Universal Truths

[Grall]

Not slowing of the rotation I'd think, but rather slowing of the earth's molten core, thus the diminishing of the earth's magnetic field - which if we don't want to get cooked into crispy bacon according to hollywood movies (or at least higher cancer rates back in the real world) is something we don't really want to do.

Anyhow, the earth's magnetic field is so weak I doubt any real amount of energy could be harvested out of it...

 

[jimbo75]

Bookmakers are to blame for much of the "match fixing" stuff. You can get odds on how long it will take for the first throw-in to be taken for example. Is that really match fixing if the goalkeeper "accidentally on purpose" kicks the ball out the park instead of up the field? In a fashion I suppose it is, however in reality it is very doubtful that any game will be changed because of it.

Bookies need to accept their portion of the blame here when they are giving odds on such things.

 

[KimB]

Anyhow, the earth's magnetic field is so weak I doubt any real amount of energy could be harvested out of it...

And given that you can only harvest energy from a magnetic field by moving relative to it, well, that's not an easy thing to do for the Earth's magnetic field.

 

[Ethatron]

Well, he was the "getting things done" kind of guy, he just ran out of resources and then time.

 

[Grall]

And given that you can only harvest energy from a magnetic field by moving relative to it, well, that's not an easy thing to do for the Earth's magnetic field.

Well, you could always build the mother of all induction coils on the moon........................

 

[Gubbi]

I think we're talking players from the less well known nations and various officials. The English game involved for example is allegedly Liverpool vs Debrecen - although it isn't known exactly how the money was made. There are a lot of ways to make money by betting on football matches - the actual result being only the most obvious way of doing it.

I can't imagine the players of Debrecen are paid much - it wouldn't take much to sway the result in subtle ways. Given this particular game was a dullish 1-0 home win, it's difficult to tell where the money would have been made.

Apparently the plan was to bribe the Debrecen keeper to concede goals to ensure an "over" result on the over/under 2.5 goals bet.

But Liverpool sucked so badly that they could only win 1-0 anyway and the criminals lost a lot of money

Cheers

 

[KimB]

Well, you could always build the mother of all induction coils on the moon........................

Hehe, well, as the magnetic field falls off as the cube of the distance, and as the magnetic field is incredibly weak on the Earth's surface, and the moon is some sixty times further, well...

Though the effect of such a large induction coil would be to amplify the current tidal effect that is speeding up the Moon's orbit (and pushing it further away) while slowing down the Earth's rotation, hastening the day when the Earth and the Moon always show the same face to one another.

 

[Grall]

Hehe, well, as the magnetic field falls off as the cube of the distance, and as the magnetic field is incredibly weak on the Earth's surface, and the moon is some sixty times further, well...

Sixty times further than what...? Anyway, yeah, it's a totally stupid idea of course, but probably the only real way to harvest power from the earth's magnetic field since you need to move a field/coil in relation to one another, and sending up a coil in earth orbit doesn't really seem to cut it.

On the other hand, we could send any power generated back to earth using those fancy-schmanzy wireless fourier transformed electromagnetism waves thingamajiggers you mentioned in a different post! W00t for science, eh!

 

[Blazkowicz]

Well astronauts in Low Earth Orbit have a nice EM shielding for free but beyond that, I guess you end up with cancer if you spend a too long time flying around. An underground moon base may be fine. Trip to Mars (with or without return), I think I wouldn't do that.

As for free energy, the cleverest solution I saw was taping a butter toast to a cat

 

[Grall]

Nuclear-powered rockets could take us to Mars in a not-unsafe amount of time. Of course, that would require people to stop spazzing out as soon as anything related to nuclear reactors in space is brought up before it could happen...

Underground moon bases? Yeah, bring it on! I've read The Moon is a Harsh Mistress like a dozen times since that first time way back in my early teens. Of course, we still don't really know what truly long-term exposure to microgravity will do to a human being. If we're to live on the moon all our lives at some point in the future it would be no good if say, giving birth to a baby broke every bone in their body...

 

[DuckThor Evil]

Sixty times further than what...?

Earths surface from the core.

 

[KimB]

Sixty times further than what...?

