Thursday, December 29, 2011

30 Second Science: Earthshine


If you look at the moon tonight, you'll see something like the picture above. The phase is a cresecent moon. The moon is lit, of course, by the light from the sun. We see the light that has traveled from the sun, reflected off the moon and traveled to the earth.

So why are there two levels of brightness seen in this picture? The answer is called planetshine (and since we're talking about the earth it's called earthshine). The darker light is from light that has traveled from the sun to the earth, reflected off the earth to the moon and back to the earth.

So, amazingly, the dim light you see has traveled from the sun, to the earth, to the moon and back to the earth. Pretty cool if you ask me.

Wednesday, December 28, 2011

Scientist of the Week: George de Hevesy

George de Hevesy

Ok, so last week's scientist was Neils Bohr, and there was probably a good amount of you that have heard of him. This week's scientist is George de Hevesy. My guess is that most of you have not heard of George de Hevesy, but I guarantee his story is one you'll be repeating at the next party you're at...if it's like a Lord of the Rings marathon kind of party. But first a quick bio:

Hevesy was a radiochemist who won a Nobel prize in 1943 for his work on radioactive tracers (In short, you inject something radioactive into anything living and you can follow reaction pathways or see how long a given reaction takes - Hevesy was studying metabolism). As part of this work he discovered hafnium (element 72), an important element used in nuclear reactors. He studied under Ernest Rutherford and was a life-long professor of Physical Chemistry - the most interesting of all the fields of chemistry1.

But the story I want to tell you about is this:

During WWII, Germany wasn't exactly a refuge for scientists. This was especially the case for Max von Laue (who helped his Jewish colleagues escape from Germany) and James Franck (a Jewish scientist living in Germany). Each had, at separate times, received a Nobel prize.

Worrying that the gold Nobel prize medals would be forcibly taken from them, George de Hevesy devised an ingenious plan to protect them - he dissolved them in acid. Hevesy dissolved both medals in a beaker of aqua regia, a very potent acid2. He then stored the beaker in his lab at the Neils Bohr Institute3 until the end of the war. To any prying eyes it would look like an old beaker filled with an unknown solution - something you would find in the laboratory of any Hollywood chemist.  Once he knew it was safe he precipitated the gold from the solution and returned it to the Nobel society where the medals were re-cast using the original gold.

While you could say that the medals were just things - the real honor is in being given the prize, not owning the prize itself - I think Hevesy's actions made an important point. The medals represented something more than Franck's work on electron motion or Laue's work on X-ray crystallography. The Nazis mocked Jewish scientists (calling Einstein's theory of relativity "Jewish Physics"). By protecting the medals he was protecting the reputation of Franck and Laue, protecting the reputation of other Jewish scientists (including himself), and taking his own personal stand against the Nazis.

Now, on a much less serious note, here's a comic from Zach Weiner on the subject:

[1] This is not an opinion. Gilbert Lewis once stated that Physical Chemistry is "the study of all things interesting!" I take the definition on his authority, even if his dot structures are overused by organic chemists.
[2] Aqua regia means "royal water" and is made by mixing nitric acid with hydrochloric acid. Interestingly, while the acid can easily dissolve both gold and platinum neither nitric nor hydrochloric acid is capable of this on its own.
[3] If Hevesy had been found to be transporting gold out of Germany he would have been severely punished. Luckily gold doesn't look the same when it's been dissolved.

Friday, December 23, 2011

The First Law of Thermodynamics

Alright, today we're going to learn all about the First Law of Thermodynamics. It states that a change in the internal energy of a closed thermodynamic system is equal to the difference between the heat supplied to the system and the amount of work done by the system on its surroundings.

...You're still here. Ok, good. 

