Big Impact: A Cosmic Collision
Heidi B. Hammel joined The Planetary Society's Board of Directors in 2005. A Senior Research Scientist with the Space Science Institute in Boulder, Colorado, Hammel herself lives in Ridgefield, Connecticut.
She received her undergraduate degree from the Massachusetts Institute of Technology in 1982 and her Ph.D. in physics and astronomy from the University of Hawaii in 1988. After a post-doctoral position at the Jet Propulsion Laboratory (Pasadena, California), Hammel returned to MIT, where she spent nearly nine years as a Principal Research Scientist in the Department of Earth, Atmospheric, and Planetary Sciences.
Hammel primarily studies outer planets and their satellites, with a focus on observational techniques. Hammel received the 2002 American Astronomical Society's Division for Planetary Sciences (AAS/DPS) Sagan Medal for outstanding communication by an active planetary scientist to the general public .
Question: What are scientists doing to protect us from cosmic collisions?
Heidi Hammel: From that comet crashing into Jupiter, we actually learned quite a bit about cosmic collisions. And you can put them in different categories. One of the first things we learned was these collisions happen on human lifetimes. This isn’t stuff that happened a billion years ago. This is going on right now, here in our solar system, massive collisions. And when I say massive, we took one of our impact sites that we had on Jupiter, and someone took it and mapped it onto a globe of the earth. Oh, it’s scary, you know. If one of these things hit the earth, we’re talking major disruption of the biosphere. We’re talking basically all of us dead. So, gosh, it’s a good thing it happened on Jupiter, not on earth. But at the same time, I mean, it was happening for real, and we could all see it. So it made the concept of cosmic collisions a very real concept on the large scale. Most people have already seen a cosmic collision. If you’ve seen a shooting star ever, you’ve seen a cosmic collision, because a shooting star is not a star. It’s a tiny dust or pea sized fragment of an asteroid or a comet hitting our atmosphere and burning up as it hits in, as it comes in. But those are tiny. It’s the big ones when they hit that could really do some serious damage to the planet and to the biosphere, the people and animals and plants and stuff living on the planet. So Shoemaker-Levy 9 made that real for us. We also learned quite a bit about the atmosphere of Jupiter. Now, you have to remember astronomy is almost always a passive science. Scientists normally like to do experiments. You know, they like to mix this with that and see what happens. They like to take this thing and poke it and see how it reacts. In astronomy we can’t do that. The stars, the planets, the galaxies, are so far away that we just look at them, and we have to learn things by looking at them. But in the case of Shoemaker-Levy 9, nature provided us with some ink that it injected into the atmosphere of Jupiter. The ink was the black material that the comet impacts created, which was basically burned up Jupiter atmosphere, we think. And that ink was dumped into the atmosphere, and then the winds of Jupiter could pick it up and throw it around and move it throughout the atmosphere. What a fantastic experiment for a planetary scientist. It’s like you couldn’t design a better experiment, you know. If I had this like giant pile of ink, inject it into an atmosphere, and watch what happened, you know, that’s what you’d want to do. And Shoemaker-Levy 9 did that. So it allowed us to trace out winds to see which direction they were blowing. Now we knew generally which way most of the winds were blowing in the cloud decks that we see, because we could watch a cloud, or we could watch what the cloud does. But in the upper atmosphere, these clouds are very, very thin and diffuse. And normally we can’t see them or trace them. But Shoemaker-Levy 9 injected chemicals into the upper atmosphere and using telescopes here on earth, we can trace the motion of those chemicals over a period of several years after the impacts, and watch the directions that the winds are blowing in the upper atmosphere. And they were moving more or less the direction that people predicted. The rates were not quite the same. And so that provides us with information we could use to better study the atmosphere of Jupiter itself. We couldn’t have done it without Shoemaker-Levy 9 impacts.
Question: What are scientists doing to protect us from collisions?
