Lawrence Krauss: The Flavors of Nothing
Lawrence Maxwell Krauss is a Canadian-American theoretical physicist who is a professor of physics, and the author of several bestselling books, including The Physics of Star Trek and A Universe from Nothing. He is an advocate of scientific skepticism, science education, and the science of morality. Krauss is one of the few living physicists referred to by Scientific American as a "public intellectual", and he is the only physicist to have received awards from all three major U.S. physics societies: the American Physical Society, the American Association of Physics Teachers, and the American Institute of Physics.
Lawrence Krauss: When you think about nothing you have to be a little more careful than you normally are because, in fact, nothing is a physical concept because it's the absence of something, and something is a physical concept. And what we've learned over the last hundred years is that nothing is much more complicated than we would've imagined otherwise.
For example, the simplest kind of nothing is the kind of nothing of the Bible. Say an infinite empty space, an infinite dark void of the Bible. You know, nothing in it, no particles, no radiation, nothing. Well, that kind of nothing turns out to be full of stuff in a way or at least much more complicated than you might have imagined because due to the laws of quantum mechanics and relativity, we now know that empty space is a boiling bubbling brew of virtual particles that are popping in and out of existence at every moment.
And in fact, for that kind of nothing, if you wait long enough, you're guaranteed by the laws of quantum mechanics to produce something. So the difference between empty space with stuff in it and empty space with nothing in it is not that great anymore. In fact, they're different versions of the same thing. So the transition from nothing to something is not so surprising. Now you might say well that's not good enough because you have space. Where did the space come from? Well, a more demanding definition of nothing is no space, but, in fact, once you apply the laws of quantum mechanics to gravity itself, then space itself becomes a quantum mechanical variable and fluctuates in and out of existence and you can literally, by the laws of quantum mechanics, create universes.
Create spaces and times, where there was no space and time before. So now you got no particles, no radiation, no space, no time, that sounds like nothing. But then you might say, well, you know what, you got the laws of physics. You got the laws of nature. The laws themselves are somehow something; although, I would argue in fact that that is not at all obvious or clear or necessary. But even there, it turns out physics potentially has an answer because we now have good reason to believe that even the laws of physics themselves are kind of arbitrary.
There may be an infinite number of universes, and in each universe that's been created, the laws of physics are different. It's completely random. And the laws themselves come into existence when the universe comes into existence. So there's no pre-existing fundamental law. Anything that can happen, does happen. And therefore, you got no laws, no space, no time, no particles, no radiation. That's a pretty good definition of nothing.
Directed / Produced by Jonathan Fowler and Elizabeth Rodd
Theoretical Physicist Lawrence Krauss explains the different types of nothing. Or something.
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We're creating pigs with human immune systems to study illness
Are "humanized" pigs the future of medical research?
The U.S. Food and Drug Administration requires all new medicines to be tested in animals before use in people. Pigs make better medical research subjects than mice, because they are closer to humans in size, physiology and genetic makeup.
In recent years, our team at Iowa State University has found a way to make pigs an even closer stand-in for humans. We have successfully transferred components of the human immune system into pigs that lack a functional immune system. This breakthrough has the potential to accelerate medical research in many areas, including virus and vaccine research, as well as cancer and stem cell therapeutics.
Existing biomedical models
Severe Combined Immunodeficiency, or SCID, is a genetic condition that causes impaired development of the immune system. People can develop SCID, as dramatized in the 1976 movie “The Boy in the Plastic Bubble." Other animals can develop SCID, too, including mice.
Researchers in the 1980s recognized that SCID mice could be implanted with human immune cells for further study. Such mice are called “humanized" mice and have been optimized over the past 30 years to study many questions relevant to human health.
Mice are the most commonly used animal in biomedical research, but results from mice often do not translate well to human responses, thanks to differences in metabolism, size and divergent cell functions compared with people.
Nonhuman primates are also used for medical research and are certainly closer stand-ins for humans. But using them for this purpose raises numerous ethical considerations. With these concerns in mind, the National Institutes of Health retired most of its chimpanzees from biomedical research in 2013.
