Sure, but also, these videos have easily more views than the professors has met students during his life, let alone teached. Wealth has been saved. Information has been propagated. It's not all hopeless.
UnOriginalOne just inhale one speck of radioactive dust, you may have an alpha radiator that can almost not be measured but it fires in your lungs for the rest of your life. No one considers and 1% only knows it. „Alpha is harmless“ yeah dream on.
I believe 18 people died in the rush to evacuate after Fukushima. Of course if the containment building hadn't done it's job then they would have been ingesting radioactive material and that's a very different matter, but of course we all know that. Arsenic is pretty harmless until you ingest it. People seem to believe all sorts of rubbish about radioactivity and I don't think that you can change their minds.
@@AndreasDelleske Thats like saying imagine people inhaling one speck of steel dust from a handrail, exactly how on earth do you get the handrail to turn into dust again? You are talking about a metal, and in the case of unenriched uranium an incredibly low radioactivity. Hell your body actually is capable of removing uranium from your lungs and body since it is soluble. The concern should be for children exposed to fallout since they incorporate radio-isotopes into their bones, and although radiation is slow give it 50 years.
At 19:40 ... There is another reason why you do not like to turn up the light when flying a bombing raid over Germany: it spoils your night vision. After turning on the light you know the time but can't see where you are going for a while. Very good lecture. The things you can do without computer animations!
One of the best videos on the topic! As an engineer, it always fascinated me how irrational people are about radiation. This climate of fear stifles development into actual clean and truly enviormental solutions to our global problems such as climate change.
I wonder why not more people are irrationally afraid of other clean energy solutions. Maintenance-workers in wind energy are exposed to a fatal dose of gravitation, at a rate of 1 excess death per 10 billion kWh produced. Although I don't have numbers on solar, the risk of gravitation there is probably much higher due to poor practices and safety procedures.
@@submijiru it's possible - Solar is typically installed at rooftop level, which is a lot less scary than a wind tower of say 100m, so people could be more blasé about safety
@@CED99 True. People are not even slightly worried about low level gravitation, or even believe exposure has a beneficial effect for bone health. Personally, I subscribe to the linear no-threshold model that exposure can prove lethal at any dose over enough time. Crazy to see these uninformed workers not only working without safety equipment, but jumping down 3 ft ledges or casually running around without helmets (mind you, some of these guys are over 6ft tall.) Madness!
About a week ago I saw a video of someone handling uranium ore, and people in the comments were freaking out, thinking the guy was going to kill himself with the stuff.
@Chetar Ruby Usually there is a trigger for these rare things going semi viral. In this situation it would have been either a large group of people all discussing this topic and sharing the videos with each other so they can get up to speed. Such as people within the govt discussing something or a conference (usually conference goers would have this knowledge though). Or a class / workshop linked these videos for students to look at for study, and now that its near exam times these students are all reviewing these videos. From the perspective of the algorithm large numbers of people are randomly accessing these videos, it trys to draw a correlation and finds one and then shares the videos to all people that fit the correlation. For either of these groups since they don't really share anything in common in terms of the content they consume except entertainment the algorithm effectively causes runaway feedback. This means we as viewers can guess at why people would be viewing these videos in critical mass to trigger the algorithm, I would guess an internal govt review somewhere in the world regarding nuclear power.
I am a 74D in the Army and am definitely very interested in the Nuclear & Radiological aspect of my job. Salamat kaayo for your videos regardless of it being made so long ago because they are still helpful today.
There is an error in the part of the lecture about the Radium Girls. These exposures from 'pointing' brushes in the mouth to paint watch dials happened in the 1920's, not during World War II.
I was looking for this too. Although radium painted instrument dials were a vital part of World War II night bombing (which, over Germany, was actually done by the British, while the Americans bombed in the day), by that time the lessons of the Radium Girls and the whole crazy radium era had been learned. Of course there were many lessons still to be learned, but the safety of radium dial painters was much improved.
Still way better than Radium Water, which was both a thing that actually existed and actually killed people back before anybody had any idea what radiation did.
These are some of the best videos I've ever watched on youtube. What a remarkable teacher who can take these subjects and relate them in everyday concepts.
This should be a required lecture in our public education system. Whatever science you take in high school, one day, learn about radiation dose relative risk.
Thank you for the video. Another great lesson in radiation. Teaching two things, radiation dose by knowing your subject and how to present it with confidence in a humble manner, also with a Stoic attitude, we all die, accept it.
We are not rational beings, we have trouble understanding levels of magnitude, we are afraid of things we cannot see, like radiation, whether it comes from a banana or nuclear fuel.
God i hate how radio phobic people are. Thanks for the amazing video helping contextualise radiation and thank god you continued to change the graph showing the threshold! I almost had a seizure when you drew the straight line haha
Two things I have seen in other documentaries on radiation that others may find interesting: * Apparently at least some of the Radium Girls used to paint their front teeth with Radium so they glowed in the dark, to joke around at night. People didn't know there was any danger ... so I was surprised to see such "low" cancer rates at 21:40 even at higher doses. * Saw a documentary a few years ago where they compared cancer rates for people in different background radiation areas and found that people in higher background radiation areas have a lower incidence of cancer - if true, if confirmed by other studies ... maybe people build up some kind of resistance in higher background radiation areas ?
There have been a few instances like that, but the studies really haven't been done enough. There may be some sort of repair mechanism that kicks in at the cellular level when subjected to certain types of hardships. There is also evidence that fasting, as well as some exposure to toxins or radiation could also cause this mechanism to activate. There is lots of evidence this mechanism exists, but not a lot of research into what causes it as of yet.
@@GeorgeTsiros oh almost certainly that is a source of random mutation. Hey fun fact; there are micro organisms living in chernobyl that have adapted to the radiation and even possibly use it as an energy source.
@@WadcaWymiaru That is true; it's why people occasionally just have remission and get better. The fact there is a cancer means that dozens of failsafes have failed. All it takes is for one of the mechanisms that hasn't been working yet to start working.
Well, a small minute number of them might sprain their ankle and stumble in front of a bus, so there's that ... But yes, it gets to the "half a chicken lays half an egg in half a day" joke...
@UCLxLMtTzKFe35Qh0RzM9E7A So as the full question goes, if half a chicken lays half an egg in half a day, how long does it take for a one-legged grasshopper to kick the seeds out of a dill pickle? alternatively, ... how many bagels does it take to shingle a doghouse? I would love to hear the answer.
@@WhereWhatHuh Well there are people who step off of curbs, fall and smack the sidewalk with the head and die. People die every year falling out of bed. At the other end are the occasional skydiver whose chute doesn't open and lives.
When he started writing backwards on the glass I was astounded and then I realized they just flipped the image. I don’t know why that’s not more popular it’s pretty cool.