Heidi Hammel: Every year they have a conference about planetary protection, because the specter has now visibly been raised at these cosmic collisions actually could happen anytime. So there are scientists and engineers who are actively thinking about ways that we could either deflect an asteroid or comet, or remove the asteroid or comet in some way, move it out of its path. I mean, Hollywood has its own ideas about how to do that. We also have Bruce Willis saving the earth. But in point of fact scientists themselves have been thinking very seriously about how we might deflect an asteroid or comet. And one of the keys is finding them early, because if you find them early enough, and I mean like, 10, 20, 30 years before they’re going to hit the earth, you only need a tiny little push to get them to go off that orbit that they’re on and move them out of the way. It’s the ones that are coming in that you don’t find out about until three days before that, you know, that’s our worst nightmare, because there’s nothing really you can do about it in that case. We have actual programs and telescopes being built now that will have the capability of figuring out the whole population of these earth crossing asteroids. Right now we only know, we think we know about 10% that are out there, 10% of the population. That’s not a happy number, is it, because that means there’s 90% of the objects out there we don’t know about. With some of the large telescopes we’re developing today, we think that within a few, five, ten years of using there large telescopes to map out the whole sky a number of times, repeating, looking for moving objects, tracking their orbits, we think within 10 years we might be able to push that number up to 90%. So we really will have a much clearer understanding of what’s out there that might threaten us. Another big problem, of course, is understanding the bodies themselves. If it’s a comet that’s coming in versus an asteroid, and we think one is rockier and harder, and one is softer and fluffier, and you would want to treat them differently. I mean, you wouldn’t want to take a fluffy thing and then like blow it up, because then you got like a gazillion fluffy bits that are all more or less coming your way. Whereas a hard thing, you know, maybe you could set off like a nuclear bomb to push it off it’s track. So understanding what those space rocks or space ice balls, what they’re physically made of, that’s a big part of the MASA exp
As other planets have demonstrated, says Heidi Hammel, the threat is real. For Earth, an early warning system is critical.
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The research also raises an intriguing question: Can we get around the Heisenberg uncertainty principle?
- New experiments with vibrating drums push the boundaries of quantum mechanics.
- Two teams of physicists create quantum entanglement in larger systems.
- Critics question whether the study gets around the famous Heisenberg uncertainty principle.
Recently published research pushes the boundaries of key concepts in quantum mechanics. Studies from two different teams used tiny drums to show that quantum entanglement, an effect generally linked to subatomic particles, can also be applied to much larger macroscopic systems. One of the teams also claims to have found a way to evade the Heisenberg uncertainty principle.
One question that the scientists were hoping to answer pertained to whether larger systems can exhibit quantum entanglement in the same way as microscopic ones. Quantum mechanics proposes that two objects can become "entangled," whereby the properties of one object, such as position or velocity, can become connected to those of the other.
An experiment performed at the U.S. National Institute of Standards and Technology in Boulder, Colorado, led by physicist Shlomi Kotler and his colleagues, showed that a pair of vibrating aluminum membranes, each about 10 micrometers long, can be made to vibrate in sync, in such a way that they can be described to be quantum entangled. Kotler's team amplified the signal from their devices to "see" the entanglement much more clearly. Measuring their position and velocities returned the same numbers, indicating that they were indeed entangled.
Tiny aluminium membranes used by Kotler's team.Credit: Florent Lecoq and Shlomi Kotler/NIST
Evading the Heisenberg uncertainty principle?
Another experiment with quantum drums — each one-fifth the width of a human hair — by a team led by Prof. Mika Sillanpää at Aalto University in Finland, attempted to find what happens in the area between quantum and non-quantum behavior. Like the other researchers, they also achieved quantum entanglement for larger objects, but they also made a fascinating inquiry into getting around the Heisenberg uncertainty principle.
The team's theoretical model was developed by Dr. Matt Woolley of the University of New South Wales. Photons in the microwave frequency were employed to create a synchronized vibrating pattern as well as to gauge the positions of the drums. The scientists managed to make the drums vibrate in opposite phases to each other, achieving "collective quantum motion."
The study's lead author, Dr. Laure Mercier de Lepinay, said: "In this situation, the quantum uncertainty of the drums' motion is canceled if the two drums are treated as one quantum-mechanical entity."
This effect allowed the team to measure both the positions and the momentum of the virtual drumheads at the same time. "One of the drums responds to all the forces of the other drum in the opposing way, kind of with a negative mass," Sillanpää explained.
Theoretically, this should not be possible under the Heisenberg uncertainty principle, one of the most well-known tenets of quantum mechanics. Proposed in the 1920s by Werner Heisenberg, the principle generally says that when dealing with the quantum world, where particles also act like waves, there's an inherent uncertainty in measuring both the position and the momentum of a particle at the same time. The more precisely you measure one variable, the more uncertainty in the measurement of the other. In other words, it is not possible to simultaneously pinpoint the exact values of the particle's position and momentum.
