Seeing Your Own Eye Blood Vessels

By Anupum Pant

Blind spots are fine and I’ve known for years how to spot your own blind spot. You can make 2 spots on a paper separated by 4-5 inches, close your right eye and look at the right side spot with your left eye. If you do that and move forward or backward ( and rest at about 15 inches from the surface you drew on), you’d find a point where your left eye’s peripheral vision would not render the left side spot. You’d have found your blind spot.

But there is something more interesting, I never knew. You can actually see the blood vessels of your eye, with your own eye. Here’s how…

Take a sheet of paper (or card), and poke a pin hole in it. Then close one eye and holding paper close to your eye, jerk around the paper in little circles. At the same time, make sure you are looking at a bright white area through that hole. You could open up MS paint, make the whole canvas white and stare at it through the hole. Try to focus on the white screen and not the paper (or card)…

The video probably explains it better.

Seeing Sound

You can skip everything under this subheading

Note: In the past, I’ve been requested by my readers to keep the articles on AweSci short. It made sense. Since I write one article everyday, for readers, it definitely is easier to read and digest a smaller article, day in and day out. Thanks to the rate at which short attention span is being nurtured by the internet, not all have the appetite to take in bigger pieces everyday.

I see it this way – doing a very little thing everyday religiously, compounds. It makes a huge difference in your life. Even devoting 2 minutes a day for a single thing makes big changes over time. Here, I’m doing more than an hour everyday! If you read these daily, you are devoting around 10 minutes a day to learn something. You’ll do great in life!

At the same time, smaller articles of about 300-500 words are good for me too. By sticking to smaller ones, I can accomplish my own goal of learning and writing about one new thing everyday, by doing less. Also, composing smaller articles doesn’t take a lot of time which allows me to take care of the primary daily activities.

However, today, a reader asked me about the decreasing length of my articles. It’s so good to know that readers actually care about these things. Nevertheless, as explained above, there’s nothing wrong in it, but it did make me think about what was causing it? Well, I’ve been busy with so much stuff for the past few days, I don’t have partners for the blog and it’s tough doing it alone. Still, with all the travelling and full day outings in a 40 degree sun for the past few days, I managed at least one article a day. Pat on the back to me for being able to do that.

Anyway, the point is that articles don’t have to be long. For the question my faithful reader asked me, I needed to write this to explain it to him. He deserves a good explanation for being faithful reader to my little blog. If I learn something and sleep a little bit smarter than the last day, I’ve accomplished my goal for the day. That way, the purpose of you reading this is served. That way, the purpose of the blog is served.

What do you say, long or short? Or, you are always welcome if you want to contribute on this blog. We have hundreds of people who’d come by daily to read your article!

Background

In the past, we’ve seen how geniuses at MIT have figured out a way to capture the beam of light on video, and have replayed it moving in slow motion. In simple words, moving light was captured on camera. Something which the human eye had never seen before was shown moving with the help of technique. But, then there are other invisible things too. Like sound!

Watching sound

Watching the iTunes visualization go, isn’t equivalent to watching sound. Visualizations and waveforms are merely a digital depictions of sound.

While listening to sounds can be too easy, seeing it with your eyes isn’t natural. For that, there is camera trick that can be used to see the actual sound waves travelling in the air. In fact, with this technique, any disturbance in the air can be seen which otherwise, would be totally invisible to the naked eye. It let’s you see sound!

The camera technique has a fairly confusing name. It’s called Schlieren flow visualization. But that shouldn’t confuse you because in simple words, with this technique it is possible to capture on film, the disturbances that are caused by things moving in the air. For example, the invisible disturbances that are caused in the air (a transparent medium) when someone claps can be made visible by using the technique – Schlieren flow visualization.

Here is how it works

Photograph of a wind tunnel model using a schlieren system along  with a schematic explaining the operation of the system

If I write it in words, I’ll only confuse you more. So, here is an NPR video that explains the mechanism very accurately. Otherwise, there’s always this NASA page for it.

Amazingly, like the video shows, it can be used to see the heat coming off the human body. Now, I can definitely think of some creative applications for that.

Human Echolocation – Seeing With Your Ears

By Anupum Pant

Bats can see, but Daniel Kish can’t. Due to Retinal Cancer (Retinoblastoma), Daniel has been completely blind since the age of 13 months. To save his life, both his eyes had to be removed at a young age. But, even with no eyes, he can see. He sees with his ears. People call him the real-life batman.

What? When Daniel was young, he started making a clicking sound with his tongue to understand his environment. Little did he know, at a young age, he had mastered Echolocation – A technique used by dolphins, and bats to navigate when there is no light. At the age of 11, only when a friend told him about Echolocation, did he realize what he was really doing.

How? By listening to the reflected clicking sound, Daniel is able to map the shape, dimension, depth and density of objects in his brain. Like we use light to see, he uses sound to create a 3D map in his brain. He has trained his visual cortex to process non-visual information. With this ability he is able to ride a bicycle around, effortlessly. Think about riding with your eyes closed. He does it everyday.

According to him, what he does isn’t rocket science. He thinks every one, if trained well, can do it. With a concern for blind people around the world who aren’t encouraged to use echolocation to move around, he started an organization where he teaches people how to do it. You can watch his TED talk here. [video]

Side note: In a Tamil movie, Taandavam, he was the one who taught Shiva to move around using echolocation.

If you think Daniel’s ability doesn’t talk enough about the amazing human brain. This video of David Eagleman talking about how our brain perceives the world, will probably make you appreciate it [the brain] more. Watch it till the end where he talks about these plug-in-brain devices.
In short, brain can learn to interpret various kinds of signals to produce an image.

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