Alternative animal models are in demand.
Swine are a viable option for medical research because of their similarities to humans. And with their widespread commercial use, pigs are met with fewer ethical dilemmas than primates. Upwards of 100 million hogs are slaughtered each year for food in the U.S.
Humanizing pigs
In 2012, groups at Iowa State University and Kansas State University, including Jack Dekkers, an expert in animal breeding and genetics, and Raymond Rowland, a specialist in animal diseases, serendipitously discovered a naturally occurring genetic mutation in pigs that caused SCID. We wondered if we could develop these pigs to create a new biomedical model.
Our group has worked for nearly a decade developing and optimizing SCID pigs for applications in biomedical research. In 2018, we achieved a twofold milestone when working with animal physiologist Jason Ross and his lab. Together we developed a more immunocompromised pig than the original SCID pig – and successfully humanized it, by transferring cultured human immune stem cells into the livers of developing piglets.
During early fetal development, immune cells develop within the liver, providing an opportunity to introduce human cells. We inject human immune stem cells into fetal pig livers using ultrasound imaging as a guide. As the pig fetus develops, the injected human immune stem cells begin to differentiate – or change into other kinds of cells – and spread through the pig's body. Once SCID piglets are born, we can detect human immune cells in their blood, liver, spleen and thymus gland. This humanization is what makes them so valuable for testing new medical treatments.
We have found that human ovarian tumors survive and grow in SCID pigs, giving us an opportunity to study ovarian cancer in a new way. Similarly, because human skin survives on SCID pigs, scientists may be able to develop new treatments for skin burns. Other research possibilities are numerous.
The ultraclean SCID pig biocontainment facility in Ames, Iowa. Adeline Boettcher, CC BY-SA
Pigs in a bubble
Since our pigs lack essential components of their immune system, they are extremely susceptible to infection and require special housing to help reduce exposure to pathogens.
SCID pigs are raised in bubble biocontainment facilities. Positive pressure rooms, which maintain a higher air pressure than the surrounding environment to keep pathogens out, are coupled with highly filtered air and water. All personnel are required to wear full personal protective equipment. We typically have anywhere from two to 15 SCID pigs and breeding animals at a given time. (Our breeding animals do not have SCID, but they are genetic carriers of the mutation, so their offspring may have SCID.)
As with any animal research, ethical considerations are always front and center. All our protocols are approved by Iowa State University's Institutional Animal Care and Use Committee and are in accordance with The National Institutes of Health's Guide for the Care and Use of Laboratory Animals.
Every day, twice a day, our pigs are checked by expert caretakers who monitor their health status and provide engagement. We have veterinarians on call. If any pigs fall ill, and drug or antibiotic intervention does not improve their condition, the animals are humanely euthanized.
Our goal is to continue optimizing our humanized SCID pigs so they can be more readily available for stem cell therapy testing, as well as research in other areas, including cancer. We hope the development of the SCID pig model will pave the way for advancements in therapeutic testing, with the long-term goal of improving human patient outcomes.
Adeline Boettcher earned her research-based Ph.D. working on the SCID project in 2019.
Christopher Tuggle, Professor of Animal Science, Iowa State University and Adeline Boettcher, Technical Writer II, Iowa State University
This article is republished from The Conversation under a Creative Commons license. Read the original article.
A new warning to sign to predict volcanic eruptions?
Satellite imagery can help better predict volcanic eruptions by monitoring changes in surface temperature near volcanoes.
- A recent study used data collected by NASA satellites to conduct a statistical analysis of surface temperatures near volcanoes that erupted from 2002 to 2019.
- The results showed that surface temperatures near volcanoes gradually increased in the months and years prior to eruptions.
- The method was able to detect potential eruptions that were not anticipated by other volcano monitoring methods, such as eruptions in Japan in 2014 and Chile in 2015.
How can modern technology help warn us of impending volcanic eruptions?
One promising answer may lie in satellite imagery. In a recent study published in Nature Geoscience, researchers used infrared data collected by NASA satellites to study the conditions near volcanoes in the months and years before they erupted.
