Are we alone in the Galaxy? Is there life in other planets? Have other species evolved to technological societies comparable to ours? Or maybe the right question is, How near are we from detecting signals of alien life?
In 2013 I met Lisa Kaltenegger at The Falling Walls event, in Berlin. She is an astronomer working now at Cornell University, looking for signatures of life in exoplanets (planets outside our solar system). She is quite convinced that we are very near to detecting them.
But last week, an article was published pointing to a star, KIC 8462852, whose light shows weird changes in luminosity. Astronomers can't explain it and, of course, some raise the question, Why not? to the possibility that the behavior is due to an alien technology.
Changes in luminosity is a well known effect in stars, some of them are called variable stars. It can be produced by the star's internal dynamics, spots in its surface, by the transit of one or various planets in front of the star, hiding a small portion of the star. This last effect is used to detect planets around stars, but it lowers, at much, about 1% of its total luminosity. Another method to detect exoplanets is by tracking the gravitational effect of the planet in its star (a small but detectable bouncing effect). For this star those reductions arrive up to an inexplicable 20%. Astronomers have checked all the known physics on luminosity variability in stars, and haven't been able to explain the observations of KIC 8462852. They have also accounted for different errors in their instruments, as well as for the effect of interstellar dust, but haven't found an acceptable explanation.
Are those irregular, unpredictable and inexplicable decreases in luminosity due to a technological structure being built near the star to get its energy to feed an alien society in a nearby planet? If that was the case we would be facing a much more advanced civilization, one that can use and control the energy of its star for its needs. This idea is not new, in fact it can be found in science fiction stories. Fred Hoyle, British astronomer that coined the term "Big Bang" Theory, wrote a novel, The Black Cloud, on something similar. Some scientists say that a civilization that can control its star energy is a type II civilization. If it can control its planet energy it is a type I civilization, and if it can control its galaxy energy it is a type III civilization. We are somewhere around type 0.8 civilization.
But this is not the kind of alien life that Dr. Kaltenegger is expecting to find in the next decades. What she and many other astronomers are studying are signals from the atmosphere of planets. The light that travels through the planet's atmosphere, is absorbed and re-emitted. This changes its properties (frequency distribution, for instance) and can give hints to astronomers about the atmosphere's content. Depending on the content, we can know it can have been produced without the help of organic life (bacteria, plants, ...).
A similar announcement took place in the 1960s, when astronomers detected a very precise periodic signal coming from a star. It was originally coined LGM, after Little Green Men. But that happened to be the discovery of a new type of stars, a pulsar or pulsating star, a star of very high density and magnetic field, that ejects powerful X rays in an specific axes. As the star is rotating and that X ray doesn't need to be in the same axes as the axes of rotation of the star, when the ray points to the Earth we detect is as a pulse, that is repeated every time the star rotates. The speed of rotation can be very high, several times per second.
If KIC 8462852 is the home of a technological alien society or new physics to understand we will know in the near future. In any case, astronomy doesn't stop being surprising and fascinating.
Thirty years after the release of the film “Back to the future“, we finally reach October, 21st, 2015. This is the day when Marty McFly, with Doc. Emmet Brown, come to visit from the year 1985. Most of us have been waiting for this day, and have wondered how similar the real 2015 will be with respect to the 2015 in the movie. Now we can compare.
It is highly surprising how science fiction writers, from the great H.G.Wells or Jules Verne, to Isaac Asimov, Arthur C. Clarke, or Philip K. Dick, didn’t predict the rise of the telecommunications and the smart devices that rule our daily lives. Many sci-fi books talk about flying cars, colonies in Mars, which needs a push in controlling high quantities of energy on demand . This is not here yet, and energy is one of the most important problem that our society faces, so it will not be here for a while.
In the movie Back to the future II, we see traffic jams in flying motorways, but we also see hoover-boards. This fun transportation media for the young ones could be closer than flying cars, although not yet, and with some restrictions. It is not new to see in some laboratories that do research with superconducting materials, some sort of levitating toy train. This is based in the magnetic properties of superconducting materials. These materials can reject the magnetic field to enter in them, creating an effective repulsion that can make them levitate. Unluckily, up to date, we only know materials that have these properties at very low temperatures (~200C below zero). Also, in case of having one hoover-board today, we would need it to operate at those very cold temperatures, and it should work over magnets.
Another cool idea showed in the movie is the highly precision of the weather forecast, which can predict the end of a storm at the level of seconds. We have to know that weather forecast has made a huge improvement with respect to the twentieth century. Nowadays, mathematical models and powerful computers are great tools to provide us with good predictions. We can know with low error margin the weather of the next two to three days, and with reasonable accuracy the weather of the next week. But that level of precision is not going to be in our hands for many years. The knowledge of the initial conditions to do that is beyond our reach, and maybe it wouldn’t really be that useful. Even though we could know with high accuracy the position and velocity of all the molecules in the atmosphere, chaos theory predict that small variations in that information could lead to very different results after a time, and the computational effort would increase exponentially.
