New Mars Forums

Official discussion forum of The Mars Society and MarsNews.com

You are not logged in.

Announcement

Announcement: As a reader of NewMars forum, we have opportunities for you to assist with technical discussions in several initiatives underway. NewMars needs volunteers with appropriate education, skills, talent, motivation and generosity of spirit as a highly valued member. Write to newmarsmember * gmail.com to tell us about your ability's to help contribute to NewMars and become a registered member.

#1 2024-03-05 13:11:52

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 17,304

Magnets Magnetic Physics of

SpaceNut, we had several topics with the word "magnet" in the title, but none were devoted to the subject itself.

The need for a topic dedicated to magnetism and magnets arises from an interesting proposal by Void, to attract suitable asteroids using magnetic force.

The Earth's magnetic field reaches far into space, and it influences the behavior if ions there.  The Earth's field is strong enough to cause compass needs to move, if the pivot is free of resistance.

Thus, the idea of using a magnetic field at a distance of 100 meters (an arbitrarily chosen asteroid diameter) seems reasonable.

What is NOT clear from a conceptual vision, is what the actual strength of a magnetic field might be at 100 meters, since the strength of a magnetic field falls off at the  cube root of the distance, compared to gravity, which falls off as the square root of the distance.

This topic is available for members to build up a solid collection of references and "Real Universe" observations.

(th)

Online

#2 2024-03-05 13:12:20

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 17,304

Re: Magnets Magnetic Physics of

This post is reserved for an index to posts NewMars members may contribute over time.

(th)

Online

#3 2024-03-05 13:21:13

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 17,304

Re: Magnets Magnetic Physics of

To open this new topic, I asked Google to look for citations about magnets, magnetism and related information....

In looking through the list below, I see that some references are confused about the rate at which magnetic force falls off.

It should be possible for anyone (NewMars member or otherwise) to confirm for themselves that magnetic force falls off as the cube root of distance, rather than the square root, as is the case with gravity.

Generative AI is experimental. Learn more
Magnetic field strength decreases as the distance from the source increases. This relationship is known as the inverse cube law.

Experiment of The Month | Millersville University

For example, if the distance between a magnet and an object doubles, the magnetic field strength drops to 1/4 of what it was.
Magnetic fields are produced by magnetic dipoles, which can be permanent magnets or current-carrying loops of wire.

Here are some activities to learn about magnetic fields and distance:
Magnetic Field Strength vs. Distance
This science project from Education.com explores the relationship between magnetic field strength and distance.
Magnetic Fields and Distance
This activity from TeachEngineering includes learning objectives such as explaining how permanent magnets work and identifying the SI units of a magnetic field.
How do magnetic field lines show strength?
Formula for magnetic field strength
Ask a follow up...

Show more
Magnetic field strength decreases by distance cubed, and light intensity decreases by distance squared. Therefore, magnetic field strength decreases more rapidly with distance than does light intensity. Q5. Magnet A is twice as strong as magnet B.

Change in Magnetic Field Strength with Distance - TI Education

TI.com
https://education.ti.com › media
PDF

People also ask
How is magnetic field strength related to distance?
How do you calculate the strength of a magnet at a distance?
How does distance affect the strength of a field?
How can the strength of a magnetic field be shown?
Ask a follow up...

Feedback

Magnetic Fields and Distance - Activity

TeachEngineering
https://www.teachengineering.org › Activities
Show students the equations relating proportional magnetic field strength to distance. Explain that data are easier to analyze when in linear form, and then ...
Introduction/motivation · Procedure · Assessment

Magnetic Field Strength vs. Distance | Science project

Education.com
https://www.education.com › ... › Second Grade
How can we describe the relationship of magnetic field strength vs. distance? Kids will find out with this free science fair project idea.
Discussions and forums
Calculate magnetic field strength vs distance - Electronics & Electrical Engineering Forum

Site favicon
forum.allaboutcircuits.com
· Mar 16, 2021
What is the relationship between magnetic field strength and the distance from a pole called? - Quora

Site favicon
www.quora.com
· Feb 6, 2017 · 2 posts
What is the relationship distance between magnetic field lines and their strength? - Quora
Site favicon
www.quora.com
· Jan 8, 2018 · 1 post

Magnetic field strength dependent on distance from source

Physics Forums
https://www.physicsforums.com › ... › Electromagnetism

Aug 17, 2011 — The strength of a magnetic field is inversely proportional to the distance from the source. This means that as the distance increases, the ...
Relation Between the Magnetic Field Strength and Distance
8 posts

Oct 5, 2013
Measuring change of magnetic field strengh over distance
9 posts

Nov 10, 2023
Magnetic field strength at a distance - Physics Forums
15 posts

Mar 7, 2018
Calculating how magnetic field strength decreases with ...
5 posts
May 18, 2014
More results from www.physicsforums.com

What is the relationship between magnetic field strength ...