The results revealed a pattern: Prior to eruptions, an unusually large amount of heat had been escaping through soil near volcanoes. This diffusion of subterranean heat — which is a byproduct of "large-scale thermal unrest" — could potentially represent a warning sign of future eruptions.
Conceptual model of large-scale thermal unrestCredit: Girona et al.
For the study, the researchers conducted a statistical analysis of changes in surface temperature near volcanoes, using data collected over 16.5 years by NASA's Terra and Aqua satellites. The results showed that eruptions tended to occur around the time when surface temperatures near the volcanoes peaked.
Eruptions were preceded by "subtle but significant long-term (years), large-scale (tens of square kilometres) increases in their radiant heat flux (up to ~1 °C in median radiant temperature)," the researchers wrote. After eruptions, surface temperatures reliably decreased, though the cool-down period took longer for bigger eruptions.
"Volcanoes can experience thermal unrest for several years before eruption," the researchers wrote. "This thermal unrest is dominated by a large-scale phenomenon operating over extensive areas of volcanic edifices, can be an early indicator of volcanic reactivation, can increase prior to different types of eruption and can be tracked through a statistical analysis of little-processed (that is, radiance or radiant temperature) satellite-based remote sensing data with high temporal resolution."
Temporal variations of target volcanoesCredit: Girona et al.
Although using satellites to monitor thermal unrest wouldn't enable scientists to make hyper-specific eruption predictions (like predicting the exact day), it could significantly improve prediction efforts. Seismologists and volcanologists currently use a range of techniques to forecast eruptions, including monitoring for gas emissions, ground deformation, and changes to nearby water channels, to name a few.
Still, none of these techniques have proven completely reliable, both because of the science and the practical barriers (e.g. funding) standing in the way of large-scale monitoring. In 2014, for example, Japan's Mount Ontake suddenly erupted, killing 63 people. It was the nation's deadliest eruption in nearly a century.
In the study, the researchers found that surface temperatures near Mount Ontake had been increasing in the two years prior to the eruption. To date, no other monitoring method has detected "well-defined" warning signs for the 2014 disaster, the researchers noted.
The researchers hope satellite-based infrared monitoring techniques, combined with existing methods, can improve prediction efforts for volcanic eruptions. Volcanic eruptions have killed about 2,000 people since 2000.
"Our findings can open new horizons to better constrain magma–hydrothermal interaction processes, especially when integrated with other datasets, allowing us to explore the thermal budget of volcanoes and anticipate eruptions that are very difficult to forecast through other geophysical/geochemical methods."
Weird science shows unseemly way beetles escape after being eaten
Certain water beetles can escape from frogs after being consumed.
- A Japanese scientist shows that some beetles can wiggle out of frog's butts after being eaten whole.
- The research suggests the beetle can get out in as little as 7 minutes.
- Most of the beetles swallowed in the experiment survived with no complications after being excreted.
In what is perhaps one of the weirdest experiments ever that comes from the category of "why did anyone need to know this?" scientists have proven that the Regimbartia attenuata beetle can climb out of a frog's butt after being eaten.
The research was carried out by Kobe University ecologist Shinji Sugiura. His team found that the majority of beetles swallowed by black-spotted pond frogs (Pelophylax nigromaculatus) used in their experiment managed to escape about 6 hours after and were perfectly fine.
"Here, I report active escape of the aquatic beetle R. attenuata from the vents of five frog species via the digestive tract," writes Sugiura in a new paper, adding "although adult beetles were easily eaten by frogs, 90 percent of swallowed beetles were excreted within six hours after being eaten and, surprisingly, were still alive."
One bug even got out in as little as 7 minutes.
Sugiura also tried putting wax on the legs of some of the beetles, preventing them from moving. These ones were not able to make it out alive, taking from 38 to 150 hours to be digested.
