Friday, September 15, 2017

Quarks

Water comprises around 71% of the earth's surface. That’s common knowledge. Each water molecule is made of 2 hydrogen and 1 oxygen atom. Well, each of those atoms are made of smaller particles known as protons, neutrons, and electrons. What? Middle school chemistry?
But there's more to atoms than just those three particles. Each of those particles is comprised of smaller particles known as quarks.

Now a brief history. The idea of a quark was suggested around the same time by two separate scientists: Murray Gellman and George Zweig in 1964. This was toyed with and tentatively accepted as there was no evidence for their existence for a while.

First there were three proposed quarks hence the name quark; in a certain book Finnegan's Wake written by James Joyce, there is a passage "three quarks for muster mark".

In the same year (1964) Sheldon Glashow and James Bjorken coin the name for the fourth quark (charm).
In 1977, Leon Lederman and crew at Fermilab discover bottom quark, and theorize for its partner, top quark.

In 1995, that theory of top quark is validated when a heavy top quark is found.

Quarks are somewhat unique in that they have fractional charges.
What's a charge?
A charge is a positive, negative or neutral property of an atom, dictated by its reactions when exposed to an electromagnetic field. Note that the charge of 1 assigned to protons is just an arbitrary number created as a point of reference.

WARNING: (Some) Repeated Information Ahead
Well, quarks have fractional charges. Currently there are six known quarks: up, down, strange, charmed, bottom, and top.
Up and down were suggested at the same time, and are named such for their spin.

These are the two naturally occurring quarks. Up quarks have a charge of 2/3rds, and down -1/3rd; and together they compose all of the building blocks of matter.
Protons are built up of two up quarks and one down quark, electrons are three down quarks, and neutrons are an up quark and two down quarks.
This addition and subtraction keeps those arbitrary charge numbers the way they were before, while adding a new concept to physics.
Also part of the first batch of quarks, strange quarks are named after their strange property of surviving much longer than normal quarks.
Charm quarks are named after how charmed the scientists were at how well they fit in to the standard model.
These two quarks have the same charges as up and down: charm with +2/3rds and strange with -1/3rd.
Top and bottom get their names from their charge as well: they mirror up and down quarks with parallel charges. Top has a charge of +2/3rds and bottom -1/3rd.
The top quark is the most massive, and thus, in its short lifespan of 5 * 10^-25 seconds, it can't hadronize, meaning it won't form hadrons (baryons (3 quarks) and mesons (quark and antiquark)).
Bottom quarks are interesting as they are almost always products in top quark decays.
So you could say (as it is said) there are three "generations" of quarks: 1st, 2nd, and 3rd. The latter two all eventually decay into the first.
But what's with these quarks? What is their purpose?
Well, electrons were found to mysteriously bounce off of protons. This was in fact due to the quarks inside of the proton deflecting the electron.

You are probably wondering by now, “How do these quarks stick together? Planets are held together by gravity, molecules by ionic or covalent bonds. So… what about the quarks in atoms?”

Quarks are bound to each other with gluons. Think of it as quarks are glued together.

Actually, scrap that: that’s not how they work. But it’s good to remember it that way. Inside of a hadron, there are gluons as well as quarks. Each quark exchanges its gluons with another quark. This is what causes them to bond together.

So, quarks and gluons are found in atoms. As far as we know, these are the smallest bits of matter out there, but there could be smaller.

Quarks make up everything out there, and though we think we know a lot, we really don’t. For instance, the recently discovered exotic hadrons (2014) break our current rules of quarks and the quark model. But it’s up to us to complete the model for better understanding, and with that we have a lot of work to do.

Sources:


Wednesday, August 23, 2017

Total Eclipse Temperature Data

Hiya folks! Haven’t written in a bit!

Everyone knows about the eclipse that occurred. Many know how mesmerizing the sight of an eclipse is. Many don’t know about the scientific boon that an eclipse is, however. The effect of an eclipse on the temperature is one of the measurable effects of an eclipse done readily at home. Before starting to talk about data, key terms should be discussed.