On the other side, they show video-conferences, tactile keys, devices that responds to the voice, some short of smart phone that Doc. uses, smart glasses too, and tactile money. There are already among us: Skype, Google glass, i-phone, ... Even the drone that takes the dog for a walk is not far from been used, or at least we have the technology.
Maybe the key element of these movies is the time leap that they take to travel through time. Time travel is allowed by the laws of physics. Indeed, we are currently time traveling to the future at a speed of one second per second. Well, this might not sound thrilling but Einstein’s theory of relativity also tells us how to time-travel to the future faster. To do it we only need a very fast ship. This theory predicts that the faster we move in space, the slower time elapses for us. This way, the faster we travel in space, the faster time will fly, and Marty could travel from 1985 to 2015 in a few hours. But the way he would do it is not by a leap as we see in the movie, but ti would be continuous. For example, having a spaceship that travel through space at relativistic speeds (near 300,000km/s) would make Marty experience a few hours while for the whole Earth time moves 30 years.
John L. Hall, physicist. He has devoted all of his life working in optics, and has contributed greatly in this field. He was awarded with the Nobel Prize of Physics 2005 for his pioneering work on laser-based precision spectroscopy. His research could shed light into the dark matter problem, or make rethink the definition of the unit of time.
Lindy Hall, educational specialist. She has been English teacher and consultant and educational material specialist. Both founded Sci-Teks Discovery Program for Kids, a program to communicate and teach science to kids. They put their long expertise to bring the charm of science to the youngest.
I had the opportunity to meet this wonderful marriage during an Optics Conference at Duke University in March, and I couldn’t help talking to them about science and teaching science.
You have been all your life doing research in optics, and you have contributed much in that field. How much has our society changed in this time, due to our better understanding and knowledge in photonics?
I spent the 44 employed years of my career as a senior research scientist for the U. S. government developing tools and techniques to support ever more precise physical measurements and defining basic standards. I interacted constantly with representatives of other nations to push research in the various areas related to photonics. Advances have been shared by many countries working cooperatively to develop basic knowledge and the innovation of new techniques. What I observe now are increasingly rapid changes and a broadening of available data in so many related fields that it is nearly impossible to keep up and understand how all of these pieces fit together. But in my area of frequency standards the progress has been incredibly powerful, and in the next few years there will be serious planning for changing the basis of timekeeping, from Cesium atoms and microwave frequencies to an optical clock.
The last years you have focussed your effort in teaching science to kids, one very important and not easy task. What led you to do that?
Often Nobel Prize winners take the opportunity to work on a particular cause or issue of social interest. As a university professor, I have always associated with high level, gifted students, while my wife, as a teacher of teenaged children in public schools, has seen examples of many different skills, abilities and attitudes. Together we became really concerned that declining achievement test scores indicate poor preparation and performance by students in mathematics and science, and this will seriously limit their future options for education and employment. We have had many visits to other countries faced with the same dilemma – how to get children to develop competence as well as positive attitudes and enjoyment of math and science subjects. The current popular idea for science education is called STEM (combining science, technology, engineering and mathematics to get better performance). We were hoping to add another “M” for motivation: helping students want to learn, remember and apply what they discovered for themselves. It was our hope that providing free expression, exploration and contact with a variety of materials would encourage expanded views and enjoyment of science learning.
At lot has been written about teaching techniques to communicate science. The activities you perform are experiment based. How do you present science in your activities? What are the goals you seek?
We developed 23 different workshops for elementary school students, 3 for each grade from kindergarten to grade 6 on topics requested by the teachers. Students come in to the library where the materials are placed on tables and have 45 minutes to use and try what interests them. Although there are teachers available, there are no formal lectures or demonstrations. Pupils can choose to work on their own, or with a partner or in a group, and they usually end up teaching each other. They are free to explore and exchange ideas and observations. The kids will often ask high level questions or make smart and insightful comments. We lend the sets of books that go with the activities to their classrooms for several weeks afterward, in case they would like to learn more on their own. The main sadness we experience is that the school runs by a strict schedule, and that often interrupts some “magic” the young people were making and experiencing.
Our society is fundamentally based in science and technology. It seems logical to think that we want our youth to be good in these subjects. From your experience, do you think it is true, or on the contrary, is there a need of these types of activities to complement their training from school?
