• All posts by Dimitra Atri

    Dimitra Atri

    About Dimitra Atri

    Dimitra is a Research Scientist at the Particle Astrophysics Group, Blue Marble Space Institute of Science. His papers can be accessed here: http://arxiv.org/a/atri_d_1 His home page is here: http://kusmos.phsx.ku.edu/~dimitra/Home.html

  • Exploding stars and DNA

    Our Galaxy is filled with high-energy subatomic particles generated by exploding stars or supernovae, also known as cosmic rays. These particles strike the Earth’s atmosphere and produce more (secondary) particles, which damages the ozone layer and causes DNA damage to terrestrial and marine life.

    In Carl Sagan’s words: ” The evolution of life is driven in parts through mutations by the deaths of distant stars. We are, in a very deep sense tied to the cosmos.”

    Life has evolved over the past ~ 3 billion years in presence of this radiation, which itself has varied considerably during the period. As demonstrated by the Miller-Urey experiment, lightning plays a very important role

  • Decoding the discovery: Another giant leap for mankind

    I have always wondered what it would have been like to be alive when Einstein proposed his theories of relativity, or when Watson & Crick cracked the structure of DNA or when Armstrong & Aldrin landed on the moon. Well, I experienced it yesterday, when I witnessed history in the making.

    It took almost half a century to discover this new fundamental particle theorized by Peter Higgs et al. in a series of seminal papers in the 60s. It is hard to explain the magnitude of this discovery in a blog post, but I’ll try. I’ll not

  • Higgs Boson: Yes/No/Maybe?

    It is always good to see science covered in the mainstream media. It is equally disheartening to see misinterpretation of scientific results. I am sure you’ve been hearing a lot about the “discovery” of the Higgs Boson particle, also (unfortunately) coined as the “God particle”. If you are not a physicist, you might find difficulty in interpreting the results. So, here is a particle physics 101 so that you can make your own opinion about the results.

    In particle physics (as in some other fields), results are statistical and are always presented with a “sigma” or standard deviation(s) away from the

  • Yesterday was April 1

    So, let me explain why one could NEVER receive an ETI signal with particle detectors. As I mentioned yesterday, in addition to electromagnetic radiation, our galaxy is filled with charged particles known as comic rays (for historical reasons). These particles are highly energetic, traveling at relativistic speeds, so one could think to use them to communicate across galactic distances, instead of light.

    But it turns out that our galaxy (like other galaxies) consists of turbulent magnetic fields distributed non-uniformly. Even our Sun has a strong magnetic field and so does the Earth. From physics 101 we know that charged particles are deflected

  • OMG! signal: Evidence of extraterrestrial life?

    As many of you may know, on August 15, 1977, Jerry Ehman of Ohio State (By the way, OSU lost to KU yesterday. Go Jayhawks!), while working on the SETI project at the Big Ear radio telescope discovered the famous Wow! signal. Since it was a narrowband radio signal, it could have been produced only by an artificial source and therefore was a clear evidence of extraterrestrial life. However, that signal was never received again and several follow-up observations failed to detect anything similar.

    I have thought about this for a long time and wondered why scientists have been

  • Neutrinos still superluminal

    By now, you must have heard about the “BREAKING NEWS” that neutrino velocity measurement conducted by the OPERA experiment was flawed because of a faulty cable connection.

    If you think about this, a loose/faulty connection (as mentioned in various media outlets) would result in a delay in the signal. So, one would record a greater time measurement than the actual value. If one rectifies it, the new measurement should show a shorter time measurement than the one previously recorded. As we all know that speed is distance/time, a smaller corrected time value should give a HIGHER value of the