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What is radioactivity?

<div> <div class="copy"> <p>We owe the discovery of radioactivity to bad weather. French physicist <a rel="noopener" href="https://en.wikipedia.org/wiki/Henri_Becquerel" target="_blank">Henri Becquerel</a> was trying to study fluorescence, a phenomenon where certain materials glow when exposed to sunlight, but overcast days thwarted his experiments and so he wrapped his fluorescing uranium salts in cloth and left them in a drawer, along with a photographic plate and a copper cross. This simple serendipitous accident, in 1896, revealed the existence of radioactivity, a phenomenon that opened a window into the subatomic world and kickstarted the nuclear revolution.</p> <h2>Understanding radioactivity</h2> <p>When he finally fetched the salts, Becquerel found that an image of the cross had appeared on the photographic plate – even though the salts had not been exposed to light.</p> <p>“I am now convinced that uranium salts produce invisible radiation, even when they have been kept in the dark,” he wrote after conducting further experiments.</p> <p>Becquerel’s doctoral student, <a href="https://cosmosmagazine.com/science/physics/this-week-in-science-history-marie-curie-dies/">Marie Curie</a>, investigated the matter with her husband Pierre and they realised the effect had nothing to do with fluorescence, instead discovering that certain materials naturally emit a constant flow of energy. They coined the term ‘radioactivity’ and also found two new radioactive elements: polonium and radium. For this profound and exciting work, Becquerel and the Curies received the Nobel Prize for <a href="https://cosmosmagazine.com/science/physics/">Physics</a> in 1903.</p> <p>Physicists Ernest Rutherford and Frederick Soddy delved deeper and found that tiny amounts of matter contain huge reserves of energy. They also realised that in the process of radioactive decay, one element can turn into another – an atom of uranium can transform (via a few intermediate steps) into an atom of lead.</p> <p>Around the world people assumed that these miraculously energetic materials could be put to good use. Until the 1920s, many manufacturers of laxatives and toothpaste proudly laced their products with radioactive thorium, and radioactive substances were only banned in consumer products in the US in 1938.</p> <h2>How does radioactivity work?</h2> <p>Today we have a much more comprehensive understanding of what radioactivity is, how it can be dangerous, and how we can use it.</p> <p>Here’s a basic rundown: imagine an atom, composed of a cloud of electrons around a central nucleus where particles called neutrons and protons are crammed in together. Some arrangements of protons and neutrons are more stable than others; if there are too many neutrons compared to protons, the nucleus becomes unstable and falls apart. This decay releases nuclear radiation in the form of alpha particles, beta particles, and gamma radiation.</p> <p>An alpha particle carries off two protons and two neutrons, and since an element is defined by its number of protons, the parent atom becomes a whole new element when an alpha particle is emitted. In beta decay, a neutron transforms into one proton and one electron, and the electron speeds off, leaving an extra proton behind and once again resulting in an atom of a different element. Alongside either of the above particles, decaying nuclei can also produce gamma rays: high energy electromagnetic radiation.</p> <h2>What are the health effects?</h2> <p>As Becquerel and the Curies discovered, radioactivity is a naturally-occurring phenomenon. Many minerals in the Earth emit a slow and steady trickle of radiation, the air we breathe contains radioactive gases, and even foods and our bodies contain a small percentage of radioactive atoms like potassium-40 and carbon-14. The Earth also receives radiation from the Sun and as high-energy cosmic rays. These sources create a natural but unavoidable level of background radiation. Many artificial sources add to this, including medical procedures such as X-rays, smoke detectors, building materials and combustible fuels.</p> <p>We generally aren’t harmed by low-level background sources of radiation, as the extent of harm depends on the length and level of exposure. Radiation can damage the body’s internal chemistry, breaking up chemical bonds in our tissue, killing cells, and damaging DNA, which may lead to cancer. In very high doses, radiation can cause sickness and death within hours.</p> <h2>Harnessing nuclear power</h2> <p>The effects of radioactivity have been felt on an even grander scale with the meltdown of nuclear power plants throughout history. The radioactive process of fission has been harnessed for several decades to produce electricity: the nucleus of an atom is split, creating at least two “daughter” nuclei and releasing energy as heat. The heat is used to boil water and create steam, turning a turbine and generating electricity.</p> <p>Unfortunately this isn’t a clean process – it produces radioactive waste that is difficult to safely dispose of, and in extreme cases reactions can spiral out of control, such as the disaster triggered by an earthquake at the Fukushima Daiichi nuclear power station in 2011.</p> <p>Another radioactive process could provide a safe way to generate clean energy: fusion. In contrast to fission, fusion involves joining two atomic nuclei together. This process also releases energy – it’s the exact process occurring in the Sun and other stars – but fusion requires extremely high temperatures and pressures, which are expensive and difficult to recreate on Earth.</p> <h2>A long road ahead</h2> <p>Becquerel died 12 years after his initial discovery at age 54, with burns and scars likely from handling radioactive materials, and Marie Curie died several decades later from leukemia. Radiation was probably slowly killing Pierre Curie too, although it’s difficult to know as he was fatally run down by a carriage in 1906.</p> <p>Today our greater understanding of radioactivity allows us to use it much more safely. Accidents with radioactive materials have decreased in frequency and produce fewer fatalities due to stringent safety measures and thorough emergency responses. In the most recent nuclear disaster at Fukushima, no deaths resulted from radiation exposure – but there’s still a long way to go before we can safely harness the immense raw power of radioactivity.</p> <em>Image credits: Shutterstock        <!-- Start of tracking content syndication. Please do not remove this section as it allows us to keep track of republished articles --> <img id="cosmos-post-tracker" style="opacity: 0; height: 1px!important; width: 1px!important; border: 0!important; position: absolute!important; z-index: -1!important;" src="https://syndication.cosmosmagazine.com/?id=76198&amp;title=What+is+radioactivity%3F" alt="" width="1" height="1" /> <!-- End of tracking content syndication -->          </em></div> <div id="contributors"> <p><em>This article was originally published on <a rel="noopener" href="https://cosmosmagazine.com/science/physics/what-is-radioactivity/" target="_blank">cosmosmagazine.com</a> and was written by Lauren Fuge. </em></p> </div> </div>

