Physics
drorzel | June 5, 2010Over at Tor.com, Kate has a Lord of the Rings re-read post about the Battle of the Pelennor Fields, which includes a shout-out to me that I missed because I was driving to NYC:
Ãomer is "scarely a mile" away when the standard unfurls and is clearly seen to bear the White Tree, Seven Stars, and a high crown. If I were at home, I could ask the resident scientist to tell me how big these elements would need to be to be visible at a mile, but I'm finishing this post on the train down to New York City (vacation! Woo! I'm going to try and write the next post while I'm there, too, so as to make up…
drorzel | June 5, 2010We missed the formal presentaion at the World Science Festival stargazing event last night, and it was cloudy enough to prevent actual stargazing, but the giant mock-up of the James Webb Space Telescope is giant and cool even in the dark. More importantly, Neil deGrasse Tyson is awesome. We got there around 9:30, and he was taking questions from an informal group of people having around where the presentation had been. When we left at 11pm, he was still going strong. More amazingly, I don't recall seeing him drink anything.
He may be a robot. A really awesome robot who is amazingly generous…
rallain | June 4, 2010I got tired of attacking ESPN Sport Science. Well, tired of attacking might not be the best term. How about, attack in a new way (here are my older Sport Science attacks).
Check out episode 1 of Spoof Science:
A couple of notes:
Watch it youtube if you want the HD version
Making videos takes WAY longer than a blog post
If you hate hearing your own voice, you will really hate hearing your own voice AND seeing yourself while you are editing
rallain | June 4, 2010Honestly, I was going to add this to my previous post about the jumping car but I didn't because I wanted to finish. So, here it is and more. Actually, I will just make a projectile motion spreadsheet. That way, anytime you want to do a projectile motion problem, you can come here. Maybe this is a bad idea, but I am going to do it anyway.
To start with, I will just say that for projectile motion the horizontal and vertical motions are independent (except for the time it takes). If you want a refresher on projectile motion, here you go. Oh, a couple of assumptions:
Object starts at x =…
drorzel | June 4, 2010Over at Inside Higher Ed they have a news report on complaints about the content of required reading for students entering college. This comes from the National Association of Scholars, a group dedicated to complaining that multiculturalism is corrupting our precious bodily fluids pushing aside the shared heritage of Western civilization, so most of it is pretty predictable. I was surprised by one thing in their list of commonly assigned books this year, though:
What are the freshmen reading? Based on the report's analysis of 290 programs (excluding books that are required parts of courses),…
rallain | June 3, 2010Reader Colin asked a great question about this popular clip.
How fast was the car moving?
First, a quick assumption. I will assume that the frame rate on the video is correct (meaning not slowed down). Colin already looked up the length of the Chevy Impala on Wikipedia for me. It has a length of 5.09 meters (I need that to scale the video).
This is the data I get from Tracker Video. The graph below is the x-position of the car with a line fit to the part of the motion before it hit the "ramp". Note that since the car is moving to the left, it has a negative x-velocity.
So, this says the…
sb admin | June 3, 2010At 8:00 pm EST tonight, tune in to the live stream of Black Holes and Holographic Worlds, which Greg Boustead and myself will also be covering live from NYU's Skirball Center. Moderator Alan Alda and physicists Raphael Bousso, Robbert Dijkgraaf, Andrew Hamilton and Kip Thorne will explore recent discoveries about what are perhaps the most mysteriously named objects in the universe - black holes - and how they have led to the idea that our entire world might be something like a hologram. Hope you join us!
drorzel | June 3, 2010A number of SF-related sites have been talking about the "Periodic Table of Women in SF" put together by Sandra McDonald, presumably passed around at Wiscon. James Nicoll has a list of the authors, and SFSignal has a link to the table, which I will reproduce here to save you the annoyance of opening a PDF:
This is an area where my nerdiness gets the best of me, because while I appreciate the concept-- listing a whole bunch of really good female authors as a way to draw attention to them-- the execution is dreadful. It's particularly disappointing given that the whole project is in reference…
drorzel | June 3, 2010This may be a job for the MythBusters, but I'll throw this out as a puzzle for interested blog readers. I don't know the answer to this (though it wouldn't be all that hard to determine experimentally), I just think it's sort of interesting. There's a poll at the bottom of this post, but it requires some set-up first.
So, it's coming up on summer now, and I've been doing a bunch of errand-running this week, which means a lot of getting in and out of the car in sunny parking lots. Which raises the question: If you have an air-conditioned car, is it better to leave the car windows open a crack…
esiegel | June 2, 2010"Vision is not enough, it must be combined with venture. It is not enough to stare up the steps, we must step up the stairs." -Vaclav Havel
It's arguable that vision is the most important tool that an astronomer can have. This was particularly important back before the invention of the telescope, as the greatest astronomers of their time (like Tycho Brahe) were renowned for their visual acuity.
How do you stack up? You were curious about learning how good your hearing was, but what about your vision? Well, you can always get your vision tested using a Snellen eye chart, and read the bottom-…
rallain | June 2, 2010This idea comes up every once in a while. The idea that an institution should remove its physics degree program because it doesn't produce enough majors. Right now, it is up again due to budget problems in our state.
