South Korea’s state-backed Institute for Basic Science has ordered the first of five cubesats to study Venus from LEO starting next year, bolstering sustained planetary research as flagship missions face budget uncertainty.
EchoStar has ordered another geostationary satellite for its Dish Network TV broadcast business, even as the company signals the possibility of seeking bankruptcy protection amid a regulatory probe into its mobile spectrum licenses.
Since 1912, we’ve known that the Andromeda galaxy is racing towards our own Milky Way at about 110 kilometres per second. A century later, in 2012, astrophysicists at the Space Telescope Science Institute (STScI) in Maryland, US came to a striking conclusion. In four billion years, they predicted, a collision between the two galaxies was a sure thing.
Now, it’s not looking so sure.
Using the latest data from the European Space Agency’s Gaia astrometric mission, astrophysicists led by Till Sawala of the University of Helsinki, Finland re-modelled the impending crash, and found that it’s 50/50 as to whether a collision happens or not.
This new result differs from the 2012 one because it considers the gravitational effect of an additional galaxy, the Large Magellanic Cloud (LMC), alongside the Milky Way, Andromeda and the nearby Triangulum spiral galaxy, M33. While M33’s gravity, in effect, adds to Andromeda’s motion towards us, Sawala and colleagues found that the LMC’s gravity tends to pull the Milky Way out of Andromeda’s path.
“We’re not predicting that the merger is not going to happen within 10 billion years, we’re just saying that from the data we have now, we can’t be certain of it,” Sawala tells Physics World.
“A step in the right direction”
While the LMC contains only around 10% of the Milky Way’s mass, Sawala and colleagues’ work indicates that it may nevertheless be massive enough to turn a head-on collision into a near-miss. Incorporating its gravitational effects into simulations is therefore “a step in the right direction”, says Sangmo Tony Sohn, a support scientist at the STScI and a co-author of the 2012 paper that predicted a collision.
Even with more detailed simulations, though, uncertainties in the motion and masses of the galaxies leave room for a range of possible outcomes. According to Sawala, the uncertainty with the greatest effect on merger probability lies in the so-called “proper motion” of Andromeda, which is its motion as it appears on our night sky. This motion is a mixture of Andomeda’s radial motion towards the centre of the Milky Way and the two galaxies’ transverse motion perpendicular to one another.
If the combined transverse motion is large enough, Andromeda will pass the Milky Way at a distance greater than 200 kiloparsecs (652,000 light years). This would avert a collision in the next 10 billion years, because even when the two galaxies loop back on each other, their next pass would still be too distant, according to the models.
Conversely, a smaller transverse motion would limit the distance at closest approach to less than 200 kiloparsecs. If that happens, Sawala says the two galaxies are “almost certain to merge” because of the dynamical friction effect, which arises from the diffuse halo of old stars and dark matter around galaxies. When two galaxies get close enough, these haloes begin interacting with each other, generating tidal and frictional heating that robs the galaxies of orbital energy and makes them fall ever closer.
The LMC itself is an excellent example of how this works. “The LMC is already so close to the Milky Way that it is losing its orbital energy, and unlike [Andromeda], it is guaranteed to merge with the Milky Way,” Sawala says, adding that, similarly, M33 stands a good chance of merging with Andromeda.
“A very delicate task”
Because Andromeda is 2.5 million light years away, its proper motion is very hard to measure. Indeed, no-one had ever done it until the STScI team spent 10 years monitoring the galaxy, which is also known as M31, with the Hubble Space Telescope – something Sohn describes as “a very delicate task” that continues to this day.
Another area where there is some ambiguity is in the mass estimate of the LMC. “If the LMC is a little more massive [than we think], then it pulls the Milky Way off the collision course with M31 a little more strongly, reducing the possibility of a merger between the Milky Way and M31,” Sawala explains.
The good news is that these ambiguities won’t be around forever. Sohn and his team are currently analysing new Hubble data to provide fresh constraints on the Milky Way’s orbital trajectory, and he says their results have been consistent with the Gaia analyses so far. Sawala agrees that new data will help reduce uncertainties. “There’s a good chance that we’ll know more about what is going to happen fairly soon, within five years,” he says.
Even if the Milky Way and Andromeda don’t collide in the next 10 billion years, though, that won’t be the end of the story. “I would expect that there is a very high probability that they will eventually merge, but that could take tens of billions of years,” Sawala says.
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Scientists who switch research fields suffer a drop in the impact of their new work – a so-called “pivot penalty”. That is according to a new analysis of scientific papers and patents, which finds that the pivot penalty increases the further away a researcher shifts from their previous topic of research.
The analysis has been carried out by a team led by Dashun Wang and Benjamin Jones of Northwestern University in Illinois. They analysed more than 25 million scientific papers published between 1970 and 2015 across 154 fields as well as 1.7 million US patents across 127 technology classes granted between 1985 and 2020.
