Here on Earth we live in an atmosphere containing a reactive compound called oxygen. It’s necessary for life as we know it to exist! It also reacts with most materials. For example, metals form oxides on their outside surfaces where they touch oxygen.
The way we think of metals has a lot to do with what this oxide is like. Everyone knows that iron rusts. This is because Fe2O3 is the oxide formed on iron, which is reddish and powdery and sticks to the iron surface. On the other hand, osmium forms osmium tetroxide (“osmium with four oxygens”)  OsO4 which is volatile and evaporates into the air. Since it’s a gas you can smell it, and this is why osmium has a name that basically means “a smell.”

Here on Earth we live in an atmosphere containing a reactive compound called oxygen. It’s necessary for life as we know it to exist! It also reacts with most materials. For example, metals form oxides on their outside surfaces where they touch oxygen.

The way we think of metals has a lot to do with what this oxide is like. Everyone knows that iron rusts. This is because Fe2O3 is the oxide formed on iron, which is reddish and powdery and sticks to the iron surface. On the other hand, osmium forms osmium tetroxide (“osmium with four oxygens”)  OsO4 which is volatile and evaporates into the air. Since it’s a gas you can smell it, and this is why osmium has a name that basically means “a smell.”

Anonymous said: I see that your profile picture is of crystallized osmium, very cool especially that deep blue tint. I personally have an iridium sample, the next best thing

The Clear Science Staff avatar is in fact crystallized osmium, good eye anonymous. The Clear Science Staff actually keeps a sample of osmium on a bookshelf. We’re big fans of iridium, too.

Tags: osmium science

pizzzatime:



BBC: HORIZON :: WHO’S AFRAID OF A BIG BLACK HOLE?




The Clear Science Staff has never liked this description of relativity, because it literally uses gravity as a metaphor to explain gravity. There are two ways to think of force fields (like gravity or electrostatics): either there is a field of forces at every point in space, or there’s no field but space is bent and distorted in an equivalent way.
There is a really great book about this by science fiction writer Rudy Rucker (or Rudolf von Bitter Rucker) called Geometry, Relativity and the Fourth Dimension. 

pizzzatime:

The Clear Science Staff has never liked this description of relativity, because it literally uses gravity as a metaphor to explain gravity. There are two ways to think of force fields (like gravity or electrostatics): either there is a field of forces at every point in space, or there’s no field but space is bent and distorted in an equivalent way.

There is a really great book about this by science fiction writer Rudy Rucker (or Rudolf von Bitter Rucker) called Geometry, Relativity and the Fourth Dimension

(Source: pizzzatime, via freshphotons)

brideyshawyer said: Hi there, I am currently doing an issue report on MS and the medicinal use of Cannabis and I came across your article on how THC impairs memory.. I clicked on the embedded link -'A recent paper by researchers at the Louisiana State University Health Sciences Center' however, I was not able to access it.. I was wondering if you could possibly send me another link, as I think it would be really useful for my research. Many Thanks

Hi username: brideyshawyer. The Clear Science staff has fixed the link to the paper, which is here. The paper is copyrighted, so only the abstract is available at the website unless you have a subscription.

All of you clear scientists can access scientific papers like this, but it takes a little effort to figure out the best way. Often a library can get you a copy by interlibrary loan (ILL). Another way is through a university library with a subscription.

THC is the main psychoactive compound in cannabis, and has been shown effective in treating several medical conditions such as MS, chronic pain, and Alzheimer’s disease. However, it also causes cognitive side effects such as impaired working memory, lethargy, and paranoia. Especially for long-term treatment, these side effects might be detrimental for some patients. Thus there is a concerted effort to understand how THC’s cognitive side effects work and how to inhibit them.
A recent paper by researchers at the Louisiana State University Health Sciences Center shows that THC causes increased production of an enzyme COX-2. Ironically COX-2 is associated with inflammation and pain because it produces the chemical agents that cause them. Certain classes of non-steroidal anti-inflammatory drugs (NSAIDs) work by inhibiting COX-2.
The researchers found that mice given THC with COX-2 inhibitors did not exhibit the characteristic memory loss and “fear conditioning” of mice given THC alone. Importantly, the anti-Alzheimer’s benefit was also retained. This could be a major finding for medical marijuana.

THC is the main psychoactive compound in cannabis, and has been shown effective in treating several medical conditions such as MS, chronic pain, and Alzheimer’s disease. However, it also causes cognitive side effects such as impaired working memory, lethargy, and paranoia. Especially for long-term treatment, these side effects might be detrimental for some patients. Thus there is a concerted effort to understand how THC’s cognitive side effects work and how to inhibit them.

A recent paper by researchers at the Louisiana State University Health Sciences Center shows that THC causes increased production of an enzyme COX-2. Ironically COX-2 is associated with inflammation and pain because it produces the chemical agents that cause them. Certain classes of non-steroidal anti-inflammatory drugs (NSAIDs) work by inhibiting COX-2.

