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Professor Hagai Perets was a guest on the pod-cast show "Three who know" (Kan 11) and explained the conditions for water formation and the feasibility of life.
How were the elements formed in the universe? What happens when a star explodes? How did our solar system form and where are the other Earth's moons?
Tune in!
https://www.kan.org.il/Podcast/item.aspx?pid=10732
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פרופ'-חבר גיא ברטל מהפקולטה להנדסת חשמל ע"ש ויטרבי בטכניון ופרופ'-חבר נתנאל לינדנר מהפקולטה לפיזיקה הצליחו לייצר "קיפודי אור" זעירים הקרויים סקירמיונים אופטיים וטומנים בחובם פוטנציאל לפריצת דרך בעיבוד מידע, בהעברתו ובאחסונו. במחקר, שהתפרסם בסוף השבוע בכתב העת היוקרתי Science, השתתפו פרופ' ברגין ג'יונאי מהפקולטה לרפואה באוניברסיטה האלבנית בטיראנה והסטודנטים שי צסס, יבגני אוסטרובסקי וקובי כהן.
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For the first time scientists were able to trace the source of a high-energy neutrino, a very low mass elementary particle that weakly interacts with matter, that was detected via the IceCube neutrino observatory [1], [2]. Promptly after the detection an extensive multiwavelength campaign followed in order to trace the emission source. The event was coincident with a blazar, an active galactic nucleus emitting a relativistic jet directed towards the Earth, 3.8 Giga light years from us. In addition, the IceCube team investigated 9.5 years of observations and found excess emission at the position of the blazar. Their findings show, for the first time, that blazars may be sources of high-energy astrophysical neutrinos.
In a report by the Israeli Space Agency [3] professor Ehud Behar, Dean of the physics department at the Technion and the former head of the Technion Asher Space Research Institute (who is not part of the detection in subject), explains that “until today the high-energy neutrino sources were not traced back to known astronomical sources, in other words when observing in the direction of the neutrinos no known astronomical source has been identified, to which the neutrino can be attributed. The present neutrino event is the first time electromagnetic emission (measured in the follow up observations) has been connected to high-energy neutrinos”. He further points out that this detection indicates that super massive black holes (centered in active galactic nuclei) accelerate the most energetic neutrinos, as well as the protons that produce them. These high-energy protons are termed cosmic rays, and they have been measured on Earth for over a century though their origin has so far been a mystery. This new discovery proves that such super massive black holes (“blazars”) are capable of accelerating cosmic rays to energies of 1015 eV and higher.
For the IceCube press release (https://icecube.wisc.edu)
References:
[1] Multimessenger observations of a flaring blazar coincident with high-energy neutrino IceCube-170922A
[2] Ice reveals a messenger from a blazing galaxy
[3] עידן חדש באסטרונומיה: זוהה "חלקיק רפאים" באנטארקטיקה שמקורו בחור שחור
GRAPHIC:
GRANT ET AL., SCIENCE, VOL. 361, 147 (2018) ADAPTED BY C. BICKEL/SCIENCE
(http://science.sciencemag.org/content/361/6398/115.full)
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It is our great pleasure to announce that Dr. Rivka Bekenstein, a graduate student of the Technion physics department, has won the prestigious Deborah Jin Award of the American Physical Society (APS) for Outstanding Doctoral Thesis Research in AMO (atomic, molecular or optical) Physics. Rivka completed her PhD in 2017 under the supervision of Prof. Moti Segev, studying gravity models with optical setups both to contribute to the fundamental understanding of gravity models and to photonics applications. Her most important contribution is the first simulation of the Newton-Schrodinger system. She has been awarded the prize on her research titled: "Emulating gravity with linear and nonlinear optical settings". This annual award is presented to one individual and Rivka is the first Israeli graduate to ever win. In 2015 Rivka won the IPS prize for a graduate student in theoretical physics awarded to one graduate a year.
Rivka is currently during her second year as an ITAMP (institute for theoretical atomic, molecular and optical physics) post-doc at Harvard University, working with Prof. Mikhail Lukin. She is studying quantum information science and is planning to relate the quantum optical setups she is working on to gravity models that take quantum effects into account. Her goal is to explore the relation between quantum physics and gravity in theory and in experiments. Congratulations Rivka we wish you all the best!
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On June 12th the department held a "women in physics event" where the graduate female students invited the bachelor female students to talk eye to eye about the graduate studies and research in the faulty. Such meetings are essential in order to encourage promising female students to continue to graduate studies and increase the number of female researchers in the faculty (while the percentage of female bachelor students in the faculty is about 26, the female graduate students are about 14 percent). The participants gathered in small groups to discuss the nature of graduate studies in physics and answer questions brought up by the students. Professor Kinneret Keren and Professor Yael Shadmi joined the celebration and shared their experience and insight with the participants. "The event was very informative and inspiring", "An enriching experience that allowed us to receive answers to burning questions and meet women physicists in different career stages", "I enjoyed the intimate platform that allowed an eye level discussion" - are only part of the positive feedbacks given by the students!
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An accelerated charge emits radiation, as taught in our course Electromagnetism and Electrodynamics.
But, how does the electric field of an accelerated charge exactly looks like?
The analytic solution for the electric field in space and time is quite complex. One typically presents approximate solutions close to the charge (near field) and far from the charge (far field). In the Computational Physics course we derive a short numerical scheme, which provides the exact solution for the field in space and time, for any velocity including relativistic.
The first video shows a charge moving in a circle at a speed of 10% of the speed
the light. The solution is similar to the electrostatic solution of a radial field of a charge with a time variable position (the quasi static approximation for the near field).
In the second video the speed of the charge increases to 50% of the speed of light. A tangential field now appears clearly, moving away at the speed of light from the charge. This is the radiation field (approximated by the far field). Note that very close to the charge the field remains quasi static. This radiation is produced in nature by electrons moving in a magnetic field, and is called cyclotron radiation.
In the third video, the speed of the charge increases to 90% of the speed of light. A relativistic effect now leads to radiation emitted into a narrow beam. This is synchrotron radiation, produced by relativistic electrons in a magnetic field. This radiation is produced by a great variety of sources in the Universe.
Thanks to Ayal Beck, a student in the Computational Physics course, for preparing the videos