It wasn't mentioned here, but there is also a hypothesis called "radiation hormesis" which states a LITTLE radiation is good for you. Seems strange at first, until you consider that your body needs to recognize DNA damage that can become cancerous. If you rarely get this damage, the body isn't as ready to fight it, and so may more likely get cancer. There are various studies, including some from NIH which can be googled.
7:17 Maximum dose for radiation workers is NOT uniform around the world. I don't know for other countries, but in Germany the limit is 20 mSv for Category A workers and 6 mSv for Category B workers.
112 Radium in Humans: A Review of U.S. Studies In the same publication, Rowland (in press) also examined dose-response functions for head carcinomas. As in previous studies, the linear, linear exponential, and dose-squared exponential functions all fitted the data satisfactorily. The reason lies in the scarcity of head carcinomas. With only 19 of these malignancies observed in the cohort examined, the data are insufficient to discriminate between alternate formulations. The records indicate that bone sarcomas occurred about twice as often as head carcinomas in the radium-exposed populations. The total known population had 85 bone sarcomas and 37 head carcinomas, while the total measured population had 64 bone sarcomas and 32 head carcinomas. Among the female dial workers, considered the best cohort for dose-response analyses, 46 bone sarcomas and 19 head carcinomas were observed. Because the number of head carcinomas is not sufficient to allow unequivocal determination of the best form for a dose-response function, the best predictor of their incidence at a given intake level is the predicted number of bone sarcomas at that level, divided by two. At the same international seminar in Heidelberg, Thomas (in press) presented work in which he used lognormal data analysis and the newly calculated skeletal dose values (presented in the appendix of this document) to reach the conclusion that a threshold exists for radium-induced malignancies. Thomas calculated threshold values of 390-620 cGy and suggested the adoption of a value of 1,000 cGy as the threshold for radium-induced malignancies in humans, the same value Evans (1974) had derived 20 years earlier.
19:49 and 18:49 and 18:35 Show that his videos are actually just mirrored. These 3 timestamps let you compare the placement of his watch and the pin on his jackets' lapels. In the classroom footage he is not writing on a transparent surface, and so does not need to mirror it; you can see his watch on his left arm, the pin on his left lapel, and how he talks by waving his right hand around. Then go to the main body of the video where he writes with his "left" hand, but also is wearing his watch on his "right" arm, the pin on his "right" lapel, and waves around his "left" hand while talking.
Wonderfully explained! You are so good at teaching! Question: I got 73 Grey during my Throat cancer treatment. How does that compare in Sieverts? Thanks, David.
A Gray is basically 1 Sievert absorbed by tissue. Alpha and neutron radiation are more biologically damaging than beta or gamma, plus it depends on where the radiation is absorbed. Note that the doses talked about in the video are whole body doses. Your whole body was not given 73 grays, but just the targeted area they were trying to kill/destroy. That being said, your whole body was dosed, but nowhere near to the same level (there's a reason why they will observe from behind leaded glass). I'm guessing the passed a rotating beam through the tumour to minimize the damage to the surrounding tissues?
What were those radium girls thinking? I wouldn't put a paintbrush with paint on it in my mouth even once, let alone every few minutes throughout the work day, even if the paint WASN'T radioactive.
19:49 and 18:49 and 18:35 Show that his videos are actually just mirrored. These 3 timestamps let you compare the placement of his watch and the pin on his jackets' lapels. In the classroom footage he is not writing on a transparent surface, and so does not need to mirror it; you can see his watch on his left arm, the pin on his left lapel, and how he talks by waving his right hand around. Then go to the main body of the video where he writes with his "left" hand, but also is wearing his watch on his "right" arm, the pin on his "right" lapel, and waves around his "left" hand while talking.
Denver is not at 1000 ft - it is the Mile High City after all, and it is not part of the Colorado Plateau. Most of Colorado is not on the Colorado Plateau (but large parts of Utah, Arizona, and New Mexico are!).
I'm suspecting his mentioning of the Colorado Plateau was a mix of both elevation and mineralogy, as much of the plateau has a higher than average uranium content. Agreed though about his mistake of the actual elevation of Denver.
It's obvious he knows Denver is higher than 1000 feet. No doubt he meant to say 1 mile and misspoke. We all make mistakes and not all will be caught in editing.
8:12 his actually shows that the health of workers is less worth than property/profits. Workers are allowed to get up to 10 Rem when "protecting valuable property". Using the formula at 13:54, this means an excess death rate of 0.02% per year which means that the chance of dying increases by 0.4% if you get this dose every year for 40 years. And even with normal limit of 5 Rem per year it increases by 0.2% in this case. Or maybe to put it in perpective: if there are 1 million workers who get the 10/5 Rem dose, 200/100 if them die in a year. If these rates of deaths where caused by accidents during work it would be deemed unacceptable in most "advanced" countries.
you forget the part where he talks about threshold doses. It is hard to say at what point the threshold is but it appears based on what he is saying somewhere a bit under 10 Rem. Also there are 2 other things to take into account, the first being that these excess deaths aren't instantaneous because it may take years to develop cancer in the first place, and then with treatment many more years until death. The second thing you have to take into account is the fatality rate of other types of jobs. For instance delivery drivers in the United States have a fatality rate of 270 people per million per year, and those fatalities presumably happen faster than cancer.
@@shockadinz9785 delivery drivers are a special case, because the US in general has many traffic deaths (from my understanding mainly because it is too easy to geg a driving license) and maybe also because they might get robbed or shot when going to the wrong house. It's easy for corporations to not clain responsibility for traffic accidents and murders, howevee I think that the fatality rate that is usually deemed acceptable in a factory or office is much lower. PS: Also theshold theory is nlt acceöted universally, while the guy in this video says thaz it is mlre likely correct than the linear theory I heared the opöosite by other experts. I heared lf a study about the connection between background radiation and cancer rates which seems to support the linear theory begause they found a difference when the radiation was only something line 0.2 Rem higher. They used a very high sample size.
@@rfvtgbzhn If delivery drivers seem like a special case for you, the national statistic is 42.9 people per million die working any job within the United States, including office workers and the like. That's already getting close to the 200/100 figures you are giving. As far as the threshold theory being valid or notl i'm not informed enough to argue. I believe the other points I make are strong enough without needing the threshold theory anyways.
Let me throw a question in the table sir. Let's say that we have 2 situations 1) i expose myself in 6 Sieverts but in time duration of 10 seconds. 2) i expose myself in 2 Sieverts but in time duration of 1 year. which state will have the most deadly effects?