To identify pivots and quantify how far a scientist moves from their existing work, the team looked at the scientific journals referenced in a paper and compared them with those cited by previous work. The more the set of journals referenced in the main work diverged from those usually cited, the larger the pivot. For patents, the researchers used “technological field codes” to measure pivots.
Larger pivots are associated with fewer citations and a lower propensity for high-impact papers, defined as those in the top 5% of citations received in their field and publication year. Low-pivot work – moving only slightly away from the typical field of research – led to a high-impact paper 7.4% of the time, yet the highest-pivot shift resulted in a high-impact paper only 2.2% of the time. A similar trend was seen for patents.
When looking at the output of an individual researcher, low-pivot work was 2.1% more likely to have a high-impact paper while high-pivot work was 1.8% less likely to do so. The study found the pivot penalty to be almost universal across scientific fields and it persists regardless of a scientist’s career stage, productivity and collaborations.
COVID impact
The researchers also studied the impact of COVID-19, when many researchers pivoted to research linked to the pandemic. After analyzing 83 000 COVID-19 papers and 2.63 million non-COVID papers published in 2020, they found that COVID-19 research was not immune to the pivot penalty. Such research had a higher impact than average, but the further a scientist shifted from their previous work to study COVID-19 the less impact the research had.
“Shifting research directions appears both difficult and costly, at least initially, for individual researchers,” Wang told Physics World. He thinks, however, that researchers should not avoid change but rather “approach it strategically”. Researchers should, for example, try anchoring their new work in the conventions of their prior field or the one they are entering.
To help researchers pivot, Wang says research institutions should “acknowledge the friction” and not “assume that a promising researcher will thrive automatically after a pivot”. Instead, he says, institutions need to design support systems, such as funding or protected time to explore new ideas, or pairing researchers with established scholars in the new field.
I co-founded Mutual Credit Services in 2020 to help small businesses thrive independently of the banking sector. As a financial technology start-up, we’re essentially trying to create a “commons” economy, where power lies in the hands of people, not big institutions, thereby making us more resilient to the climate crisis.
Those goals are probably as insanely ambitious as they sound, which is why my day-to-day work is a mix of complexity economics, monetary theory and economic anthropology. I spend a lot of time thinking hard about how these ideas fit together, before building new tech platforms, apps and services, which requires analytical and design thinking.
There are still many open questions about business, finance and economics that I’d like to do research on, and ultimately develop into new services. I’m constantly learning through trial projects and building a pipeline of ideas for future exploration.
Developing the business involves a lot of decision-making, project management and team-building. In fact, I’m spending more and more of my time on commercialization – working out how to bring new services to market, nurturing partnerships and talking to potential early adopters. It’s vital that I can explain novel financial ideas to small businesses in a way they can understand and have confidence in. So I’m always looking for simpler and more compelling ways to describe what we do.
What do you like best and least about your job?
What I like best is the variety and creativity. I’m a generalist by nature, and love using insights from a variety of disciplines. The practical application of these ideas to create a better economy feels profoundly meaningful, and something that I’d be unlikely to get in any other job. I also love the autonomy of running a business. With a small but hugely talented and enthusiastic team, we’ve so far managed to avoid the company becoming rigid and institutionalized. It’s great to work with people on our team and beyond who are excited by what we’re doing, and want to be involved.
The hardest thing is facing the omnicrisis of climate breakdown and likely societal collapse that makes this work necessary in the first place. As with all start-ups, the risk of failure is huge, no matter how good the ideas are, and it’s frustrating to spend so much time on tasks that just keep things afloat, rather than move the mission forward. I work long hours and the job can be stressful.
What do you know today, that you wish you knew when you were starting out in your career?
I spent a lot of time during my PhD at Liverpool worrying that I’d get trapped in one narrow field, or drift into one of the many default career options. I wish I’d known how many opportunities there are to do original, meaningful and self-directed work – especially if you’re open to unconventional paths, such as the one I’ve followed, and can find the right people to do it with.
It’s also easy to assume that certain skills or fields are out of reach, whereas I’ve found again and again that a mix of curiosity, self-education and carefully-chosen guidance can get you surprisingly far. Many things that once seemed intimidating now feel totally manageable. That said, I’ve also learned that everything takes at least three times longer than expected – especially when you’re building something new. Progress often looks like small compounding steps, rather than a handful of breakthroughs.
Trips to synchrotron facilities could become a thing of the past for some researchers thanks to a new laboratory-scale three-dimensional X-ray diffraction microscope designed by a team from the University of Michigan, US. The device, which is the first of its kind, uses a liquid-metal-jet electrode to produce high-energy X-rays and can probe almost everything a traditional synchrotron can. It could therefore give a wider community of academic and industrial researchers access to synchrotron-style capabilities.
