Two New Elements Named, and Some Notes on the Periodic Table

In the thrilling sequel to the naming of darmstadtium, roentgenium and copernicum, two more of the heaviest elements in the periodic table have finally been named: give a warm periodic table welcome to flerovium and livermorium!

From LiveScience:

Element 114, previously known as ununquadium, has been named flerovium (Fl), after the Russian institute’s Flerov Laboratory of Nuclear Reactions founder, which similarly is named in honor of Georgiy Flerov (1913-1990), a Russian physicist. Flerov’s work and his writings to Joseph Stalin led to the development of the USSR’s atomic bomb project.

The researchers got their first glimpse at flerovium after firing calcium ions at a plutonium target.

Element 116, which was temporarily named ununhexium, almost ended up with the name moscovium in honor of the region (called an oblast, similar to a province or state) of Moscow, where the research labs are located. In the end, it seems the American researchers won out and the team settled on the name livermorium (Lv), after the national labs and the city of Livermore in which they are located. Livermorium was first observed in 2000, when the scientists created it by mashing together calcium and curium.

Textbooks are changing before our eyes! This same lab has also synthesized elements 113, 115, 117 and 118, but those have yet to be confirmed so they won’t be named just yet. That leaves the race to elements 119 and 120, which I discussed earlier.

According to different ideas there could be up to 137 or 173 physically possible elements, so element-hunters are eventually going to run out of real estate. Here’s what an extended periodic table might look like, via WikiMedia:

The 8th period (row) would introduce a new block, making the whole table much wider. These blocks represent the type of the highest-energy orbitals occupied by each element’s electrons. The types of orbitals are categorized by the shapes of the areas with the highest probability of an electron being inside. Weird, I know.

For example, pink elements’ most energetic electrons are in the s-orbital, which is shaped like a sphere. That means their outermost (from the nucleus), most energetic, electrons are most likely to be in that sphere (their exact paths are impossible to know due to the Heisenberg uncertainty principle). Each different colour in the periodic table above means that the outermost orbital is a particular shape, and elements over 120 are theorized to have a new orbital shape, which is why they get a new block.

That’s just a quick and dirty summary of course, but if you didn’t before, now you know why the periodic table is blocked off how it is. Those green elements in the extended periodic table above (the f-block) are usually shown separately below the periodic table, so that it’s not as wide. Here’s a standard table for reference, from Jefferson Lab:

In this table the yellow elements are gases at room temperature (ex. hydrogen, oxygen, nitrogen, helium), the greens are solid and the blues are liquid (only mercury and bromine). Notice that block I mentioned, the f-block, at the bottom, keeping the table nice and thin, although out of order. One technicality I have to note though is that elements 71 and 103 on the right end, lutetium and lawrencium, are actually part of the d-block, not f-block, but they’re still grouped with the bottom series, called the lanthanide and actinide series. 

Since I’m getting into the periodic table, I might as well explain why there is a periodic table in the first place: a scientist named Dmitri Mendeleev realized that if you organized atoms by their mass, they fell into a repeating pattern in terms of chemical properties, like helium, neon and argon having similar properties, for example. With what I’ve explained above, it should be easier to understand just why: the periodic table is effectively organized by the properties of the outermost electron orbital, which is generally what interacts in chemical reactions. Every element in a particular column has the same thing going on in its outermost electron orbital, so it’ll have similar chemical reactions compared to the elements above and below it.

Since you’re all up on your science news, you’ve probably heard of the idea of silicon- instead of carbon-based life, which makes sense when you see that silicon is directly below carbon in the periodic table. You may have also heard of the recent report on bacteria that possibly incorporated arsenic into their DNA instead of phosphorous (although that story should be taken with a pound of salt); arsenic is also directly below phosphorous in the table. The table is magic, is what I’m trying to tell you.

In summary: flerovium and livermorium, and I’m easily distracted, but I hope you learned (or at least remembered) something!

