Author Topic: Radiation  (Read 18565 times)

Offline Luke Pemberton

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Re: Radiation
« Reply #2115 on: April 15, 2018, 03:20:58 PM »
I've studied physics a little bit? Does that count?
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Offline Zakalwe

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Re: Radiation
« Reply #2116 on: April 15, 2018, 03:51:13 PM »
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.  ::)
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Offline smartcooky

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Re: Radiation
« Reply #2117 on: April 15, 2018, 03:56:23 PM »
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...



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Offline Luke Pemberton

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Re: Radiation
« Reply #2118 on: April 15, 2018, 03:58:07 PM »
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.
Only two things are infinite, the universe and human stupidity, and I'm not sure about the former - Albert Einstein.

I can calculate the motion of heavenly bodies, but not the madness of people – Sir Isaac Newton.

A polar orbit would also bypass the SAA - Tim Finch

Offline molesworth

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Re: Radiation
« Reply #2119 on: April 15, 2018, 04:51:46 PM »
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!!  ;D  (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...
Days spent at sea are not deducted from one's allotted span - Phoenician proverb

Offline MBDK

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Re: Radiation
« Reply #2120 on: April 15, 2018, 05:35:47 PM »
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.
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Offline Luke Pemberton

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Re: Radiation
« Reply #2121 on: April 15, 2018, 05:43:12 PM »
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.
« Last Edit: April 15, 2018, 07:44:54 PM by Luke Pemberton »
Only two things are infinite, the universe and human stupidity, and I'm not sure about the former - Albert Einstein.

I can calculate the motion of heavenly bodies, but not the madness of people – Sir Isaac Newton.

A polar orbit would also bypass the SAA - Tim Finch

Offline Luke Pemberton

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Re: Radiation
« Reply #2122 on: April 15, 2018, 08:21:28 PM »
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.
« Last Edit: April 15, 2018, 08:48:03 PM by Luke Pemberton »
Only two things are infinite, the universe and human stupidity, and I'm not sure about the former - Albert Einstein.

I can calculate the motion of heavenly bodies, but not the madness of people – Sir Isaac Newton.

A polar orbit would also bypass the SAA - Tim Finch

Offline gillianren

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Re: Radiation
« Reply #2123 on: April 15, 2018, 11:05:54 PM »
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.
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Offline nomuse

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Re: Radiation
« Reply #2124 on: April 16, 2018, 10:36:23 AM »
Maybe he should post his GOATs score, too.

Offline Abaddon

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Re: Radiation
« Reply #2125 on: April 17, 2018, 04:18:12 AM »
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...
Quote
​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.

Offline Luke Pemberton

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Re: Radiation
« Reply #2126 on: April 17, 2018, 10:51:59 AM »
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.
Only two things are infinite, the universe and human stupidity, and I'm not sure about the former - Albert Einstein.

I can calculate the motion of heavenly bodies, but not the madness of people – Sir Isaac Newton.

A polar orbit would also bypass the SAA - Tim Finch

Offline Luke Pemberton

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Re: Radiation
« Reply #2127 on: April 17, 2018, 01:08:55 PM »
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 wasn't shielded.

Corrected.
Only two things are infinite, the universe and human stupidity, and I'm not sure about the former - Albert Einstein.

I can calculate the motion of heavenly bodies, but not the madness of people – Sir Isaac Newton.

A polar orbit would also bypass the SAA - Tim Finch

Offline Luke Pemberton

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Re: Radiation
« Reply #2128 on: April 17, 2018, 10:45:02 PM »
... and if to prove the point that not all SPEs are created equally and astronauts can be given warning.

Science News Reporter - Solar Storm to Hit Earth
Only two things are infinite, the universe and human stupidity, and I'm not sure about the former - Albert Einstein.

I can calculate the motion of heavenly bodies, but not the madness of people – Sir Isaac Newton.

A polar orbit would also bypass the SAA - Tim Finch

Offline molesworth

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Re: Radiation
« Reply #2129 on: April 18, 2018, 02:41:35 AM »
... and if to prove the point that not all SPEs are created equally and astronauts can be given warning.

Science News Reporter - Solar Storm to Hit Earth
To be fair, that's from a coronal hole stream, and we can see them coming round into earth-facing positions over several days.  The sudden-onset CMEs are harder to predict, although, as already noted, the particle mass can take several hours to reach Earth, giving plenty of time for astronauts to get into the most sheltered part of their vehicle.

On the bright side, if you have clear skies over the next couple of nights, there's a good chance of aurorae!
Days spent at sea are not deducted from one's allotted span - Phoenician proverb