Ibrahem is correct. Also, 6 Sieverts in 10 seconds would be so severely acute a dose that it could be instantly fatal. A better comparison for acute versus long-term would be 6 Sieverts in a day. While radiation does not exactly have a physical impact per se, one might compare falling off of a cliff to rolling down a hill. The energy of impact is distributed for a longer period of time rolling down the hill, thus there is less damage over all compared to falling off of a cliff, even though the energy absorbed is the same. By analogy, the longer the period over which the dose is received, the lower the amount of immediate damage that is done.
Enjoyable lecture. curious, what the curve of the graph would appear ( & how "linear" it might look) if the dose exposed rate figures stay same but are compressed to say, a 30 day period instead of a year. on a side note, although Radium dial painting was done thru late '60's in US, most severe dangers to the women dial painter w/licking their brushes occurred during painting watch dials in WWI. Cheers
Probably similar. Sun burns are radiation burns. A bit of sun is good, since we need it to make vitamin d out of cholesterol. But too much too quickly may cause more DNA damage than the body can repair, potentially leading to melanoma. I can have exposed skin all day in winter, but I'll burn in fifteen minutes around the summer solstice, because the dose rate is too high for me.
17:57 Like the way you address that our cells have learned to repair themselves based off of an evolutionary response to rad and other carcinogenetic material.
Don’t know how to provide a link here, but there was an amazing NPR story of a man in Japan that was exposed at both nuclear bombings during WW2. The best part was the study of cancer, inherited cancer, and genetic modification.
Excellent demonstration on radiation and its dangers (and lack of danger). Unfortunately, radiation is poorly understood in the US, and you fear what you don't know. This is not very different from the folks in Salem blaming things they couldn't understand on witches.
I have had about 12 abdominal CT scans. 2 or 3 were done with and without contrast, so a double scan. I have of course had other x rays , flouroscopy I and 1 or 2 CT of head. At age 65, should this concern me? I have kidney stones , thus the high numbers of CT and flouroscopy,. I will likely need more CT to visualise kidney stones. Am I doomed?
Are you able to update with typical mobile phone / WiFi / 5G exposure and health? Those are a lot more prevalent in daily life now (compared to nuclear radiation etc).
EMF, WiFi and 5G have been linked with health issues. Would be interested to hear an expert like this analyse each of them in more detail. To really see how big an effect they could actually have.
my worry was about fish from the north pacific ocean. Since they had radio active water from Fukushima flushed in the ocean. Would it effect the fish and us?
Different radionuclides have a different half-life. Those with shorter half life are „more radioactive“ per mol (number of atoms) so to speak, because a very much higher number of atoms will decay in the same time. Some radionuclides can be taken up by the body and used in tissues: Iodine has some radioactive isotopes (with very short half life of hours respectively days) that can end up in your thyroid gland (and lead to thyroid cancer), if you are exposed and incorporate it in the very first days, that’s why states have stocks of non radioactive iodine as tablets in case of a nuclear disaster (or war) for immediate distribution, so that the spot in the tissue is already taken / so there is many more times the „competition“ with non-radioactive iodine for the uptake. Caesium 137 (it has a half-life of 30 years) is chemically similar enough to potassium that it can end up in muscles (and nerves). Strontium 90 (half-life of 28 years) is chemically similar enough to Calcium that it can end up in bones (and lead to bone cancer). Plutonium on the other hand is extremely toxic when incorporated: very small doses will kill you, and not from radiation... (half-life of Pu 239 is more than 24000 years) I am no expert. I am a layman, and I have googled this for you. - If you are really interested, there is probably a lot of good sources out there (- I just looked stuff up on Wikipedia...). I just wanted to indicate that a nuclear incident has a bit more intricacies than just the amount of ionizing radiation you get from standing near it... (- also note that in the talk he compares timescales of two weeks with timescale of a year with one-time events (x-rays) with exposition over a few hours (on an airplane). You really need to pay attention with what exactly you take away. Certain radionuclides get concentrated in certain foods for the same reasons: Here in Bavaria (Germany) for example after the Chernobyl accident the hay had not to be used for feeding cows that year, so the strontium would not end up in the milk (I don’t remember if they had to plow it under or burn it, so it would dissipate more). But because the Caesium was accumulating in mushrooms (for biological reasons) there was advisory against eating locally grown mushrooms in certain areas even five or ten years after... - so your question about concentration in the food chain might still be valid: I don’t know anything about fish though.
To simplify what Stadtpark said: The really bad stuff in the water will decay pretty fast. So even if the fish eat it, it will affect them, but by the time they get here, it will have passed from their system or mostly decayed into more stable stuff. Stuff that has a short "half-life" is very bad for you, but disappears quickly. Stuff with a long half life will last eons, but isn't really so bad for you. Even so, a very tiny tiny part of any water flushed out of Fukushima would have any radionuclides at all, and a very very tiny part of those radionuclides would be the very bad stuff. So to my non-professional off-the-cuff SWAG, based on stuff I learned decades ago and mostly forgot, I'd say you'll have a higher radiation risk if you eat ten bananas in rapid succession.
The Earth was much more radioactive when it formed. Life had to have had reasonable repair mechanisms capable of dealing with worse radiation then at present. Hence the threshold.
The reason for that was the Solar System was close to a supernova, which injected A LOT of highly radioactive isotopes into it after the first solid matter coagulated out of the Solar nebula, but before the planets formed.
@@taraswertelecki7874 The way I would have put that is that the Solar System formed from the wreckage of several short-lived giant stars, which on their way to neutron stars and black holes had released _ALL possible atomic matter,_ some of which was radioactive, and immediately began to diminish. The more important point is that Life originated in far more radioactive conditions than the present, and radiation damage toleration was an intrinsic part of the way it came to be.
Yes, it was highly radioactive in the beginning, because a supernova both irradiated the Solar System and put a lot of radioisotopes into it, such as Aluminum-26 and Iron-60. Subsequent supernova near the Earth have added more radioactive isotopes to the Earth.
Fun Fact: In hospitals, especially ER rooms, "Organ donor" is slang for a patient who rides motorcycles, e.g. if they bring in a guy into the E.R.who crashed his motorcycle in traffic they'll say "we got the organ donor from the crash on 5th and Broadway., which operating room?...OK number 4".
Would you allow this video to be mirrored on my channel? Full credit given with links back to your channel. My channel is a collection of different authors that debunk Fukushima and radiation fear mongering.
The Radium Girls suffered from phosy jaw caused by the phosphorus in the radium dye. This disease also afflicted workers in early match stick factories. That is why modern matches are called safety matches, not because they are safe for the user, but because they are safe for the worker making them. Marie Curie discovered and worked with Radium her entire life without any protection. She died age 80 something of anemia, which is a common cause of death for elderly women of that time. Her husband and lab mate Pierre Curie was un over by a tram and died from trauma.
I love how good he writes mirrored right to left with his left hand... - I guess it is more likely they play the video mirrored though... (edit: I should have scrolled down the comments - of course someone said that before me...)