Temperature: “The measured amount of heat in a place or a body” (Cambridge Dictionary)
To measure temperature, you use a thermometer. Some issues with thermometers are that they increase and affect their environment temperature, but this is negligible if not in subatomic levels.


Relative Humidity: Relative humidity is the ratio of absolute humidity compared to the maximum possible humidity. Absolute humidity is the mass of water vapour over the mass of dry air at a given time and temperature. The maximum possible humidity is dependent on the temperature. Humidity is generally measured in gm/m3.


Dew point: Dew point is the temperature at which the current amount of moisture will saturate the air. As the relative humidity increases, the dew point decreases. An example of this relationship is shown below:
DATA:
Equipment:
For the experiment, we used an Extech RHT10 USB Datalogger (Details at the end). It was basically rubber banded onto a pole, in the shadow of a tree.
The Datalogger (referred hereafter as the Extech) was set to record data every five seconds, and initially set for 8000 samples. 8000 samples would require staying way after the eclipse, so it was ended early, but data was still claimed: a whopping 4594 points.
Times:
The eclipse (in local time) was:
Start: 12:01:59.0
Start of total: 13:30:49.7
Maximum eclipse: 13:32:00.6
End of total: 13:33:11.3
End: 14:57:08.2
Location:
In case it matters, the location for measuring was (roughly) 35* 39’ 20.11” N, 85* 21’ 24.43” W, at Fall Creek Falls State Park, Tennessee. True, it wasn’t an ideal location but it was quite empty, so was great for a viewing ground. Look at the handy data below.
The experiment was conducted in the shade, under a tree in order to prevent the sun from heating up the gauge too much. This doesn’t affect the data too much, because, after all, it’s still a relative drop in temperature and humidity.
Actual Data:
Instead of listing all 4000 and some data points, I’m listing the averages of important groups and specific data (all data linked at bottom).
The average of the first hour was 82.65 degrees, second was 85.25, third was 84.9. After these the eclipse began. These were the three hours of 8:47:42-11:47:42. The first hour to second hour increase was due to the natural warming of the day, and the drop from second to third was due to a cloud. Annoying cloud, worried all the eclipse viewers.
At the beginning of the eclipse (rounded up as it didn’t fall exactly with the measurement cycle) the temperature was 82.78 degrees. The averages of the ten minutes after were 86.71, 88.4, 88.25, 86.1, 85.21, 84.9, 82.65. That was from minutes 0-80 of the eclipse. The next even interval is five minutes after, 85 minutes in, with a temperature of 81.1. The totality began 87 minutes in, and the temperature then was 80.49.

The totality had another drop in temperature. This data is averaging five measurements, starting from total till end. The data is as follows: 80.2, 80.2, 80, 79.93 and 79.8. The data after the eclipse is (in ten minute averages) 79.0, 78.99, 79.77, 80.25, 82.4, 85.5, 88, 88.6, and then 82.5 minutes in for 89.5 and at 84 minutes 89.9. The final two were at that weird offset due to the eclipse having ended.

So the temperature went down! This (to the right, graph 1) is the graph of the temperature change during the eclipse from start to finish in temperature. The jump up was due to a cloud.

The peak temperature (excluding end) was around 1/5th of the way in nearly matches the end temperature of the eclipse.
The next graph includes data before and after the eclipse. This is ten minutes before and after (only data I have for after :p)

As you can see to the left, the graph is much the same, but the peaks and drop are apparent. This reduction, however, may seem like a lot on the graph, but is just an 11 degree drop. This is, of course, Fahrenheit, and not Celsius. I only wish, but I set the Extech to Fahrenheit (sadly). In the graph (through the magic of Excel) the 1-2017 or 2143 is the reading number. The 1 is where the readings for that graph start, with each reading having a five second interval before the other.
This graph doesn’t show the relative humidity and dew point information, however.
Okay. To reiterate, relative humidity is the percent that the air is saturated compared to its maximum possible saturation at the temperature. It has no real purpose but is an indicator of both temperature and moisture. It can be used to predict the weather (obvious reasons), and the higher it is, the higher the moisture in the air.