I think the idea of removing low-completer programs is dangerous. It comes from administrators who like to think of the university as a business. If you are a business, and you want to save money - it seems obvious to cut things that don't produce as much 'product'. Really, this brings up several issues.
Is a university like a business?
I am going to go with "no". Let me…
drorzel | June 2, 2010I mentioned in a previous post that one of the cool talks I saw at DAMOP had to do with generation of coherent X-Ray beams using ultra-fast lasers. What's particualrly cool about this work is that it doesn't require gigantic accelerators or nuclear explosions to produce a laser-like beam of x-rays-- it's all done with lasers that fit on a normal-size optical table in an ordinary lab room.
The specific talk I saw was by Margaret Murnane of JILA, who co-leads their ultra-fast laser group, and dealt with a new technique for producing soft-x-rays (~500 eV photons) with ultrafast lasers. We'll do…
rallain | June 1, 2010Sue from Math Mama Writes... sent me an email about wrapping a rope around a pole. In that post, Sue thinks about rope looped around a post. When you wrap a rope around a post, the friction between the rope and the post can help you hold something (like a horse) that is much stronger than you.
The first case she thinks about is using several posts. What if you wrap a rope around one post and pull? What if you use 2, or three posts? The idea is that if one posts 'multiplies' the force by 10, two posts would have an effect of multiplying by 100 and so forth. That seems reasonable.
The…
drorzel | June 1, 2010While I mostly restricted myself to watching invited talks at DAMOP last week, I did check out a few ten-minute talks, one of which ended up being just about the coolest thing I saw at the meeting. Specifically, the Friday afternoon talk on observing relativity with atomic clocks by Chin-Wen Chou of the Time and Frequency Division at NIST in Boulder.
The real technical advance is in a recent paper in Physical Review Letters (available for free via the Time and Frequency Publications Database, because government research isn't subject to copyright): they have made improvements to their atomic…
drorzel | June 1, 2010Two noteworthy events related to How to Teach Physics to Your Dog in the next month:
First, and most important, I'm going to be signing books at the Author's Alley portion of the World Science Festival Street Fair. The fair itself is in Washington Square Park in Manhattan, though the name of the signing program is a little misleading-- rather than being in an actual alley, the signings will be on the eighth floor of NYU's Kimmel Center, on the south side of the square. I'm signing at 1:30, and there are plenty of other books and presentations on offer, not to mention festive happenings…
rallain | May 31, 2010We went to the aquarium, the kids like it. In the Amazon river section, they have an electric eel. Here is the sign next to the Eel.
Sorry for the poor image quality. I took the picture with my crappy phone and didn't even realize it was bad until later. I used some magic on it to make parts of it readable, but if that was not good enough, here is what it says:
The Electric Eel is the most powerful of all the electric fishes. It can discharge up to 650 volts: six times the power of a household current. A shock can fend off attackers or stun prey so the eel doesn't risk getting hurt in…
rallain | May 31, 2010So suppose you saw something that looked like this:
This is a ball shot out of a shooter device. Well, it is a vypthon animation of a ball. What would you do if you came to see this video? If I had not made it, I would say it is an unrealistic video. It does not agree with my basic model of how things move after being thrown or shot or whatever. Interestingly (but unrelated) there was a set of physics questions that showed different possible paths of a thrown ball. The path representing the motion above was a common choice.
Like I said, I made that animation. Here is another one. In…
drorzel | May 30, 2010Some late nights and wireless problems conspired to keep me from posting anything Friday or Saturday, but I was still at the meeting, and saw some cool talks on coherent X-ray production with lasers, opto-mechanics, and ridiculously good atomic clocks, some of which I hope to talk about later. For the moment, I'm just enjoying being home with Kate and SteelyKid and Emmy, so a real wrap-up post with physics content will have to wait a bit.
I will put up a quick note that I'll be signing books one week from today as part of the Authors Alley program at the World Science Festival. More on that…
grrlscientist | May 27, 2010tags: Doctor Who Theme Song Accompanied by Tesla Coils, music video, DIY, Do-It-Yourself, science, physics, music, performing arts, weird, offbeat, Tesla Coils, ArcAttack, Maker Faire 2010, streaming video
The musical group, ArcAttack, constructed a set of Tesla Coils that they use to perform "an electrifying" live performance at Maker Faire 2010, held in San Mateo, California. Maker Faire is an event created by Make Magazine to "celebrate arts, crafts, engineering, science projects and the Do-It-Yourself (DIY) mindset."
According to the filmographer, the HVDJ pumps music through a PA system…
rallain | May 27, 2010Sometimes (ok - just once) I get asked for recommendations about reading material on the ideas of teaching physics. I used to recommend Arnold Arons book on teaching introductory physics. Still, that is a classic and a great resource. However, there is a better one.
Teaching Physics with the Physics Suite - Edward Redish
Originally, this was kind of like the instructor's manual that went with one of the big name intro-physics books (maybe the new version of Halliday and Resnick). But this book is way more than an instructor's manual. What is even better is that it is online and free (see…