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Tuesday, September 12, 2017

Understanding Matter and Forces: Standard Model

The Standard Model is the name of the theory we use to help us understand what makes up the universe (i.e. particles of matter) and how matter interacts (fundamental forces of nature). It breaks down the hundreds of particles in nature down to 6 quarks, 6 leptons, and a few force carrying bosons, along with the Higgs boson that provides mass to particles in the first place. Check out a summary video!

Big Bang - Start of our Universe

What is the Big Bang theory for the creation of the universe? In principle it is as easy as saying there was a large explosion of unimaginably hot energy, which 'cooled' to form the fundamental particles and forces that we see in the universe today. This happened about 13.7 billion years ago, according to present-day best measurements and calculations.

As with any scientific theory, no one should put any belief into it until there are predictions made from the theory that are then tested experimentally and through physical observations. Over the past 100 years, the theories of Einstein and the eventual Big Bang models have gone through this slow process, and confirmation of the key ideas have occurred, making this the best understanding we have for the universe's creation.

Check out this video that explains the gist of the Big Bang theory, and a couple reasons why scientists believe it is a valid theory. Check here for a quick example of the Doppler effect.

Wednesday, September 6, 2017

Projectile Review

As we get back into motion, projectiles are a classic case of 2-D motion from sophomore year. Let's bring it back! Check out one video that focuses on the basic properties and concepts of projectiles, a video with a couple examples of how to set up these problems (and they are all pretty much the same!), and if interested, one that goes into the reason why projectiles move on a parabolic path, as well as the effect of air friction on that parabola.

Check these out as needed as you bring back the problem solving skills with the homework set of problems.

Tuesday, August 29, 2017

Fact or Fake?!?! Try to tell which articles are which!

If you are alive an breathing, you should know there is a battle going on, especially in the political world, over factual or fictitious news, reality versus alternative facts. Check out a site, Factitious, that provides real articles, but some of which are from legitimate, reputable news organizations (meaning stories are verified, vetted by journalists), and others are from well-known tabloids (usually made-up or embellished stories). You may be surprised by many of these! I was duped on several!  :-(

Sunday, August 27, 2017


Let's make the ETHS 2017-18 school year your best one yet!! 

Why include UN Sustainable Development Goals in classes? How can we not?!

The United Nation's Sustainable Development Goals, or SDGs, include 17 aspects of global life that can be and NEED to be addressed in the next decade. These goals are related to everything from global education to climate change to ending hunger to gender equality to clean water and air. The motto is "17 Goals to Transform Our World."

Another reason to take action on these NOW, rather than later, is because the techniques/methods/knowledge that will be developed to achieve these goals by 2030 are necessary to have in place as the population continues to grow, where we expect to have an additional 2 billion people on the planet by around 2050.

Let's be aware of these, see which goals our studies are related to, and make even a small difference where we can! It is our world, so let's fix it and take care of it together@TeachSDGs 

Friday, August 18, 2017

Why are Astronauts "weightless" in the space station?

This is easily one of the biggest MISCONCEPTIONS there is in science!!! A good majority of people would guess because there is no gravity in space....NNNNNOOOOOOO!!!!!


So if there is a lot of gravity acting on the astronauts from the earth, how can they float???

It is actually because all satellites are constantly FREE FALLING towards the earth, because of gravity. And if you are on a scale in an elevator that is free falling, guess what the scale would read....0!! You would be 'apparently weightless' because everything falls with the same acceleration when gravity is involved. You would not be truly weightless, since there is still gravity acting on you.

Check out this really good video from the Veritasium channel.

How do Satellites Work? The very basics...

Satellites are cool and help make modern life possible, but they are also confusing to many people - how can these things stay in orbit for decades without crashing into the earth?

The key ideas come from projectile motion. Gravity creates acceleration downward, but we need to give a fast enough speed perpendicular to gravity so the satellite moves in a curve. If you play with that speed, what you'll find is that there is a special speed where, as it falls, it moves very far forward. The trick is to have the curve of the satellite match the curve of the earth - thankfully the earth is more or less round!! This special speed is called the orbital velocity.

Check out the video, and I hope it helps!