Synchrotrons are high-energy particle accelerators that produce bright, high-quality beams of coherent electromagnetic radiation at wavelengths ranging from the infrared to soft X-rays. To do this, they use powerful magnets to accelerate electrons in a storage ring, taking advantage of the fact that accelerated electrons emit electromagnetic radiation.
One application for this synchrotron radiation is a technique called three-dimensional X-ray diffraction (3DXRD) microscopy. This powerful technique enables scientists to study the mechanical behaviour of polycrystalline materials, and it works by constructing three-dimensional images of a sample from X-ray images taken at multiple angles, much as a CT scan images the human body. Instead of the imaging device rotating around a patient, however, it is the sample that rotates in the focus of the powerful X-ray beam.
At present, 3DXRD can only be performed at synchrotrons. These are national and international facilities, and scientists must apply for beamtime months or even years in advance. If successful, they receive a block of time lasting six days at the most, during which they must complete all their experiments.
A liquid-metal-jet anode
Previous attempts to make 3DXRD more accessible by downscaling it have largely been unsuccessful. In particular, efforts to produce high-energy X-rays using electrical anodes have foundered because these anodes are traditionally made of solid metal, which cannot withstand the extremely high power of electrons needed to produce X-rays.
The new lab-scale device developed by mechanical engineer Ashley Bucsek and colleagues overcomes this problem thanks to a liquid-metal-jet anode that can absorb more power and therefore produce a greater number of X-ray photons per electrode surface area. The sample volume is illuminated by a monochromatic box or line-focused X-ray beam while diffraction patterns are serially recorded as the sample rotates full circle. “The technique is capable of measuring the volume, position, orientation and strain of thousands of polycrystalline grains simultaneously,” Bucsek says.
When members of the Michigan team tested the device by imaging samples of titanium alloy samples, they found it was as accurate as synchrotron-based 3DXRD, making it a practical alternative. “I conducted my PhD doing 3DXRD experiments at synchrotron user facilities, so having full-time access to a personal 3DXRD microscope was always a dream,” Bucsek says. “My colleagues and I hope that the adaptation of this technology from the synchrotron to the laboratory scale will make it more accessible.”
The design for the device, which is described in Nature Communications, was developed in collaboration with a US-based instrumentation firm, PROTO Manufacturing. Bucsek says she is excited by the possibility that commercialization will make 3DXRD more “turn-key” and thus reduce the need for specialized knowledge in the field.
The Michigan researchers now hope to use their instrument to perform experiments that must be carried out over long periods of time. “Conducting such prolonged experiments at synchrotron user facilities would be difficult, if not impossible, due to the high demand, so, lab-3DXRD can fill a critical capability gap in this respect,” Bucsek tells Physics World.
Rose Yu has drawn on the principles of fluid dynamics to improve deep learning systems that predict traffic, model the climate, and stabilize drones during flight.
The White House is withdrawing the nomination of Jared Isaacman to be administrator of NASA, throwing an agency already reeling from proposed massive budget cuts into further disarray.
Blue Origin sent six people to space on a suborbital spaceflight May 31 that the company’s chief executive says is both a good business and a way to test technology.
Firm evidence of Majorana bound states in quantum dots has been reported by researchers in the Netherlands. Majorana modes appeared at both edges of a quantum dot chain when an energy gap suppressed them in the centre, and the experiment could allow researchers to investigate the unique properties of these particles in hitherto unprecedented detail. This could bring topologically protected quantum bits (qubits) for quantum computing one step closer.
Majorana fermions were first proposed in 1937 by the Italian physicist Ettore Majorana. They were imagined as elementary particles that would be their own antiparticles. However, such elementary particles have never been definitively observed. Instead, physicists have worked to create Majorana quasiparticles (particle-like collective excitations) in condensed matter systems.
In 2001, the theoretical physicist Alexei Kitaev at Microsoft Research, proposed that “Majorana bound states” could be produced in nanowires comprising topological superconductors. The Majorana quasiparticle would exist as a single nonlocal mode at either end of a wire, while being zero-valued in the centre. Both ends would be constrained by the laws of physics to remain identical despite being spatially separated. This phenomenon could produce “topological qubits” robust to local disturbance.
Microsoft and others continue to research Majorana modes using this platform to this day. Multiple groups claim to have observed them, but this remains controversial. “It’s still a matter of debate in these extended 1D systems: have people seen them? Have they not seen them?”, says Srijit Goswami of QuTech in Delft.
Controlling disorder
In 2012, theoretical physicists Jay Sau, then of Harvard University and Sankar Das Sarma of the University of Maryland proposed looking for Majorana bound states in quantum dots. “We looked at [the nanowires] and thought ‘OK, this is going to be a while given the amount of disorder that system has – what are the ways this disorder could be controlled?’ and this is exactly one of the ways we thought it could work,” explains Sau. The research was not taken seriously at the time, however, Sau says, partly because people underestimated the problem of disorder.