Quora
https://www.quora.com › What-is-the-relationship-betw...
Feb 6, 2017 — Magnetic field lines are used to show information about the strength and orientation of the magnetism. To show where the magnet is strongest ...
2 answers

·

4 votes:
It's called the inverse square law. Field strength is the inverse of the square ...

Determine How Magnetic Field Varies With Distance

Instructables
https://www.instructables.com › Workshop › Science
This Instructabler describes how to make a scientific investigation to determine how magnetic field varies with distance. Two methods are presented ...
Step 1: Some Background... · Step 4: There Is No Simple... · Step 5: The Best Experiment...
Questions & answers

Quora
Question
What is the relationship between magnetic field strength and the distance from a pole called?

Answer · 4 votes

It's called the inverse square law. Field strength is the inverse of the square of the distance. Edit: This is likely the expected answer for 8th grade general science. But technically, a single magnetic pole doesn't exist in isolation. The magnetic field of a particle is unlike an electric field. The latter is a point-symmetric source; the former is more like a vector indicating the north direction while its negation indicates the south direction. North and south are not two distinct or separable points. The inverse square law is actually incorrect for magnetism. (Also the primary colors of paint are not red, blue and yellow, as anyone with a color printer should know.)

More
Study.com
Question
What happens to magnetic field strength as distance increases?

Answer · 0 votes
As the distance between an object and a magnet increases, the strength of the magnetic field decreases. Think of this by looking at a simple flash light that is pointed on an object. Although you may be able to see the object if you are close by, the object can become difficult to see if the distance between the object and light is increased. The magnetic field's strength is said to follow a similar law close to Coulomb's law, where the distance or radius is inverse and squared. If the distance is halved, the force increased by four. However, if the distance is doubled, the force will decrease to a fourth of the value. That is why simple magnets need to be closer to one another in order to attract better.
More
Brainly.co
Question
HELPP !! 50 POINTS How does distance affect the strength of the magnetic force?
Answer · 1 vote
Answer: Explanation: Depending on how far away the magnets are, will determine the strength of the magnetic force.

More
Study.com
Question
What is the range of a magnetic field's strength?
Answer · 0 votes
Technically speaking there is no limit to the range of a magnetic field. Practically speaking however the field strength drops by the inverse square of the distance from the source. This means that if the distance between a magnet and the object in question doubles the magnetic field strength drops to 1/4 of what it was. It is a subjective decision by an observer or limited by the lower detection limit of measurement equipment as to when the field strength is negligible.

More
Brainly.co
Question
What does the distance between magnetic field lines indicate
Answer · 5 votes

Answer: A magnetic field surrounds any electric charge in motion. ... The distance between the lines indicates relative strength of the magnetic field. The closer the lines are, the stronger the magnetic field is. Iron filings and a compass may be used to trace the shape, strength, and direction of magnetic field lines. Explanation:
More
Stack Exchange
Question
Can a magnetic field be focused at a distance?
Answer · 2 votes

Probably not. Here's a simple argument. First, Gauss' law implies the magnetic field lines are closed. Thus the concentration of field lines would look something like the image below. However, then we could pick a closed rectangle-like loop as in the image, but with curved edges (in the image, the edges are straight). The edges would be chosen so that the first, HI, is always along a field line in the dense region, IJ is always perpendicular to magnetic field, JK, is always in opposite direction to the field in the non-dense region and KH is again perpendicular to magnetic field. However applying Ampere's law implies that the average magnetic field along HI should be the same or weaker than that of JK (the field is curved "outside", as implied by localization, which makes JK in practice shorter than HI), which is a contradiction. Note that for electromagnetic waves my derivation is not valid, as Ampere's circuital law actually depends on the time-derivative of electric flux through H…

More
Stack Exchange
Question
Why is the magnetic field proportional to distance?
Answer · 5 votes

Because there are no magnetic charges the simplest system that can generate a magnetic field is a dipole. The field from a dipole (magnetic or electric) falls off as 1/r3 rather than 1/r2 so the field strength falls off more rapidly with distance than the electric field from a point charge. Increasing the current or the number of turns will certainly increase the strength of the magnetic field from a solenoid, but you're still stuck with the 1/r3 dependance on distance. You might be interested in this article that describes one way of channeling a magnetic field over (relatively) large distances.
More
Quizlet
Question
Does the magnetic field strength decrease more rapidly with distance closer to the wire or farther from the wire? Explain.
Answer · 0 votes

