Upcoming Event: “The Life and Mind of Dr. Martin Zinke – Listen to his Advice, His Experiences, His Story”
Date: March 7, 2012
Time: 6:00 pm
Place: UCC Rm 56
A $3 donation to “Students Offering Support (SOS)” is accepted towards their educational projects in Latin America.
http://singularityhub.com/2009/06/23/stem-cells-used-to-grow-hearts-cool-new-pics-and-vid/
I fully intend on living for a long long time. For this to happen, this is the kind of research that will need to succeed. The ability to grow new organs to replace old ones should mean that we will be able to live a lot longer. It will also mean that transplant waits will become a thing of the past. The question though is not, “is this possible?”, we know it is, and just a matter of time and research to find out how to do it. The real question is, “How will this technology intersect with society”. I think that question bears some thinking about now. Is it ethical to grow new organs and replace them for people who can afford it? Is it ethical to allow people to live for hundreds of years. I know where I stand on these kind of issues, but do you now what you think? What will happen to the global population? The environment? Jobs?
For me, immortality beckons, what about for you?
Dr. Peter Brown and the Meteor Physics group at Western have come up with a preliminary data analysis of the Chelyabinsk meteor.
The earlier estimate of 300 kT for the Feb 15, 2013 airburst was based on Infrasound period measurements at the four closest stations. Five additional stations have now been found which show the signal clearly, including one as far away as Alaska (range of 6500 km). Based on the infrasound period at all stations and using the yield relation for multi-station fireball detections found in;
Ens T. a., Brown P., Edwards W. N., and Silber E. 2012. Infrasound production by bolides: A global statistical study. Journal of Atmospheric and Solar-Terrestrial Physics 80: 208–229.
a mean period of 32.5 second for the event is found. This corresponds to a nominal yield of 470 kT TNT equivalent. This represents a best estimate for the yield of this event from infrasound records. As before there remains a potential uncertainty of order a factor of two in this value.
What follows are *initial* information gleaned for multiple instrumental sources recording various aspects of the Feb 15, 2013 airburst over Chelaybinsk, Russia (55.2N, 61.4E)
1. Time: The time of the main flare/airburst was 03:20:26 UT on Feb 15, 2013; the fireball began ablation about 30 secs before this time.
2. Based on the long duration of the event and videos, it is clear this was a very shallow entry (certainly less than 20 degrees, maybe more shallow).
3. It is *not* related to 2012 DA14
4. Speed: The fireball entered the atmosphere at 18 km/s
5. Damage: The airblast clearly caused window breakage and light structural damage in downtown Chelaybinsk. The exact overpressure at which window failure occurs tends to be probabilistic and varies by construction design (ANSI S2.20, 1983). Normally some damage begins to occur around 500 Pa of overpressure, widespread window damage is expected to occur up to around ten-20 times this value. As the fireball had a shallow trajectory, the cylindrical blast wave would have propagated directly to the ground and would be expected to be intense. This could be further compounded by any fragmentation, quasi-spherical blasts. My impression is that the key here is that the terminal part of the fireball (probably between 15-20 km altitude) occurred almost directly over Chelaybinsk; this was perhaps the single greatest contributor to the blast damage (short range to the main part of the terminal detonation).
6. Comparators: The Sikhote-Alin fall (Feb 12, 1947) in the former Soviet Union was the equivalent of about 10 kilotons TNT, BUT as an iron impactor much of this energy was deposited at the ground rather than at altitude. The Oct 8, 2009 Indonesia event is the most recent similar event at about 50 kTons, but over the ocean (paper attached for quick reference).
7. Size: The pre-impacting asteroid was about 15 meters in diameter and had a mass of ~7000 tonnes.
Peter Brown tells us to expect revision of some of the numbers above, particularly the estimate of the yield which could *easily* change by a factor of two upon more complete analysis and will likely change as the day progresses.
[Dust trail photo c/o: Russian Emergency Ministry and space.com]
There is an interesting article on the back page of the latest issue of APS news about using the GRE exam as part of the admission criteria for physics graduate programs. It’s also available on-line here: http://www.aps.org/publications/apsnews/201302/backpage.cfm
Here is a short excerpt:
Of these [physics grad programs], none … have concluded the GRE predicts success in research …. Our analysis finds that the QGRE correlates with only one metric, the graduate GPA (but it is such a weak correlation the scientist in me rebels when fitting it to a line). That said, we find undergraduate GPA to be a better predictor of graduate GPA.
The recent entry of the astronomy department into an arms race (I am of course referring to the Helium Filled Attack Shark launched by Gallagher et al) has disturbed many members of the Department who do real Physics for a living. Well despair no more. With the arrival of the latest in drone technology from the US military we have all the weaponry we need to keep the atrium free from spying eyes. There are of course the usual bugs to iron out and Brian Dalrymple would like to apologize, profusely, to the student who was sitting too close to our launch area and was unfortunate enough to be struck in the leg. (They were studying some notes for a Cami course though, so no loss.)
I am glad to see Rhett Allain of Wired doing the necessary work of figuring out the mass of Darth Vader such that he doesn’t tip over while “interrogating” a subordinate in the original Star Wars. According to his calculations, Vader has to be about 200 kg in order to keep the centre of mass of the Vader-peon system over his toes. This seems unreasonably large. However, I think the trick is that Vader’s cape is REALLY heavy.
This is an analysis and visualization tool for astrophysical simulation data from various codes. This is a tool that astronomers have developed and support with a wide range of features that grow everyday. I have not gone through a test run yet but it seems useful for those who may need quick comparison to simulation results.
Link: The yt Project
The International Space Station, carrying Canadian commander Chris Hadfield, flew over Western’s campus at 6:55pm on Saturday, Feb. 9, 2013.
[photo: Allan Leparskas]
