Friday, May 30, 2014

"The Milky Way is Not Just a Refrigerator Magnet"

This is a nice video from NASA on the mapping of the magnetic fields of our galaxy. So not only do we have our Earth's own magnetic field, but there are larger scale magnetic fields generated by the sun and the galaxy.


Wednesday, May 28, 2014

Behavior Change Because Of What You Do

I was thinking about how, when I became a practicing physicist, some of the things that I got used to was directly due to what I do for a living. This all came to me because I have been thinking of buying a new watch.

Now that may sound strange, but hear me out. I used to work with a Class 4 laser. If you had ever worked with one, you know that there's a whole issue of safety training and stuff that one needs to know before dealing with such a dangerous equipment. One of the things that I do is doing a laser alignment. This often involves repositioning or adjusting the laser path.

The safety guidelines highly recommend that you do not wear anything shinny on your hands and arms. This is to prevent specular reflection of the laser that may bounce either at you or at someone else in the room. So for as long as I can remember, I've always wore plastic watches that have very few, or no shinny, reflective surfaces. I'm sure I could easily just take off my watch before I perform the work, but there's another thing you need to remember and at the rate I was going, I could easily forget where I left my watch at the lab! So the best option for me was to wear a plastic watch.

The cheap option turns out to be also useful, mainly because I also often got close to strong magnetic fields. I lost count how many watches that I had killed due to this, so I needed something which won't drain my bank account if I had to throw it away and replace with another one.

Well now, I no longer had to deal with such a thing, but I still find that I only want cheap, plastic watches. I like the classic Swatch watches, with black plastic strap, white face, clear numbers, and day/date display. Again, no shinny surface. It may be more expensive than your regular plastic watches, but hey, I think I can handle that now that I don't have to stick my hand near any strong magnetic field.

Do you have an ingrained characteristics or preferences as a result of what you do for a living?


Sunday, May 18, 2014

Slowing Down Sound So That You May Hear It?

Sometime you just have to shake your head at how badly science is mangled.

This is a "verdict" on the latest Godzilla movie. Of course, one doesn't expect accurate science reporting when it is an article on such a movie. Still, read this passage at the very end and tell me if you can't find, in this single paragraph, a couple of really glaring and puzzling errors.

But what you think you are hearing with that Godzilla roar may be deceiving. The roar is actually a decibel beyond the human range of hearing, so the design duo used special Japanese microphones to slow the sound so it falls within audience's hearing range.


A "decibel" measures the sound "loudness" or intensity. A sound may be too loud for a human being to hear comfortably, but it certainly isn't outside a human range. So to say that the roar is "a decibel beyond the human range of hearing" is rather puzzling.

But the kicker comes next where you can actually use these "Japanese microphones" to slow the sound, and thus, make it fall within the hearing range! I can understand the microphones picking up these ultra or sub-sonic sounds and then alter the frequency so that it falls within the hearing range. But slowing down the sound so that you can hear it?

I suppose if the microphone itself is filled with some dense medium that actually changes the speed of the incoming sound. But if we use our understanding of light going from one medium to the next, we see that the frequency remains constant even when its group velocity and wavelength change from one medium to the next. So I don't see even via such a picture, how one would "slow down" sound and make it fall within the hearing range.

After the earlier mistake being made on what a "decibel" is, I suppose it is hard to take anything written down after that seriously. So I am definitely making a big deal out of a mole hill.


Monday, May 12, 2014

US Senator Marco Rubio Shifts Position And Thinks He's A Climate Expert

A while back, I started a series of blog entry titled "You Can Teach Yourself To Think Like A Scientist". In Part 3 of this series, I mentioned about the general principal that one might be able to draw when reading the statements made by a US Senator Marco Rubio of Florida. To refresh your memory, in a GQ Magazine interview, the senator was asked on how old he thinks the Earth is. He evaded answering the question by claiming that he's not a scientist, and that the issue has nothing to do with the economy of the US, which one would gather is the more important issue on his plate at that time.

Based on that interview, I tried to illustrate trying to extract the principals that Senator Rubio was using, which presumably are the principals that guide him in his decisions. His refusal to answer this question and based on his responses, one can conclude that he would rather defer such questions to experts. There's nothing wrong with that, and certainly, being put in a position like that, deferring to the experts is a rather smart way to respond to such a question.

