astro
catdynamics | August 21, 2008Andy Lawrence is blogging?
Andy Lawrence is blogging!
From California.
And his peeps are commenting.
catdynamics | August 20, 2008The prevalent US system of offering a year of high school physics, late in high school, with some schools offering a second year of "advanced" physics, is disastrous.
Some commenters in the "So, you want to be an astrophysicist? Part 0" thread felt I was too harsh in saying a year of High School Physics was NOT ENOUGH.
In particular, they only had a year, and are now tenured professors.
Sorry folks, but this is selection bias.
There are people who could do no high school physics and get up to speed on university level physics in less than three months, though most of those would still need…
catdynamics | August 20, 2008What should a high school student do to get on a track to become an astrophysicist?
Reworked from an oldie.
So, you're in high school wondering what to do with yourself, and you think: "hey, I could be an astrophysicist!"
So, what should YOU do, wanting to get into a good university and an astro/physics major?
1) Take all the math that is offered, and do well in it.
The limiting factor for most students wanting to do astronomy or astrophysics is poor math preparation in school. You need to get as far and as fast in calculus as you can and be proficient and comfortable with advanced…
catdynamics | August 19, 2008Why do people worry about being scooped, how do scoops happen, how can there be rumours of discoveries and why isn't the whole process made transparent?
Asked a commenter a few weeks ago during the speculation about Greg Laughlin's teasing anagram hint about a pending discovery or new result.
Why do academic scientists worry about being scooped?
Are there situations where it is not a concern? And if so, why the secrecy?
And why isn't there a way to publicly record precedent without the games and rumouring?
The essence of the scoop is someone working on a result, and a competing group…
catdynamics | August 15, 2008Mars haz dust.
Phoenix get atom force microscopy images of individual dust grains
I'm happy.
Hope you're happy too.
more cat pictures
catdynamics | August 13, 2008Cassini did a flyby, piccies are here
Cassini main page
Raw images are online - all 500 or so
catdynamics | August 13, 2008This has been pointed to by many blogs, but just in case you didn't see it...
The ever popular Large Hadron Rap.
It is actually quite good.
Take a peek if you haven't come across it before.
catdynamics | August 13, 2008"...and the guiding is easy"
Yes, the Photomixers have a new video out!
Not as funny as Hotel Mauna Kea, but perfect for a moments distraction late at night at the computertelescope while waiting those five minutes for some autmagic task to complete.
Nice visuals.
catdynamics | August 12, 2008The astrodyke found some neat astro stuff
Movie of the variability of the x-ray sky from RXTE
and
Hubble Kaleidoscope from the Onion
catdynamics | August 11, 2008Don't forget the Perseid meteor shower is tonight
The Perseids are one of the more reliable annual meteor showers, and occur when the Earth passes through the dust tail of Comet Swift-Tuttle.
Gratuitous Perseid image from APoD
Expect rates of about one per minute, best viewing is after the moon sets at about 2 am, it is waningwaxing gibbous, unfortunately, little pastbefore full.
There are some speculations of localised peaks in the rate, the Swift-Tuttle tail is banded, it is relatively young and hasn't smoothed out well as it spreads out along the orbit.
So, may be some half-hour spikes…
catdynamics | August 7, 2008SpaceX has explanation for Falcon 1 stage separation failure in 3rd launch failure
With mo' better video.
Should be easy to fix.
SpaceX telecon: "...on Flight 3, with the regeneratively cooled engine, there was some residual thrust after engine shut down and this caused the first stage to be pushed back toward the second stage after separation and there was a recontact between the stages." (via NASAwatch)
See for your selves.
video link
From NASAwatch
catdynamics | August 4, 2008No says NASA.
Not yet.
(h/t NASAwatch)
NASA is surreptitiously downplaying blog buzz that the Phoenix lander has found something very interesting...
In particular it is absolutely definitely not life!
As we know it.
But, there is a lot of heat and smoke and hints of an upcoming paper in Science or something.
I know nothing. So, I will feel free to wildly speculate in the hope someone who does know will correct me, because that is how the web works, as you know:
I am guessing, that the Thermal and Evolved Gas Analyzer found something juicy in the sample that had the water ice that they…
catdynamics | August 4, 2008Third Falcon launch failed also.
Three satellites lost.
From NASAwatch - with launch video - first stage engine performed, but stage separation failed.
SpaceX homepage has comments - they have raised capital, have booked customers and plan multiple future launches including the Falcon 9 heavy launcher. I hope they get the bugs shaken out soon.
Falcon 1 - 3rd launch attempt press kit - lets just skip over the section on stage separation on page 9...
Payloads were Marshall's NANOSail-D - a solar sail demo
Ames' PRESat - a biological experimental microsat
and DOD's Trailblazer - a Jumpstart…
catdynamics | July 31, 2008Do Not Panic!
Do Not Blink!
Do Not Go Back to Sleep.
Go out, in about 3 hours, and watch the solar eclipse
It is short, about 2 mins, but it will be beautiful (unless it is raining, is it raining?) and you in Gooseland will be just about the only people with a chance to see it.
From Natural Sciences.org
Dude.
h/t Greg for reminder
catdynamics | July 29, 2008Pontifications on Physics Personified, from two perspectives.
Here is the Harry Potter personification of physics.
0. Newtonian gravity is Ron.
Solid, dependable, good long heritage.
It has its limits, but is surprisingly powerful.
1. Electromagnetism is Snape.
You must master E&M, but so many have irrational fear or hatred of it.
It leads to deep unification and glimpses of fundamental symmetries, and is strangely beautiful yet powerful.
2. Special Relativity is Ginny.
Transcends classical mechanics, but in touch with its heritage.
Practical, explosive, generally high energy.…
catdynamics | July 25, 2008NASA's Jet Propulsion Laboratory has a nice little group blog
Lots of pretty pictures.
h/t NASAwatch
catdynamics | July 2, 20081 47 48
22 1 58
3 0 842
I have remembered these numbers for 35 years.
They are phone numbers. Those I would need to call if I needed my family to get me, or if I was in trouble. (Yeah, Iceland is small, and five digits were enough back then - I didn't list the other numbers that are still good... with the extra digits that when the number space was expanded a few years ago).
In the last ten years, I have had occasion to memorize precisely three phone numbers - not, I think, because my brain is ossified, but because I don't need to memorize phone numbers.
My phone remembers them.
So does my…
catdynamics | June 30, 2008What would it take to capture our life, in full fidelity?
It may be less than you think.
I think.
The body has about 1028 or so atoms, but to reproduce our existence it is not necessary to record the 1029 or so bits, per dynamical time, necessary to keep track of them.
We lose, add and move a lot of atoms around without it really affecting our existence.
Our primary sense of existence is the input to our senses - this is totally dominated by the optic nerve, which consists of about a million fibres, linking a hundred million sensors to the brain, with a firing rate of order 10 Hz. It is not…
catdynamics | June 26, 2008Early tantalizing Phoenix lander results from Mars.
Phoenix wet lab results
Soil is alkaline and loaded with (probably) water soluble salts - Mg/Na/K and chloride.
Suggestive of liquid water processing at some point.
Ph is 8-9 - not bad, certainly survivable.
No carbon, yet.