Technology

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You can now visit Chernobyl’s control room

<p><span style="font-weight: 400;">Tourists are now able to visit the radioactive control room at Chernobyl which has been within the exclusion zone of access since the disaster more than 30 years ago.</span></p> <p><span style="font-weight: 400;">The control room is in decay and is located at Unit Four, where the reactor exploded.</span></p> <p><span style="font-weight: 400;">It is also the location of the deadly “elephant’s foot” radioactive mass which was discovered in the basement under the remains of the reactor.</span></p> <blockquote style="background: #FFF; border: 0; border-radius: 3px; box-shadow: 0 0 1px 0 rgba(0,0,0,0.5),0 1px 10px 0 rgba(0,0,0,0.15); margin: 1px; max-width: 540px; min-width: 326px; padding: 0; width: calc(100% - 2px);" class="instagram-media" data-instgrm-captioned="" data-instgrm-permalink="https://www.instagram.com/p/ByiXTkBIbSz/?utm_source=ig_embed&amp;utm_campaign=loading" data-instgrm-version="12"> <div style="padding: 16px;"> <div style="display: flex; flex-direction: row; align-items: center;"> <div style="background-color: #f4f4f4; border-radius: 50%; flex-grow: 0; height: 40px; margin-right: 14px; width: 40px;"></div> <div style="display: flex; flex-direction: column; flex-grow: 1; justify-content: center;"> <div style="background-color: #f4f4f4; border-radius: 4px; flex-grow: 0; height: 14px; margin-bottom: 6px; width: 100px;"></div> <div style="background-color: #f4f4f4; border-radius: 4px; flex-grow: 0; height: 14px; width: 60px;"></div> </div> </div> <div style="padding: 19% 0;"></div> <div style="display: block; height: 50px; margin: 0 auto 12px; width: 50px;"></div> <div style="padding-top: 8px;"> <div style="color: #3897f0; font-family: Arial,sans-serif; font-size: 14px; font-style: normal; font-weight: 550; line-height: 18px;">View this post on Instagram</div> </div> <p style="margin: 8px 0 0 0; padding: 0 4px;"><a style="color: #000; font-family: Arial,sans-serif; font-size: 14px; font-style: normal; font-weight: normal; line-height: 17px; text-decoration: none; word-wrap: break-word;" rel="noopener" href="https://www.instagram.com/p/ByiXTkBIbSz/?utm_source=ig_embed&amp;utm_campaign=loading" target="_blank">ChNPP from the inside: the “golden corridor” connects all the blocks of the station, including the destroyed fourth one. The name comes from the appearance of wall cladding, which creates a golden glow in the hallway. The length of the corridor is more than a kilometer! ⠀ ЧАЕС зсередини: "золотий коридор" з'єднує всі блоки станції, в тому числі, і зруйнований четвертий. Назва походить від зовнішнього вигляду обшивки стін, яка створює в коридорі золотисте світіння. Протяжність коридору - більше кілометра! ⠀ ЧАЭС изнутри: "золотой коридор" соединяет все блоки станции, в том числе, и разрушенный четвертый. Название произошло от внешнего вида обшивки стен, которая создает в коридоре золотистое свечение. Протяженность коридора - более километра!</a></p> <p style="color: #c9c8cd; font-family: Arial,sans-serif; font-size: 14px; line-height: 17px; margin-bottom: 0; margin-top: 8px; overflow: hidden; padding: 8px 0 7px; text-align: center; text-overflow: ellipsis; white-space: nowrap;">A post shared by <a style="color: #c9c8cd; font-family: Arial,sans-serif; font-size: 14px; font-style: normal; font-weight: normal; line-height: 17px;" rel="noopener" href="https://www.instagram.com/chernobyltour/?utm_source=ig_embed&amp;utm_campaign=loading" target="_blank"> CHERNOBYL TOUR</a> (@chernobyltour) on Jun 10, 2019 at 10:03am PDT</p> </div> </blockquote> <p><span style="font-weight: 400;">As the control room is still a hotbed of radioactive activity and measures at around 40,000 times the safe level, visitors are only able to visit the control room for five minutes.