When does it spike? That happens when clouds are near, or some event happens to interfere with the normal weather, like an eclipse. The eclipse did manage to raise the relative humidity, but as you can see in the next graph, it occurred while the temperature was regaining from its drop. The graph here (below) is the one showing only the eclipse, not before. In it, the Y axis to the left is temperature and the Y axis to the right is relative humidity. As you can see, the relative humidity peaked a bit after the temperature’s own divet. This could have been the Extech, but the increase in relative humidity is supported by prior studies (PMC).


The relative humidity peaked at 77.4% at 14:09:12 (2:09:12). There is another peak visible on the graph. It is due to a cloud (the same one), and actually comes in handy here as it shows how other objects change the relative humidity. The cloud did alter it, but the RH was still greater during eclipse.


I haven’t mentioned the temperature peak, or rather where it was the lowest. This was a 78.8, and it happened at 13:39:37 (1:39:37), 30 minutes before the humidity peak. This is slightly cooler than the air before (slightly from the view of stones and such), but for us, means a lot: ~10 degrees below the highest average temperature.
Of course, who could forget the official Extech generated graph! The one they make is interactive, meaning you can zoom into parts of it, but the one below is all the data.


This is the first of two parts, the second dealing with the corona of the sun. Expect that up some time soon. And, if you are here for the eclipse pictures, here: some photos taken at home (yes, from home and not the internet):



You can see the corona in those!

Sources:
See also:
Extech RHT10 USB Datalogger info: http://www.extech.com/display/?id=14707 (if you want to buy this, Fry’s electronics was selling one a bit cheaper than retail price. Just saying)


Sunday, June 18, 2017

Memory

Memory


This was a post I started to write the minute I finished the Alzheimer's post, and I wasn't too pleased with it. I just got round to posting it. Try and enjoy!

Many people believe that memory is a rapid storing of information like you hitting CTRL + S to save an image to your computer, and recalling is like opening it from your file explorer. (Sorry, I hate Macs)

The truth is, it’s complex. It’s like when you try to move your mouth. It seems like one fluid motion, but in reality is 43 muscles working in conjunction. This is how your brain does it, through a process often called distributed processing.

Currently, the leading neuroscientists believe that memory is a series of complicated actions done by your brain. Basically, each memory is divvied up into several parts, such as speech, sights, sounds, sensory emotions, and such. Each part of your brain responsible for that action then encodes the parts they receive and store it for later reference.

So, imagine you are trying to remember sitting on a beach chair. Everything you see, namely the sea, (or ocean you specific people), part of your legs, hopefully some sand, some other people unless it’s winter, and the sky will be saved in your visual cortex, the people talking around you will be stored in your language areas, and such for temperature and feelings.

While recalling this information, you access that encoded data and decode it to reform that memory. That is the basic principle behind memory: instead of a file cabinet, it’s a torrent system.

Why? Well, say you want to remember stuff, but half of your brain is sliced off. Would you like to remember half of your memories or all of them just with less detail? Ignore the fact that you would die if half of your brain was cleaved off.

But wait! There’s more! There is more than a single kind of memory! There are explicit, implicit, episodic, semantic, retrospective, prospective, and short term memory.

Explicit (declarative) memory is where you consciously recall the information. It isn’t subconscious like implicit (procedural). Explicit is generally for facts, or things that can be stored and retrieved at will. An example would be knowing where the struts are on a guitar. You consciously recall that information.

Implicit memory would be like just knowing how to play the guitar itself because you’ve done it before. It’s also known as procedural due to it strengthening through repetition, known in general as LTP (long term potentiation).

Explicit memory can be divided into two types: episodic and semantic. Episodic memories are specific events from your own past, such as places you’ve been to.

Semantic is a memory that you acquire throughout your life. It may have had a personal context earlier, but now is just a placeholder for knowledge.

Semantic memory derives from episodic memory, while episodic supports semantic. The main difference is that semantic mainly occurs in the frontal and temporal cortexes, whilst episodic is mostly centered in the hippocampus, and stored in the neocortex.

