Could metamaterials protect you from a GRB?

[tgoolsby2]

If the Earth were to be cloaked from gamma rays using metamaterials, would it be left unaffected by a gamma ray burst?

[korjik]

Isnt this question: If the Earth were immune to gamma rays, would it be affected by gamma rays?

[Shaula]

Metamaterials are not immune to the energy the shield from. They have to absorb and re-radiate it in a very particular way to work. So it depends on the energy density. If it is high enough the cause the structure of the metamaterial to break down then after time we'd get hit by the GRB anyway as the shield stopped shielding

[tgoolsby2]

Yes, the question does seem to answer itself. I should have added additional information. I was unsure because someone doing a demo on metamaterials said that if you were in a microwave cloak, you would still be able to see microwaves originating from outside the cloak. So it seems waves are entering the cloak, but at the same time they say the waves are guided by the metamaterial to go around the cloak. Which is it?

[Swift]

Metamaterials that are used for "cloaking" or other similar applications have spacings in them that are about of the order of magnitude as the wavelength of the radiation they are "bending". Microwaves have wavelengths on the order of millimeters. Gamma rays have wavelengths on the order of angstroms. Given that and their typical energies, they would blow through most metamaterials.

[trinitree88]

Gamma rays usually dissipate their energy by:
1. Compton scattering off electrons
2. matter/antimatter pair production, such as e⁺/ e^-....around 1.022 Mev
3. photoelectric effect...kicking electrons out of the atoms
4. photodissociation of nuclei...~ 10 Mev for most nuclei, or slightly higher

I agree, if the energy is high, they'd blow right through. The focusing done by Chandra is by use of grazing incidence nested cylinders with coatings that enhance the effect, so a very large conical device might attenuate a burst slightly, but only if it arrived from your expected direction. pete

[antoniseb]

If a nearby GRB aimed our way and we had some meta material that blocked gamma rays, we would still have some other issues, including:
- energy added to the environment from non-gamma photons
- radiation from absorbed neutrinos turning our environment radioactive
- heat radiated from the meta-material as it absorbs the gammas
- maybe other stuff that didn't come immediately to mind.

[neilzero]

Let me attempt to summarize. We would need several concentric metametal shields, each rather wavelength specific, just to reduce the gamma by several times. Absorbing the gamma would produce a bunch of new stuff, such as neutrinos. Some of the new stuff is dangerous, but not neutrinos, except in incredible numbers. Perhaps enough consecutive shields can increase our average life expectancy from one day to one year, but don't GRBs typically last seconds, so heat build up and shield deterioration should be small, unless our life expectancy is seconds without the shields? I'm assuming our life expectancy is seconds, if the radiation heats our average internal body temperature to 100 c = 212 f = 373 k Neil

[Swift]

Let me attempt to summarize. We would need several concentric metametal shields, each rather wavelength specific, just to reduce the gamma by several times.

There is a more fundamental problem. There is no known metamaterial for radiation of the wavelength of gamma rays. There isn't anything that will even bend UV like that. Given the processes involved, I'm not sure it is even possible.