Radiation

[molesworth]

I'll also freely admit I've never taken the ASVAB.  Why would I?

I think most of the contributors here would never have taken it either.  As a non-US citizen, I'd never heard of it before now, but tried a sample test to get an idea of the level of knowledge and ability expected.

I admit I didn't finish it, as I got bored after about 70 questions...    Overall, the questions were fairly straightforward, and of a first to second year high school level.  Maths covered basic algebra, percentages and the like, and didn't get into trigonometry or calculus (although I recall doing trig in my first couple of years at high school).  General science, reading comprehension, basic mechanics (mainly relating to vehicle mechanics) and electronics were all of a similar level.

I'm not intending to disparage anyone who volunteers for military service, and I would expect the test to be a good basis for specialisation selection amongst military recruits, but it is perhaps a bit short of what's required for calculations of radiation exposures in the space environment, or understanding the complexity of the science, engineering and sheers scale of the Apollo project.

[bknight]

I took the ASVAB or its predecessor in 1970, twice.  Once before entering the Army and then during Basic Training.  I hadn't thought again of that until this thread, wow almost 50 years ago.

[nomuse]

I took it -- was I think compulsory at the time -- and scored high, but it otherwise doesn't stand out in my memory. It's not an intelligence test (well, nothing is, not really) but a weird mashup of a vocational placement test and a recruiting pitch. As in; "The test says you'd be really great at being in the infantry. Sure you don't want to join?"

As long as we're waving them in the air like this, I got into and passed jump school and was assigned to an airborne unit. That was at the time about a one in six pass rate. That doesn't say anything about my qualifications to understand space weather, either.

[Luke Pemberton]

I've studied physics a little bit? Does that count?

[Zakalwe]

I'll also freely admit I've never taken the ASVAB.  Why would I?

I've never heard of it until now. Being Irish, living in England I guess my ignorance of it is understandable. Out of curiosity I had a look at an online practice exam. It looks similar to the general aptitude test that the Irish education system used to give to 14/15 year olds to assess their abilities to go into apprenticeships as skilled labour.

It's also a measure of timfinch's level of education that he considers it worthwhile mentioning. Also it appears to me as measure of his arrogance that he thinks that it is noteworthy enough to use as a supercilious slur. What a plonker. 

[smartcooky]

The objection of using ground based neutron monitors to correlate terrestrial detection events with the solar cycle was most revealing. Most high school students understand that GCR impact on our upper atmosphere to produce neutrons. An increase in neutrons at ground level correlates with increased GCR fluxes or an SPE. Ground based monitors are a valuable source in GCR studies. There are even details on YouTube to make a rudimentary cloud chamber to detect GCR.

And the brilliant physicist, and Science populariser Prof Brian Cox, does exactly that, and then demonstrates its use...

[Luke Pemberton]

And the brilliant physicist, and Science populariser Prof Brian Cox, does exactly that, and then demonstrates its use...

I had forgotten all about that video. Thanks for posting it.

[molesworth]

The objection of using ground based neutron monitors to correlate terrestrial detection events with the solar cycle was most revealing. Most high school students understand that GCR impact on our upper atmosphere to produce neutrons. An increase in neutrons at ground level correlates with increased GCR fluxes or an SPE. Ground based monitors are a valuable source in GCR studies. There are even details on YouTube to make a rudimentary cloud chamber to detect GCR.

And the brilliant physicist, and Science populariser Prof Brian Cox, does exactly that, and then demonstrates its use..

Another Scottish invention!!    (C.T.R.Wilson, inspired by the typically rubbish weather when working as a student at the Ben Nevis observatory.)

Very easy to make, and quite amazing to watch cosmic rays zapping through, realising they might have come from events millions of light years away...

[MBDK]

What Tim is failing (and honestly I can only believe it is deliberate now) to grasp is that when it comes to particle radiation such as CGRs, SPEs, VABs and so on, all matter will shield all of it to some degree. That's simply the physics of putting something in the way.