Much like gravity, the magnetic force obeys the inverse square law with distance. Which means, it responds exponentially to the distance in between. $$ F \propto \dfrac{1}{r^{2}}$$ Where $F$ is the magnetic force and $r$ is the distance in between. The graph also indicates how the magnetic field strength plummets as the distance from the wire increases. For example, at distance $0\text{ cm}$, the magnetic strength is $20\, \mu\text{T}$, and at a distance of $10\text{ cm}$, the magnetic field strength is $2\, \mu\text{T}$. Hence, the magnetic field strength decreases more rapidly with distance farther from the wire. The magnetic field strength decreases with distance farther from the wire.
More
Generation Genius
Question
How can you increase the strength of the magnetic force on an object like a paper clip?
Answer · 0 votes
Magnetic forces get stronger as the magnet moves closer to the object it is attracting or
More
Answers
Question
What happens to the strength of the magnetic field as you move away from a magnet?
Answer · 0 votes
When you increase the distance the force is decreased, and when you decrease the distance you increase the force.
More
Feedback

Magnetic field strength and distance: collect your own data

YouTube · Dr Richard Walding
4K+ views · 2 years ago

30:21
... students to make it in the lab. The experiment is filmed in a way to allow viewers to collect their own data. It shows the reading on an ...

How does distance affect the strength of a magnetic field?

PocketLab
https://archive.thepocketlab.com › educators › lesson › h...
Jun 1, 2017 — This lesson specifically looks at how the strength of magnetic forces acting at a distance can change when the distance changes. This lesson ...

Magnetic Fields and Magnetic Field Lines | Physics
Lumen Learning

https://courses.lumenlearning.com › chapter › 22-3-mag...
The pictorial representation of magnetic field lines is very useful in visualizing the strength and direction of the magnetic field.
Learning Objective · Making Connections: Concept... · Section Summary

Education about magnetic field showing strength with distance pdf
Education about magnetic field showing strength with distance answers
Education about magnetic field showing strength with distance essay
magnetic field vs distance equation
magnetic field strength vs distance experiment
magnetic field strength formula
how does magnetic field strength vary with distance
magnetic force vs distance calculator

Magnetic Fields Varying as an Inverse Cube

Millersville University
https://www.millersville.edu › physics › experiments
For electric dipoles, the field strength decreases more rapidly with distance; as R -3 . Magnetic monopoles have never been observed. Instead, the basic ...

Action-at-a-distance and magnetic fields | IOPSpark

IOPSpark
https://spark.iop.org › action-distance-and-magnetic-fiel...
The space around a magnet where the magnetic force acts is called the magnetic field (just as the space around a mass where the gravitational force acts is ...

How Does Magnetic Field Vary With Distance? : 5 Steps

Instructables
https://www.instructables.com › Workshop › Science
It is often assumed that the strength of a magnetic field also obeys the inverse square law. Researching the Internet produces many complex equations, some ...

Magnetic forces (video) - Khan Academy

Khan Academy
https://www.khanacademy.org › science › ms-physics

3:21
The strength of a magnetic force depends on the strength of the magnets and the distance between them. Stronger magnets can even levitate trains! Understanding ...
Khan Academy · Aug 21, 2022

The Magnetic Field due to a Current in a Straight Wire

Nagwa
https://www.nagwa.com › explainers
The strength of a magnetic field, B , some distance d away from a straight wire carrying a current, I , can be found using the equation B = ? I 2 ? d , ...

Measuring Magnetic Fields | Science Project

Science Buddies
https://www.sciencebuddies.org › electricity-electronics
The strength of the magnetic field diminishes (lessens) with increasing distance from the magnet. Drawing of the magnetic field lines and directions of a bar ...

20.1 Magnetic Fields, Field Lines, and Force - Physics

OpenStax
https://openstax.org › books › physics › pages › 20-1-...
Mar 26, 2020 — As with electric fields, the pictorial representation of magnetic field lines is very useful for visualizing the strength and direction of the ...

Setup for Magnetic Field Strength vs. Distance Lab ... - YouTube

YouTube · Siebert Science
1.8K+ views · 2 years ago

6:12
In this video, I show the setup for a lab experiment to determine the relationship between magnetic field strength and distance from the ...

10 key moments
in this video

Determining the Magnitude of the Magnetic Field Some ...