Understanding some Properties of Projectiles

Forget the math for a few minutes - focus on some of the important concepts and interesting properties of projectiles, at least under ideal conditions (i.e. no air friction!). This gets into the importance of independent horizontal and vertical motions that are really the key to understanding projectile motion, and multi-dimensional motion in general. To understand why parabolic paths form, check out this video. To check out some basic math for projectile problems, check out this video.

Check it out, and hopefully this will make some sense to help you understand what the math is telling us when we do problems.

Thursday, August 17, 2017

Projectile trajectories - With and Without Air Friction

All of us are familiar with the arch-shaped path, or trajectory, a ball follows when we throw it. When symmetric, this is a parabola, and is the common shape we use in physics classes for projectiles. But WHY is it an arch of any kind, let alone a parabola? And why are we lying to you about projectiles???

We ignore air friction when we do projectile problems, but in life this makes it more complicated, and also no longer a perfect parabola. Check out this video to get a sense of why parabolas form when there is no air friction, and what the trajectory looks like in a more realistic environment, with air friction.

How to do Relative Motion problems: Getting across a moving river

Relative motion has to do with multiple objects moving with respect to one another, and trying to think about how it all looks depending on what point of view different observers have when watching the objects.

A classic example of this is trying to get a boat across a flowing river, without being pushed off-course or downstream. How is this done? This is the same problem as trying to fly a plane when the wind hits it from the side, or a bird trying to fly on a windy day. What do you have to do to the boat, airplane or bird in order to not be pushed off-source?!

Check out this video to see how to use basic vector rules with the velocity vectors involved in the problem!

How to do Projectile Motion problems

Projectiles are objects that fly through the air or space, under the influence of gravity (and ignoring air friction for now), but not using any of its own energy to do so. It has been 'projected' by something else to start moving, like kicking or throwing a ball, shooting an arrow, a satellite, or even when you run and jump - you're a projectile once in the air!

Projectiles follow an arch, which is technically a parabola when there is no air resistance.

The key to understanding this motion is to realize there are two motions simultaneously: constant horizontal velocity, and constant vertical acceleration due to gravity. And when two things are perpendicular to each other, they are also independent of each other. Sideways motion could care less about what happens vertically, and vice versa!

Check out this video, which goes through two related projectile problems, and how to set them up.

Tuesday, July 18, 2017

Chem/Phys Reunion in September!!

We will have a Chem/Phys reunion on September 23, at ETHS. We are trying to get as many alums from as many decades as possible, and current students will be a part of this as tours of the classrooms and schools will be coming through. It can be a wonderful chance to meet people who were in your same seats years ago, and also start networking prior to going to never know when there might be a summer internship or connection at a school you are looking at, etc. Save the date! And if a parent or sibling is an alum, pass this along! Check out

Friday, July 14, 2017

Studies Suggest We Should Expect More Lightning With Warmer Climates

For the past five or so years, one thing we've discussed in 4 Chem/Phys E&M is lightning. It is a naturally curious phenomenon for human beings, and simply really cool from the science perspective! But one aspect of this that most never think about is how lightning is related to climate change and a warming atmosphere. In the video we watch on lightning, it was surmised that the sheer number of lightning strikes should increase with warming - makes sense at first thought since moisture drives cloud and lightning production, and a warmer atmosphere should mean more moisture in the atmosphere. A relatively new study shows evidence for this prediction. If anyone is interested in this sort of thing, there could be some research possibilities! See me.

Monday, July 3, 2017

Malawi Fundraiser - GoFundMe for wells for crop irrigation

Thank you to the students who put together this GoFundMe campaign for our Malawi brothers and sisters! We have helped them get land, seed and fertilizer so schools can grow their own crops, but now, for long-term self subsistence, they need funds to drill wells and irrigate those crops when the next drought happens.

Check out Even small donations matter A LOT, since $1 is some 730 kwacha!

Wednesday, June 14, 2017

A Shameless Plug for UIUC Engineering

Just because I went reality, some say the College of Engineering is tops in the world. It certainly is among the most elite, with 16 top-5 programs!

Monday, June 12, 2017

Northwestern's work on Climate Change - A lot going on!!

If you have any interest in climate change and want to get a sense of the research efforts going into this important topic, or if you are interested in checking out research labs involved in these studies, you really need to read this extensive site outlining Northwestern's involvement in climate science! Let Doc V know if you want to learn more about any piece of this work.