Basically, the first law says that energy can't be created or destroyed. Instead, energy can be converted from one form to another. For example, if I'm holding a ball high in the air it has potential energy. Energy is stored in the ball because of its height. If I let that ball go the stored energy is converted to kinetic energy and it falls to the ground. That's the example you'll see in about every textbook - here's a more real world explanation:

A power plant (nuclear, wind, water, coal, solar - any type of power) doesn't generate energy - that would break the first law.  Instead, energy is converted from one form to another. Nuclear power plants generate electricity by nuclear fission - a reaction that releases (not creates) large amounts of energy. This energy heats a bath of water and creates steam. The steam then turns a turbine that generates electricity[1]. All other forms of harnessing energy work in similar ways (wind spins a turbine, coal creates steam that turns a turbine etc).

Sometimes someone will say they have created a machine that shows thermodynamics is wrong. Mostly they just don't understand science or sometimes they don't realize where energy is being lost or coming from. Watch the videos I linked. They're pretty funny in some cases. Here's one thing to look for - if the machine makes noise it's loosing energy somewhere. You need to realize that if these people were creating energy they would not only be world famous but filthy rich. Energy is a global issue and if a solution were that readily available it would be exploited - the first law is not a conspiracy.

The first law is stated simply enough, but still misunderstood (or ignored) by self-titled geniuses who are certain they have solved the energy crisis. The reality, though, is that the first law is in our favor not working against us. 

[1] The large cylinders that most people associate with a nuclear power plant is the cooling tower, seen above. It's basically just an outlet for steam. Neither radiation nor radioactive material escape from them (The difference between radiation and radioactive material may be discussed later).

Monday, December 19, 2011

Scientist of the week: Neils Bohr

Once a week I am planning on highlighting the life of a great past or present scientist. Today I chose Neils Bohr. 

Quantum mechanics is sometimes seen by the general public as a weird, hard to understand, probably not even real science. Some scientists (I'm looking at you, Michio Kaku) expand on some small aspect of quantum mechanics until it's nothing more than science fiction. 

I don't mean any disrespect to current day theoretical physicists. I'm just pointing out that when it comes to theoretical physics, Neils Bohr is the man. The Bohr model of the atom is...incorrect. Even so, we still use it all the time. If you were asked to describe the structure of an atom, you would probably describe it like this:

...and you would be wrong. Not completely wrong - this model explains a great deal of physics and chemistry - but it isn't the truth. Even so, it's helpful to start explaining the basics of chemistry and the interesting things that can happen at the quantum level.

The Bohr model of the atom is arguably the most recognized of his contributions to the field, but it isn't the only one. He contributed substantially to the Copenhagen interpretation of quantum mechanics, helped develop the atom bomb[1], and remained a proponent for the continued use of nuclear energy.

Bohr received  a Nobel prize in Physics for his investigation into the structure of the atom. On par with that achievement, he is the first scientist of the week for the collapsed wavefunction.

[1] Maybe you, like Winston Churchill, don't think developing the atom bomb should be listed as a contribution. Speaking of Neils Bohr, he said "It seems to me Bohr ought to be confined or at any rate made to see that he is very near the edge of mortal crimes." 

Sunday, December 18, 2011

Searching for the Higgs boson

The Standard Model of particle physics describes the interaction of subatomic particles. You probably know all about atoms. An atom has a protons, neutrons, and electrons. Subatomic particles are the even smaller pieces of matter that make up what was once thought as the smallest piece of matter.

The Standard Model describes 16 different particles:
No, no, no...not THAT Quark

We have experimental evidence of all of these particles. The Higgs boson is a yet to be seen particle proposed in 1964 by British physicist Peter Higgs. Under the Standard Model, the Higgs boson would have to exist to explain why certain types of bosons (called W and Z) have mass but photons - which are also bosons - do not have mass1.

Fast forward from Peter Higgs to present day. You may have heard of the Large Hadron Collider (LHC). The LHC is arguably the most expensive, impressive, and...well, most awesome experiment ever. It has a 17 mile circumference, cost 6.4 billion dollars, and caused a big panic that the world was going to end (it didn't).

