On 3/8/2017 9:44 PM, Yousuf Khan wrote:
On 3/8/2017 12:51 PM, S Ergio wrote:
thanks for the info,

that dude should have provided the numbers to back himself up, back of
the envelope should do.

I'm sure he has, this is just a popular science article which summarizes
his proposal, and gives you an idea about what some scientists have come
up with. It's up to you to go see his original proposal paper, if you
want more details.

so how much is the field 655,000 miles away from a one T source ?

Actually the magnetic field strength drops away by a factor of inverse
cubed not inverse squared.

so it is far weaker than d^(-2),
for a rough order of magnitude, compair 1 mile out vs 655,000 miles out
1/(655000)^3 = 3.56 * 10^(-18)

so if the source could generate a 1 T field a mile away, then 655,000
miles away the field is 3.56 E-18, so the generator has no field on Mars.



But it really doesn't matter how strong the
magnetic field is at the surface of Mars, just so long as it's ahead of
Mars and it produces a large enough bow shock pattern, similar to how
the bow shock pattern is produced ahead of Earth, diverting the solar
wind away from Earth.

but the L1 is not in the path of Sun to Mars, where particles go. It is
at L1 way out of the way, 60 degrees off.
diagram here;
http://www.spaceacademy.net.au/libra...s/lagrangp.htm


how much fuel on board with the sattilite need to compensate for pushing
particals around?

Don't know, perhaps they'll find a clever way to use the magnetic field
itself as a propulsion tool to keep it stable in the L1?

nothing to push aginst. one has to eject mass.


Gamma rays are not deflected and come in at full strength to the ground,
on earth the atmosphere protects us from 95% of them. so how much gamma
can a crew take ? a year or two ?

The magnetic field doesn't protect against any kind of EM radiation, no
matter what. All it protects against is the solar winds. This in turn
creates a shield of the upper atmosphere to protect against the high
energy photons from penetrating into the lower atmosphere.

No such shield on Mars, need a lot of atmosphere, on earth yes, [that is
why we are able to live on the surface of earth, atmosphere blocks most
gammas]


Fortunately, gamma rays are usually an uncommon type of photons in the
universe, as most of the gamma rays occur inside the cores of stars
during nuclear fusion, and they all get diffused into lower energy
photons by the time they exit the star's photosphere. Most sources of
raw gamma rays are things such as supernovas and quasars, and those are
very directional in their nature. Another advantage is that these
sources of gamma rays are also pretty distant.

the sun emits gamma, and being distant does not make them weaker,

I havent found gamma ray radiation levels in space yet, there is a lot
of data NASA has already but they make it very hard to find;

"Measuring Space Radiation Between the Earth
and Mars
As the Mars Odyssey spacecraft made its way to Mars between
April and October 2001, the Mars radiation environment
experiment (MARIE) measured the amounts and kinds of space
radiation the spacecraft encountered along the way. These data
are essential to understanding how much and what kinds of
radiation future space travelers might encounter on a long trip
to explore the red planet.
Now in orbit around Mars, MARIE continues to measure the
amount of harmful radiation at the planet itself. Unlike Earth,
Mars does not have a global magnetic field to shield it from
solar flares and cosmic rays. Mars’ atmosphere is also less
than one percent as thick as the Earth’s. These two factors
make Mars very vulnerable to space radiation.
Aboard the International Space Station and in our own solar
system, NASA researchers continue to quantify the amounts
of space radiation our explorers face every day and will face
in the future. Understanding space radiation will not only protect
the crew currently aboard the International Space Station, but
those first humans who will continue the exploration of our
solar system."


and again, to cosmic rays, at what angle can they be deflected from
orgional their path, using a magnetic field, is it only 1 or 2 degrees ?

Earth's magnetic field doesn't stop cosmic rays either, they tend to hit
the Earth relatively unopposed.

they get changed, typically they smash into the atmosphere and cause
partical showers, into thousands of less energetic particals, and hit
the surface as a disk shape a few hundred meters across and about 1 or 2
meters thick.

Again fortunately due to the fact that
cosmic rays are high energy particles produced by supernovas and active
galactic nuclei, they are relatively rare.

sun makes a lot of them for local use, sun spots etc

Most of the cosmic rays are
diverted by the Sun's magnetic field rather than any single planet's
(though Jupiter's might be strong enough to divert some too).

"diverted" only means the ray's path was changed, not that the partical
went away.
and the ray travels so fast a local magnetic field has little time to
affect change


Most cosmic rays are travelling at relativistic speeds, so no puny
magnetic field short of a magnetar is going to do much to divert any
cosmic rays. We used to use cosmic ray showers in the atmosphere to
detect new particles, prior to the advent of supercolliders.

yep. with a PMT, some plastic, and Oscope you can detect them coming
in. (all bought off ebay)

so there are some questionable points that NASA guy's idea still has.
I think he moved it from the surface, because the path would not be long
enough to effect change, and moving to L1 is good for stability of
orbit, but not for diverting particals in path from sun, then the loss
infield strength...