Fusion

maverickmathematics

Hey,

I remember watching a program (Horizon - UK) on an indian scientist who claimed to have caused cold fusion in a lab.

The program tried to recreate it (the procedures were not actually the same - but some big name scientists advised them which equipment would be used), and failed.

I was wondering, what was the scientists name? I know its a long shot you will know but I am curious!

regards,

M

Spin_Network

Hi, Ive the video somewhere, but I found this from bbc wbsite:The experiment was carried out by Seth Putterman, one of the world's leading practitioners of sonoluminescence.

Link here for your inquiry:http://www.bbc.co.uk/sn/tvradio/prog..._summary.shtml

maverickmathematics

Cheers!

Can i just ask - did you get really excited/laughing a lot when they said - and tonight we are going to perform cold fusion etc?!

On the one hand I knew it was too good to be true, on the other, I was very excited!

-M

Spin_Network

The defination of 'Hot-Fusion' is pretty ill-defined, I have no doubt that Cold-fusion is likewise, I mean, one can class the bringing together of two buttered slices of bread, as a form of 'Cold-Fusion' process

maverickmathematics

I just reckoned it must be wrong because otherwise my salivating mathematics professor would be extatic as he loves the idea of fusion!

Morbius

Spin_Network,

I don't believe "Hot-Fusion" is ill-defined at all.

Hot Fusion is when the temperature is high enough so that the nuclei can
overcome the Coulomb barrier.

You know what nuclei you are trying to fuse - and their charge - so you
can calculate the height of the Coulomb barrier - i.e. the repulsion of
the like-charged nuclei.

Then determine the temperature needed for a reasonable number of
nuclei to be able to scale the barrier energy.

Dr. Gregory Greenman
Physicist

maverickmathematics

And I'm guessing - as a mathematician that cold fusion is when the temperature is too cold for the nuclei to overcome the Coulomb barrier?

-M

Morbius

maverickmathematics,

Well - we'd all like to see nuclear fusion.

The problem is that, as of yet; there seems to be no way around the
Coulomb barrier - the mutual repulsion of the like-charged nuclei.

In order for the nuclei to overcome that barrier - they have to have
enough kinetic energy to get over it - and that means their are hot.

Dr. Gregory Greenman
Physicist

Morbius

Maverick,

You got it.

The "Cold Fusion" claims of Ponds and Fleischman were at room temperature.

Dr. Gregory Greenman
Physicist

maverickmathematics

The problem is - as I understand it - you cannot get the atoms to touch because of electrostatic repulsion (I think thats the term for charges repelling each other.

The solution would be somehow to get them close enough together. Now, in my limited knowledge of physics I think I have a plan. Heat the particles up - very hot - as hot as they need to be. And then switch on a huge magnet, I mean big which has a -ve charge.

The +ve particles (nuclei) will be attracted to the -ve charge and will hopefully collide, producing energy, and causing other reactions as they increase the overall kinetic energy of the nuclei.

Alternatively, create a black hole - as the black hole is a point in space, and has infinite mass, the atoms must be touching each other - of course getting the energy out of the black hole, and indeed containing it...may not be easy!

-M

sid_galt

I thought of nearly exactly the same thing.

The problem is due to nuclear scattering and a Coulomb scattering, the no. of particles fused will be a fraction of the ones colliding. You're going to lose more than half of the energy used in colliding the particles and you'll only get a little bit of energy back.

z-component

I was always under the impression that the term "cold" in cold fusion meant that the fusion was under a controlled setting and having nothing to do with the temperature.

russ_watters

No, P&F's "fusion" was called "cold" because it supposedly occurred near room temperature. Instead heat and pressure, the fusion was said to occur by disolving hydrogen in a metal matrix. The higher the concentration, the more "pressure" via chemical forces (magnetism). If the "pressure" gets high enough, the hydrogen nuclei are forced together and they fuse.

There are, of course, some severe problems with that logic... ie, the coulomb barrier Morbius cited is much higher than the force that can be generated by dissolving hydrogen in a metal.

Morbius

Russ,

Exactly!

A little calculation will show that the pressure needed would blow the
Palladium to smithereens - no way does Palladium, nor any other material,
have anywhere near the strength needed.

Dr. Gregory Greenman
Physicist

Morbius

maverickmathematics,

If you get the nuclei hot enough - you don't need the magnet.

Additionally, a magnet doesn't have a charge. Magnetic fields form
closed loops. A bar magnet has positive and negative poles - but the
field is a closed loop that runs from positive pole, through the air to
the negative pole, and back through the magnet to the positive pole.

Courtesy of NASA's Marshall Space Flight Center:

http://liftoff.msfc.nasa.gov/academy...mag_field.html


Contrary to popular belief, charged particles are not "drawn" toward
the poles of magnetic fields. First, the charged particle has to be
moving, and the strength of the force is proportional to the strength
of the magnetic field, the velocity of the charged particle, and the
sine of the angle between the velocity of the particle and the direction
of the field. [ The force on a motionless particle is zero, and the force
on a particle travelling in the same direction as the field is also zero
because the sine of the angle is zero. ] The direction of the force is
mutually perpendicular to the magnetic field direction, and the velocity
of the particle.

Consider how the Earth's magnetic field protects us from charged
particles from space. The Earth is a big magnet with field lines emerging
from the North Pole, wrapping around the planet, and coming back in
at the South Pole.

The field lines that are over your head are parallel to the ground [ roughly].
Therefore, if a charged particle is heading downwards at right angles
to the magnetic field - then the force will be maximal. The direction
will be sideways. So downward moving charged particles from the Sun
and the rest of space are deflected.

If a charged particle is moving in the same direction as the magnetic
field - then the force will be ZERO! At the poles, the magnetic field
lines are approximately vertical. If a charged particle is travelling
in a downward direction at the poles; it is moving in the same direction
as the field lines - so it will not be deflected.

Therefore, there is an influx of charged particles at the poles. These
charged particles interact with the air to produce the Aurora Borealis,
or "northern lights" effect. It's also why your radiation dose is higher
if you fly a polar route from the USA to Europe in an airliner.

Dr. Gregory Greenman
Physicist

russ_watters

The thing about P&F is that they were, iirc, electrochemists, not physicists. Still, you'd think they'd be able to make that little calculation and realize something was amis. I'm not a physicist either, but it seems like its something that should have been a basic "reality check" calculation prior to even starting the experiment.

Art

Cold fusion is still a 'hot' research topic

http://www.wired.com/wired/archive/6.11/coldfusion.html

It's an unpopular topic amongst some physicists because it contravenes existing theories but there there have been some inexplicable results including the production of helium nuclei and other particles which you would expect to find in a fusion reaction. The link above is a very good investigation of the work currently being undertaken.