The LHC was built, in part, to look for the Higgs boson. Physicists have been looking since 2009, but this week a major announcement was made. I'd like to say, as this overconfident blogger, that the Higgs boson has been found, but I don't think it's quite the time for that celebration.  However, some really compelling evidence has surfaced in favor of the elusive Higgs. The two following quotes came this week from researchers at CERN:
"We have restricted the most likely mass region for the Higgs boson to 116-130 GeV, and over the last few weeks we have started to see an intriguing excess of events in the mass range around 125 GeV. This excess may be due to a fluctuation, but it could also be something more interesting."  - ATLAS experiment spokesperson Fabiola Gianotti 
"We cannot exclude the presence of the Standard Model Higgs between 115 and 127 GeV because of a modest excess of events in this mass region that appears, quite consistently, in five independent channels. The excess is most compatible with a Standard Model Higgs in the vicinity of 124 GeV and below but the statistical significance is not large enough to say anything conclusive. As of today what we see is consistent either with a background fluctuation or with the presence of the boson." - CMS experiment Spokesperson, Guido Tonelli
That may not sound like a very big deal. Each group found evidence of what may be the Higgs boson, but it is a very small signal that could just be noise. What makes this interesting is that two independent groups saw the same signal. It's not enough to say we've found it yet, but it's some very exciting news (at least for nerds like me).
[1] It is a really weird thing to think that photons (light) do not have mass but they do have momentum - which is usually described in physics as mass times velocity.

Further reading
 A BBC News articles: Here
CERN Press releases: Here and Here
A Nature article: Here

Wednesday, December 14, 2011

A Real Look: Homeopathy

Before we begin talking about homeopathy, I need to make one quick remark about what we are talking about and what we are not talking about.

Homeopathy is often confused as anything that is natural (herbal medications, etc). This is not true. Homeopathy dates back to the early 1700s and a man named Samuel Hahnemann. The basic principle is that of "like cures like". That is, a substance that causes a symptom in a healthy person will relieve that same symptom in a diseased person. A critical point is that homeopathic remedies are extremely dilute. In fact, homeopaths believe that further dilution (combined with the magical succussion) makes a remedy more potent, not less.

Homeopathy is just plain bad science, and has three strikes against it:

1. It doesn't make sense scientifically.
2. It doesn't work.
3. It kills.

It doesn't make sense scientifically

Homeopaths are deceitful in how they describe their dilutions. They say things like 10X, 200C, 1M. These don't appear to be very dilute, but are in fact so dilute that in most cases none of the original ingredient is even left. For example:

  • A 10X dilution is 1:10. This is a legitimate dilution. The original ingredients are still at a detectable level. This dilution is considered to be a "low potency" homeopathic dilution.
  • A 30C dilution is 1:10030. That's a one followed by 60 zeros. This is a very common homeopathic dilution. However, at this point there are already none of the original ingredients. In fact, to make this dilution you would need only one molecule and a container more than 30,000,000,000 times the size of the Earth.
  • A 200C dilution is 1:100200 . That's a one followed by 400 zeros. Let's put that in perspective: To make this dilution you would need one molecule of the original substance followed by more molecules than exist in the entire universe. But homeopaths don't stop there. Another possible dilution is the "M" dilution.
  • A 1M dilution is 1:1001000 (That's a one followed by 2,000 zeros). I have found homeopathic remedies available at as high as 80M. That's a one followed by 80,000 zeros.

The homeopath's defense
Homeopaths agree that none of the original substance is present in their dilutions. They call upon the magical properties of water memory; the essence of the substance is left in the water. While it is a very "sciencey" sounding explanation, it can't possibly be true. If this type of water memory existed, drinking from any water source would be potentially dangerous (or helpful depending on your ailment), since every water molecule you drink has been in contact with just about every other type of molecule you could imagine. If we attribute the water memory to the specific succussion that homeopaths do the theory still fails; I shake my water bottle as a nervous twitch and I know I'm not the only one.

It doesn't work

I'm a physical chemist. I've studied some very weird things. Maybe homeopathy is just one of those things we can't understand. If it works, then maybe there is something to this water memory idea and we need to change our understanding of the world around us.