The center of the Earth, which is the effective location of the dipole as measured from far away

Anyway, it's the Sun, really, that provides the greatest possibility for broad power generation. One day, if we have the will, we may place a series of satellites in orbit with gigantic solar arrays which then beam the solar energy to power stations on the ground.

 

[Mariner]

Of course, we still don't really know what truly long-term exposure to microgravity will do to a human being. If we're to live on the moon all our lives at some point in the future it would be no good if say, giving birth to a baby broke every bone in their body...

The latest worry was damage to eyesight:

http://theweek.com/article/index/225533/does-space-travel-damage-eyesight

Our bodies really, really don't seem to like a lack of gravity.

For space travel, we just need to create the engines that can accelerate (and decelerate) at 1G for a long time - no problem with Zero or Low-G then!

The only issue is what to do when in space when not travelling anywhere. How big a wheel would a spacestation need to have to provide decent centrifugal gravity?

 

[KimB]

For space travel, we just need to create the engines that can accelerate (and decelerate) at 1G for a long time - no problem with Zero or Low-G then!

If we could actually do that, then the galaxy would be our playground, basically: such a spaceship would reach relativistic speeds rapidly enough that most any trip would be no more than a handful of years long, as far as the onboard crew was concerned.

Perhaps unsurprisingly, the energy requirements of such a vessel are so absurd that there's basically no way to do it.

Rotating ships, however, are a realistic mechanism to achieve gravity in space The main problem there is getting the material to make such a ship into orbit: such a ship needs to be pretty big, and it also needs to have quite a lot of structural integrity, which means mass to hold it together.

 

[Mariner]

The main problem there is getting the material to make such a ship into orbit: such a ship needs to be pretty big, and it also needs to have quite a lot of structural integrity, which means mass to hold it together.

Von Neumann machines to mine rocky asteroids, perhaps? For that to be practical, all we need to do is design them, power them, find suitable asteroids and find ways to return the mined/refined material back close to Earth orbit. Easy peasy!

Alternatively, a permanent moon base? There should be plenty of resources available on the moon. The only problem then is chicken-egg - will living in microgravity cause too many physical problems for the pioneers.

Thinking about it, perhaps the Japanese obssession with robots isn't so unusual after all?

 

[Davros]

Hehe, well, as the magnetic field falls off as the cube of the distance,

I thought it obeyed the inverse square law ?

 

[fellix]

The only issue is what to do when in space when not travelling anywhere. How big a wheel would a spacestation need to have to provide decent centrifugal gravity?

For 1G (Earth gravity force), a centrifuge structure with a radius of 10 meters rotating at ~10 RPM would suffice.

 

[pcchen]

For 1G (Earth gravity force), a centrifuge structure with a radius of 10 meters rotating at ~10 RPM would suffice.

Yes, but the gradient is probably not enough for everyday life (i.e. the G force would be only ~ 80% a little above a man's head). There are also problems with Coriolis effect, which may cause dizziness. A 100 meters radius craft needs only 3 RPM and probably enough for most people to overcome Coriolis effect.

 

[fellix]

Indeed, a longer radius is preferred in this case.

I wonder, at what point a hypothetic space elevator can "naturally" provide a gravity force, since the thing will track Earth's rotation anyway, and the counter-weight terminal would be situated past the geostationary orbit?

 

[KimB]

I thought it obeyed the inverse square law ?

Nope. You're thinking the electric field. The difference is that there are electric charges. There are no magnetic charges: only dipoles. And dipole fields fall off as the cube of the distance.

Here's a rather detailed description:

The falloff depends upon the structure of the field. You can decompose the structure of an electromagnetic field of any source into a monopole (a charge), a dipole (a field with a plus in one direction, and a minus in the opposite direction...like a magnetic), a quadrupole (two pluses in oppose directions, two minuses perpendicular), and more complex configurations. The effect of each component falls off increasingly-rapidly with distance. The monopole (charge) falls off as 1/r^2. The dipole falls off as 1/r^3. The quadrupole falls off as 1/r^4.

So far away from the magnetic source, no matter what the overall structure, the field will look like the least-complex structure that isn't zero. And there is no such thing as a magnetic charge, so the magnetic monopole is always identically zero, which means that unless you carefully construct the magnetic field to have no dipole, then the falloff will be as the cube of the distance (if you construct it to have no dipole, then it will fall off more rapidly).