Big Think contributor astrophysicist Adam Frank, known for the 13.8 podcast, called this "a really fascinating paper as it shows that it's possible to make larger entangled systems which behave like a single quantum object. But because we're looking at a single quantum object, the measurement doesn't really seem to me to be 'getting around' the uncertainty principle, as we know that in entangled systems an observation of one part constrains the behavior of other parts."
Ethan Siegel, also an astrophysicist, commented, "The main achievement of this latest work is that they have created a macroscopic system where two components are successfully quantum mechanically entangled across large length scales and with large masses. But there is no fundamental evasion of the Heisenberg uncertainty principle here; each individual component is exactly as uncertain as the rules of quantum physics predicts. While it's important to explore the relationship between quantum entanglement and the different components of the systems, including what happens when you treat both components together as a single system, nothing that's been demonstrated in this research negates Heisenberg's most important contribution to physics."The papers, published in the journal Science, could help create new generations of ultra-sensitive measuring devices and quantum computers.
As bad as this sounds, a new essay suggests that we live in a surprisingly egalitarian age.
- A new essay depicts 700 years of economic inequality in Europe.
- The only stretch of time more egalitarian than today was the period between 1350 to approximately the year 1700.
- Data suggest that, without intervention, inequality does not decrease on its own.
Economic inequality is a constant topic. No matter the cycle — boom or bust — somebody is making a lot of money, and the question of fairness is never far behind.
A recently published essay in the Journal of Economic Literature by Professor Guido Alfani adds an intriguing perspective to the discussion by showing the evolution of income inequality in Europe over the last several hundred years. As it turns out, we currently live in a comparatively egalitarian epoch.
Seven centuries of economic history
Figure 8 from Guido Alfani, Journal of Economic Literature, 2021.
This graph shows the amount of wealth controlled by the top ten percent in certain parts of Europe over the last seven hundred years. Archival documentation similar to — and often of a similar quality as — modern economic data allows researchers to get a glimpse of what economic conditions were like centuries ago. Sources like property tax records and documents listing the rental value of homes can be used to determine how much a person's estate was worth. (While these methods leave out those without property, the data is not particularly distorted.)
The first part of the line, shown in black, represents work by Prof. Alfani and represents the average inequality level of the Sabaudian State in Northern Italy, The Florentine State, The Kingdom of Naples, and the Republic of Venice. The latter part, in gray, is based on the work of French economist Thomas Piketty and represents an average of inequality in France, the United Kingdom, and Sweden during that time period.
Despite the shift in location, the level of inequality and rate of increase are very similar between the two data sets.
Apocalyptic events cause decreases in inequality
Note that there are two substantial declines in inequality. Both are tied to truly apocalyptic events. The first is the Black Death, the common name for the bubonic plague pandemic in the 14th century, which killed off anywhere between 30 and 50 percent of Europe. The second, at the dawn of the 20th century, was the result of World War I and the many major events in its aftermath.
The 20th century as a whole was a time of tremendous economic change, and the periods not featuring major wars are notable for having large experiments in distributive economic policies, particularly in the countries Piketty considers.
The slight stall in the rise of inequality during the 17th century is the result of the Thirty Years' War, a terrible religious conflict that ravaged Europe and left eight million people dead, and of major plagues that affected South Europe. However, the recurrent outbreaks of the plague after the Black Death no longer had much effect on inequality. This was due to a number of factors, not the least of which was the adaptation of European institutions to handle pandemics without causing such a shift in wealth.
In 2010, the last year covered by the essay, inequality levels were similar to those of 1340, with 66 percent of the wealth of society being held by the top ten percent. Also, inequality levels were continuing to rise, and the trends have not ended since. As Prof. Alfani explained in an email to BigThink:
"During the decade preceding the Covid pandemic, economic inequality has shown a slow tendency towards further inequality growth. The Great Recession that began in 2008 possibly contributed to slow down inequality growth, especially in Europe, but it did not stop it. However, the expectation is that Covid-19 will tend to increase inequality and poverty. This, because it tends to create a relatively greater economic damage to those having unstable occupations, or who need physical strength to work (think of the effects of the so-called "long-Covid," which can prove physically invalidating for a long time). Additionally, and thankfully, Covid is not lethal enough to force major leveling dynamics upon society."
Can only disasters change inequality?