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Why Empty Space Isn’t Empty

New Scientist has a nice little video explaining that vacuums, empty space, aren’t really empty. You, my dear reader, already know that from reading about the big laser that will tear apart virtual particles, and the recent experiment that materialized virtual photons, but you should check this short video out if you’re interested (can’t embed the video here, sadly). 

They also link to a full-length article discussing how the theory of the vacuum has evolved over time, which it looks like you’ll have to register (for free) to read. I won’t go into all of it, but in essence it portrays a somewhat philosophical struggle over the millennia about how emptiness could be empty, which led to and away from the idea of a luminiferous aether filling everything, and finally to quantum mechanics.

Now we know that because of the quantum uncertainty involved at the smallest scales, there are always fluctuations of fields and particles in a vacuum, meaning that any vacuum does indeed have energy in it. There’s never nothing. Is that reassuring? I think a constantly fluctuating space is much more interesting than a giant, vast emptiness. 

Explaining the Earth’s Liquid Outer Core

Weekends are lean times here at Science Picks; I see a few dozen new articles a day as opposed to the ~500 new articles per weekday that I get to choose from. Fortunately, some articles/blog posts aren’t news but are just interesting reviews of some aspects of science, so they’re good for whenever I want to share them. So from my bag of saved articles, I bring you:

Why does the Earth have a liquid core? from Starts With a Bang. I really enjoy Starts With a Bang, and I think you should definitely check out other posts from there if Ethan’s style is appealing to you. Also, check out the comments on his blog posts, since his readers have pretty interesting questions and comments as well. Enjoy!

A Giant Planet Ejected From Our Solar System

Based on studying the lunar craters and the bodies in the Kuiper belt beyond Neptune, scientists have deduced that something big happened in our solar system when it was about 600 million years old, throwing off the orbits of the giant planets and sending smaller bodies flying every which way, including to impact the moon. Now one astronomer showed that the best model for how this could occur involves having a fifth giant planet that was ejected from our solar system.

This means that the early sky from an Earth viewpoint 4 billion years ago would’ve been rather different – having another planet in the sky, having the gas giants in different orbits, and having a much less dinged up moon, at least. If you ever time travel to the dawn of life on Earth, remember not to be too startled by this. 

You can read the full deal on this at Wired or see the press release from the Southwest Research Institute. Wired has a related article from May about the discovery of “orphan planets,” planets wandering the galaxy without a star to orbit. Maybe we can see our orphaned planet out there? 

Our neighbours in the solar system. The interplanetary distances are definitely not to scale, and not depicted are the other 334 moons in the solar system (168 around the planets). Image courtesy of jasonirwin.ca.

While we’re here, let’s see what Wikipedia can teach us about the Kuiper belt. You’ve probably heard of the asteroid belt, which is a region between Mars and Jupiter occupied by, naturally, a lot of asteroids. It’s the division between the four inner and four outer planets, or the terrestrial planets and the gas giants. About a third of the mass of the asteroid belt is in Ceres, the solar system’s smallest dwarf planet and largest asteroid, which is about 950 km in diameter. A space probe from NASA was launched in 2007 and will investigate Ceres in 2015.

Meanwhile, the Kuiper belt is past Neptune, the farthest planet in the solar system, and is about 20 times as wide as the asteroid belt. Its existence was first hypothesized in 1930 shortly after the discovery of Pluto, by an astronomer who thought Pluto looked awfully lonely. Starting in 1992, he was proven right as asteroids in the Kuiper belt were discovered. Now there are four bodies labeled as dwarf planets in the Kuiper belt – Pluto, Eris, Makemake, and Haumea, although more may be added in the future.

The more scientists learned about the Kuiper belt – particularly the discovery of Eris, which is larger than Pluto – the harder it was to maintain that Pluto was, in fact, a planet comparable to the others, leading to its downgrading in 2006 and the creation of the “dwarf planet” classification. Although this upset quite a few people, it’s not the first time this has happened – asteroids used to be classified as planets before we discovered how many of them there were, in the early 1800s. The asteroids that were once considered planets are Ceres, Pallas, Juno and Vesta, all in the asteroid belt. 