So how much of the danger of smoking cigarettes is due to inhalation of radioactive particles that were absorbed by the tobacco plants? Is it a secondary concern to the chemotoxic/cytotoxicity of all the junk in the smoke (including from the radioactive particles)? I'm not an engineer or doctor, but hopefully my question makes sense to you all. Anyone have any ideas?
I thought exactly the same thing... but now that I think about it more: 1) when bombing, you are probably flying low, 2) even when people on the ground won't see you, they are still shooting and trying hard to see you, so perhaps pilots did not want to rely on "they won't likely notice my light"
Gunners on the ground can't possibly see cockpit lights in a bomber flying at 30,000 feet. Airplane crews needed to maintain night vision at all times in order to see other planes, both friend and foe. Also, they needed to see their gauges which were barely lit, again to preserve night vision.
People in Ramsar Iran (and some other parts of the world) have high background radiation due to the rock formations in the area. In Ramsar, the dose from background radiation is up to 260 mSv y−1. That’s 13 times higher than the 20 mSv y−1 permitted for radiation workers. Yet the people have no radiation injury and seem to have fewer cancers than the general non irradiated population. This being so why are occupational exposure levels set so low?
Regarding the suggestion that data supports the threshold model rather than the linear model at the 5,000,000 * 1 mRrem/y level... Call me dubious. It's not specifically that I doubt the threshold model, but I simply don't see any way to get the kind of precision of measurement needed to back up that claim.
Exactly my doubts. Those "some out of some people develop cancer anyway" situations exactly the questionable ones. If nobody actually knows, why some people develop cancer and others not, how one can exclude them as "they are not because of radiation". No proof for either side. Might be because of more or less environmental radiation. On the other hand: there are other environmental properties in real life which are behaving threshold-like. Temperature, pressure, sound pressure level, light brightness to name everyday ones... It looks like there are safe operating areas. If you do not exceed these limits then the continuous exposure won't degrade your body at all. Might or might not be the same for radiation...
Exactly how much cosmic radiation do you get living in Denver? What is cosmic radiation even made of? I can't find any solid information about that online.
That's why most interplanetary ship designs store the water as a jacket around the ship, with other supplies as another layer. The first interplanetary voyagers aren't going to get an expansive Ten Forward view, sadly.
bone and muscle loss in zero acceleration is worst effect when traveling to mars. after year of travel suddenly goes into gravity well, its not going very well, scott kelly need help even when going outside the capsule after year experiment in ISS.
@@zapfanzapfan it would be huge, maybe the radius would be 30-40 meter @3RPM produce 0.3g at least so the crew would get confused from artificial gravity gradient from a different height. it would be a huge spacecraft and need to be assembled in space
A very nice lecture. But why use a unit for radiation that's been outdated for decades when even the XKCD chart used Sievert. Why not just stick to that?
It's criminal these lectures have so few views.
Sure, but also, these videos have easily more views than the professors has met students during his life, let alone teached. Wealth has been saved. Information has been propagated. It's not all hopeless.
Hit the thumbs up and tell the algorithm!
@@Tenebrousable it's taught, more information has been propagated. Please don't worry, your point and comment are excellent 👌
Tells you where society is, doesn't it?
Love his way of teaching. Keeps me alert and focused the entire time!
Wish more people were informed about this info.
Hysteria is much more dangerous than radiation.
UnOriginalOne just inhale one speck of radioactive dust, you may have an alpha radiator that can almost not be measured but it fires in your lungs for the rest of your life. No one considers and 1% only knows it. „Alpha is harmless“ yeah dream on.
I believe 18 people died in the rush to evacuate after Fukushima. Of course if the containment building hadn't done it's job then they would have been ingesting radioactive material and that's a very different matter, but of course we all know that. Arsenic is pretty harmless until you ingest it. People seem to believe all sorts of rubbish about radioactivity and I don't think that you can change their minds.
@@benchapple1583 Those people didn't die of radiation exposure. Many of them were elderly and had complications evacuating.
@@FutureMartian97 Oh I know. They died of panic and not their own. As soon as you say the 'N' word, everyone loses their mind.
@@AndreasDelleske Thats like saying imagine people inhaling one speck of steel dust from a handrail, exactly how on earth do you get the handrail to turn into dust again? You are talking about a metal, and in the case of unenriched uranium an incredibly low radioactivity.
Hell your body actually is capable of removing uranium from your lungs and body since it is soluble.
The concern should be for children exposed to fallout since they incorporate radio-isotopes into their bones, and although radiation is slow give it 50 years.
At 19:40 ...
There is another reason why you do not like to turn up the light when flying a bombing raid over Germany: it spoils your night vision. After turning on the light you know the time but can't see where you are going for a while.
Very good lecture. The things you can do without computer animations!
One of the best videos on the topic!
As an engineer, it always fascinated me how irrational people are about radiation.
This climate of fear stifles development into actual clean and truly enviormental solutions to our global problems such as climate change.
I wonder why not more people are irrationally afraid of other clean energy solutions.
Maintenance-workers in wind energy are exposed to a fatal dose of gravitation, at a rate of 1 excess death per 10 billion kWh produced.
Although I don't have numbers on solar, the risk of gravitation there is probably much higher due to poor practices and safety procedures.
@@submijiru it's possible - Solar is typically installed at rooftop level, which is a lot less scary than a wind tower of say 100m, so people could be more blasé about safety
@@CED99 True. People are not even slightly worried about low level gravitation, or even believe exposure has a beneficial effect for bone health. Personally, I subscribe to the linear no-threshold model that exposure can prove lethal at any dose over enough time. Crazy to see these uninformed workers not only working without safety equipment, but jumping down 3 ft ledges or casually running around without helmets (mind you, some of these guys are over 6ft tall.) Madness!
People naturally panic about dangers they can't see or understand. Education can only help the latter.
About a week ago I saw a video of someone handling uranium ore, and people in the comments were freaking out, thinking the guy was going to kill himself with the stuff.
Really appreciate these videos. the XKCD chart is such a great resource.
There's always a relevant XKCD.
"Sleeping next to somebody Why is it dangerous... well there could be lots of reason"
LOST
Lol
The real mystery is the TH-cam algorithm. These videos are all months old but nearly all the comments are days old
Somehow this lectures showed up in suggested videos around the world
@Chetar Ruby Usually there is a trigger for these rare things going semi viral. In this situation it would have been either a large group of people all discussing this topic and sharing the videos with each other so they can get up to speed. Such as people within the govt discussing something or a conference (usually conference goers would have this knowledge though).
Or a class / workshop linked these videos for students to look at for study, and now that its near exam times these students are all reviewing these videos.