Goswami and others have previously observed “poor man’s Majoranas” (PMMs) in two quantum dots. While they share some properties with Majorana modes, PMMs lack topological protection. Last year the group coupled two spin-polarized quantum dots connected by a semiconductor–superconductor hybrid material. At specific points, the researchers found zero-bias conductance peaks.
“Kitaev says that if you tune things exactly right you have one Majorana on one dot and another Majorana on another dot,” says Sau. “But if you’re slightly off then they’re talking to each other. So it’s an uncomfortable notion that they’re spatially separated if you just have two dots next to each other.”
Recently, a group that included Goswami’s colleagues at QuTech found that the introduction of a third quantum dot stabilized the Majorana modes. However, they were unable to measure the energy levels in the quantum dots.
Zero energy
In new work, Goswami’s team used systems of three electrostatically-gated, spin-polarized quantum dots in a 2D electron gas joined by hybrid semiconductor–superconductor regions. The quantum dots had to be tuned to zero energy. The dots exchanged charge in two ways: by standard electron hopping through the semiconductor and by Cooper-pair mediated coupling through the superconductor.
“You have to change the energy level of the superconductor–semiconductor hybrid region so that these two processes have equal probability,” explains Goswami. “Once you satisfy these conditions, then you get Majoranas at the ends.”
In addition to more topological protection, the addition of a third qubit provided the team with crucial physical insight. “Topology is actually a property of a bulk system,” he explains; “Something special happens in the bulk which gives rise to things happening at the edges. Majoranas are something that emerge on the edges because of something happening in the bulk.” With three quantum dots, there is a well-defined bulk and edge that can be probed separately: “We see that when you have what is called a gap in the bulk your Majoranas are protected, but if you don’t have that gap your Majoranas are not protected,” Goswami says.
To produce a qubit will require more work to achieve the controllable coupling of four Majorana bound states and the integration of a readout circuit to detect this coupling. In the near-term, the researchers are investigating other phenomena, such as the potential to swap Majorana bound states.
Sau is now at the University of Maryland and says that an important benefit of the experimental platform is that it can be determined unambiguously whether or not Majorana bound states have been observed. “You can literally put a theory simulation next to the experiment and they look very similar.”
The Leinweber Foundation has awarded five US institutions $90m to create their own theoretical research institutes. The investment, which the foundation says is the largest ever for theoretical physics research, will be used to fund graduate students and postdocs at each institute as well as several Leinweber Physics Fellows.
The Leinweber Foundation was founded in 2015 by the software entrepreneur Larry Leinweber. In 1982 Leinweber founded the software company New World Systems Corporation, which provided software to the emergency services. In 2015 he sold the company to Tyler Technologies for $670m.
Based in Michigan, Leinweber Foundation supports research, education and community endeavours where it has provided Leinweber Software Scholarships to undergraduates at Michigan’s universities.
A Leinweber Institute for Theoretical Physics (LITP) will now be created at the universities of California, Berkeley, Chicago and Michigan as well as at the Massachusetts Institute of Technology (MIT) and at Princeton’s Institute for Advanced Study (IAS), where the institute will instead be named the Leinweber Forum for Theoretical and Quantum Physics.
The MIT LIPT, initially led by Washington Taylor before physicist Tracy Slatyer takes over later this year, will receive $20m from the foundation and will provide support for six postdocs, six graduate students as well as visitors, seminars and “other scholarly activities”.
“This landmark endowment from the Leinweber Foundation will enable us to support the best graduate students and postdoctoral researchers to develop their own independent research programmes and to connect with other researchers in the Leinweber Institute network,” says Taylor.
Spearing innovation
UC Berkeley, meanwhile, will receive $14.4m from the foundation in which the existing Berkeley Center for Theoretical Physics (BITP) will be renamed LITP at Berkeley and led by physicist Yasunori Nomura.
The money will be used for four postdoc positions to join the existing 15 at the BITP as well as to support graduate students and visitors. “This is transformative,” notes Nomura. “The gift will really have a huge impact on a wide range of research at Berkeley, including particle physics, quantum gravity, quantum information, condensed matter physics and cosmology.”
The remaining $37.2m will be split between the Leinweber Forum for Theoretical and Quantum Physics at the IAS and at Michigan, in which the existing Leinweber Center for Theoretical Physics will expand and become an institute.
“Theoretical physics may seem abstract to many, but it is the tip of the spear for innovation. It fuels our understanding of how the world works and opens the door to new technologies that can shape society for generations,” says Leinweber in a statement. “As someone who has had a lifelong fascination with theoretical physics, I hope this investment not only strengthens U.S. leadership in basic science, but also inspires curiosity, creativity, and groundbreaking discoveries for generations to come.”
Connexion