I guess the lesson in all this is that there’s a lot going on in the solar system, and we have a lot to learn about our neighbourhood, so don’t get too emotionally attached to your solar system model. If you thought downgrading Pluto from a planet to a dwarf planet was sad, imagine how people in the 1500s felt about downgrading Earth from the center of the universe to a planet. Oh the Facebook groups they would have made…

What We Do and Don’t Know About Climate Change

As I said in the last post, the science behind climate change has been in the news recently, which brings the side benefit of having New Scientist publish a series of articles on climate change for our education. You may not be able to access the articles without registering with them (for free), but they’re very short in any case and I’ll summarize them here. Because they’re very short though, be warned that they’re probably slight-to-gross oversimplifications, so don’t take any of this as whole, perfect truths. 

This ended up being super duper long – feel free to just skim over the titles and read more only if you’re interested. I think the important thing to note is that we don’t know everything – and we likely never will. That applies to every field of science though, as the final article eloquently explains. Climate change science has been brutally politicized, but that shouldn’t distract people from the facts.

Climate known: Greenhouse gasses are warming the planet

From melting glaciers and earlier springs to advancing treelines and changing animal ranges, many lines of evidence back up what thermometers tell us – Earth is getting warmer. Over the 20th century, the average global temperature rose by 0.8 °C

Studies of Earth’s past climate tell us that whenever CO2 levels have risen, the planet has warmed. Since the beginning of the industrial age in the 19th century, CO2 levels in the atmosphere have increased from 280 parts per million to 380 ppm. Satellite measurements now show both that less infrared of the specific frequencies absorbed by CO2 and other greenhouses gases is escaping the planet and that more infrared of the same frequencies is being reflected back to Earth’s surface. While many factors affect our planet’s climate, there is overwhelming evidence that CO2 is the prime cause of its recent warming.

Climate unknown: How much greenhouse gas to expect

The biggest uncertainty is human… Our current emissions trajectory is close to the worst-case scenario of the Intergovernmental Panel on Climate Change (IPCC). If we continue on this path, CO2 levels could hit 1000 ppmby 2100 – or perhaps even higher.

The second uncertainty is Earth’s response… Currently, rising CO2 levels are driving global warming, but in the past CO2 levels have naturally risen in response to rising temperatures. We do not know why exactly, but the reduced solubility of CO2 in warm water and changes in biological activity have been suggested as reasons. If such mechanisms kick in, even bigger cuts in emissions will be needed to limit warming.

There are also vast quantities of greenhouse gases locked away in permafrost, in peat bogs and undersea methane hydrate deposits. We don’t know how big these stores are. Nor do we know how much permafrost will melt, or how much peat will dry out and decay, or whether the seas will get warm enough to trigger the release of methane – an even more potent greenhouse gas than CO2 – from the hydrates.

Climate known: Other pollutants are cooling the planet

We pump all kinds of substances into the atmosphere. Nitrous oxide and CFCs warm the planet as CO2 does. Black carbon – soot – warms things up overall by soaking up heat, but cools Earth’s surface by shading it. But other pollutants reflect the sun’s heat back into space and so cool things down…

Burning sulphurous fossil fuels has been adding huge amounts of SO2 to the atmosphere. Between the 1940s and 1970s, this pollution was so high that it balanced out warming from CO2. But as western countries limited sulphur emissions to tackle acid rain, the masking effect was lost and global warming resumed.

