GRB 130427A, an interesting burst of gamma radiation during finals week

An interesting gamma ray burst happened during finals week, GRB 130427A

Back in the early 1960s, the United States launched a few satellites, the Vela satellites, to detect secret nuclear weapons testing by the Soviet Union. By treaty between the US and USSR, no one was to test nuclear weapons above ground; underground testing was permitted. To monitor the Russians, US scientists at Los Alamos developed the Vela platform.

Nobody ever saw the Russkies nuking off any above ground tests, but while the detectors were not over Siberia, they could definitely see bursts of high energy gamma rays from sources outside the solar system.

Excellent.

In the 1970s, they began publishing scientific studies of these gamma ray bursters. The image below is an animation of the April 27 burst. Click the image to see the animation.

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There is still a lot of study going on as to why these GRBs happen all over the universe. We do not know for sure, and neither do the Russians. This GRB was so close and so well-imaged, that maybe someone will now crack the puzzle, using F = ma and all the concepts we study in PHY2048 and PHY2049.

Grades going UP

I just hoisted the WebAssign homework pointage, your labs pointage and updated class participation. Also, the best 8 written homework scores are up.

I am still working on the final exam problems, and I expect to finish them tonight. Look for them to be uploaded tomorrow morning.

And everything has to be done and semester grades uploaded to the registrar by noon Friday. Still a ton of stuff to do.

Scantron scores are IN.

You can see that the scantron scores are in as of about 8 AM today. I will unmute them, then convert to the pointage: double the raw score, because it is two points per item.

I have not even attacked any of the problems yet, being as how I have been as busy as a subhumanoid maniac with my other finals, the last of which is today. I expect to start grading tonight or so.

Let's see how it goes.

As predicted

As Clubber Lang once predicted for his boxing opponent, so I have experienced whilst uploading your graded homework files: Pain.

It was so painfully slow, it made me want to grade more papers -- i.e., I was delirious.

Anyway, your HW 10 papers are all out to you, and your score is UP. I shall see you in 24 hours, 1:00 PM, in our lecture hall, for the final exam. Bring scantron, calculator, pencils, and be ready.

Pressure under the sea solution UP

You can now view the solution PDF for homework 10.

Homework 10, pressure under the sea

I have your written homework assignment set up in PDF, on Webcourses2.

I think you will want a good table of integrals to execute this assignment properly.

Combo homework in WebAssign

Your WebAssign homework for Monday is now available. It is a combination of Ch. 13 problems on universal gravitation and Ch. 14 problems concerning fluids. It is due on Monday, April 15, 3:30 PM.