The researchers found that mice given THC with COX-2 inhibitors did not exhibit the characteristic memory loss and “fear conditioning” of mice given THC alone. Importantly, the anti-Alzheimer’s benefit was also retained. This could be a major finding for medical marijuana.

The Clear Science staff recently read a couple of articles about researching a scientific basis for the widely-believed health benefits of cranberry juice. Cranberry juice is renowned for preventing urinary tract infections (UTIs), and there is evidence that it hinders E. coli attachment to cells in the urinary tract. Also, molecules found in cranberries can chelate or bind iron atoms. They do this because they have a lot of phenolic OH group on them. Lone pairs on the oxygens chelate positive metals (chelate means “hold like a claw”). This could remove extra iron from your system.
But these theories are not without counter-evidence. The residence time of cranberry components in your system after you drink them is low. Some argue that to make a real difference, they would have to stick around much longer, or you would have to drink a lot of juice.

The Clear Science staff recently read a couple of articles about researching a scientific basis for the widely-believed health benefits of cranberry juice. Cranberry juice is renowned for preventing urinary tract infections (UTIs), and there is evidence that it hinders E. coli attachment to cells in the urinary tract. Also, molecules found in cranberries can chelate or bind iron atoms. They do this because they have a lot of phenolic OH group on them. Lone pairs on the oxygens chelate positive metals (chelate means “hold like a claw”). This could remove extra iron from your system.

But these theories are not without counter-evidence. The residence time of cranberry components in your system after you drink them is low. Some argue that to make a real difference, they would have to stick around much longer, or you would have to drink a lot of juice.

As the Clear Science Labs are based in the United States, we’ll be away for Thanksgiving for the rest of the week. We’re thankful for volts and amps and watts this year. How about you?

As the Clear Science Labs are based in the United States, we’ll be away for Thanksgiving for the rest of the week. We’re thankful for volts and amps and watts this year. How about you?

(Source: vintageedition, via freshphotons)

We called the voltaic pile the first modern battery, because some believe that objects discovered in the 1930s (that date to the biblical era) were early batteries, called “Baghdad batteries.” These have iron rods surrounded by copper tubes, and the two metals could be separated by an electrolyte. This is the basic construction of the electrochemical cell we described earlier, with iron replacing zinc.
However, it is unknown if these objects were used this way, or for some other purpose that has not been thought of. This type of battery would have a very low potential (about 0.44 volts) and would not have a lot of power. (The voltage of the cell is the difference between the individual electrode potentials.)

We called the voltaic pile the first modern battery, because some believe that objects discovered in the 1930s (that date to the biblical era) were early batteries, called “Baghdad batteries.” These have iron rods surrounded by copper tubes, and the two metals could be separated by an electrolyte. This is the basic construction of the electrochemical cell we described earlier, with iron replacing zinc.

However, it is unknown if these objects were used this way, or for some other purpose that has not been thought of. This type of battery would have a very low potential (about 0.44 volts) and would not have a lot of power. (The voltage of the cell is the difference between the individual electrode potentials.)

By connecting zinc and copper discs separated by brine-soaked cloth, a zinc-hydrogen cell in made. Alessandro Volta studied the effect produced when metals were connected this way. One of his papers (from 1769) was called De vi attractiva ignis electrici or “On the attractive force of electric fire.” In the 1800s the concept of a battery began to be developed. By connecting several cells, stacking them, a higher voltage is produced. The word voltage comes from his name.
This is essentially the same idea as a citrus battery, where instead of brine you have citrus juice.

By connecting zinc and copper discs separated by brine-soaked cloth, a zinc-hydrogen cell in made. Alessandro Volta studied the effect produced when metals were connected this way. One of his papers (from 1769) was called De vi attractiva ignis electrici or “On the attractive force of electric fire.” In the 1800s the concept of a battery began to be developed. By connecting several cells, stacking them, a higher voltage is produced. The word voltage comes from his name.

This is essentially the same idea as a citrus battery, where instead of brine you have citrus juice.

Batteries are electrochemical cells. Electrochemical cells are two electrochemical half-reactions coupled to each other. A zinc-hydrogen battery, which is what you make if you make a citrus battery, has:
a hydrogen-forming half-reaction that happens at 0 V
a zinc-dissolving half-reaction that happens at -0.76 V
In reality, half-reactions cannot exist independently. They must always be coupled to make a cell. This is because otherwise you have electrons without a home. 

Batteries are electrochemical cells. Electrochemical cells are two electrochemical half-reactions coupled to each other. A zinc-hydrogen battery, which is what you make if you make a citrus battery, has:

  1. a hydrogen-forming half-reaction that happens at 0 V
  2. a zinc-dissolving half-reaction that happens at -0.76 V

In reality, half-reactions cannot exist independently. They must always be coupled to make a cell. This is because otherwise you have electrons without a home.