Sulphur emissions began rising again in 2000, largely as China built more coal-fired power stations. Now China is installing sulphur-scrubbing equipmentin those power stations. If SO2 emissions fall, global warming could accelerate…

Climate unknown: How great our cooling effects are

Pollutants that form minute aerosol droplets in the atmosphere have horrendously complex effects. How much radiation is reflected by sulphur dioxide aerosols varies according to the size of the droplets, their height in the atmosphere, whether it is night or day, what season it is and several other factors…

But if aerosol cooling is larger than generally assumed, the planet will warm more rapidly than predicted as soon as aerosol levels fall.

Climate known: The planet is going to get a lot hotter

Take water. Water vapour is a powerful greenhouse gas. When an atmosphere warms, it holds more of the stuff. As soon as more CO2 enters a watery planet’s atmosphere, its warming effect is rapidly amplified.

This is not the only such “positive feedback” effect. Any warming also leads to the rapid loss of snow cover and sea ice, both of which reflect sunlight back into space. The result is that more heat is absorbed and warming escalates. Longer timescales bring changes in vegetation that also affect heat absorption, and the possibility that land and oceans begin to release CO2 rather than absorb it. Over hundreds or thousands of years, vast ice sheets can melt away, further decreasing the planet’s reflectivity. Barring some unexpected catastrophe such as a megavolcano eruption, then, the planet is going to warm considerably.

Climate unknown: Just how much hotter things will get

The bulk of the evidence still points to a short-term climate sensitivity of around 3 °C, as the IPCC’s models suggest. But while a figure much lower than that is unlikely, there is a significant probability of higher sensitivities (see diagram)…

Climate unknown: How things will change in each region

Even with an average global temperature rise of just 2 °C, there will be some pretty dramatic changes. Which regions are going to turn into tropical paradises? Which into unbearably humid hellholes? Which into deserts? For planning purposes it would be useful to know.

Unfortunately, we don’t. The broad picture is that the tropics will expand and get a bit wetter. The dry zones either side of the tropics will get dryer and move towards the poles. High latitudes will get much warmer and wetter.

When it comes to the finer details, though, there is not much agreement…

Climate known: Sea level is going to rise many metres

Studies of sea level and temperatures over the past million years suggest that each 1°C rise in the global mean temperature eventually leads to a 20-metre rise in sea level.

That makes the effects of a rise of at least 2°C rather alarming. How alarming depends on how quickly the great ice sheets melt in response to warming – and that is another big unknown.

Climate unknown: How quickly sea level will rise

We have little clue how much room we have for manoeuvre. Past melting episodes provide little help. Melting can be rapid: as the last ice age ended, the disappearance of the ice sheet covering North America increased sea level by more than a metre per century at times. It is unclear if Greenland’s ice will melt as rapidly.

To predict exactly how quickly sea level will rise, we would first need to know how much hotter the planet is going to get. As we have seen, we don’t.

Climate unknown: How serious the threat to life is

Many species will have to move to stay within a tolerable temperature range. Animals will also have to change their time of hatching or migration to stay in sync with food sources. Many won’t make it: theoretical studies based on relatively conservative warming scenarios have come up with dire estimates of a third or more terrestrial species going extinct. Real-world studies of the effects of warming so far have backed these conclusions.

Climate known: There will be more floods and droughts

Warm air holds more moisture: about 5 per cent more for each 1°C temperature increase. This means more rain or snow overall, and more intense rain or snowfall on average.This trend is already evident, and is stronger than models predict.

More intense precipitation means more floods…

Although most of the world will get more rainfall on average, dry periods will still occur from time to time. When they do, soils will dry out faster because of the higher temperatures. Once soils dry out, the sun’s heat goes into warming the land rather than evaporating water, triggering or exacerbating heatwaves.

Climate unknown: Will there be more hurricanes?

As the lower atmosphere gets warmer and wetter over the coming decades, there will be more fuel available to power extreme storms. But how often will this fuel ignite? Hurricanes are relatively rare because they form only when conditions are just right. While higher sea-surface temperatures will favour their formation, stronger high-level winds may rip them apart. The result could be fewer hurricanes overall, but with greater strength when they do occur. As the destructive power of hurricanes rises exponentially with increasing wind speed, a few intense storms could wreak more havoc than many weak ones.