</span></p> <p><span style="font-weight: 400;">The decision to open the site up to tourists came after the success of the HBO mini series </span><span style="font-weight: 400;">Chernobyl</span><span style="font-weight: 400;">, which outlined the disaster and what mistakes led to it happening. </span></p> <blockquote style="background: #FFF; border: 0; border-radius: 3px; box-shadow: 0 0 1px 0 rgba(0,0,0,0.5),0 1px 10px 0 rgba(0,0,0,0.15); margin: 1px; max-width: 540px; min-width: 326px; padding: 0; width: calc(100% - 2px);" class="instagram-media" data-instgrm-captioned="" data-instgrm-permalink="https://www.instagram.com/p/B06dUzTALb8/?utm_source=ig_embed&amp;utm_campaign=loading" data-instgrm-version="12"> <div style="padding: 16px;"> <div style="display: flex; flex-direction: row; align-items: center;"> <div style="background-color: #f4f4f4; border-radius: 50%; flex-grow: 0; height: 40px; margin-right: 14px; width: 40px;"></div> <div style="display: flex; flex-direction: column; flex-grow: 1; justify-content: center;"> <div style="background-color: #f4f4f4; border-radius: 4px; flex-grow: 0; height: 14px; margin-bottom: 6px; width: 100px;"></div> <div style="background-color: #f4f4f4; border-radius: 4px; flex-grow: 0; height: 14px; width: 60px;"></div> </div> </div> <div style="padding: 19% 0;"></div> <div style="display: block; height: 50px; margin: 0 auto 12px; width: 50px;"></div> <div style="padding-top: 8px;"> <div style="color: #3897f0; font-family: Arial,sans-serif; font-size: 14px; font-style: normal; font-weight: 550; line-height: 18px;">View this post on Instagram</div> </div> <p style="margin: 8px 0 0 0; padding: 0 4px;"><a style="color: #000; font-family: Arial,sans-serif; font-size: 14px; font-style: normal; font-weight: normal; line-height: 17px; text-decoration: none; word-wrap: break-word;" rel="noopener" href="https://www.instagram.com/p/B06dUzTALb8/?utm_source=ig_embed&amp;utm_campaign=loading" target="_blank">Nowadays you can go inside the Chernobyl nuclear power station, see the main circulation pumps and one of the control rooms. Book a private tour to visit the ChNPP ☢️ ⠀ На сьогоднішній день ви можете побувати всередині Чорнобильської АЕС, побачити головні циркуляційні насоси та відвідати один з блочних щитів управління. Замовляйте приватний тур для відвідування ЧАЕС ☢️ ⠀ На сегодняшний день вы можете побывать внутри Чернобыльской АЭС, увидеть главные циркуляционные насосы и посетить один из блочных щитов управления. Заказывайте частный тур для посещения ЧАЭС ☢️</a></p> <p style="color: #c9c8cd; font-family: Arial,sans-serif; font-size: 14px; line-height: 17px; margin-bottom: 0; margin-top: 8px; overflow: hidden; padding: 8px 0 7px; text-align: center; text-overflow: ellipsis; white-space: nowrap;">A post shared by <a style="color: #c9c8cd; font-family: Arial,sans-serif; font-size: 14px; font-style: normal; font-weight: normal; line-height: 17px;" rel="noopener" href="https://www.instagram.com/chernobyltour/?utm_source=ig_embed&amp;utm_campaign=loading" target="_blank"> CHERNOBYL TOUR</a> (@chernobyltour) on Aug 8, 2019 at 11:40am PDT</p> </div> </blockquote> <p><span style="font-weight: 400;">Vitalii Viktorovych Petruk, the head of Ukraine's state agency for the Exclusion Zone, mentioned the popular TV series by name when talking on the decision to open up the site.</span></p> <p><span style="font-weight: 400;">"The HBO series boosted the interest to Chernobyl. Everybody now wants to see more, and we are going to satisfy the demand."</span></p> <p><span style="font-weight: 400;">This year alone has seen more than 85,000 visitors flock to the Ukraine to visit the infamous abandoned city.</span></p>

