One of the basic assumptions that Astronomers and Cosmologists start with as the try to understand this Universe we live in is that on the very largest scales it’s the same in every direction. That is, when we look deep into space at all the galaxies and clusters of galaxies, and voids between galaxies, the Universe looks pretty much the same in whatever direction we look. This property is know as isotropic.
This assumption is very basic to our understanding of reality. When I taught physics I always tried to impress on my students how, when you’re trying to solve a problem, you can put your origin anywhere you want and point your x, y and z axis in whatever direction want in order to make the problem easier to solve. So this idea is not only fundamental, it is also very useful.
Assumptions have to be tested however, and a group of Cosmologists at University College in London have used the data obtained by the Planck satellite’s observations of the Cosmic Microwave Background (CMB) to see if they could find any evidence that our Universe had a preferred direction or even if it had a spin. Now the CMB is radiation left over from the very earliest time after the big bang, photons of light that have whizzed through space for over thirteen billion years without interacting with any other particles giving us a baby picture of our Universe. (See the Image at the top)
The Cosmologists looked at the CMB data for any signs for elongations or spiral patterns that would indicate a preferred direction or an axis of rotation and they calculate that there is only a 1 in 121,000 chance that there is any anisotropic (non-isotropic) behavior in the CMB.
So it appears that all of our theories that are based on an isotropic Universe are still good, for now. In another decade or so another group of scientists will think of another way of testing this assumption with even greater precision and that’s as it should be. As human being we have to make assumptions, but we have to test them again and again.
For those who are interested, you can read more about the work of the University College of London cosmologists here:
Last night we saw the third season premier of Star Talk on the National Geographic channel with host Neil deGrasse Tyson the director of Hayden Planetarium. Basically a talk show in format and billed as “Where Science and Pop Culture Collide” the show is actually broadcast from the Hayden Planetarium and featured Pop guests Whoopi Goldberg and comedian Chuck Nice along with Science guests astrophysicist Charles Liu and neuroscientist Staci Gruber.
Now I’ll be honest, I think the show has a little too much Pop and too little Science but of course the show is intended to make science more accessible to the general audience and nobody is better at that Dr. Tyson. Still, you didn’t get to hear anything about Dr. Liu’s work on the evolution of galaxies and Chuck Nice, who was funny, interrupted the other guests a bit too often.
The first half of the program revolved around Whoopi’s starring on Star Trek the next generation and covered Star Trek and superheroes in general. The funniest moment came when Chuck Nice was doing some “nerd in the street” interviews and asked one gentleman “How does a nerd get revenge?” the answer was “You get your Ph.D. and you hire the people that bullied you!”
The second half talked about the uses of medical marijuana and consisted in Whoopi talking about how she used it and Dr. Gruber evaluating it versus the oxycontin and other opioids. Now, I’m not going to get involved in the argument about Marijuana so I’ll just say that Dr. Gruber did a good job of stating the case for reasonable use of ‘grass’ instead of many of the drugs now being overprescribed.
Personally I was a bit disappointed in the season premier of Star Talk but hopefully Dr. Tyson will soon move on to subjects more to my taste. Again, the biggest problem was simply that Dr. Liu had little to say aside from what a nerd he was and how much he liked Science Fiction. Maybe he’ll be back to talk to talk about the Cosmic Evolution Survey (COSMOS).
P.S. During the show there was also an ad for the new series (or miniseries) Mars that will premier on National Geographic channel on November 14. It looks good and I will certainly be watching and writing about it.
A panel of scientists and researchers at Stanford University have completed the first in a series of studies on the effect of Artificial Intelligence (AI) on human society. This series of studies is expected to continue over the next century so this is a LONG TERM project.
It will have to be, automation and robotics already have an enormous effect on our lives and careers from automated assembly lines to robot vacuum cleaners in our homes. However, recent advances in AI seem to have brought us to a tipping point. Remember when the computer Watson won Jeopardy, well that same level technology will soon be driving on our highways, doing much of the work around the house and even helping physicians by doing routine medical procedures and exams.
The study published by the group at Stanford is entitled “Artificial Intelligence and Life in 2030 and can be found at www.ai100.stanford.edu/2016-report
The report covers eight general areas:
Home / Service Robots
Low Resource Communities
Public Safety and Community
Employment and Workplace
No one doubts that the effect of AI in these areas will be a tremendous advance for humanity in the long run. It’s just that things which are tremendously beneficial in the long run are very often hated and despised in the short term. In fact it has been estimated that as much as one third of the jobs people currently hold will no longer exist and the people who lose those jobs will hardly be overjoyed by all the wonderful new jobs they’re not qualified for.