Sunday, June 11, 2017

Fractal planting patterns yield optimal crop yields

Some students have been intrigued by fractals. And the more we look around in Nature in all sorts of systems, we find fractal patterns develop. It appears that this is also true for crop yields and production. An interesting article about some patterns that have developed, without planning, indicate that optimal yields are nearly reached when fractal patterns are used. This could lead to some interesting research options!

Sunday, May 21, 2017

Video analysis and the mass of the moon

We will investigate physics through the use of video analysis. The reasons for doing this includes a primary one of using Logger Pro software, which the school has from the Vernier electronic sensors, to do a video analysis. I want you to realize you can take any YouTube video, or any video (or digital photo) you take with your phone, and analyze any type of motion in any event you capture! This is a powerful tool that we all have access to in this day and age, and allows us to do so many more analyses. And with high-speed video options that more phones are providing, such as 120 frames per second (fps), 240 fps, and even 480 fps, or digital cameras that now provide 1000 fps or more, we can use video analysis software to look at finer details of motion than we ever could before in a high school lab. Keep in mind that a normal video is around 30 fps.

Watch this video for getting an introduction to using Logger Pro for video analysis.

One thing I recommend is to download a free piece of software called Tracker on a home computer (cannot do this with the Chromebooks, unfortunately), so you have the chance to check out details if you ever get the urge. This is an introductory video for using Tracker.

All you need is a few seconds of video to get into an analysis. For today we have as a goal to figure out the mass of the moon, perhaps using the original video footage of the first men on the moon in 1969! All you need is a bit of projectile motion to figure out the acceleration due to gravity, and the fact that the radius of the moon is 1079 miles. Work with a partner, and keep in mind you need to Google some conversions and get the mass of the moon in kilograms based on data from the video.You can use any moon landing video you want, including the moon buggy, dropping a hammer and falcon feather, or any other that involves some gravitational action you can use to figure this out. Also come up with a percent error compared to an accepted value of the moon mass.

Note that to import a video clip into Logger Pro or Tracker, you need to have the video file. To get this from your phone, of course you would need to just upload the video to your computer and then import into the software. For a YouTube video, you can make a screencast video file of the YouTube video, and save it to your computer. A quick, easy way to do this is to use Screencast-o-matic. Just select the brief scene you need to do the analysis, and capture it with the screencast! Here's a how to video for making a Screencast-o-matic video, which I suggest saving to your desktop or to your student My Documents folder. You will be able to Insert this video file into Logger Pro.


Monday, May 15, 2017

Video on the human eye

One video on the details of our eyes is here, or click on the embedded video below. An alternative is here.

Saturday, April 29, 2017

Funding site for the Kranti School in India

We were so fortunate for many students to meet Robin Chaurasiya, who stopped by ETHS while in Chicago. Her work in Mumbai, India, at the Kranti School, has gained her international attention, including a Top 10 Finalist rating in the 2016 Global Teacher Prize! She works with girls who have either been in or whose mothers were in the sex trade.

What needs to be known is Robin's school is a NGO (Non-Government Organization), and every penny to run the school and pay for some of the girls to study abroad and go to college has to be raised - there is no tax money or fixed revenue for such a school. If there is any interest in making any donation, whether small or large, one can check it out at this site. Through this site, 100% of the donations go to Kranti!

Wednesday, April 26, 2017

EM Work

For review, let's go into the AP Multiple Choice folder on your chromebook, and try the 2015 test (if this link does not work, go to the AP Exams folder and then into the Mult Choice folder). Remember you need to be logged into your account to access these folders. You'll need to scroll down in that file to get to the questions, and the answer key is towards the end of the file.

It is up to you if you want to start by yourself and then work with others on anything you missed, or if you want to talk through things with one or two others. If individually, also keep a sense of pace by timing yourself for some number of questions.

*The important thing is to find things that you have forgotten or have had some trouble with in the past. Turn in your answer sheet and score. Whatever time you have left, you can work on the review set from the other day. Come with questions Thursday!  😊

Wednesday, April 19, 2017

Visitor on Tuesday, April 25: Robin Chaurasiya

Check out a brief bio of Robin Chaurasiya, who will be in town and visiting ETHS on Tuesday, April 25, in room H322. Come by during lunch periods to meet her and hear some thoughts about what she does in India with her students. There is also a good video showing what the girls do in terms of performance at the Kranti School.

