Hermann's Grid

This is Hermann's Grid.  It's a really cool grid that shows how receptive fields and lateral inhibitions.  We were just talking about the eye and how light goes into the eye and hits the cones and rods and I was like.. OH! We just learned some stuff about the eye in AP Biology!

So basically, neurons in the eye send electrodes to the brain that then interprets the images creating an image in our brain.  When light is sensed, action potentials go down the axon if the nerve cells, which transmits the signal to the brain.  Action potentials are caused by sodium and potassium flowing into the cell/being actively pumped out.  The change in concentration changes the voltage within the cell, which causes the signal to be transfered basically.  The axons are insulated with myelin sheaths, which speed up the reactions because less action potentials need to be generated.  

Anyways, without going too much into biology, the white intersections have more light falling on it than the white spaces between two black blocks.  Lateral inhibition increases visual response by contrast and sharpness.  Receptive fields are the space where the photoreceptors respond.  The increased luminance in the intersection causes the intersection to appear darker because of the increased inhibition.  

So I thought this would be a cool thing to do my journal on, but it involved a lot of biology, which I kind of did know about and some that I did not know about.  The physics of this is less of an impact on the illusion, but it is still really cool.  When we learned about this in AP bio, I thought it was pretty cool, but then didn't really think about it again.  But we started talking about eye stuff in Physics too so I thought, wow, COOOL! Well, sorta.

Light Waves

I was hanging out with my friends this weekend and these guys are really into cars and racing.  My friend has a Subaru WRX and its so nice!  Anyways, he has HID lights on his car and its purpleish.  Its because its like 6 or 7K, or 6000K or 7000K.  I forget how bright his lights were.  So he was just showing off at how bright his lights were, and I was like, "OH! THIS REMINDS ME OF SOMETHING WE SAID IN PHYSICS!"

We were talking about waves in class and how they were able to pass through each other.  We said that we can tell light waves travel through each other instead of just combining into one wave because you can shine a flashlight in a lighted room and still see it.  The car reminded me of that because it was still really bright out, but you could see the light from the car.  

The picture is supposed to show this because I'm shining a flashlight in a lighted room and you can still see the light from the flashlight separately from the light in the room.  I was going to take a picture of my friend's car, but I forgot.  

Oh, funny story involving HID lights.  My friend bought 8K headlights for fun, even though they are technically illegal to put in your car because the light is blue.  He decided to put it in his dad's car for fun so he changed it out and replaced them.  While he and his dad were driving in the dad's car on the freeway, a police pulled them over and asked the dad if he knew that his headlights were illegal and the dad said no, because he really didnt know. Then he got this ridiculously huge ticket. So yeah, I thought it was funny.

Phone

So I usually don't do many journals a quarter.  Probably because I forget about doing them or I just get too lazy to do them.  But on friday, I wrote a big reminder in my assignment book and I even colored it and highlighted it!  I'm gonna do all of the journals this quarter for sure!

  Anyways... the picture is of my phone and it is usually on vibrate, however, you can still hear the vibrations when someone calls you, especially if the phone is sitting on the table.  When the phone vibrates on the table, the entire table then vibrates at the same frequency of the phone, increasing the volume.  That is why the vibrations sound louder when lying on top a surface than when you are holding it in your hand.

Its so retarded that people put their phone on "silent," but its still loud enough for people to hear.  Silent should mean silent.  

ELECTRiCAL METER

So I was searching around my house for the meter.  It was on the side of the house!  I never knew that those guys come by once a month to read the meters.  Its kind of creepy actually when you think about it because you have total strangers in your yard without your permission.  I also wonder how they would get back there because the two gates going to our yard are locked all the time.  We also have two dogs back there that would go crazy.

BALLOON

When I rub the balloon against my hair, the balloon becomes negatively charged on the side that was in contact with my hair.  Water is a polar molecule, meaning that it has a negative side and a positive side.  The oxygen side becomes more negative and the hydrogen becomes more positive.  When the negatively charged balloon is brought near the stream of water, it deflects the negative side of the water molecules.  These molecules are repelled causing the stream to deflect away from the balloon.  The water also looks like it is attracted to the balloon at times and this is because the positive side of the water molecule is becoming attracted to the negative balloon.  Opposites attract and likes repel.  

Rubik's Cube

So basically I have a rubik's cube at home and I do it every once in a while whenever I get bored or thinking about homework.  When I was doing it I realized that physics was involved!  Each of the side stuff rotates around the middle of the rubik's cube.  That's why the very middle square on each side never changes, but each block around it can change.  I was applying a torque in order to rotate the side I want to rotate.  Torque is force multiplied with the lever arm.

The first time I got the rubik's cube, I thought it was impossible and I'd never be able to finish it.  But it turned out to be really simple when I thought about it.  The real trick is knowing where each piece goes because each cube has a specific place to go and just because you complete one face doesn't mean that its the correct way.  Now I can finish it really easy.  My best time was like little over 2 minutes (:

Algae time!

Couple weeks ago, we were learning about the animal kingdom "Protista" in A.P. Biology.  This kingdom includes algae, the stuff that accumulates in aquariums and on beaches.  Among the different kinds of algae like golden, brown, and diatoms, there are also red and green algae.  Aside from the biological difference in the red and green algae, physics can also be used to describe the difference.  Both red and green algae are photosynthetic multicellular organisms, but the red algae reflects red light and absorbs the green light, while the green algae reflects the green light an absorbs the red light.  

We can see the color that is reflected off the algae.  Light can either be reflected, absorbed, or passed right through an object.  It passed through objects like glass because our eyes can see right through it.  I think it is pretty cool how physics can help explain why some biology concepts make sense in a different way.  I know that the different types of chlorophyll in the algae is the biology way of describing the different colors (like how green algae contains chlorophyll a and b, while red algae contains chlorophyll a and d), but physics concepts help explain it further.