From the perspective of the algorithm large numbers of people are randomly accessing these videos, it trys to draw a correlation and finds one and then shares the videos to all people that fit the correlation. For either of these groups since they don't really share anything in common in terms of the content they consume except entertainment the algorithm effectively causes runaway feedback.
This means we as viewers can guess at why people would be viewing these videos in critical mass to trigger the algorithm, I would guess an internal govt review somewhere in the world regarding nuclear power.
I'm glad of the algorithm linking these, they're both good quality and educational
CPanic , I only came here after watching one of his newer videos, so I’m playing catch-up. Probably happens like this for a lot of peeps
Sheep and Goat sorting, what else?
Watching a lectures on a Webcomic... What a time to be alive.
A web comic with a physics degree who used to work at NASA.
@@cpanic1153 what's Randall doing now? I've not read xkcd in ages?
@@CED99 Still making comics regularly. And doing book tours and talks occasionally.
I am a 74D in the Army and am definitely very interested in the Nuclear & Radiological aspect of my job.
Salamat kaayo for your videos regardless of it being made so long ago because they are still helpful today.
These lectures are so eye opening and informative. Easy to understand and comprehend information for the masses, everyone needs to learn this
There is an error in the part of the lecture about the Radium Girls. These exposures from 'pointing' brushes in the mouth to paint watch dials happened in the 1920's, not during World War II.
Mark Miller Thank you, I was looking for this.
And from painting clock and watch dials and a lot of other things. There was a fascination with radium at the time.
Olaf V. Yes, like radium tonics... what a world.
I was looking for this too. Although radium painted instrument dials were a vital part of World War II night bombing (which, over Germany, was actually done by the British, while the Americans bombed in the day), by that time the lessons of the Radium Girls and the whole crazy radium era had been learned. Of course there were many lessons still to be learned, but the safety of radium dial painters was much improved.
Still way better than Radium Water, which was both a thing that actually existed and actually killed people back before anybody had any idea what radiation did.
Incredibly enlightening. And lectured in a manner you would understand and remember for a long time. Thanks, professor Ruzic.
These are some of the best videos I've ever watched on youtube. What a remarkable teacher who can take these subjects and relate them in everyday concepts.
I'm reminded of the book "Innumeracy: Mathematical Illiteracy and Its Consequences" by John Allen Paulos.
Great book
@@Mo95793 I'm going to have to get it.
This should be a required lecture in our public education system. Whatever science you take in high school, one day, learn about radiation dose relative risk.
Thank you for the video. Another great lesson in radiation. Teaching two things, radiation dose by knowing your subject and how to present it with confidence in a humble manner, also with a Stoic attitude, we all die, accept it.
We are not rational beings, we have trouble understanding levels of magnitude, we are afraid of things we cannot see, like radiation, whether it comes from a banana or nuclear fuel.
Science...once again dispels fear while teaching respect.
God i hate how radio phobic people are. Thanks for the amazing video helping contextualise radiation and thank god you continued to change the graph showing the threshold!
I almost had a seizure when you drew the straight line haha
Fantastic teacher, very clear and concise, easy to understand..... Thank you 😊
This has been said many times but these are the best videos! Professor Energy is pretty damn cool!
Two things I have seen in other documentaries on radiation that others may find interesting:
* Apparently at least some of the Radium Girls used to paint their front teeth with Radium so they glowed in the dark, to joke around at night. People didn't know there was any danger ... so I was surprised to see such "low" cancer rates at 21:40 even at higher doses.
* Saw a documentary a few years ago where they compared cancer rates for people in different background radiation areas and found that people in higher background radiation areas have a lower incidence of cancer - if true, if confirmed by other studies ... maybe people build up some kind of resistance in higher background radiation areas ?
There have been a few instances like that, but the studies really haven't been done enough. There may be some sort of repair mechanism that kicks in at the cellular level when subjected to certain types of hardships. There is also evidence that fasting, as well as some exposure to toxins or radiation could also cause this mechanism to activate. There is lots of evidence this mechanism exists, but not a lot of research into what causes it as of yet.
@@hosmerhomeboy wouldn't be surprised if levels of background radiation is partly responsible for the process of evolution.
@@GeorgeTsiros oh almost certainly that is a source of random mutation. Hey fun fact; there are micro organisms living in chernobyl that have adapted to the radiation and even possibly use it as an energy source.
Our body has AWESOME ability to regenerate and kill the cancer...50 times per second XD
(and some senescent cells)
@@WadcaWymiaru That is true; it's why people occasionally just have remission and get better. The fact there is a cancer means that dozens of failsafes have failed. All it takes is for one of the mechanisms that hasn't been working yet to start working.
Good thing I always sleep alone
Linear no threshold be like: I'd die if I fell off a 100 foot cliff, so if 200 people step off a 6 inch curb, one of them will die too.
Well, a small minute number of them might sprain their ankle and stumble in front of a bus, so there's that ... But yes, it gets to the "half a chicken lays half an egg in half a day" joke...
@UCLxLMtTzKFe35Qh0RzM9E7A So as the full question goes, if half a chicken lays half an egg in half a day, how long does it take for a one-legged grasshopper to kick the seeds out of a dill pickle? alternatively, ... how many bagels does it take to shingle a doghouse?
I would love to hear the answer.
@@WhereWhatHuh
Well there are people who step off of curbs, fall and smack the sidewalk with the head and die.
People die every year falling out of bed.
At the other end are the occasional skydiver whose chute doesn't open and lives.
@@mpetersen6 So at what point would we opine that their venturing outside of their homes caused their deaths (or substantially increased its risk)?
Thank you for the information. You present information so very effectively.
I am highly obliged of your precious knowledge sharing
Excellent teaching sir !!!
Very logical and we'll presented. Thank you! Should be required viewing for all leaders (politicians?)
Excellent lecture.
thanks for vivid diagrams and interesting explanations with good examples !
When he started writing backwards on the glass I was astounded and then I realized they just flipped the image. I don’t know why that’s not more popular it’s pretty cool.
It took me a while to figure out he is not left handed,
Underappreciated observation.
Well done Randall Munroe!
It wasn't mentioned here, but there is also a hypothesis called "radiation hormesis" which states a LITTLE radiation is good for you. Seems strange at first, until you consider that your body needs to recognize DNA damage that can become cancerous. If you rarely get this damage, the body isn't as ready to fight it, and so may more likely get cancer. There are various studies, including some from NIH which can be googled.
8:21 I don't think there is limit on life saving but it has to be voluntary after a potential dose of 25 rem/250mSv
Your students must be queuing to attend your lectures. Thank you for sharing.
7:17 Maximum dose for radiation workers is NOT uniform around the world. I don't know for other countries, but in Germany the limit is 20 mSv for Category A workers and 6 mSv for Category B workers.