However, such a principal no longer applies anymore, it seems. In the latest news report, it seems that Senator Rubio thinks that he's a climate expert.

"I do not believe that human activity is causing these dramatic changes to our climate the way these scientists are portraying it," Rubio said.

"I do not believe that the laws that they propose we pass will do anything about it, except it will destroy our economy," he added.

In the week since the Obama administration released a national climate change report that named Miami as the city most vulnerable to rising sea levels, Rubio has been critical of the White House push on global warming.

"I think it's an enormous stretch to say that every weather incident that we read about or the majority of them are attributable to human activity," he told CNN.
Not only did he not defer to the experts on this subject, it seems that he has the expertise, he thinks, to even dispute them! Based on what, you may ask? Why, based on his "belief", of course. He believes in these things, thus, it must be true, regardless of what the evidence and the experts say.

So what happened here? There are certainly two contradictory events. If one lives by the principal that one defers to experts and won't offer an answer on something one isn't well-informed in (as in the age of the Earth), isn't it rather contradictory to then turn around and behave the opposite way by contradicting those experts in another subject area?

And let's not ignore the very annoying, and often dangerous, traits of some people of relying on their "beliefs" that seem to trump expert opinions and evidence. It is one thing to question the validity of something when one has evidence to back it up. It is another when all one can offer is simply one's beliefs. This is a sign of someone who can't think properly when faced with a problem, and simply decides not on what the evidence say, but rather on some preconceived ideas on how things should be. I think this is another example where the public, and a politician in this case, put more emphasis on their "values" rather than facts.

Think of these things when you vote for your candidate next time.


Friday, May 09, 2014

Freeman Dyson's Podcast

The recently-controversial physicist Freeman Dyson did an interview, the podcast of which you can listen to at the link. The HuffPost article highlights what they call as the one thing about science that people do not get:

The whole point of science is that most of it is uncertain. That's why science is exciting--because we don't know. Science is all about things we don't understand. The public, of course, imagines science is just a set of facts. But it's not. Science is a process of exploring, which is always partial. We explore, and we find out things that we understand. We find out things we thought we understood were wrong. That's how it makes progress.

This is certainly true. However, it is also true that there ARE things that we do know. Otherwise, there would be no progress. We explore things that we don't understand based on the stuff that we know. It may turn out that as we learn more, the stuff that we know might become more of a special case, or a simplified case, as in what happened with Newton's laws, but we do know it works and when and where it works.

I happen to be in the camp where Dyson's controversial view on climate change isn't a big deal. I don't know why it created that much of a controversy, and it is also certainly not as if he had seriously did a scholarly research on it the way Richard Muller did. What is annoying is that this is done in the media, rather than among the experts, i.e. via publications in which all the experts can scrutinize everything. This is also part of science, and how science is practiced.


Tuesday, May 06, 2014

Can You Find The Current In This Circuit?

A father of a high-school freshman is puzzled by this assignment given to his daughter. Can you find Ix in that circuit, or is there something wrong in this picture?

He also asked what you would do if you were the teacher responsible for this.


Thursday, May 01, 2014

7 Great Innovators In Physics

National Geographic has listed what it considers to be the 7 Great Innovators in Physics. The list is the usual, big names in physics, but also include what I think are names that the public may not be aware of.

Did I ever told you that I once sat next to Ray Davis (who is listed here) on a Southwest flight from Islip, Long Island to Chicago's Midway? At that time, I didn't know who he was. He was sitting with his wife in the same row as I was, and I was by the window. We started talking and he told me he his name (it didn't ring a bell at that time) and that he was retired but still came in now and then to do stuff in the Chemistry Dept. at Brookhaven (I was doing my postdoc at Brookhaven also at that time).

We started talking and I certain inquired what he did. He told me about the problem with the solar neutrinos, and at that time, the initial results on the flavor oscillation had just came in, so the solar neutrinos problem hadn't been solve just yet. All that time, somehow his name, and the fact that he worked on solar neutrinos, never clicked in my head on who he really was (I must have been totally tired and totally dense back then, which is a common state for a postdoc!).

It was later on when it was announced that he had been awarded the Nobel prize, and I saw his picture in the papers, that I finally put two and two together. Oh yeah, I wanted to kick myself a few times because had I known who he was, I certainly would had asked him a lot of other questions. After all, we had at least 2 boring hours in the plane!

Oh well. I wonder how many other important, noteworthy people I've sat next to and not even aware of it?