Memories are scattered through the brain as stated, and are all retrieved to form an episode in the hippocampus.

An interesting subset of memory is something known as “flashbulb memory”, a memory of a particular event and its details, of an event that is particularly surprising or upsetting. These are speculated to be highly resistant to being forgotten, possibly due to the strong emotions associated with them.

Memory is important in our complex, crazy life. Without it, we wouldn't have anything we take for granted (except the earth).

science.howstuffworks.com


Tuesday, May 30, 2017

Alzheimer's Disease

Seems like I've been forgetting the blog. Well, Alzheimer's disease this week. Concise sources this time.

Alzheimer’s is a serious disease affecting 44 million people in the world. Though not from birth, it is typically considered worse than other lifelong diseases. It strikes late in life, but takes its toll: the disease is a progressive destruction of brain cells responsible for memory and important mental functions.

In the beginning the disease may seem to be a small matter, leading to people forgetting childhood memories, but can quickly escalate into forgetting loved ones or having massive personality shifts.

Asides from the memory loss aspect, Alzheimer's is also the most common cause of dementia. Dementia is an extension of what Alzheimer’s does: it’s a collective group of brain disorders causing loss of intelligence and a sheer drop in social skills.

The fact that only 1 in 4 cases are diagnosed makes the disease worse. What does this disease do?
It creates a plethora of problems for those affected, such as increasingly worse memory lapses leading to misplacing items, forgetting conversations, repeating statements, and forgetting family members.

Alzheimer’s can cause difficulty in concentrating and thinking, especially with math. Though it's not like math is ever without difficulty for the common folk. Multitasking becomes difficult and finance, bills, and checkbook managing becomes hard. The cause of these last few disabilities may be due to the decrease in mathematical skills by the disease.

Responses to ‘normal’ problems becomes a problem, and planning becomes an issue as well. As the disease progresses, people may begin to forget basic tasks such as dressing and bathing. FOr now, let’s forget that once those two things were unessential.

The disease can also lead to changes in emotions, leading to depression, apathy, mood swings, often changes in sleeping habits, and delusions. Alzheimer’s works backwards from modern memories in its path of destruction, and so abilities gained early in life are protected until the later ends of disease progression.

In its last stages, it can lead to additional unrelated health problems such as aspiration (inhaling food or liquid into lungs), pneumonia, fractures, malnutrition or dehydration, and issues in balance and bower control.

Alzheimer’s patients require extensive care as well, and an estimated $605 billion are spent yearly for Alzheimer’s patients, equivalent to 1% of the world GDP.

Currently, scientists believe that Alzheimer’s is a combination of three factors: genetic, lifestyle, and environmental. This is most of the time, applying to the majority (95%) of people, as there are some purely genetic causes.

The effect of the disease is clear, it damages connections in the brain that are responsible for memory.  Memory works by creating bonds in your brain. When your brain receives constant messages the information is stored through a process called long-term potentiation (LTP). The strength of the memory created is determined through the amount of times the neuron recording the memory is bombarded with the same neurotransmitter signal.

A memory will be stronger the more signals you have to remember it. Alzheimer’s damages the connections created through the brain remembering stuff. The brain will eventually have much less connections and healthy brain cells.

Ooh, should have done memory before this. Well, that’s next!

As disease progression reaches a peak, more brain cells die, and leads to significant brain shrinkage. Doctors examining Alzheimer’s brain tissue under a microscope, they see two abnormalities characteristic of Alzheimer’s: plaques and tangles.

Run! Or just go to a doctor. Your teeth and hair have begun to invade your brain!

No, plaques are proteins, not bacteria. They are, according to the Mayo Clinic, ‘clumps of a protein called beta-amyloid (that) may damage and destroy brain cells in several ways, including interfering with cell-to-cell communication.’ This could be a cause of memory weakening.

Also, tangles aren’t like hair tangles in a literal sense, except they are. A protein called tau is necessary for internal support and a transport system to carry nutrients through long extensions in the brain. Tangles occur when the threads of tau twist into abnormal tangles in brain cells, leading to the failure of the transport system. This is a major factor in the death of brain cells.