112 Radium in Humans: A Review of U.S. Studies
In the same publication, Rowland (in press) also examined dose-response
functions for head carcinomas. As in previous studies, the linear, linear
exponential, and dose-squared exponential functions all fitted the data
satisfactorily. The reason lies in the scarcity of head carcinomas. With only 19
of these malignancies observed in the cohort examined, the data are insufficient
to discriminate between alternate formulations.
The records indicate that bone sarcomas occurred about twice as often as
head carcinomas in the radium-exposed populations. The total known population
had 85 bone sarcomas and 37 head carcinomas, while the total measured
population had 64 bone sarcomas and 32 head carcinomas. Among the female
dial workers, considered the best cohort for dose-response analyses, 46 bone
sarcomas and 19 head carcinomas were observed. Because the number of head
carcinomas is not sufficient to allow unequivocal determination of the best form
for a dose-response function, the best predictor of their incidence at a given
intake level is the predicted number of bone sarcomas at that level, divided by
two.
At the same international seminar in Heidelberg, Thomas (in press)
presented work in which he used lognormal data analysis and the newly
calculated skeletal dose values (presented in the appendix of this document) to
reach the conclusion that a threshold exists for radium-induced malignancies.
Thomas calculated threshold values of 390-620 cGy and suggested the adoption
of a value of 1,000 cGy as the threshold for radium-induced malignancies in
humans, the same value Evans (1974) had derived 20 years earlier.
the fact he gives entire lectures writing backwards with no errors is impressive...
They flip the video
19:49 and 18:49 and 18:35 Show that his videos are actually just mirrored. These 3 timestamps let you compare the placement of his watch and the pin on his jackets' lapels. In the classroom footage he is not writing on a transparent surface, and so does not need to mirror it; you can see his watch on his left arm, the pin on his left lapel, and how he talks by waving his right hand around. Then go to the main body of the video where he writes with his "left" hand, but also is wearing his watch on his "right" arm, the pin on his "right" lapel, and waves around his "left" hand while talking.
Wonderfully explained! You are so good at teaching!
Question: I got 73 Grey during my Throat cancer treatment. How does that compare in Sieverts?
Thanks, David.
A Gray is basically 1 Sievert absorbed by tissue. Alpha and neutron radiation are more biologically damaging than beta or gamma, plus it depends on where the radiation is absorbed.
Note that the doses talked about in the video are whole body doses. Your whole body was not given 73 grays, but just the targeted area they were trying to kill/destroy. That being said, your whole body was dosed, but nowhere near to the same level (there's a reason why they will observe from behind leaded glass). I'm guessing the passed a rotating beam through the tumour to minimize the damage to the surrounding tissues?
Another excellent presentation, Prof.
How much enjoyment from these videos is too much? :D
What were those radium girls thinking? I wouldn't put a paintbrush with paint on it in my mouth even once, let alone every few minutes throughout the work day, even if the paint WASN'T radioactive.
Anyone else just impressed that he can write normally from BEHIND his marker board? This guy is levels ahead of us mortal humans.
They mirror the video in post processing
@@ExpiredCartonOfEggNogg Really? That's very disappointing. LOL
Extremely interesting! Thanks for the posting.
Much respect for the ability of writing like that, i couldn't do that.
19:49 and 18:49 and 18:35 Show that his videos are actually just mirrored. These 3 timestamps let you compare the placement of his watch and the pin on his jackets' lapels. In the classroom footage he is not writing on a transparent surface, and so does not need to mirror it; you can see his watch on his left arm, the pin on his left lapel, and how he talks by waving his right hand around. Then go to the main body of the video where he writes with his "left" hand, but also is wearing his watch on his "right" arm, the pin on his "right" lapel, and waves around his "left" hand while talking.
Denver is not at 1000 ft - it is the Mile High City after all, and it is not part of the Colorado Plateau. Most of Colorado is not on the Colorado Plateau (but large parts of Utah, Arizona, and New Mexico are!).
I'm suspecting his mentioning of the Colorado Plateau was a mix of both elevation and mineralogy, as much of the plateau has a higher than average uranium content. Agreed though about his mistake of the actual elevation of Denver.
It's obvious he knows Denver is higher than 1000 feet. No doubt he meant to say 1 mile and misspoke. We all make mistakes and not all will be caught in editing.
8:12 his actually shows that the health of workers is less worth than property/profits. Workers are allowed to get up to 10 Rem when "protecting valuable property". Using the formula at 13:54, this means an excess death rate of 0.02% per year which means that the chance of dying increases by 0.4% if you get this dose every year for 40 years. And even with normal limit of 5 Rem per year it increases by 0.2% in this case. Or maybe to put it in perpective: if there are 1 million workers who get the 10/5 Rem dose, 200/100 if them die in a year. If these rates of deaths where caused by accidents during work it would be deemed unacceptable in most "advanced" countries.
you forget the part where he talks about threshold doses. It is hard to say at what point the threshold is but it appears based on what he is saying somewhere a bit under 10 Rem. Also there are 2 other things to take into account, the first being that these excess deaths aren't instantaneous because it may take years to develop cancer in the first place, and then with treatment many more years until death. The second thing you have to take into account is the fatality rate of other types of jobs. For instance delivery drivers in the United States have a fatality rate of 270 people per million per year, and those fatalities presumably happen faster than cancer.
@@shockadinz9785 delivery drivers are a special case, because the US in general has many traffic deaths (from my understanding mainly because it is too easy to geg a driving license) and maybe also because they might get robbed or shot when going to the wrong house. It's easy for corporations to not clain responsibility for traffic accidents and murders, howevee I think that the fatality rate that is usually deemed acceptable in a factory or office is much lower.
PS: Also theshold theory is nlt acceöted universally, while the guy in this video says thaz it is mlre likely correct than the linear theory I heared the opöosite by other experts. I heared lf a study about the connection between background radiation and cancer rates which seems to support the linear theory begause they found a difference when the radiation was only something line 0.2 Rem higher. They used a very high sample size.
@@rfvtgbzhn If delivery drivers seem like a special case for you, the national statistic is 42.9 people per million die working any job within the United States, including office workers and the like. That's already getting close to the 200/100 figures you are giving. As far as the threshold theory being valid or notl i'm not informed enough to argue. I believe the other points I make are strong enough without needing the threshold theory anyways.
Is it dangerous to visit the Chernobyl exclusion zone in 2020 on a tour? Is inhaling an alpha emitter a real danger?
Nope, just don't live there for years.
Very clear and concise. Many thanks.
Let me throw a question in the table sir.
Let's say that we have 2 situations
1) i expose myself in 6 Sieverts but in time duration of 10 seconds.
2) i expose myself in 2 Sieverts but in time duration of 1 year.
which state will have the most deadly effects?