Travel Trouble

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Meet the “radioactive” man who returned to Fukushima to feed the animals that were left behind

<p>The tragedy of the Fukushima disaster in Japan left a trail of untold human suffering but as people fled from the radioactive area, the animal population was left behind. One man, however, has not forgotten. Former construction worker, Naoto Matsumura, is the only person brave enough to live in the exclusion zone to care for the four-legged survivors.</p><p>The 55-year-old is known as the “guardian of Fukushima’s animals”. He fled at first, but returned in 2011 to look for his own pets. Once there, he realised that so many animals needed his help and has stayed for four years. He is aware of the radiation he lives with on the daily basis, but he says he “refuses to worry about it.”</p><p>“They also told me that I wouldn’t get sick for 30 or 40 years. I’ll most likely be dead by then anyway, so I couldn’t care less,” he said.</p><p>The government has forbidden him to stay but that has not prevented Matsumura, who relies on donations to help feed the animals.&nbsp;</p><p><img width="628" height="416" src="http://static.boredpanda.com/blog/wp-content/uploads/2015/03/fukushima-radioactive-disaster-abandoned-animal-guardian-naoto-matsumura-5.jpg" alt="fukushima-radioactive-disaster-abandoned-animal-guardian-naoto-matsumura-5" class="alignnone size-full wp-image-177775"></p><p><img width="626" height="417" src="http://static.boredpanda.com/blog/wp-content/uploads/2015/03/fukushima-radioactive-disaster-abandoned-animal-guardian-naoto-matsumura-14.jpg" alt="fukushima-radioactive-disaster-abandoned-animal-guardian-naoto-matsumura-14" class="alignnone size-full wp-image-177782"></p><p><img width="624" height="440" src="http://static.boredpanda.com/blog/wp-content/uploads/2015/03/fukushima-radioactive-disaster-abandoned-animal-guardian-naoto-matsumura-13.jpg" alt="fukushima-radioactive-disaster-abandoned-animal-guardian-naoto-matsumura-13" class="alignnone size-full wp-image-177781"></p><p><img width="624" height="416" src="http://static.boredpanda.com/blog/wp-content/uploads/2015/03/fukushima-radioactive-disaster-abandoned-animal-guardian-naoto-matsumura-2.jpg" alt="fukushima-radioactive-disaster-abandoned-animal-guardian-naoto-matsumura-2" class="alignnone size-full wp-image-177773"></p><p><img width="618" height="412" src="http://static.boredpanda.com/blog/wp-content/uploads/2015/03/fukushima-radioactive-disaster-abandoned-animal-guardian-naoto-matsumura-3.jpg" alt="fukushima-radioactive-disaster-abandoned-animal-guardian-naoto-matsumura-3" class="alignnone size-full wp-image-177774"></p><p><img width="619" height="426" src="http://static.boredpanda.com/blog/wp-content/uploads/2015/03/fukushima-radioactive-disaster-abandoned-animal-guardian-naoto-matsumura-9.jpg" alt="fukushima-radioactive-disaster-abandoned-animal-guardian-naoto-matsumura-9" class="alignnone size-full wp-image-177778"></p><p><img width="622" height="399" src="http://static.boredpanda.com/blog/wp-content/uploads/2015/03/fukushima-radioactive-disaster-abandoned-animal-guardian-naoto-matsumura-16.jpg" alt="fukushima-radioactive-disaster-abandoned-animal-guardian-naoto-matsumura-16" class="alignnone size-full wp-image-177783"></p><p><span><a href="http://ganbarufukushima.blog.fc2.com/" target="_blank"><span style="text-decoration: underline;"><strong>Find out more information and make donations at his blog.</strong></span></a></span></p><p><span><strong>Related links:</strong></span></p><p><a href="/news/news/2015/02/australia-oldest-man-knits-for-penguins/" target="_blank"><span style="text-decoration: underline;"><em><strong>Australia’s oldest man knits mini-sweaters for injured penguins</strong></em></span></a></p><p><a href="/news/news/2015/02/three-legged-greyhound/" target="_blank"><span style="text-decoration: underline;"><em><strong>Never give up: this greyhound lost a leg and still loves to run</strong></em></span></a></p><p><span style="text-decoration: underline;"><em><strong><a href="/news/news/2015/02/loyal-dog-finds-owner/" target="_blank">Loyal dog travels 20 blocks to reach owner in hospital</a></strong></em></span></p>

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