wp-content/uploads/2017/03/MgL_A10-Brochure.pdf) and accept that the manufacturer knows far more than YOU about an absolute gravimeter!
Title: Re: Gravity and the equivalence principle
Post by: Tom Bishop on December 01, 2019, 09:21:59 PM
Absolute gravimeters are described with sources in the TFES.org wiki link, as detecting and comparing the microseisms affecting the mirror in the device to the ball in freefall that is unconnected to the earth.

The PhD's quoted to tell us how the gravimeter works know far more about it than you do.  ;)
Title: Re: Gravity and the equivalence principle
Post by: JackBlack on December 01, 2019, 09:56:04 PM
Seismometers don't drop projectiles like the claims here. So how can it have a gravimeter mode?
So you admit that gravimeters aren't just seismometers?

Gravimeters look for the density variations of "gravity waves" in the subseismic band.
Care to back that up, because it is nothing like how they actually work.
Title: Re: Gravity and the equivalence principle
Post by: markjo on December 02, 2019, 01:44:58 PM
Absolute gravimeters are described with sources in the TFES.org wiki link, as detecting and comparing the microseisms affecting the mirror in the device to the ball in freefall that is unconnected to the earth.

The PhD's quoted to tell us how the gravimeter works know far more about it than you do.  ;)
Tom, please stop citing the FE wiki as if it's an unbiased, infallible source of reliable information, especially when you're the primary author of the article that you're citing.
Title: Re: Gravity and the equivalence principle
Post by: Tom Bishop on December 02, 2019, 03:31:56 PM
Clearly, you cannot contradict it, or produce sources otherwise, and so you are attempting to whine and discredit. I authored very little of that content, markjo. The primary authors are traditional science sources, and your fe-fees can't seem to handle that science shows you to be wrong.
Title: Re: Gravity and the equivalence principle
Post by: rabinoz on December 02, 2019, 03:35:31 PM
Absolute gravimeters are described with sources in the TFES.org wiki link, as detecting and comparing the microseisms affecting the mirror in the device to the ball in freefall that is unconnected to the earth.

The PhD's quoted to tell us how the gravimeter works know far more about it than you do.  ;)
Fine because they agree and even cite that same absolute gravity meter, the Scintrex A10 Portable Absolute Gravimeter, as an example of a highly portable unit!
And the only reason that they might detect microseisms is to minimise their effects on the mirror in the device
Title: Re: Gravity and the equivalence principle
Post by: rabinoz on December 02, 2019, 03:36:55 PM
Clearly, you cannot contradict it, or produce sources otherwise, and so you are attempting to whine and discredit. I authored very little of that content, markjo. The primary authors are traditional science sources, and your fe-fees can't seem to handle that science shows you to be wrong.
Title: Re: Gravity and the equivalence principle
Post by: Tom Bishop on December 02, 2019, 03:41:00 PM
Clearly, you cannot contradict it, or produce sources otherwise, and so you are attempting to whine and discredit. I authored very little of that content, markjo. The primary authors are traditional science sources, and your fe-fees can't seem to handle that science shows you to be wrong.

You need to contradict what the scientists and researchers say in the article. They don't need to contradict what you claim or think on an internet forum.
Title: Re: Gravity and the equivalence principle
Post by: sokarul on December 02, 2019, 03:43:47 PM
Clearly, you cannot contradict it, or produce sources otherwise, and so you are attempting to whine and discredit. I authored very little of that content, markjo. The primary authors are traditional science sources, and your fe-fees can't seem to handle that science shows you to be wrong.
You changed your claim from “gravimeter” to “absolute gravimeter”.

Title: Re: Gravity and the equivalence principle
Post by: markjo on December 02, 2019, 04:33:02 PM
Clearly, you cannot contradict it, or produce sources otherwise, and so you are attempting to whine and discredit. I authored very little of that content, markjo. The primary authors are traditional science sources, and your fe-fees can't seem to handle that science shows you to be wrong.
Tom, when you cherry pick your quotes and post them in a different context, you remind me of a Weird Al interview.  Yes, they said what they said, but that doesn't mean that they support your argument.
Title: Re: Gravity and the equivalence principle
Post by: Tom Bishop on December 02, 2019, 05:13:33 PM
So you think that what was quoted does support the argument, but it might be misquoted. Interesting hypothesis. Another hypothesis is that the researchers mean what they say.
Title: Re: Gravity and the equivalence principle
Post by: rabinoz on December 02, 2019, 05:46:37 PM
So you think that what was quoted does support the argument, but it might be misquoted. Interesting hypothesis. Another hypothesis is that the researchers mean what they say.
We aren't doubting the researchers just your interpretations of what they write.
Title: Re: Gravity and the equivalence principle
Post by: Tom Bishop on December 02, 2019, 05:49:27 PM
So you think that what was quoted does support the argument, but it might be misquoted. Interesting hypothesis. Another hypothesis is that the researchers mean what they say.
We aren't doubting the researchers just your interpretations of what they write.