Study.com
https://study.com › skill › learn › determining-the-mag...
Learn how to determine the magnitude of the magnetic field some distance from a straight current carrying wire and see examples that walk through sample ...
Images

earth's magnetic

straight wire

field lines

air gap

carrying wire

current carrying

neodymium magnet

bar magnet

iron filings

magnetic forces

geomagnetic field
Magnetic Fields and Distance - Activity - TeachEngineering

Teach Engineering
How Does Magnetic Field Vary With Distance? : 5 Steps ...

Instructables
Calculated and measured values of magnetic field strength ...

ResearchGate
Feedback
6 more images
Sponsored
Learn Physics For Free | Learn Physics Online

Brilliant.org

Magnetic Fields Produced by Currents: Ampere's Law
Lumen Learning

https://courses.lumenlearning.com › chapter › 22-9-mag...
Find the current in a long straight wire that would produce a magnetic field twice the strength of the Earth's at a distance of 5.0 cm from the wire.
Missing: education | Show results with: education

Strength of a magnetic field at various distances ... - YouTube

YouTube · Dr Richard Walding
1.5K+ views · 2 years ago

36:55
In this video I give some ideas about how to get this experiment to work. It is very tricky. The magnetic field about a wire diminishes ...


The Science of Magnetic Field Lines

ThoughtCo
https://www.thoughtco.com › magnetic-field-lines-4172...
Dec 2, 2019 — The distance between the lines indicates relative strength of the magnetic field. The closer the lines are, the stronger the magnetic field is.
Missing: education | Show results with: education

How the strength and direction of the magnetic field are ...

bitWise Academy
https://bitwiseacademy.com › Blog › Electromagnetism
The direction of the magnetic field is tangent to the field line at any point in space. · The strength of the field is proportional to the closeness of the lines ...

12.2 Magnetic Field Due to a Thin Straight Wire

UCF Pressbooks
https://pressbooks.online.ucf.edu › chapter › magnetic-f...
by SJ Ling · 2016 — Since the field decreases with distance from the wire, the spacing of the field lines must increase correspondingly with distance. The direction of this ...

Magnet strength and action at a distance | IOPSpark

IOPSpark
https://spark.iop.org › magnet-strength-and-action-dista...
This is a simple exploration of the reduction of the magnetic force with distance. ... Ask the children to use a magnet to pick up a paper clip. Then see how many ...

Strength of a Magnet at Various Distances - Physics

Art of Smart
https://artofsmart.com.au › QCE Learning pages
In this post, we conduct an experiment to investigate the strength of a magnet at various distances. This syllabus dot point is a part of the QCE Physics ...
Rating: 4.8 ·  496 votes

Magnetic Field | Overview & Ferromagnetic Materials

Study.com
https://study.com › ... › CLEP Natural Sciences Prep
The spacing of the field lines is related to the strength of the magnetic field. Field Line Magnetic Field. Each one of the lines is called a field line, and it ...

Surface Fields 101

K&J Magnetics
https://www.kjmagnetics.com › blog › p=surface-fields-...
... magnets often show some relatively low values for their Surface Field. How can ... The Magnetic Field strength at that distance is 599 Gauss. Now, look at a ...

How Is The Strength Of A Magnet Measured

First4Magnets
https://www.first4magnets.com › tech-centre-i61 › how-i...
The magnetism falls instantly to a much lower level and this value depends on the ratio between the surface area and its relative magnetic length. Magnets with ...

Magnetic Field - Definition, History, Illustration, Intensity ...

BYJU'S
https://byjus.com › Physics › Electricity And Magnetism
Ampere's law describes this. According to the law, the equation gives the magnetic field at a distance r from a long current-carrying conductor I.

3 Ways to Determine the Strength of Magnets

wikiHow
https://www.wikihow.com › ... › Electromagnetism
From either of the poles, magnetic field strength drops off by the square of the distance from the magnetic pole. Therefore, if the distance is doubled, the ...

Magnet
CK-12
https://flexbooks.ck12.org › lesson › magnets-ms-ps
Oct 15, 2019 — The pattern of the iron filings shows the lines of force that make up the magnetic field of the magnet. The concentration of iron filings near ...

Magnetic field

Wikipedia
https://en.wikipedia.org › wiki › Magnetic_field
In the magnetic pole model, the elementary magnetic dipole m is formed by two opposite magnetic poles of pole strength qm separated by a small distance vector d ...
Missing: education | Show results with: education

Electric & Magnetic Fields Video For Kids - Generation Genius

Generation Genius
https://www.generationgenius.com › videolessons › elec...

14:04
If two magnets are made of the same material, then the larger magnet will have a stronger magnetic field. The strength of a magnet also depends ...
Generation Genius · Aug 1, 2020

The graph showing the variation of the magnetic field strength ...