The truth doesn't work. I don't mean there aren't groups of people that will risk their reputation, their lives, and even the lives of those they love to defend homeopathy. People take homeopathic remedies and get better. The question is: did they get better because they took the remedy or for some other reason. You are most likely to buy a homeopathic flu remedy1 when you feel the sickest - which is also the time you're most likely to start feeling better. You would have recovered without the sugar pill. On top of this, we are all very susceptible to the placebo effect2. So yes, people take homeopathic remedies and then feel better.

When I say it doesn't work, I mean in a controlled environment when you are studying specifically the question "Does homeopathy work" the answer is no. In study after study homeopathy has been shown to work no better than placebo. Small positive effects have been seen in various studies, but those studies are methodologically flawed in one way or another. Even when these studies are included in a meta-analysis (a study of studies) the results show that homeopathy doesn't work. To quote the conclusion section of that study:
"The evidence from rigorous clinical trials of any type of therapeutic or preventive intervention testing homeopathy for childhood and adolescence ailments is not convincing enough for recommendations in any condition."
To accent the point that homeopathy doesn't work, there is an offer of $1,000,000 to anyone that can show that homeopathy works. The prize has yet to be claimed.

The homeopath's defense
When confronted with these studies, homeopaths will claim that since homeopathy is not understood by scientists it can't be tested by scientists. This is a logical fallacy (special pleading), but remember the studies aren't testing how homeopathy works. They are looking for any evidence that is has worked and the evidence just isn't there.

Homeopathy kills

If anything I write in this blog will bring controversy, it will be this next subject. It needs to be said, though. Homeopathy kills. Homeopathy kills because it is seen as a viable substitute for real medication when real medication is needed. I really don't care if you want to pay $5 for a box of sugar pills when you have the sniffles because you feel like you get better. I think it's unethical that many homeopathic remedies appear to conceal the fact that they are selling sugar pills. The bigger problem, though, is when homeopathic remedies are given to children in West Africa as the primary treatment for malaria3. But we don't have to look that far from home to find homeopathic remedies that kill. In 2009 the parents of a nine month old baby were charged with manslaughter. The father, a homeopathic physician, ignored a severe case of eczema and instead used only homeopathic remedies. The child died from a bacterial infection that could have been easily treated. This sad story isn't the only example of the dangers of substituting real treatment for sugar pills.

The homeopath's defense
Advocates for homeopathy will claim that homeopathy is superior to allopathic medicine because there are no side effects. The pills are harmless. You could never overdose on a homeopathic remedy. The only claim made by homeopathy that I agree with is there are no side effects - of course as stated before there are no effects either. A favorite quote is one by Mark Twain:
"You may honestly feel grateful that homeopathy survived the attempts of allopaths to destroy it."
Of course, when Mark Twain spoke homeopathy was arguably better than current medical practices. Not because homeopathy was more effective but because doing nothing was better than some of the medical practices of the time (blood-letting, etc).

Now what?

This is the point of the post that I'm supposed to call you to action. Write your congressman, tell your neighbors, etc. I'm not going to do that. In fact, if you have favorite homeopathic remedy that, after reading this, you still want to take before heading to sleep I don't care. I just feel passionate about this subject and it was fun to spend an few hours researching it and writing about it. If you have any comments or questions I'd love to continue a discussion. If you want to argue with me I welcome the debate.

[1] Yes, you can buy it at Walgreen's - and no, they aren't required to tell you you're only buying sugar pills. They can even list something that isn't there as an active ingredient!
[2] Our mind is amazingly efficient at tricking us. This will no doubt be the subject of a later post. 
[3] I don't believe that those involved in the Senya/Tamale Homeopathy Project are acting maliciously or with anything but the best of intentions. I don't think they understand the harm they are almost certainly causing.

Let's be clear what we're talking about here...

Blogging Demotivator

So, why did I just create a blog?

The truth is I don't care if you read this. I'm not going to post pictures of  my family because you don't care, I'm not going to tell you how amazing my sandwich recipe is because you'll never make it, and I'm not going to give my opinion about the latest political scandal because it's nothing new.

What I do need is a chance to write more on anything scientific. If someone can read what I write about and understand some principle they didn't understand before that's great. If I can dispel some myths and expose some quacks along the way even better.

Let's take a look at some science and collapse the wavefunction.