Explain to me this: radioactivity

[Wayston]

How come if you're in one hallway of a building you're good, and a couple hallways down the right you're instantly exposed to a lethal dosis of radiation? Shouldn't it be a bit more gradual?

[DigiFluid]

I would think it would depend on the construction materials of the building. Certain materials block radiation more than others.

[D Toccs]

Well we don't really know that they were ok before they found the geiger counter. Given how crazy that geiger counter was going I would think that everyone in the building and even the people outside where Telford was would all have been exposed to dangerously high amounts of radiation.
Of course that's not how it will turn out, Greer/Covel and Wray/Michaels will be the only 2 people exposed to the radiation. Just like in SG1 Meridian all the Langaran scientists die from radiation poisoning, Daniel defuses the bomb and dies a day or two later from extreme radiation poisoning yet Jonas who was about 5 feet away from Daniel goes on to live happily ever after.

[thekillman]

How come if you're in one hallway of a building you're good, and a couple hallways down the right you're instantly exposed to a lethal dosis of radiation? Shouldn't it be a bit more gradual?

actually you could be safe from lethal radiation because of a sheet of paper.

various forms of radiations have highly varying degrees of penetration. plus that the air itself could have become radioactive.

[Tajis]

How come if you're in one hallway of a building you're good, and a couple hallways down the right you're instantly exposed to a lethal dosis of radiation? Shouldn't it be a bit more gradual?

The dust could have also been contaminated. Wray complained about it, and they were inhaling a massive amount. Some forms of radiation are only dangerous if you consume contaminated substances.

[The Destiny]

actually you could be safe from lethal radiation because of a sheet of paper.

Really?

How cool is that!

[DigiFluid]

Really?

How cool is that!

Yeah it really depends. Certain types of radiation are blocked by something as simple and thin as paper, others will only be slowed down by a wall of lead. It really depends on the kind of radiation that's being....radiated.

[Rylor]

How come if you're in one hallway of a building you're good, and a couple hallways down the right you're instantly exposed to a lethal dosis of radiation? Shouldn't it be a bit more gradual?

Radiation gets weaker according to the inverse-square-law (assuming a point-shaped radiation source). So, if you double your distance the radiation dose reduces to 1/4, if you triple your distance the radiation dose reduces to 1/9, and so on. By getting a lot closer to the bomb the radiation dose could easily be several dozen times higher than what they were exposed to before.

Or it could be the contaminated dust, as Tajis mentioned. A radiation source inside the body is highly dangerous.

[thekillman]

Yeah it really depends. Certain types of radiation are blocked by something as simple and thin as paper, others will only be slowed down by a wall of lead. It really depends on the kind of radiation that's being....radiated.

and some only by a lightyear of lead

[Rylor]

and some only by a lightyear of lead

Or in the words of Jack O'Neill: "Hey! If you'd been listening, you'd know that Nintendos pass through everything."

[garhkal]

Well we don't really know that they were ok before they found the geiger counter. Given how crazy that geiger counter was going I would think that everyone in the building and even the people outside where Telford was would all have been exposed to dangerously high amounts of radiation.
Of course that's not how it will turn out, Greer/Covel and Wray/Michaels will be the only 2 people exposed to the radiation. Just like in SG1 Meridian all the Langaran scientists die from radiation poisoning, Daniel defuses the bomb and dies a day or two later from extreme radiation poisoning yet Jonas who was about 5 feet away from Daniel goes on to live happily ever after.

Cause Jonas had screening in front of him... plus some forms of radiation dwindle out quickly the further out you go.

Or it could be the contaminated dust, as Tajis mentioned. A radiation source inside the body is highly dangerous.

Being they both admitted to breathing in a lot of dust, i feel that was more of it than the radiation in the air itself.

[SG-1-AU]

How come if you're in one hallway of a building you're good, and a couple hallways down the right you're instantly exposed to a lethal dosis of radiation? Shouldn't it be a bit more gradual?

Radiation exposure is based on distance, shielding, and exposure time. Radiation dose falls by the inverse square of distance (like gravity and other forces). For instance, if you see 1 Rem at 1 meter away from the source, you will see 0.25 Rem at 2 meters from the source.

For distance, radiation does not act like radio waves, but it is more like line of sight (only some time you can get radiation to reflect off surfaces, but this is a minor effect). Therefore, as you get to be more in the line of sight with respect to materials that can shield the radiation, the radiation will spike.

Now, with all that said, I know how to read a Geiger counter and those levels WERE NOT lethal for the amount of TIME they were exposed, it was just added for dramatic effect. I also don't understand how the levels did not change all that significantly from the hallway till when you were standing right next to the device.

All in all, this episode was not very factual about radiation and as a nuclear engineer, it pisses me off to always see the public be so misinformed about radiation and dosage.

[SG-1-AU]

Yeah it really depends. Certain types of radiation are blocked by something as simple and thin as paper, others will only be slowed down by a wall of lead. It really depends on the kind of radiation that's being....radiated.

Alpha - Blocked by dead skin (or paper) (dangerous if consumed)
Beta - Blocked by all of your skin together (dangerous if consumed)
Gamma/Neutron - Pretty much go through anything. 2" of lead will reduce gamma by 90% (this is called tenthing factor). Gamma is reduced by dense materials like lead and tungsten, neutrons are reduced by materials high in hydrogen (such as water and certain types of plastics. Lead can also work).

[D Toccs]

Cause Jonas had screening in front of him... plus some forms of radiation dwindle out quickly the further out you go.

Jonas didn't have screening in front of him. Daniel shot the screen and then jumped through it. Jonas was about 5 feet away from Daniel with no screening when Daniel disarmed the bomb. Not to mention they later reveal that all the Langaran scientists who have worked on the project suffered horrible deaths from radiation poisoning and Jonas had been working on the project for yeas.

[DigiFluid]

He was further than that by at least double. Also: re-read the posts above about distance to decay ratios.