YouTube · Doubtnut
90+ views · 1 year ago

4:17
The graph showing the variation of the magnetic field strength (B) with distance (r) from a long current carrying conductor is ... Teaching, SSC ...

Electric & Magnetic Fields

National Institute of Environmental Health Sciences (.gov)
https://www.niehs.nih.gov › health › topics › agents › emf
While some of these studies showed a possible link between EMF field strength ... strength of a magnetic field decreases dramatically with increasing distance ...

Show the Direction of Magnetic Field Lines | Science project

Education.com
https://www.education.com › ... › Second Grade
Magnetic fields are invisible. You can't see them, but you can see what they do, like attract a paper clip or push another magnet away.

What is the relationship distance between magnetic field ...

Quora
https://www.quora.com › What-is-the-relationship-dista...
Jan 8, 2018 — It's called the inverse square law. Field strength is the inverse of the square of the distance. Edit: This is likely the expected answer for ...
1 answer

·

0 votes:
I think you’re giving magnetic field lines (or flux lines, as they’re also called) more ...

Electric and Magnetic Fields from Power Lines

U.S. Environmental Protection Agency (.gov)
https://www.epa.gov › radtown › electric-and-magnetic...
Sep 27, 2023 — As current moves through a power line, it creates a magnetic field called an electromagnetic field. The strength of the EMF is proportional to ...

Magnetic Field Strength Lab Introduction - YouTube

YouTube · Debbink Physics
510+ views · 3 years ago

9:09
This video is an introduction to a lab which investigates how the magnetic field strength around a current carrying wire is related to the ...

(th)

Online

#4 2024-03-05 13:23:35

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 17,304

Re: Magnets Magnetic Physics of

This is an invitation for anyone (NewMars member or otherwise) to help to answer the question:

Can a magnet pull a suitable asteroid towards the magnet with sufficient strength to reach the outer edge of the asteroid, if the diameter is given as 100 meters?

If so, how strong must the magnet be to achieve the desired effect?

What practical considerations apply in this situation?

A corollary question is: If such a magnet is moved into the center of a rubble pile asteroid, can it pull the entire asteroid toward itself, and thus provide a way to pull on the entire asteroid, if the asteroid presents a risk to Earth or Mars?

(th)

Online

#5 2024-03-05 20:08:39

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 28,958

Re: Magnets Magnetic Physics of

The article you are starting with fore fusion is a super conductor and these fall into ceramic or glass which is insulative and the power going through the conductor makes a field. The fields could be DC is similar to a permanent magnet where an AC is fluctuating and is quite different too in that flipping field has the frequency of the cycle.

Offline

#6 2024-03-05 20:59:42

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 17,304

Re: Magnets Magnetic Physics of

For SpaceNut re #5

Thanks for noting the fusion magnet is using superconducting material to increase the magnetic field strength.

I'm not sure you've had time to read Void's idea, so i'll try to quickly summarize what I understand about it.

From what I can gather, Void is thinking about a powerful magnet capable of pulling an entire asteroid.  To my knowledge (admittedly limited) no one has previously considered such an idea. Once again, Void is far ahead of the rest of us.

Can you answer the question posted in #4?  For simplicity, assume you are working with a standard metal washer that is made of magnetic material (ie, soft iron). The washer has a mass of one gram, and it is 40 meters away from the powerful magnet. How strong would the magnet need to be to exert a force of one gram on the magnet?

It is entirely possible you have the background to handle this question.  The answer would be given in Teslas, so you can round to the nearest Tesla. 

Bing/CoPilot found an asteroid that would meet Void's criteria... it is 2007 UN12.  That asteroid is 40 meters in diameter, so it is a good candidate for Void's idea.

(th)

Online

#7 2024-03-05 21:02:18

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 17,304

Re: Magnets Magnetic Physics of

The following is from a conversation with CoPilot/Bing on Windows 10 using Edge ...

Copilot
You’re welcome. I understand that you are looking for a free flying asteroid that has magnetic materials and is less than 100 meters in diameter. Based on my web search, I found one possible candidate for your experiment. It is an asteroid that belongs to the M-type, which means it has a metallic composition. It is also less than 100 meters in diameter, as you requested. ?
The name of this asteroid is 2007 UN12. It was discovered in 2007 by the Catalina Sky Survey. It has an orbital period of about 1.3 years and a minimum orbit intersection distance with Earth of about 0.02 AU. It has an estimated diameter of about 40 meters and a high albedo of about 0.4. It is also classified as a potentially hazardous asteroid, which means it has a chance of colliding with Earth in the future. You can read more about it here: 2007 UN12 - Wikipedia.
I hope this helps you with your experiment. Please note that I cannot guarantee the accuracy or completeness of this information, as it is based on web sources that may be outdated or unreliable. You may want to do further research on this or other asteroids before proceeding with your experiment. ?