Tuesday, April 11, 2017

PhET simulation for EM induction

We will be trying the generator and transformer simulations for class. Check it out! The link is

Monday, April 10, 2017

Inductor Circuits!

We are moving into the final topic of high school physics: Inductors!

Check out a few videos if you need to review or double-check anything:

- series RL circuit
- Parallel RL circuit 
- LC circuit 

- Maxwell's displacement current, about how capacitors work and the final piece to Maxwell's equations
- Maxwell's equations (Mechanical Universe episode; good graphics of EM waves)

Tuesday, April 4, 2017

EM Induction Links

For Tuesday:

Check out the case emf = B dA/dt, where the circuit moves and the area changes. This is an example of a magnetic brake, where the loop will start to slow down due to the weird induction phenomena.

Then, a special example of this type of induction, where the circuit falls through a magnetic field (in other words, when there is a constant force trying to accelerate the circuit/loop. This is going to end up looking a lot like air friction on a skydiver, with a terminal velocity!

By the way, check this one out if you want to see a strange case of finding the magnetic flux through a circuit due to the magnetism from a long, straight wire next to the circuit.

On Wednesday, which you have off, check out a preview of the other case, where emf = A dB/dt. This is going to involve a circulating electric field! Weird, but welcome to the world of electromagnetism. Here is a video specifically on the circulating E-field that is created when there is dB/dt.    :-)

Tuesday, March 14, 2017

Links for the week

I hope the rest of the week is great for everyone!

For periods 1-2, 8-9:

Check out and take notes on a video about the parallel-axis theorem. This is a nice way of getting moments of inertia in certain instances.
Also, let's try to figure out rolling without slipping, and finding things like the friction and accelerations associated with rolling objects.

Today, let's try two other cases. The first is rolling without slipping, but then going up a frictionless incline. Then, the dreaded rolling WITH slipping!

Can watch the video "Runaway Universe," on DVD. Check out the methods used to figure out what the universe is doing. Have a good weekend!

Check out an introduction to angular momentum. We will pick up with this Tuesday.

For Period 3:
Here is a bit of a break from electricity. Let's watch the video "Runaway Universe," on DVD. Check out the methods used to figure out what the universe is doing; write down some techniques you see in the video.

Back to electricity. Today let's get an introduction into some basics of an electric circuit. Check out a Khan video about a circuit and Ohm's law. Then, check out some basics of materials we find in a circuit, with resistivity and conductivity.

There's an interesting documentary on electricity - check it out and take notes on different applications of electricity, and the main concept behind the applications. Have a good weekend!

Saturday, March 11, 2017

A good description of what schools SHOULD look like, but don't

Anyone who knows me is aware of my stance on what schools generally are doing to prepare students for the world, compared to what schools SHOULD be doing...I have been preaching for years that we are NOT running schools the way we should that would best benefit the students, but do to politics, we continue to think in terms of accountability and standardized test scores, and the traditional schedule and curricula. One model for what a high school could look like is here, and another model for a grade 9-10 science course can be found here. I've had these lying around for some number of years, and am always looking for thoughts and feedback, and a chance to try them!

Ted Dintersmith does a really nice job in this talk as he addresses this issue. He is responsible for the film "Most Likely to Succeed," and as someone who made his money as an innovator, he has firsthand experience of the qualities, skills, and topics schools should be getting to the next generation.

Monday, February 27, 2017

Links Useful to Tuesday, Feb. 28

Happy Tuesday, one and all!

For Periods 1-2, 5-6, 8-9:

It is time to start digesting Biot-Savart for magnetic fields, due to real wires. Unfortunately, real wires do have ends, and this means Ampere's law does not always give a good enough approximation for one's needs. Check out two videos that will take you through B-S for straight wires with ends, and one for a loop of wire with a current flowing (like the Helmholtz coil we used in the CRT lab last time).

Note that there is another video showing an example of B-S with multiple wires and currents, where we try to determine the B-field at some point from the two wires. If you need a review of B-S for moving point charges, there is a video for this here.

After watching the first two for wires, see if you can figure out the practice problems: Ch. 28 #59,60 for point charges (on page 7 of packet), and the collaboratives for wires on page 9 of the packet.

For Period 3:

Let's check out one video on defining the electric field some more. Take good notes on this since it will help with some of the problems we have coming up. Then, a second video will get into some examples of how to work with our formula for the electric field, E = kQ/r^2; you should take good notes on this one, too.

