I was watching that masterpiece, War of the Worlds, on cable the other day and it got me thinking. The aliens were unstoppable because of their invincible shields. The humans in Independence Day faced the same problem. Fortunately, Jeff Goldbloom was able to hack into the aliens mainframe with his mac laptop and upload a virus to disable the shields.

But if not for the alien compatible mac, we'd have been screwed. Anyway, a "shield" would certainly confer a tremendous advantage to whoever developed it first. Imagine American helicopters, humvees, and aircraft carriers all protected by shields. The 'insurgents' could set off all the ied's they wanted to, no problem. Helicopters could provide close support with no risk. On the opposite ends or the spectrum, perhaps whole cities could be protected from incoming nukes, or individual soldiers could wear shields.

Is any of this possible by physics as we now understand it?

I suppose you could generate a magnetically contained plasma that would vaporize anything that touched it.

not very practice though =]

the short answer is: no

Is any of this possible by physics as we now understand it?
Billions of dollars of DARPA funds say "probably not". Force fields are all around us, but the kind of planar/spheroid concentrate fields off of which things and energy beams bounce, are not possible given current physics. You are essentially talking about a "wall" of atomic force without the atoms.

You are essentially talking about a "wall" of atomic force without the atoms.
but then, what is it that keeps me from falling through the floor? practicality is a concern because we do not yet have a good enough powerplant.

You could have an active shield like Reagan's star wars that fired a beam back at an incoming target. If this beam were focused at some distance from the generation point, it could be scanned rapidly around to create a barrier of sorts.

The Ionosphere (http://en.wikipedia.org/wiki/Ionosphere) count towards anything?

Not exciting enough, obviously.

Might it be possible to so construct a magnetic field which could catch and redirect large caliber bullets? Likely not, yes?

Might it be possible to so construct a magnetic field which could catch and redirect large caliber bullets? Likely not, yes?
Possible? - Yes.
Practical? - No.

Well, research into protection against futuristic energy weapons is well under way. All that's missing is the futuristic energy weapons to protect against. :rolleyes:

http://www.space.com/businesstechnology/technology/cold_plasma_000724.html

"This Star Wars stuff is coming," said Igor Alexeff. "Laser and high-power microwave weapons are on the way; theyre almost here. Lasers are fierce weapons. To protect against them, youd need a very dense plasma, almost a solid. But a good cold plasma could really help out by reflecting or absorbing energy from a microwave-powered war weapon."

I am pretty sure that eventually a force shield can be produced. We might actually refer to it as something entirely different because it's not like force is the primary method of detering an object. Most likely it can be done, if you are able to think it then everything should be possible. Considering this ideas been around since science fiction was invented I don't think it's a ridiculious notion something similar can be produced.

I might try a few methods for designing one. You could create a ship that is circular an has points located accross it's surface which would act like motion sensors, then if an objects motion were detected a high plasmatic thingie could be forced from all areas of the ship to a single location, thus creating an impact.

You could also try using heat around the vessel at a distance to dissolve incoming matter, perhaps a Sun Ship could be developed that would mimic the suns corona.

In the final logic if gravity can be bent so that an object occupies a bubble of space-time then anything impacting it will be impossible. Then all we'd need were some pretty colors to make it look like a shield, lol

You are essentially talking about a "wall" of atomic force without the atoms.

Why get rid of the atoms? A solid object is always going to be more reliable and effective than a poor imitation of one made from generated fields.

Let's start with what is possible. What is the safest place on Earth? ...a nuclear bunker. Is is possible to make a mobile nuclear bunker? Is it possible to shrink it to the size of an aircraft carrier? ...a tank? ...a humvee? ...a helicopter? You could surround these things with 20 feet of reinforced concrete, but they would be difficult to move. It's only a matter of energy. Still, a force field would require alot of energy, too.

Maybe more of a control field. If you could control a magnetic field to the point where you could move and condense say "iron" at will- then you could move in a cloud of "iron" particles and then condense them in front of an incoming weapon.

One SF story suggested a shield made by generating particles ( I forget which ones) that when focused together would increase the interatomic bonding of the aoms, thus effectively making a wall of strongly bound atoms.
It was a Peter F Hamilton story, perhaps "the nanoflower"

One SF story suggested a shield made by generating particles ( I forget which ones) that when focused together would increase the interatomic bonding of the aoms, thus effectively making a wall of strongly bound atoms.
It was a Peter F Hamilton story, perhaps "the nanoflower"
In Pandora's Star he had a shield that would somehow "freeze" molecules of air. It was strong enough to withstand nuclear blasts and kinetic attacks from space.

Really good book, by the way.

Is it theoretically possible to generate a "shield"?

yes, tesla did it.

yes, tesla did it.
Do you have reliable, reproducible evidence?

yes, tesla did it.
If you start bringing tesla into it then you might as well point out Faraday.

Look into the plasma window (http://en.wikipedia.org/wiki/Plasma_window). It's a start! :P

There are three disadvantages to using such technology for defensive purposes:

1. Very large amounts of power would be needed to create a plasma dense enough to block and/or destroy weapons (read: projectiles) fired against it.

2. Such a plasma would necessarily be extremely hot and would incinerate anything in its path. Thus it wouldn't be a good idea to use it on the ground... but it would make it a weapon in itself.

3. It would not block any electromagnetic radiation. So if the shield-bearing vehicle/craft carries projectile weapons, the shield would have to be off when it fires them. Otherwise, if it uses energy weapons, the shield could stay on and the beams would pass through, but one better hope that the enemy is not using energy weapons too!

Interestingly enough, this last part could explain the shield for the Tripods in War of the Worlds, if the "heat rays" were in fact particle beams.

I was watching that masterpiece, War of the Worlds, on cable the other day and it got me thinking. The aliens were unstoppable because of their invincible shields. The humans in Independence Day faced the same problem. Fortunately, Jeff Goldbloom was able to hack into the aliens mainframe with his mac laptop and upload a virus to disable the shields.


sorry to nitpick but I think you saw Independence Day with Goldbloom & Smith. War of the Worlds was with Tom Cruise. They also had sheilds btw :)

You could combine a high-powered lazer unit that could surround your body. Look into tesla. Why couldn't you assemble a devise consisting of multiple poles that shoot electrons out to adjacent poles that would zap anyone entering?

Maybe we will some sort of materal in panel form that can obsorbe most of the energy if we do start using high-powered laser to kill each other. We usually manage to come up with personal body armour to suit the calibar of weapon we are fighting wars with.
Chainmail
Flack Jackets
Kevler