At temperate northern latitudes, the news might be better. There winter storms are powered largely by the temperature differences between cold air from the poles and warmer air masses from the tropics. Such storms may become less common as rapid warming in the Arctic reduces the temperature differences.

Climate unknown: If and when tipping points will come

If the Arctic suddenly cooled, sea ice would recover within a few years. If the great ice sheets of Greenland and Antarctica lose enough ice to raise sea level a metre or more, though, it would take thousands of years for snowfall to build up the ice sheets again. The risk is real: we know that the West Antarctic ice sheet has collapsed many times in the past, raising sea levels at least 3 metres.

We can identify many other such dangerous “tipping points“. The Amazon could flip from being rainforest to grassland, just as the Sahara suddenly dried up 8000 years ago. Massive amounts of methane could be released from undersea methane hydrates.

I really like the concluding article. Here it is (most of it anyway) in its sciency glory:

The biggest climate change uncertainty of all

WOULD you jump off a skyscraper? What if someone told you that physicists still don’t fully understand gravity: would you risk it then?

We still have a lot to learn about gravity, but that doesn’t make jumping off a skyscraper a good idea. Similarly, we still have a lot to learn about the climate but that doesn’t make pumping ever more greenhouse gases into the atmosphere a good idea.

Uncertainty is one of the defining features of science. Absolute proof exists only in mathematics. In the real world, it is impossible to prove that scientific theories are right in every circumstance; we can only prove that they are wrong. This provisionality can cause people to lose faith in the conclusions of science, but it shouldn’t. The recent history of science is not one of well-established theories being proven wrong. Rather, it is of theories being gradually refined. Newton’s laws of gravity may have been superseded, but they are still accurate enough to be used for many purposes…

In fact, perhaps the biggest source of uncertainty is not to do with the science at all, or the global climate system, but with us.

Will we burn every last drop of fossil fuel? Or will some amazing technological advance make the switch to renewable energy a no-brainer? Will we keep building cities in places vulnerable to sea-level rise, like Shanghai?

Even politicians who back action to curb global warming are not delivering on their promises. Many of the countries that signed up to the Kyoto protocol have failed to achieve their very modest targets. Meanwhile, some countries in Europe are signing up to more ambitious goals for reducing emissions by 2030, while still commissioning coal-fired power stations.

By the time the need for drastic action becomes blindingly obvious, the best opportunity to curb harmful change will have been squandered. Yet if draconian action is taken today, any success in limiting warming will be greeted with scepticism that drastic measures were ever worthwhile or even necessary. Perhaps the greatest unknown, then, is how to persuade people to act today to help protect their long-term future, not to mention future generations.

One more thing is certain: only science can reveal how our planet can provide a decent home for billions of people without toppling over the precipice.

I love it. Succinct, honest and forthright. 

Reviews of Dark Matter and the Big Bang

There are two new articles today with some nice overviews of central topics in cosmology: The Status of Dark Matter from Starts With a Bang!, and The Big Bang: What Really Happened at Our Universe’s Birth from Space.com. They’re both relatively brief and easy to read, and afterwards you’ll be able to teach your friends about the nature of the universe, and how cool and smart you are.

The latter article is part 5 of an 8 day series at Space.com called The History & Future of the Cosmos; I’ll probably check out the rest of the articles soon, and you should too.

The Science of Cloning

LiveScience has a good FAQ article on the basics of how animals are cloned. Cloning is only going to get more prominent in the future, so it wouldn’t hurt to have an idea of what it is and how it’s done. I won’t summarize it here, since it’s already explained briefly and nicely. The last paragraph mentions the recent successful cloning of a human embryo for harvesting embryonic stem cells, which I discussed a while ago along with some background on stem cells.

As always, feel free to let me know if you’d like any aspect explained in more detail.

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