Your observation represents the basic truth about the American culture and experience 100 years ago. New kinds of machines were appearing and were very appealing. However the designs were early and not well evolved, so “repairing” was a natural hobby or occupation. So the people who were skilled with their hands, or had mechanical insights were very important in that society. Nowadays, it seems much of the complexity and design issues concern embedded software and micro-electronics. So the sophisticated analysis and design classes for the University students have only a marginal advantage to them if they need to maintain their gear. In affluent times it leads to a huge turnover of high-tech hardware – cellphones for example are discarded long before their functioning is degraded. I worry about our evolution and extreme specialization but, still, the networking tools are so powerful that I can easily find a service I need – say keeping my small grassy area tidy and growing well. A few moments online will let me learn other people’s experience with this or that service organization, and the competition keeps the price low. The system is comfortable and works well for the established person, who can thereby grow ever more detached from the reality outdoors. I think the new model will win out, especially if we can understand how to engage the interest and energies of people who no longer have a meaningful and valuable occupation. But the problem is that quick internet answers for a young person does not form a strong enough educational foundation.
I once read the book “Physics for future presidents: the science behind the headlines”, by Richard Muller, which I think is a good idea not just for future presidents, but for all society. From my experience in Spain, science is not seen as culture, but as something weird only accessible to freaks. On the other hand, when I have taught Physics to the broad audience I have seen how well people feel when they understand scientific concepts. Is the situation in the U.S. different? I think you have a long experience in outreach activities and very good science communicators.
The roles of contemporary science and technology are not well understood in the U. S. On the one hand, the society enjoys the products developed for business, communication and entertainment but on the other hand, the step by step necessary preparation for a career in research or development is not so clearly The roles of contemporary science and technology are not well understood in the U. S. On the one hand, the society enjoys the products developed for business, communication and entertainment but on the other hand, the step by step necessary preparation for a career in research or development is not so clearly defined and attractive. Traditionally, four years of college or university experience would be the entry way for a comfortable and satisfying middle class life. I believe this channel is still open, but works well mainly for the extra-bright student, or one whose parents had the time to deeply invest in his/her broader education. A new highway of growth and expanding possibilities involves the front edge of technology adoption by the general public. For example my new iPhone is vastly too complex for a mere University professor to learn efficiently by himself, so a visit to the Apple store was in order. Their young lady (maybe 26 yrs) had served in the US Navy, with extended terms in Japan, Taiwan, as well as two years on the ship. She absolutely knew the iOS system and understood a zillion subtle issues that I didn’t know about, in spite of my being a long-term Apple user, ever since the Apple II days. I am absolutely sure that her future will be wonderful, and with the rewards and freedom to make choices on a scale no ordinary University Graduate could dream about.
But your question is larger: there are fantastic and fascinating Physics questions opened up by the synthesis of advances in experimental techniques, coupled with advances in the theoretical frameworks. We have gone from a secure belief in the Big Bang, to the present case where many people think that Multiverses might well have come from “phase fluctuations,” along the lines believed involved in our Big Bang. The questions about the properties of space and time especially are interesting now, due to progress in the atomic clock business. I was a US representative on the committee of 50 nations that in 1982 proposed the 1983 adoption of a constant numerical value for the speed of light. At that time there were experiments showing the speed of light was constant to 9 digits over a decade of years, and had the same value at microwave and optical frequencies. But now, some 30 years later, the measuring precision is basically 18 digits and a number of questions can be perceived: 1) Is the speed of light really constant over cosmological time scales? (This is just one way the Dark Energy idea may not be correct.) ; 2) Is there a preferred direction or position effect that we traditionally are ignoring? ; 3) Is the Dark Matter arranged smoothly, or is it in clumps? Does it have an optical index of refraction effect? ; 4) Gravity and Quantum theory seem hard to combine – do we need more patience, or is there a real issue? One really good experiment would be to have several types of precise clocks exploring different gravitational fields, while comparing them to each other and an earth-based station, but with the full precision possible.
One current issue is whether Einstein’s preference for having clocks have a standard gravitational redshift is actually correct: Of course the General Relativity gravitational redshift is real – all the GPS satellites must be set with an offset frequency so that the waves at the earth have the correct atomic frequency. But consider a light-pulse clock, where a stiff crystalline material spaces the mirrors, and the repeating light pulses are compared to optical frequencies using an Optical Frequency Comb. The atomic physics forces defining the crystal lattice spacing have a coefficient 42 orders of magnitude larger than the gravitational interactions: how can the gravitational potential have any effect, when the gravitational force is itself nearly negligible? There is an international collaboration called STAR that is planning a ‘satellite in earth orbit’ experiment to check these ideas. The strongly elliptical orbit will scan us through the ranges of Special Relativity time and length effects, in addition to the General Relativity redshift and Shapiro time delay. Of course there is a noon-midnight GR shift due to the sun, which will be observable when we have a full-earth coherent time/frequency transfer system in operation.
Physicist, working in quantum optics and nonlinear dynamics in optical systems. Loves to communicate science.