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General Discussion => New Physics for Space Technology => Topic started by: Bandito8888 on 04/28/2019 08:28 am

Title: Question about the reaction force
Post by: Bandito8888 on 04/28/2019 08:28 am
I tried to discuss my idea on the foum, but the topic was closed too soon:
https://forum.nasaspaceflight.com/index.php?topic=48041.0 (https://forum.nasaspaceflight.com/index.php?topic=48041.0)

I only would like to find out, where is the reaction force in this theory:
Quote
"Imagine 2 enormous electromagnets spaced a few light-minutes apart. Initially, electricity flows in them and attracts. After destroying one of them, the second one will still be attracted for a few minutes. If the distance between them is smaller, then this force will last shorter."
Title: Re: Question about the reaction force
Post by: meberbs on 04/28/2019 05:23 pm
The answer for basically any situation like this is electromagnetic radiation.

When you turn on electromagnets, this results in electromagnetic radiation that communicates the change in state of the currents. As the fields reach each magnet, this causes the magnets to accelerate and therefore emit more radiation. Turning off one of the magnets (destroy is unnecessary for an electromagnet) causes another jump in the fields. While both magnets were accelerating equally, the momentum stored in the electromagnetic fields cancelled out. once 1 magnet is off, the EM fields emitted are no longer symmetric, and when added up over all space will cancel out the (extremely small) force on the one magnet until the fields indicating that the other magnet was turnd off catch up, and then it will stop accelerating and therefore stop emitting the balancing radiation.

If you want the details on how to do this math, a general proof of conservation of momentum can be found in any good electrodynamics textbook, but the full math gets a bit complicated.
Title: Re: Question about the reaction force
Post by: elektryx tech on 04/28/2019 05:42 pm
If you put your magnets several light minutes apart you will get very little force here, to get any force on this you need to get into near field radiation effects between the magnets. In the near field, I believe you will get inductive coupling between the circuits used to generate the magnetic field. So instead of getting a force, more energy will be required in the circuit to set the field up the initial fields. Probably the best you can do is get photon level momentum out of this.

I had the same idea and am currently investigating. See topic below....

Here is another topic dealing with the same concept, but also including electric field:
https://forum.nasaspaceflight.com/index.php?topic=36911.0 (https://forum.nasaspaceflight.com/index.php?topic=36911.0)
Title: Re: Question about the reaction force
Post by: elektryx tech on 04/28/2019 06:21 pm
If you want the details on how to do this math, a general proof of conservation of momentum can be found in any good electrodynamics textbook, but the full math gets a bit complicated.

Actually the math isn't that complicated, if you take Einstein's formula (E^2 = momentum^2 * C^2 + m^2*c^4) and solve for momentum you get:
momentum = √(E²/c²-m²×c²)

This should be the maximum momentum you can get out of any electromagnetic system.
Title: Re: Question about the reaction force
Post by: Bandito8888 on 04/28/2019 06:28 pm
The answer for basically any situation like this is electromagnetic radiation.

We are in: "Forum Section for space technology concepts that rely on non-conventional physics - such as EM Drive."

In conventional physics everything is known, just as you write.

In "non-conventional physics" we can assume that there may be unknown physical phenomena – similar to EM Drive - (I don’t know  does it work  or not - I have not seen any evidence for or against).
Therefore, it's good to do an experiment too
Title: Re: Question about the reaction force
Post by: meberbs on 04/28/2019 06:34 pm
If you want the details on how to do this math, a general proof of conservation of momentum can be found in any good electrodynamics textbook, but the full math gets a bit complicated.

Actually the math isn't that complicated, if you take Einstein's formula (E^2 = momentum^2 * C^2 + m^2*c^4) and solve for momentum you get:
momentum = sqrt( E^2 / c^2 -  m^2*c^2)

This should be the maximum momentum you can get out of any electromagnetic system.
I was referring to the math for showing the conservation of momentum result in electrodynamics using the fields, where you can show that the net force on all charges inside a volume is equal to the rate that momentum leaves the volume through the fields plus the rate of change in net momentum stored in the fields inside the volume. This involves a fair bit of multivariable calculus. The energy and momentum law in special relativity that you provided is built into electrodynamics, but seeing that from Maxwell's equations is not obvious.
Title: Re: Question about the reaction force
Post by: meberbs on 04/28/2019 06:39 pm
The answer for basically any situation like this is electromagnetic radiation.

We are in: "Forum Section for space technology concepts that rely on non-conventional physics - such as EM Drive."

In conventional physics everything is known, just as you write.

In "non-conventional physics" we can assume that there may be unknown physical phenomena – similar to EM Drive - (I don’t know  does it works  or not - I have not seen any evidence for or against).
The evidence against is every experiment that has confirmed every aspect of standard electrodynamics. You have proposed no new law to support your claim. The forces you are talking about are all standard electromagnetic forces, and standard electromagnetism says that momentum is perfectly conserved, with momentum stored in electrodynamic fields filling in in cases that look at first glance like conservation laws would break down if you ignore the momentum in the fields.
Title: Re: Question about the reaction force
Post by: JohnFornaro on 04/30/2019 01:15 pm
In "non-conventional physics" we can assume that there may be unknown physical phenomena – similar to EM Drive - (I don’t know  does it work  or not - I have not seen any evidence for or against).
Therefore, it's good to do an experiment too

Build a device.
Title: Re: Question about the reaction force
Post by: Bandito8888 on 04/30/2019 05:39 pm
My idea is over 10 years old. I haven't built the device yet, so it's unlikely that I will do it. I don't have enough practical knowledge and resources. Maybe someone will like this idea and will want to try it.
Title: Re: Question about the reaction force
Post by: meberbs on 04/30/2019 06:10 pm
My idea is over 10 years old. I haven't built the device yet, so it's unlikely that I will do it. I don't have enough practical knowledge and resources. Maybe someone will like this idea and will want to try it.
For that to happen you will have to describe something more specific. So far you have not described anything different from standard electrodynamics, or any conditions where standard electrodynamics would not hold, so exactly what conditions are you proposing that someone tests?

It is well known what force can be achieved from a photon rocket, so new measurements of that don't help anything.
Title: Re: Question about the reaction force
Post by: ChrisWilson68 on 04/30/2019 06:11 pm
My idea is over 10 years old. I haven't built the device yet, so it's unlikely that I will do it. I don't have enough practical knowledge and resources. Maybe someone will like this idea and will want to try it.

This thread has run its course.

The poster's idea is entirely based on conventional physics.  It is not new.  It is just the well-known small propulsive effect of emitting photons.

When that was pointed out, the poster claimed that maybe new physics could somehow make the idea a good one.  But new physics has nothing to do with the reasoning given for the idea.  It makes no sense at all to claim "new physics".

The original poster clearly has no intention of listening to anything that says his idea isn't useful, and is ignoring even the most basic, obvious logic.

The original poster has convinced nobody of anything, and nobody has convinced the original poster of anything.

Please lets lock this thread and all move on.
Title: Re: Question about the reaction force
Post by: Lar on 04/30/2019 06:12 pm
My idea is over 10 years old. I haven't built the device yet, so it's unlikely that I will do it. I don't have enough practical knowledge and resources. Maybe someone will like this idea and will want to try it.
I think you need someone who actually thinks it will work. Not seeing any of those.

Because building devices to prove that physics works the way we think it does and disprove your theory aren't nearly as fun.

Thread locked.