(th)

Online

#8 2024-03-06 10:31:25

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 17,304

Re: Magnets Magnetic Physics of

The following table was prepared by ChatGPT4 to show how magnetic field strength falls off with distance:

Magnetic Field Strength at Distances up to 40 Meters

We've calculated the magnetic field strength at each meter from the magnet, starting with an initial strength of 1 Tesla at the magnet's pole. Here's how the field strength decreases over distance, following the inverse cube law:

  • 1m - 1.000 Tesla

  • 2m - 0.125 Tesla

  • 3m - 0.037 Tesla

  • 4m - 0.0156 Tesla

  • 5m - 0.008 Tesla

  • 6m - 0.00463 Tesla

  • 7m - 0.00292 Tesla

  • 8m - 0.00195 Tesla

  • 9m - 0.00137 Tesla

  • 10m - 0.001 Tesla

  • 11m - 0.000751 Tesla

  • 12m - 0.000579 Tesla

  • 13m - 0.000455 Tesla

  • 14m - 0.000364 Tesla

  • 15m - 0.000296 Tesla

  • 16m - 0.000244 Tesla

  • 17m - 0.000204 Tesla

  • 18m - 0.000171 Tesla

  • 19m - 0.000146 Tesla

  • 20m - 0.000125 Tesla

  • 21m - 0.000108 Tesla

  • 22m - 0.000094 Tesla

  • 23m - 0.000082 Tesla

  • 24m - 0.000072 Tesla

  • 25m - 0.000064 Tesla

  • 26m - 0.000057 Tesla

  • 27m - 0.000051 Tesla

  • 28m - 0.000046 Tesla

  • 29m - 0.000041 Tesla

  • 30m - 0.000037 Tesla

  • 31m - 0.000034 Tesla

  • 32m - 0.000031 Tesla

  • 33m - 0.000028 Tesla

  • 34m - 0.000025 Tesla

  • 35m - 0.000023 Tesla

  • 36m - 0.000021 Tesla

  • 37m - 0.000020 Tesla

  • 38m - 0.000018 Tesla

  • 39m - 0.000017 Tesla

  • 40m - 0.000016 Tesla

Conclusion at 40 Meters:
At a distance of 40 meters, the magnetic field strength diminishes to 1.5625 x 10^-5 Tesla. Given this extremely weak magnetic field, the force exerted on a 1-gram washer made of highly magnetically susceptible material (like Electrolytic Iron) would be too weak to be measured. This illustrates the challenges in utilizing magnetic fields over large distances for practical applications, especially when attempting to exert forces on small objects.

(th)

Online

#9 2024-03-06 15:08:44

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 17,304

Re: Magnets Magnetic Physics of

As a follow up to the work done earlier today, to explore Void's idea of using magnetic force to assist with asteroid mining, I asked ChatGPT4 to try to explain what a Tesla of magnetic force might be.  Here is a first try at an answer:

Understanding the Tesla: A Summary by ChatGPT

In our exploration of magnetic fields, particularly focusing on what constitutes a Tesla (T) and its practical implications, we've compared several scenarios where magnetic fields of this magnitude play a crucial role. Here's a summary to provide a clearer understanding of the significance of a Tesla:

  • MRI Machines: These medical imaging devices typically operate with magnetic fields ranging from 1.5 to 3 Teslas. Some specialized systems can reach up to 7 Teslas or more, showcasing the substantial effect Tesla-level fields have at the atomic and molecular scales for diagnostic purposes.

  • Laboratory Magnets: High-field lab magnets can achieve fields upwards of 10 to 45 Teslas in short pulses, used in material science, physics, and chemistry research to investigate material properties under extreme magnetic conditions.

  • Particle Accelerators: Superconducting magnets in facilities like the Large Hadron Collider (LHC) generally operate around 7-8 Teslas. These magnets are essential for manipulating and focusing high-energy particle beams for groundbreaking scientific research.

  • Neodymium Magnets: Among the strongest permanent magnets commercially available, neodymium magnets can exceed 1 Tesla at their surface. Their use spans a wide range of applications, from motors in electric vehicles to personal electronics.