Precisely. A thick piece of card will be a good shield for alpha particles. A beta source is usually stored in a box constructed of aluminium and wood. Of course, the HB connects a radiation shield to lead or concrete because of everyday experiences such as visits to radiologists or their understanding of nuclear reactors. They do no understand that those materials are used to attenuate x-rays and gamma rays, and in the case of a nuclear reactor there are other reasons for having a thick concrete surrounding the reactor walls.

The claim of an unshielded CM exposes their understanding immediately, yet we need to remind Tim that he was citing the use of polythene on the ISS as a radiation shield. Of course, he now fails in his consistency when applying his 'knowledge' to the CM, which was constructed of metals and polymers.

Actually, when dealing with the Alpha particles emitted by most sources, they swill not penetrate beyond the dead layer of one's skin.  It is only the soft internal tissues, such as the lungs, where they interact with live tissue and create a concern.

[Luke Pemberton]

Actually, when dealing with the Alpha particles emitted by most sources, they swill not penetrate beyond the dead layer of one's skin.  It is only the soft internal tissues, such as the lungs, where they interact with live tissue and create a concern.

Yes, ingested alpha sources are problematic. A uranium miner is 10-20 times more likely to develop lung cancer than a heavy smoker. With a 2+ charge and their mass, it make them far more ionising than beta and gamma; so DNA comes off second best. Of course, it's no always about ionisation but a combination of ionisation and biochemical effects. Some elements tend to concentrate in the body. Iodine for example absorbs in the thyroid gland, so beta emitting iodine is problematic following nuclear waste release. I am sure you know all this though, but it's good to share ideas and knowledge.

Typically they have a range of 6 - 12 cm in air too. It would be most irresponsible to leave an alpha source on the side and clearly they need to be stored and locked away. However, a person can 'shield' themselves from an alpha source by simply keeping a good layer of air between themselves and the source. It's the same with beta particles, just a bit more air need in that case.

[Luke Pemberton]

Very easy to make, and quite amazing to watch cosmic rays zapping through, realising they might have come from events millions of light years away...

When I look at distant stars, I often explain to others that the photons striking one's retina have taken millenia to reach us; and by per chance they have entered into our pupil at that precise point in time, whereupon they have ended their existence. Had we not gone out into the garden at that point, and looked up at the sky, they would have been simply absorbed by the ground and no one would have even known they had existed.

[gillianren]

It's also a measure of timfinch's level of education that he considers it worthwhile mentioning. Also it appears to me as measure of his arrogance that he thinks that it is noteworthy enough to use as a supercilious slur. What a plonker. 

I could post my SAT scores, and they'd be just as relevant, [mumble mumble] years from having taken them.

[nomuse]

Maybe he should post his GOATs score, too.

[Abaddon]

Maybe he should post his GOATs score, too.

Well, he is already posting "scores".

He claims the badge of being banned from CQ, even though he has not been banned from CQ. He was simply suspended for violating the rules.

As presented here, this is a "score" to TF in his own mind even though it never happened at all.TF must know this, because he clearly visits while suspended and reads mod posts like this...

​Thread closed pending moderator discussion.

Edit to Add:

OP suspended for refusing to follow the rules in spite of warnings not to do so.

TimFinch,

If you wish to resume this discussion upon your return, report this post to ask that the thread be reopened.

That seems to me to be fairly clear. But somehow not to TF.

[Luke Pemberton]

That seems to me to be fairly clear. But somehow not to TF.

I'd judge his comprehension as either poor or deliberately selective given his recent evidence with NASA's 'kids counting squares' fun pack; where it was candidly pointed out that the exposure was shielded. He submitted this material at CQ. Speculating on motives is poor form on my part, but I now have my suspicions about his presence here and at CQ.

I was reading through the old Neil Baker thread last night. There are parallels with that thread and this, namely making a claim, rejection of claim and then the claimant throwing so much information in the air in the hope of something sticking. At least I felt there was an element of sympathy for Neil Baker from members, even amongst some of the bad spirited replies. This has the hallmarks of calculated mischief with the soul purpose of antagonism.