Are there trends in Alzheimer’s diagnosis? Surprisingly, yes!

There are some risk factors, including but not limited to age, genetics, lineage, gender, lifestyle, location, and social engagement.

Age is the greatest risk factor for Alzheimer’s. Though not part of the normal ageing cycle, your risk increases significantly over 65. The rate of dementia basically doubles every decade after 60.

Genetics can lead to early onset Alzheimer’s as early as 30, but genetic studies show that your risk for Alzheimer’s is considerably higher if your first degree relatives have the disease. There are rare mutations in three genes that almost guarantee Alzheimer’s, though this accounts for less that 5% of diagnosed people.

The gene mutation leading to the highest risk for Alzheimer’s is apolipoprotein e4 (APoE4). If a patient has this mutation, his child has a 50/50 chance for receiving it and thus having a high risk of ALzheimer’s.

People with Down Syndrome have a high chance of developing the disease. In their case, the symptoms appear earlier: up to 20 years earlier than the general population.

Women have a slightly higher chance of developing Alzheimer’s partly due to life expectancy.

Those with mild cognitive impairment have memory problems as expected for age, but not classified as dementia. However, people with MCI do have a higher chance of being diagnosed with dementia later on.

Also, people with past head trauma have a higher risk of Alzheimer’s. Lack of exercise, obesity, high blood pressure and cholesterol and smoking can all increase your chance of developing Alzheimer’s.

Location seemes to have a difference in concentration: the disease is most common in Western Europe, and is least prevalent in Sub-Saharan Africa.

The major question is, “is there a cure, my knowledged doctors?” Well, they are working on it.

Here enters Antioquia, the largest concentration of people carrying the Apolipoprotein e4 mutation in the world.

A family here, headed by mother Cecilia and seven children and many grandchildren lost their patriarch, Alonso to Alzheimer’s. He carries the APoE4 switch, and has been diagnosed with Alzheimer’s. His family acts as his caregiver.

When he first began to show signs of memory loss, the doctor suggested exercise and vitamins, but his condition didn’t get better.

He knew what was going on, and asked about why his memory was dying. His family has a high chance of Alzheimer’s, and wish to know what causes it.

The Banner Alzheimer’s Institute wanted to try removing amyloids from the brain to prevent Alzheimer’s, but they couldn’t tell for certain if someone had the disease or not. This was a crucial piece of information because they believed that if you administered the medicine too late, when Alzheimer’s had already begun, it would have no effect.

They went to Ken Kosik, a man who had been studying the family in Antioquia for fifteen years. They wanted to try their medicine and prevent the disease.

They started a double-blind study: 300 people in total; 200 with Alzheimer’s guaranteed and 100 without. Half the people with the mutation will receive medicine and the other half harmless placebo. This method was meant to ensure that nobody participating in the study would know their condition of the disease.

The participants would check in every two weeks for five years, in order to see if the people with the medicine will have less amyloid buildup than those with the placebo.

This is an ongoing study, and is expected to run till 2021. This is just the start, though, as if this doesn’t work it means something else will have to be targeted in the body.

There are two drugs that are made to manage the symptoms of Alzheimer’s, if not prevent: cholinesterase inhibitors, and memantine (namenda).

Cholinesterase inhibitors work by boosting levels of a neurotransmitter that is depleted in Alzheimer’s, in order to increase cell-to-cell communication. This improvement is modest, but can also treat agitation and depression.

Memantine slows the progression of moderate to severe Alzheimer’s in another brain cell communication network.

The two are often paired together to slow the progression of Alzheimer’s, but it isn’t a cure, and the progression is inevitable.

Currently, 1 in 3 seniors die with Alzheimer’s, and this disease is on an unstoppable rampage. Perhaps the future generation will solve the problem. But for now, the disease is here to stay, and knowledge of it will help those afflicted.



CBS documentary series 60 Minutes episode The Alzheimer’s Laboratory (Nov. 27 2016)