Contextualizing the Tesla in Asteroid Mining:
While a 1 Tesla magnetic field is potent, especially in controlled environments or at close range, its influence diminishes quickly with distance due to the inverse cube law. This presents challenges in applications like asteroid mining, where distance and material properties significantly impact the feasibility and effectiveness of magnetic manipulation.

This summary, prepared by ChatGPT, aims to demystify the concept of a Tesla and illustrate its importance across various technological and scientific applications. Understanding these principles helps bridge the gap between theoretical physics and practical, real-world applications, illuminating the challenges and possibilities inherent in working with magnetic forces.

Feel free to ask for further clarification or exploration on this topic or any other areas of interest.

(th)

Online

#10 2024-03-06 16:33:19

Calliban
Member
From: Northern England, UK
Registered: 2019-08-18
Posts: 3,449

Re: Magnets Magnetic Physics of

A strong field isn't strictly necessary, as the gravity field you are working against is extremely weak.  But the ability to switch the field on and off is valuable, as you must otherwise mechanically remove material from the magnet.  Using electromagnets, it is possible to pump ferromagnetic material.


"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."

Offline

#11 2024-03-07 13:08:12

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 17,304

Re: Magnets Magnetic Physics of

Noting post #10 by Calliban ...

The post below is  follow up regarding strengths of various magnets ...
https://www.coolmagnetman.com/magflux.htm

Experiments with magnets and our surroundings

How strong are magnets?

Typical Values

Here is a list of how strong some magnetic fields can be:

    Smallest value in a magnetically shielded room    10^-14 Tesla      10^-10 Gauss
    Interstellar space    10^-10 Tesla      10^-6 Gauss
    Earth's magnetic field    0.00005 Tesla      0.5 Gauss
    Small bar magnet    0.01 Tesla      100 Gauss
    Within a sunspot    0.15 Tesla      1500 Gauss
    Small NIB magnet    0.2 Tesla      2000 Gauss
=>>> I found a 1 Tesla 10,000 Gauss bar magnet for sale on Amazon <<<=
    Big electromagnet    1.5 Tesla      15,000 Gauss
    Strong lab magnet    10 Tesla      100,000 Gauss
    Surface of neutron star    100,000,000 Tesla      10^12 Gauss
    Magstar    100,000,000,000 Tesla      10^15 Gauss
What is a Tesla?  It is a unit of magnetic flux density.  It is also equivalent to these other units:
    1 Weber per square meter
    10,000 Gauss (10 kilogauss)
    10,000 magnetic field lines per square centimeter
    65,000 magnetic field lines per square inch.

Now, 1Gauss is about 6.5 magnetic field lines per square inch.

If you place the tip of your index finger to the tip of your thumb, enclosing approximately 1 square inch, four magnetic field lines would pass through that hole due to the earth's magnetic field!

Measuring the strength of magnets

1.    Hall-Effect Devices

(th)

Online

#12 2024-03-07 13:24:30

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 17,304

Re: Magnets Magnetic Physics of

For Calliban re #10

There are many gravity fields in play in a rubble pile asteroid ...

First of all, there is the Sun, which I expect is superior to all others.

Second, all the major planets are in play, to varying degrees based upon mass and distance.

Third, every individual mass within the rubble pile has it's own gravity.

The challenge is to find a magnetic field that is strong enough to reach through the entire asteroid with strength greater than the inertia/momentum of the particles. We have seen (thanks to Void's original inspiration) that magnetic force falls off as the Inverse Cube of distance, while the force of gravity falls off as the Inverse Square of distance.  Thus, even a 1 Tesla magnet has negligible (immeasurable) strength just a few meters from the pole.  It is for that reason I am doubtful of the ability of a magnetic field humans could produce to move an entire asteroid.

In other words, I am pretty sure that even a 1 Testla magnet would have no effect on asteroid material a short distance away from the magnet.

An example for our readers might be the experiment often performed with bar magnets and iron filings.  A bar magnet dipped into a pile of iron filings will attract a number of filings, but the number attracted is limited by the strength of the magnet.  The Inverse Cube Law is at work. After some distance, the magnetic force is insufficient to overcome the pull of Earth's gravity on the iron filings.

I believe that the same effect would be apparent on one of Void's iron rich asteroids.  An experimenter might dip an electromagnet into the material and apply a current.  Magnetic susceptible material would jump to the magnet, which could then be withdrawn so that the collection could be delivered to a bag or other container for shipment to a processing center.  The reach of such a magnet would be limited by the Inverse Cube Law, but it might be sufficient to facilitate efficient harvesting of a suitable asteroid.

Such a magnet could NOT move the entire asteroid.

We appear to have come full circle.  Void reminded me today that his original idea had to do with asteroid mining, and we seem to have found a way to accomplish that.