1-Acute Radiation Sickness 2-Higher chance of Cancer with chronic radiation effects
Ibrahem is correct. Also, 6 Sieverts in 10 seconds would be so severely acute a dose that it could be instantly fatal. A better comparison for acute versus long-term would be 6 Sieverts in a day.
While radiation does not exactly have a physical impact per se, one might compare falling off of a cliff to rolling down a hill. The energy of impact is distributed for a longer period of time rolling down the hill, thus there is less damage over all compared to falling off of a cliff, even though the energy absorbed is the same.
By analogy, the longer the period over which the dose is received, the lower the amount of immediate damage that is done.
Just brilliant! Thank you so much.
What radiation level would or could cause respiratory issues or failure?.
If I install a LFTR unit in the tail, how long does the plane have to be for 1/r2 to be safe as high altitude exposure?
That should be part of the education of every person on the Earth.
Enjoyable lecture. curious, what the curve of the graph would appear ( & how "linear" it might look) if the dose exposed rate figures stay same but are compressed to say, a 30 day period instead of a year. on a side note, although Radium dial painting was done thru late '60's in US, most severe dangers to the women dial painter w/licking their brushes occurred during painting watch dials in WWI. Cheers
Probably similar. Sun burns are radiation burns. A bit of sun is good, since we need it to make vitamin d out of cholesterol. But too much too quickly may cause more DNA damage than the body can repair, potentially leading to melanoma. I can have exposed skin all day in winter, but I'll burn in fifteen minutes around the summer solstice, because the dose rate is too high for me.
Why am I just finding this channel now?
3:20 Denver is at about 5000 ft not 1000 ft AMSL
Very informative. One thing, so many of these numbers are dependent on time.
Thank you professor
Any evidence of hormesis for low doses of radiation?
17:57 Like the way you address that our cells have learned to repair themselves based off of an evolutionary response to rad and other carcinogenetic material.
Great speak! but the sound of that marker gave something close to 500 Sievert per letter! 🙉
Don’t know how to provide a link here, but there was an amazing NPR story of a man in Japan that was exposed at both nuclear bombings during WW2. The best part was the study of cancer, inherited cancer, and genetic modification.
Excellent demonstration on radiation and its dangers (and lack of danger). Unfortunately, radiation is poorly understood in the US, and you fear what you don't know. This is not very different from the folks in Salem blaming things they couldn't understand on witches.
I have had about 12 abdominal CT scans. 2 or 3 were done with and without contrast, so a double scan. I have of course had other x rays , flouroscopy I and 1 or 2 CT of head. At age 65, should this concern me? I have kidney stones , thus the high numbers of CT and flouroscopy,. I will likely need more CT to visualise kidney stones. Am I doomed?
No!
I'm in my 40s. I've had 10 CTs , 15 X-rays, 3 NM, ( nuclear medicine), and I've had two or so contrast.
Some others I can't remember.
@@felicitydeikos5250 I had 2 head scans in my 20s. Will my future be full and bright? I worry a lot.
Are you able to update with typical mobile phone / WiFi / 5G exposure and health? Those are a lot more prevalent in daily life now (compared to nuclear radiation etc).
If you look at the chart, it actually addresses this. Cell phones don't produce radiation with a high enough energy to cause any health problems.
EMF, WiFi and 5G have been linked with health issues. Would be interested to hear an expert like this analyse each of them in more detail. To really see how big an effect they could actually have.
@@GKFC What study or studies in peer-reviewed journals link cell phones, WiFi, or 5G with "health issues?"
I love that little bit at the bottom on the 1 slide about cell phones. That's fucking hilarious!
"It's unfortunate, but everybody dies...."😂😂😂😂😂😂
my worry was about fish from the north pacific ocean. Since they had radio active water from Fukushima flushed in the ocean. Would it effect the fish and us?
Different radionuclides have a different half-life. Those with shorter half life are „more radioactive“ per mol (number of atoms) so to speak, because a very much higher number of atoms will decay in the same time. Some radionuclides can be taken up by the body and used in tissues: Iodine has some radioactive isotopes (with very short half life of hours respectively days) that can end up in your thyroid gland (and lead to thyroid cancer), if you are exposed and incorporate it in the very first days, that’s why states have stocks of non radioactive iodine as tablets in case of a nuclear disaster (or war) for immediate distribution, so that the spot in the tissue is already taken / so there is many more times the „competition“ with non-radioactive iodine for the uptake. Caesium 137 (it has a half-life of 30 years) is chemically similar enough to potassium that it can end up in muscles (and nerves). Strontium 90 (half-life of 28 years) is chemically similar enough to Calcium that it can end up in bones (and lead to bone cancer).
Plutonium on the other hand is extremely toxic when incorporated: very small doses will kill you, and not from radiation... (half-life of Pu 239 is more than 24000 years)
I am no expert. I am a layman, and I have googled this for you. - If you are really interested, there is probably a lot of good sources out there (- I just looked stuff up on Wikipedia...). I just wanted to indicate that a nuclear incident has a bit more intricacies than just the amount of ionizing radiation you get from standing near it... (- also note that in the talk he compares timescales of two weeks with timescale of a year with one-time events (x-rays) with exposition over a few hours (on an airplane). You really need to pay attention with what exactly you take away.
Certain radionuclides get concentrated in certain foods for the same reasons: Here in Bavaria (Germany) for example after the Chernobyl accident the hay had not to be used for feeding cows that year, so the strontium would not end up in the milk (I don’t remember if they had to plow it under or burn it, so it would dissipate more). But because the Caesium was accumulating in mushrooms (for biological reasons) there was advisory against eating locally grown mushrooms in certain areas even five or ten years after... - so your question about concentration in the food chain might still be valid: I don’t know anything about fish though.
@@Stadtpark90 Thank you, I will keep looking.
To simplify what Stadtpark said: The really bad stuff in the water will decay pretty fast. So even if the fish eat it, it will affect them, but by the time they get here, it will have passed from their system or mostly decayed into more stable stuff.
Stuff that has a short "half-life" is very bad for you, but disappears quickly. Stuff with a long half life will last eons, but isn't really so bad for you.
Even so, a very tiny tiny part of any water flushed out of Fukushima would have any radionuclides at all, and a very very tiny part of those radionuclides would be the very bad stuff.
So to my non-professional off-the-cuff SWAG, based on stuff I learned decades ago and mostly forgot, I'd say you'll have a higher radiation risk if you eat ten bananas in rapid succession.
@@WhereWhatHuh thank you
Everything is great about the lectures. Except the squeeky markers. Thx
You do understand that LNT is invalid at low doses (less than a 1 Sv per year)?
Very informative - Thank you.
The Earth was much more radioactive when it formed. Life had to have had reasonable repair mechanisms capable of dealing with worse radiation then at present. Hence the threshold.