We will come back Wednesday and take a look at some examples of finding electric fields, and also electric potential, which is what we will call voltage.

We will try chapter 21, #66, 67, and 69; copies of these are in the packet you receive today.

Wednesday, February 15, 2017

Python Lesson for Wednesday

Hump Day!!!

Last week Fani was able to show us the importance and huge role of computer programming and simulations in science research. It is essential, and it is now a fact of life that if you do anything in STEM (and most other fields outside of STEM, as well), knowing even the very basics about what a program is, and how to manipulate existing code (not necessarily writing your programs from scratch) is invaluable and, frankly, expected.

We will do a bit of coding in Python throughout the semester, to expose you to this area of work.

The lesson for today is here.

First thing: In the computer lab, log into your student account and open the program Canopy. Do not click on it more than once - it will take several minutes for it to boot up. Canopy is something you can download for free on a home computer, and allows you to write and run your own Python scripts.

Tuesday, February 7, 2017

Earth's magnetic field articles

Check out a Scientific American article online, as well as a NASA article on reversals. Last but not least, a NASA article about the way the earth's magnetic field is constantly moving around and changing!

From your article notes and the video notes in class, summarize how scientists know all this, especially if there were no scientists around 800,000 years ago when the earth's field last reversed!!

Monday, February 6, 2017


We will try to bring back momentum, p = mv, from last year. Keep in mind two of the big things: it is a vector, and it is conserved.

To see WHY it is conserved, check out this video and take good notes.

Then, check out perfectly inelastic collisions that combine momentum with energy conservation, using something called a ballistic pendulum. Again, take good notes since it will help with some homework problems.

Tuesday, January 31, 2017

Ampere's law introduction

Check out an introductory video on something called Ampere's law, which has to do with the production of B-fields from 'long,' straight wires, long solenoids, and toroids. Ampere's law will be similar to Gauss's law for E-fields in the past.

Friday, January 27, 2017

For Today

Happy Friday, everyone.  :-) 

Periods 1-2, 5-6, and 8-9:

Check out magnetic forces on charged particles. A moving charged particle produces its own magnetism, which means magnets will make a force on that moving charged particle. This is where cross products start.

The magnetic force is F = qv x B.  Remember how to do the math for cross products (the 3x3 determinant thing), and that for A x B = C, the magnitude of C is C = ABsin(theta).

Check out two videos, one on the magnetic force on particles, and the second on an application called a mass spectrometer (along with a so-called velocity selector). Take good notes since you will need them for the practice set, which is the book problems and the first AP problem in the new packet you are receiving.

Period 3

We will be going into magnetism, so check out videos on this. First, watch and take good notes on an introduction to magnetism. A second video is on magnetic force. We will begin a lab with magnets on Monday, where you will get to begin (literally) feeling these forces, sometimes attractive and other times repulsive.

For practice and to begin thinking about magnetic fields, try the sheet you will receive. Use the side with diagrams to try and answer the questions.

Saturday, January 21, 2017

Scientists can watch an 'optical boom' with photons moving through material

For the first time, scientists can use high-speed videos (we are talking over one trillion frames per second...crazy short time intervals!) of a pulsed laser beam moving through a gaseous material to see the optical equivalent of a sonic boom. A sonic boom happens when a sound producing object like a plane moves faster through air than sound waves - we get a cone shaped structure of sound. The video in the link has a clear image of the cone-shaped pattern of light as the laser pulse moves at different speeds in a material compared to a gas layer that is also in the system. This is really cool!

Sunday, January 15, 2017

Here's Problem Solving/Engineering 21st Century Style - Agricultural MRI from Above

What a very cool application of high resolution photography, drones/airplanes/satellites, and computing - a UIUC professor has started a company that may be revolutionary for farmers to be able to identify issues in large farm fields (hundreds or thousands of acres). The company takes large numbers of photos of the farm fields, and then uses software it developed to identify even small areas within the field where there is an issue with disease, weather damage, lack of moisture, weed growth, and so on. In the past this has not been possible, and certain types of issues could spread to large sections of a crop before it was known - crop yields can only be improved using this technology and diagnostic technique. I personally love seeing creative, multidisciplinary solutions that can help make the world just a bit better!