This sort of change in society has happened before and at least this time it appears that some people are examining the consequences before the problem becomes too great. But we as a society need to think about the kind of future we want and how to get it. AI could go a long way in making this world a place where everybody has a career that truly makes their life worth living, or it could make this world an actual hell on Earth.
Over the past few years the discovery of planets outside of our solar system has almost become routine. So many planets, and of such a wide variety of sizes, orbits and composition have been found that it now looks as though almost ever star comes with planets.
But the recent announcement in the journal nature ( http://www.nature.com/news/earth-sized-planet-around-nearby-star-is-astronomy-dream-come-true-1.20445) is something special. Not only does the planet orbit Proxima Centauri, the closest star to our own Sun, but the planet is similar to the Earth in size and orbits Proxima Centauri at a distance where liquid water could exist on its surface.
The newly discovered planet has been named Proxima B and has a mass estimated to be 30% greater than Earth’s. If it possesses an atmosphere and oceans it could easily be a home for life and astronomers are organized a coordinated effort to learn all we can with our present and future technology.
The sun our new planet orbits is very different from our own star. Proxima Centauri is a small red dwarf with a mass of only 12% that of our Sun and emits only 1.5% of the energy of our Sun. Notice that, while Proxima Centauri is smaller it emits much less energy. This means that the fuel powering Proxima Centauri could last almost ten times longer than the fuel remaining for our Sun. That’s true of stars in general, the larger they are the shorter their lifespan.
So here we have an interesting plot for a Science Fiction novel. It’s several billion years in the future and the Sun is running out of fuel so the inhabitants of the solar system, not necessarily Earth nor necessarily human, are striving to reach Proxima B as a new home.
Of course, that’s just fiction!
In a little more than a year from now, late 2017 or early 2018, the first commercial manned space flight will take place as either Boeing or Space-X launch their first manned missions to the International Space Station (ISS).
There’s much more to come. Last week in a news conference NASA’s deputy associate administrator Bill Hill discussed NASA’s goal of turning over control of the ISS to a commercial firm(s) on or around 2024.
NASA’s plan is to support private investment in Low Earth Orbit (LEO), private development of the infrastructure of Space between Earth’s surface and LEO while NASA concentrates on it’s program of exploration to Mars, Asteroids and back to the Moon.
Other corporations are also investing in the colonization of LOE, that’s what it is really. Orbital Sciences, Blue Origin and Sierra Nevada are developing manned spacecraft while Bigelow has already launched an inflatable habitation module which is currently undergoing testing at the ISS.
The question of course is whether these companies can make a profit in space? For the next decade or so these Space-X and the others will be heavily if not exclusively dependent on NASA for orders. There’s been a lot of talk about space tourism or mining asteroids but it’s hard to see those industries providing the billions of dollars the commercialization of LEO will require.
The next decade will see a lot of hard work, a lot of plans that won’t fulfill their promise but by 2025 or so we should see the beginnings of the real colonization of Space.
During the past week there’s been a lot of talk about Theoretical Physics at the University of California Irvine analyzing data from the Institute for Nuclear Research at Debrecen Hungary, some news articles have even called the UC Irvine analysis a conformation. What’s all this about.
First of all, a little background. Modern Physics recognizes four Forces of nature: Gravity, Electromagnetism and two Forces that only work over the immensely short nuclear distances. These are called the Strong (or color) force and the Weak force.
For nearly forty years now physicists have been looked for something beyond the standard model of particles and forces because the standard model cannot describe gravity at the nuclear scale, nor does it describe the motions of galaxies attributed to “Dark Matter” nor finally the accelerated expansion of the universe attributed to “Dark Energy”.
Now, what the researchers in Hungary were doing was to take nuclei of Lithium and bombard them with energetic protons turning them into nuclei of Beryllium in an excited state, excited state in important. The excited Beryllium nuclei would then sometimes decay into Beryllium in the ground state by emitting a gamma ray photon (a very high energy particle of light) and the gamma ray would then split into an electron-positron pair.
Measuring the energy spectrum of the gamma rays the group in Hungary found a bump at an energy of 17 million electron volts that could be due to a particle other than the gamma photons, an unknown particle. The theoreticians at UC Irvine then looked at the Hungarian data and determined that the new particle would be a force carrying Boson. The data implied not just a new particle but a new force.
First of all, the work at UC Irvine is not a conformation it is an analysis. Conformation requires another laboratory to replicate the data from Hungary. Fortunately the energy levels involved are low enough to allow many laboratories to do the experiment and confirm the Hungarian’s work, or otherwise. we should have an answer soon, a year or so.
This is the fourth time in my career someone has announced a fifth force and each time previously the new force quickly disappeared when subject to additional scrutiny. I’m hopeful, because a new force would be really cool, and I’ll keep reading the published articles, but I’m not holding my breath.