Yeah, it's just a coincidence that I found multiple sources and examples to back up the argument, and it's only a coincidence that multiple researchers say that gravimeters are seismometers. Weak argument. You are better off calling the researchers lackluster scientists who don't know what they are talking about, and who fell for an old science myth that caused them to write what they wrote. At least that wouldn't rely on unbelievable coincidence to maintain that your viewpoint is correct.
Title: Re: Gravity and the equivalence principle
Post by: markjo on December 02, 2019, 06:06:47 PM
So you think that what was quoted does support the argument, but it might be misquoted. Interesting hypothesis. Another hypothesis is that the researchers mean what they say.
We aren't doubting the researchers just your interpretations of what they write.

Yeah, it's just a coincidence that I found multiple sources and examples to back up the argument, and it's only a coincidence that multiple researchers say that gravimeters are seismometers.
Do any of those sources say that the earth is flat?

BTW, what's the whole point of the "gravimeters are seismometers" claim in the first place?
Title: Re: Gravity and the equivalence principle
Post by: rabinoz on December 02, 2019, 06:39:44 PM
So you think that what was quoted does support the argument, but it might be misquoted. Interesting hypothesis. Another hypothesis is that the researchers mean what they say.
We aren't doubting the researchers just your interpretations of what they write.

Yeah, it's just a coincidence that I found multiple sources and examples to back up the argument, and it's only a coincidence that multiple researchers say that gravimeters are seismometers. Weak argument. You are better off calling the researchers are college dropouts who don't know what they are talking about, and who fell for an old science myth that caused them to write what they wrote. At least that wouldn't rely on unbelievable coincidence to maintain that your viewpoint is correct.
But what I am saying is that absolute gravimeters are not seismometers. Try to debunk that.

In any case, while they are both accelerometers a seismometer must be connected firmly to the ground of bedrock if possible.
Quote
USGS: Seismometers, seismographs, seismograms - what's the difference? How do they work? (https://www.usgs.gov/faqs/seismometers-seismographs-seismograms-whats-difference-how-do-they-work?qt-news_science_products=0#qt-news_science_products)
Seismographs are instruments used to record the motion of the ground during an earthquake. They are installed in the ground throughout the world and operated as part of a seismographic network. The earliest "seismoscope" was invented by the Chinese philosopher Chang Heng in A.D. 132. This did not, however, record earthquakes; it only indicated that an earthquake was occurring. The first seismograph was developed in 1890.

A seismograph is securely mounted onto the surface of the earth so that when the earth shakes, the entire unit shakes with it EXCEPT for the mass on the spring, which has inertia and remains in the same place. As the seismograph shakes under the mass, the recording device on the mass records the relative motion between itself and the rest of the instrument, thus recording the ground motion. In reality, these mechanisms are no longer manual, but instead work by measuring electronic changes produced by the motion of the ground with respect to the mass.
You might also read: Site Selection, Preparation and Installation of Seismic Stations by Amadej Trnkoczy, Peter Bormann, Winfried Hanka, L. Gary Holcomb and Robert L. Nigbor (http://gfzpublic.gfz-potsdam.de/pubman/item/escidoc:4023:5/component/escidoc:4024/Chapter_7_rev1.pdf)
Would you care to dispute any of that?

Gravity meters, on the other hand, must be isolated from seismic events but because they of necessity have to be mounted on a stable platform they must include some type of seismic isolation.

The simplest is a super-spring arrangement but more advanced units include a seismic detector whose output can cancel any seismic effects on the gravity meter.
For example see:
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NCBI: Gravity measurements below 10−9g with a transportable absolute quantum gravimeter (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6098009/)
(https://i.postimg.cc/L4Dwn4wS/41598-2018-30608-Fig1-HTML-1.jpg)
Figure 1. (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6098009/figure/Fig1/)
A high-precision accelerometer is attached to the top of the vacuum chamber, as close as possible to the pyramidal reflector. Its signal is used to apply a real-time correction to the laser phase, in order to reject seismic noise. Two tiltmeters and a barometer are also attached to the sensor to ensure high accuracy and long-term stability of the gravity measurement.

Far from being a seismometer this Absolute Quantum Gravimeter (AQG-A01) takes steps to "in order to reject seismic noise".

Title: Re: Gravity and the equivalence principle
Post by: JackBlack on December 03, 2019, 02:01:26 AM