Naturally, as anyone would upon encountering such a story, you're wondering where's the video. Thankfully, the scientists recorded the proceedings:
The Regimbartia attenuata beetle can be found in the tropics, especially as pests in fish hatcheries. It's not the only kind of creature that can survive being swallowed. A recent study showed that snake eels are able to burrow out of the stomachs of fish using their sharp tails, only to become stuck, die, and be mummified in the gut cavity. Scientists are calling the beetle's ability the first documented "active prey escape." Usually, such travelers through the digestive tract have particular adaptations that make it possible for them to withstand extreme pH and lack of oxygen. The researchers think the beetle's trick is in inducing the frog to open a so-called "vent" controlled by the sphincter muscle.
"Individuals were always excreted head first from the frog vent, suggesting that R. attenuata stimulates the hind gut, urging the frog to defecate," explains Sugiura.
For more information, check out the study published in Current Biology.
Moral and economic lessons from Mario Kart
The design of a classic video game yields insights on how to address global poverty.
- A new essay compares the power-up system in Mario Kart to feedback loops in real-life systems.
- Both try to provide targeted benefits to those who most need them.
- While games are simpler than reality, Mario's example makes the real-life cases easier to understand.
Poverty can be a self-sustaining cycle that might require an external influence to break it. A new paper published in Nature Sustainability and written by professor Andrew Bell of Boston University suggests that we could improve global anti-poverty and economic development systems by turning to an idea in a video game about a race car-driving Italian plumber.
A primer on Mario Kart
For those who have not played it, Mario Kart is a racing game starring Super Mario and other characters from the video game franchise that bears his name. Players race around tracks collecting power-ups that can directly help them, such as mushrooms that speed up their karts, or slow down other players, such as heat-seeking turtle shells that momentarily crash other karts.
The game is well known for having a mechanism known as "rubber-banding." Racers in the front of the pack get wimpy power-ups, like banana peels to slip up other karts, while those toward the back get stronger ones, like golden mushrooms that provide extra long speed boosts. The effect of this is that those in the back are pushed towards the center, and those in front don't get any boosts that would make catching them impossible.
If you're in last, you might get the help you need to make a last-minute break for the lead. If you're in first, you have to be on the lookout for these breakouts (and the ever-dreaded blue shells). The game remains competitive and fun.
Rubber-banding: A moral and economic lesson from Mario Kart
In the real world, we see rubber-banding used all the time. Welfare systems tend to provide more aid to those who need it than those who do not. Many of them are financed by progressive taxation, which is heavier on the well-off than the down-and-out. Some research suggests that these do work, as countries with lower levels of income inequality have higher social mobility levels.
It is a little more difficult to use rubber-banding in real life than in a video game, of course. While in the game, it is easy to decide who is doing well and who is not, things can be a little more muddled in reality. Furthermore, while those in a racing game are necessarily antagonistic to each other, real systems often strive to improve conditions for everybody or to reach common goals.
As Bell points out, rubber-banding can also be used to encourage sustainable, growth programs that help the poor other than welfare. They point out projects such as irrigation systems in Pakistan or Payments for Ecosystems Services (PES) schemes in Malawi, which utilize positive feedback loops to both provide aid to the poor and promote stable systems that benefit everyone.
Rubber-banding feedback loops in different systems. Mario Kart (a), irrigation systems in Pakistan (b), and PES operations in Malawi (c) are shown. Links between one better-off (blue) and one worse-off (red) individual are highlighted. Feedback in Mario Kart (a), designed to balance the racers, imprAndrew Bell/ Nature Sustainability
In the Malawi case, farmers were paid to practice conservation agriculture to reduce the amount of sediment from their farms flowing into a river. This immediately benefits hydroelectric producers and their customers but also provides real benefits to farmers in the long run as their soil doesn't erode. By providing an incentive to the farmers to conserve the soil, a virtuous cycle of conservation, soil improvement, and improved yields can begin.
While this loop differs from the rubber-banding in Mario, the game's approach can help illustrate the benefits of rubber-banding in achieving a more equitable world.
The task now, as Bell says in his paper, is to look at problems that exist and find out "what the golden mushroom might be."