The reason for that was the Solar System was close to a supernova, which injected A LOT of highly radioactive isotopes into it after the first solid matter coagulated out of the Solar nebula, but before the planets formed.
@@taraswertelecki7874 The way I would have put that is that the Solar System formed from the wreckage of several short-lived giant stars, which on their way to neutron stars and black holes had released _ALL possible atomic matter,_ some of which was radioactive, and immediately began to diminish.
The more important point is that Life originated in far more radioactive conditions than the present, and radiation damage toleration was an intrinsic part of the way it came to be.
Yes, it was highly radioactive in the beginning, because a supernova both irradiated the Solar System and put a lot of radioisotopes into it, such as Aluminum-26 and Iron-60. Subsequent supernova near the Earth have added more radioactive isotopes to the Earth.
When land life formed and evolved our ozone layer was far less developed, biggest reason.
@@weasle2904 Nope.
3:25 Denver is a mile high, not 1000 feet.
Well, since I’m already a motorcycle rider, maybe I should just go ahead and get a job cleaning up after nuclear disasters.
Road dirt has been everywhere, and contains everything.
It would probably lower your death risk... Because you'd have less time to ride!
Fun Fact: In hospitals, especially ER rooms, "Organ donor" is slang for a patient who rides motorcycles, e.g. if they bring in a guy into the E.R.who crashed his motorcycle in traffic they'll say "we got the organ donor from the crash on 5th and Broadway., which operating room?...OK number 4".
Would you allow this video to be mirrored on my channel? Full credit given with links back to your channel. My channel is a collection of different authors that debunk Fukushima and radiation fear mongering.
i love this guy !
Why to quit?what heppend with 3 billion dollar for fusion ?
The Radium Girls suffered from phosy jaw caused by the phosphorus in the radium dye. This disease also afflicted workers in early match stick factories. That is why modern matches are called safety matches, not because they are safe for the user, but because they are safe for the worker making them.
Marie Curie discovered and worked with Radium her entire life without any protection. She died age 80 something of anemia, which is a common cause of death for elderly women of that time. Her husband and lab mate Pierre Curie was un over by a tram and died from trauma.
I love how good he writes mirrored right to left with his left hand... - I guess it is more likely they play the video mirrored though... (edit: I should have scrolled down the comments - of course someone said that before me...)
Do commercial pilots die lots becos of extreme radiation poisoning
So how much of the danger of smoking cigarettes is due to inhalation of radioactive particles that were absorbed by the tobacco plants? Is it a secondary concern to the chemotoxic/cytotoxicity of all the junk in the smoke (including from the radioactive particles)?
I'm not an engineer or doctor, but hopefully my question makes sense to you all. Anyone have any ideas?
I serious doubt people on the ground can see a dim flash light in the cockpit. Radium was used because its reliability and longevity.
I thought exactly the same thing... but now that I think about it more: 1) when bombing, you are probably flying low, 2) even when people on the ground won't see you, they are still shooting and trying hard to see you, so perhaps pilots did not want to rely on "they won't likely notice my light"
Shouldn't there be a top threshold as well? A point where the dose is high enough that everyone will die?
That's around that 8 sievert mark ...
Gunners on the ground can't possibly see cockpit lights in a bomber flying at 30,000 feet. Airplane crews needed to maintain night vision at all times in order to see other planes, both friend and foe. Also, they needed to see their gauges which were barely lit, again to preserve night vision.
10 mS of background radiation and 10mS of radiation from nuclear plant have the same effect on body??
Yes. As in none.
7:27 If you take out everyone that is below 100 mrem at a nuke plant the average dose to the rest of the workers is 400 to 500 mrem.
Where does roentgen come in compared to sieverts.
This guy can write backwards better than I can write forwards...
Re at 18:00, the "radium girls" disaster happened around WWI, circa 1917.
en.wikipedia.org/wiki/Radium_Girls
How about radiation treatment for cancer?
People in Ramsar Iran (and some other parts of the world) have high background radiation due to the rock formations in the area. In Ramsar, the dose from background radiation is up to 260 mSv y−1. That’s 13 times higher than the 20 mSv y−1 permitted for radiation workers.
Yet the people have no radiation injury and seem to have fewer cancers than the general non irradiated population.
This being so why are occupational exposure levels set so low?
avoid getting sued
Let's eat all the bananas!
the thumbnail looks like a minecraft chest inventory
Regarding the suggestion that data supports the threshold model rather than the linear model at the 5,000,000 * 1 mRrem/y level... Call me dubious. It's not specifically that I doubt the threshold model, but I simply don't see any way to get the kind of precision of measurement needed to back up that claim.
Exactly my doubts. Those "some out of some people develop cancer anyway" situations exactly the questionable ones. If nobody actually knows, why some people develop cancer and others not, how one can exclude them as "they are not because of radiation". No proof for either side.
Might be because of more or less environmental radiation.
On the other hand: there are other environmental properties in real life which are behaving threshold-like. Temperature, pressure, sound pressure level, light brightness to name everyday ones... It looks like there are safe operating areas. If you do not exceed these limits then the continuous exposure won't degrade your body at all.
Might or might not be the same for radiation...
Exactly how much cosmic radiation do you get living in Denver? What is cosmic radiation even made of? I can't find any solid information about that online.
Good radiation 101. Geraldine Thomas imperial collage of London does a great presentation also. On youtube.
This one or another link? m.th-cam.com/video/X7sGESRhpqg/w-d-xo.html
A 3 year round trip to Mars is expected to get you on the order of 1 Sv in total. Shouldn't be a problem compared to the other risks involved :-)
That's why most interplanetary ship designs store the water as a jacket around the ship, with other supplies as another layer. The first interplanetary voyagers aren't going to get an expansive Ten Forward view, sadly.
Yes, the water will stop the particles from the Sun anyway. The galactic cosmic rays they will just have to live with.
bone and muscle loss in zero acceleration is worst effect when traveling to mars.
after year of travel suddenly goes into gravity well, its not going very well, scott kelly need help even when going outside the capsule after year experiment in ISS.
@@royk7712 Yes, a rotating space craft to get at least some gravity would be good.
@@zapfanzapfan it would be huge, maybe the radius would be 30-40 meter @3RPM produce 0.3g at least so the crew would get confused from artificial gravity gradient from a different height. it would be a huge spacecraft and need to be assembled in space
I think that it was radium and zinc sulfide not radium and phosphorus. The zinc sulfide is called a phosphor.
A very nice lecture. But why use a unit for radiation that's been outdated for decades when even the XKCD chart used Sievert. Why not just stick to that?
A lot of US industry and regulations still uses the old units, so the people attending his school probably need to know them.
In the time since you produced this excellent video, we have all unfortunately become much more familiar with the concept of “excess deaths”.