(th)

Online

#13 2024-03-07 18:40:18

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 28,958

Offline

#14 2024-03-09 10:04:57

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 17,304

Re: Magnets Magnetic Physics of

For SpaceNut re #13

Thank you for the interesting link. It appears to be a link to an entire topic devoted to the challenge of creating a magnetosphere.

This post is an in-depth study of the Earth's magnetic field, with the goal of obtaining a reasonable estimate for it's strength.

Estimating the Earth's Core Magnetic Field Strength

This report, prepared by ChatGPT, presents a theoretical calculation to estimate the Earth's magnetic field strength at its core, using the observed magnetic field strength at the Earth's surface and applying the Inverse Cube Law.

Background

The Earth's magnetic field is a complex and dynamic phenomenon, essential for navigation, animal migration, and protecting the planet from cosmic radiation. While direct measurements of the magnetic field strength at the Earth's core are not possible due to the inaccessible depths involved, we can use mathematical laws and surface observations to make educated estimates.

Observations and Calculations
  • Observed Surface Magnetic Field Strength: The strongest magnetic field strength recorded at the Earth's surface is approximately 67 nanoteslas (nT).

  • Radius of the Earth: 6371 kilometers (km), which is equivalent to 6.371 x 10^6 meters.

Methodology

Using the Inverse Cube Law, we sought to estimate the magnetic field strength at the Earth's core based on the known surface strength. The Inverse Cube Law allows for the calculation of the field strength at a different point if the distance and initial field strength are known.

Calculation Steps

1. Apply the Inverse Cube Law: B_core = B_surface x (r_Earth)^3, where B_surface is the magnetic field strength at the surface, and r_Earth is the radius of the Earth.
2. Calculate the Estimated Core Magnetic Field Strength: With B_surface = 67 nT and r_Earth = 6.371 x 10^6 meters, the estimated core magnetic field strength was calculated to be approximately 1.73 x 10^13 Tesla.
3. Validate the Calculation: Using the estimated core magnetic field strength, we then applied the Inverse Cube Law in reverse to estimate the surface magnetic field strength from the core, which resulted in a calculated value of 67 nT, matching the observed surface value.

Conclusion

This theoretical exercise demonstrated that applying the Inverse Cube Law to the observed surface magnetic field strength yields an estimated core strength that, when recalculated for the surface, matches the original observation. This approach offers a fascinating insight into how mathematical models can be used to infer conditions in inaccessible parts of the Earth's system, despite the simplified nature of the calculation and the complex reality of the Earth's magnetic field generation process.

Report Prepared by ChatGPT

I have no way of knowing if further checking by NewMars members will verify or falsify the field strength estimate above, but I'm offering this as a starting point for further work. It should be possible to validate the number by adding more actual observations to the computation. For example, it appears that readings may have been taken from orbit, and since those would be actual readings, they can be used as observational data along side the actual physical readings taken all over the planet at the surface.

The greatest value measured anywhere on the surface appears to be 67 nT at one of the magnetic poles.

(th)

Online

#15 2024-03-09 20:22:05

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 17,304

Re: Magnets Magnetic Physics of

In an effort to better understand the Earth's magnetic field, I consulted with ChatGPT4 and with Gemini and the consensus seems to be that an ESA site is the best place to look for readings of magnetic field strength in orbit around the Earth.

https://earth.esa.int/eogateway/missions/swarm/data

A swarm of three satellites has been in operation for 10 years, collecting vast amounts of data, and apparently all of that data has be archived in easy-to-access form. I was only looking for two pieces of data so am overwhelmed by ten years of readings from the entire orbital space around the planet.

That said, if there is anyone in the forum readership who is interested, the web site at the link above invites you (or anyone) to visit.

(th)

Online

#16 2024-03-10 09:48:17

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 28,958

Re: Magnets Magnetic Physics of

Earth has natural magnetic materials of a variety of elements that rely on domain alignment which can be changed after heating the material, and as it cools alongside of a material of different orientation means we can change the alignments. This is what happens with the modern CD that we enjoy storing data on.

magnet.jpg

Why are rare earth elements so rare?


Of course earth also contains convection cause fields and so much more that is part of the internal structure of the earth its self.
Most are aware of all of the forms derived from a power source whether its DC,AC of IF/RF in nature of the formed field.

Recently I found that we have another form in https://en.wikipedia.org/wiki/Antimagnetic_watch
Introducing the ‘antimagnet’

Offline

#17 2024-03-23 11:33:36

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 28,958

Offline

Board footer

Powered by FluxBB