That is the subject of some debate. While inequality can occur in any economy, even one that doesn't grow all that much, some things appear to make it more likely to rise or fall.
Thomas Piketty suggested that the cause of changes in inequality levels is the difference in the rate of return on capital and the overall growth rate of the economy. Since the return on capital is typically higher than the overall growth rate, this means that those who have capital to invest tend to get richer faster than everybody else.
While this does explain a great deal of the graph after 1800, his model fails to explain why inequality fell after the Black Death. Indeed, since the plague destroyed human capital and left material goods alone, we would expect the ratio of wealth over income to increase and for inequality to rise. His model can provide explanations for the decline in inequality in the decades after the pandemic, however- it is possible that the abundance of capital could have lowered returns over a longer time span.
The catastrophe theory put forth by Walter Scheidel suggests that the only force strong enough to wrest economic power from those who have it is a world-shattering event like the Black Death, the fall of the Roman Empire, or World War I. While each event changed the world in a different way, they all had a tremendous leveling effect on society.
But not even this explains everything in the above graph. Pandemics subsequent to the Black Death had little effect on inequality, and inequality continued to fall for decades after World War II ended. Prof. Alfani suggests that we remember the importance of human agency through institutional change. He attributes much of the post-WWII decline in inequality to "the redistributive policies and the development of the welfare states from the 1950s to the early 1970s."
What does this mean for us now?
As Professor Alfani put it in his email:
"[H]istory does not necessarily teach us whether we should consider the current trend toward growth in economic inequality as an undesirable outcome or a problem per se (although I personally believe that there is some ground to argue for that). Nor does it teach us that high inequality is destiny. What it does teach us, is that if we do not act, we have no reason whatsoever to expect that inequality will, one day, decline on its own. History also offers abundant evidence that past trends in inequality have been deeply influenced by our collective decisions, as they shaped the institutional framework across time. So, it is really up to us to decide whether we want to live in a more, or a less unequal society."
A team of archaeologists has discovered 3,200-year-old cheese after analyzing artifacts found in an ancient Egyptian tomb. It could be the oldest known cheese sample in the world.
A team of archaeologists has discovered 3,200-year-old cheese after analyzing artifacts found in an ancient Egyptian tomb. It could be the oldest known cheese sample in the world.
The tomb that held the cheese lies in the desert sands south of Cairo. It was first discovered in the 19th century by treasure hunters, who eventually lost the knowledge of its location, leaving the Saharan sands to once again conceal the tomb.
“Since 1885 the tomb has been covered in sand and no-one knew about it,” Professor Ola el-Aguizy of Cairo University told the BBC. “It is important because this tomb was the lost tomb.”
In 2010, a team of archaeologists rediscovered the tomb, which belonged to Ptahmes, a mayor and military chief of staff of the Egyptian city of Memphis in the 13th century B.C. In the tomb, the team found a jar containing a “solidified whitish mass,” among other artifacts.
“The archaeologists suspected [the mass] was food, according to the conservation method and the position of the finding inside the tomb, but we discovered it was cheese after the first tests,” Enrico Greco, the lead author of the paper and a research assistant at Peking University in Beijing, told the The New York Times.
To find out what the substance was, the team had to develop a novel way to analyze the proteins and identify the peptide markers in the samples. They first dissolved parts of the substance and then used mass spectrometry and chromatography to analyze its proteins.
Despite more than 3,000 years spent in the desert, the researchers were able to identify hundreds of peptides (chains of amino acids) in the sample. They found some that were associated with milk from goat, sheep and, interestingly, the African buffalo, a species not usually kept as a domestic animal in modern Africa, as Gizmodo reports.
Those results suggested that the substance was cheese, specifically one that was probably similar in consistency to chevre but with a “really, really acidy” taste, as Dr. Paul Kindstedt, a professor at the University of Vermont who studies the chemistry and history of cheese, told the The New York Times.
“It would be high in moisture; it would be spreadable,” he said. “It would not last long; it would spoil very quickly.”
The researchers also found traces of the bacterium Brucella melitensis, which causes brucellosis, a debilitating disease that can cause endocarditis, arthritis, chronic fatigue, malaise, muscle pain and other conditions. It’s a disease usually contracted by consuming raw dairy products.
“The most common way to be infected [with Brucella melitensis] is by eating or drinking unpasteurized/raw dairy products. When sheep, goats, cows, or camels are infected, their milk becomes contaminated with the bacteria,” the U.S. Centers for Disease Control wrote on its website. “If the milk from infected animals is not pasteurized, the infection will be transmitted to people who consume the milk and/or cheese products.”
Dr. Kindstedt said one reason the study is significant is for its novel use of proteomic analysis, which is the systematic identification and quantification of the complete complement of proteins (the proteome) of a biological system.
“As I say to my students every year when I get to Egypt, someone has to go ahead and analyze these residues with modern capabilities,” he told the The New York Times. “This is a logical next step and I think you’re going to see a lot more of this.”
'The Great Pyramid of Chee-za'. An artist's interpretation of a very ripe, slightly deadly Egyptian tomb cheese. (Credit: Creative commons/Big Think)
However, Dr. Kindstedt did offer a bit of caution on the conclusions the researchers drew from the findings.
“The authors of this new study did some nice work,” he told Gizmodo in a statement. “But in my view, on multiple grounds (I suspect in their zeal to be “the first”), they inferred considerably beyond what their data is capable of supporting within reasonable certainty, and almost certainly they are not the first to have found solid cheese residues in Egyptian tombs, just the first to apply proteomic analyses (which is worthy achievement on its own).”
Our love-hate relationship with browser tabs drives all of us crazy. There is a solution.
- A new study suggests that tabs can cause people to be flustered as they try to keep track of every website.
- The reason is that tabs are unable to properly organize information.
- The researchers are plugging a browser extension that aims to fix the problem.
A lot of ideas that people had about the internet in the 1990s have fallen by the wayside as technology and our usage patterns evolved. Long gone are things like GeoCities, BowieNet, and the belief that letting anybody post whatever they are thinking whenever they want is a fundamentally good idea with no societal repercussions.
While these ideas have been abandoned and the tools that made them possible often replaced by new and improved ones, not every outdated part of our internet experience is gone. A new study by a team at Carnegie Mellon makes the case that the use of tabs in a web browser is one of these outdated concepts that we would do well to get rid of.
How many tabs do you have open right now?
We didn't always have tabs. Introduced in the early 2000s, tabs are now included on all major web browsers, and most users have had access to them for a little over a decade. They've been pretty much the same since they came out, despite the ever changing nature of the internet. So, in this new study, researchers interviewed and surveyed 113 people on their use of — and feelings toward — the ubiquitous tabs.
Most people use tabs for the short-term storage of information, particularly if it's information that is needed again soon. Some keep tabs that they know they'll never get around to reading. Others used them as a sort of external memory bank. One participant described this action to the researchers:
"It's like a manifestation of everything that's on my mind right now. Or the things that should be on my mind right now... So right now, in this browser window, I have a web project that I'm working on. I don't have time to work on it right now, but I know I need to work on it. So it's sitting there reminding me that I need to work on it."
You suffer from tab overload
Unfortunately, trying to use tabs this way can cause a number of problems. A quarter of the interview subjects reported having caused a computer or browser to crash because they had too many tabs open. Others reported feeling flustered by having so many tabs open — a situation called "tab overload" — or feeling ashamed that they appeared disorganized by having so many tabs up at once. More than half of participants reported having problems like this at least two or three times a week.
However, people can become emotionally invested in the tabs. One participant explained, "[E]ven when I'm not using those tabs, I don't want to close them. Maybe it's because it took efforts [sic] to open those tabs and organize them in that way."
So, we have a tool that inefficiently saves web pages that we might visit again while simultaneously reducing our productivity, increasing our anxiety, and crashing our machines. And yet we feel oddly attached to them.
Either the system is crazy or we are.
Skeema: The anti-tab revolution
The researchers concluded that at least part of the problem is caused by tabs not being an ideal way of organizing the work we now do online. They propose a new model that better compartmentalizes tabs by task and subtask, reflects users' mental models, and helps manage the users' attention on what is important right now rather than what might be important later.
To that end, the team also created Skeema, an extension for Google Chrome, that treats tabs as tasks and offers a variety of ways to organize them. Users of an early version reported having fewer tabs and windows open at one time and were better able to manage the information they contained.
Tabs were an improvement over having multiple windows open at the same time, but they may have outlived their usefulness. While it might take a paradigm shift to fully replace the concept, the study suggests that taking a different approach to tabs might be worth trying.
And now, excuse me, while I close some of the 87 tabs I currently have open.