Thoughts

I had a quick brainstorm and I want to put it here before I forget it. It’s one of those ‘nice and simple ideas that I’ll probably never get around to coding,’ so maybe you will!

Proposal:

The advent of internet video has opened the doors to many phenomenal lectures from world renown professors around the globe. Unfortunately, many of these professors tend to speak at length. They also spend a good amount of time scribbling on a blackboard writing long words or equations. They tend to pause while doing so, or worse, continue talking in a tangent direction! The former is time wasted in my opinion.
I propose a very simple video-viewer application that allows one to listen to the audio and video on-line lectures in a faster way… by speeding up the sound-track, but also by reducing the pitch of the sped up voice, so that the voice still sounds natural (instead of having an Alvan-And-The-Chipmonks-like quality). This can potentially allow people to “absorb” the big picture of what the lecturer is saying in half the time it would normally take. Since people usually only retain the big picture of a lecture, this could let people absorb twice as much as they would watching through it at normal speed. For fun, I’ll call this “Pedagogy Optimization.”

Problems with the Idea:

This of course ignores other modalities associated with learning. Speeding up the video would probably be too disorienting, though this should be experimentally verified. Also, professors couple blackboard or whiteboard writing with their lecturing. These visuals are key tools that enable the learning process, and lessening their display time may negatively impact perception of the ideas at hand. Another subtle issue may arise in time-sensitive lectures. These are lectures that only make sense in the context of normal time passage. For example, the demonstration of gravity in a physics lecture wouldn’t be natural in a framework of increased time speed.

Solutions to problems:

Allow for dynamic adjustment of playback. Default it to 2x speed, then, when the user decides they ‘missed’ something, with very simple and natural gestures, they ought to be able to ’slow down’ or ‘back up’ the feed, and change it continuously. They can do this through something like a digital touch surface on which different areas represent different parameters for playback, and simple slips of the fingertips in these areas adjust the parameters.

More Problems:

Modern day video compression is usually keyframe-based, meaning that in a compressed video like mpeg4, skipping to an arbitrary location takes processing time, and I believe reverse-playback isn’t possible with certain formats. Many algorithms assume a forward-playing invariant and exploit it during their lossy optimization.

More Solutions:

To get reversal, one can replicate the original source frames of the movie and make two versions, one compressed moving forward through time and another compressed moving backward through time. They can then be correlated via software, and toggled between when the user decides to ‘reverse.’

Slow-down and skipping in the videos can be achieved in the typical way done with today’s compressed video.

God bless Randy Pausch.

His last lecture. A world’s lecture.

The back story.

His take on things.

Alice.

It’s hard to know what to say. But it’s important to listen.

Ok so… I’m lying in the grass on a lawn at Stony Brook University, relaxing, taking the sun, and typing …

Honestly! I’m surrounded by grass (and a few bees, unfortunately) with laptop in chest, sun in closed eyes, typing my thoughts into the laptop as I relax and take rays. It’s times like this that I’m grateful I learned to type with my eyes closed =)

I know it sounds out-there, but honestly, this is fantastic. Everyone out there, especially bloggers, try this! I’m telling you.

So, what am I doing besides schlepping around in grassy meadows with my laptop? I’m actually trying to get a tan. I convinced myself that I need one after my talk of the good qualities of sunlight in my last post.

Though I got to thinking about it, and I can’t ignore that there are bad qualities of sunlight as well. Most obvious, skin cancer and 3^rd degree burns are a risk of prolonged exposure to the sun’s rays. I need to figure out how much sunlight it takes to get a healthy dose of vitamin D and brownish complexion, without the whole irreversible-skin-damage thing. I guess it’s a function of exposure time, skin cell regeneration rate, and skin cell degradation rate in the presence of sunlight. Which I guess also makes it a function of latitude and time of day … ozone layer thickness … solar storm activity … so this is getting complicated. Ah well …

Something physics-related popped into my head today. Did you ever wonder how those sun rays are propagated from the sun to the earth?  My understanding from undergrad physics is that photons basically shoot off the surface of the sun and connect with the earth at some point. My question is, how do they know what path to take? The idea is that they propagate radially outward from the surface of the sun, and the sun is a a sort of sphere-like ball of mostly-hydrogen (as far as we know), but is there something written in stone that says photons absolutely must propagate radially outward perpendicular to the surface of their energetic emitter in a vacuum? This makes me wonder about the sun.

Actually, the reason i’m even thinking about it is because I read some interesting findings about the sun’s plasma today. This is the hot gas that floats around and ejects off the sun’s surface. Scientists recently observed, by tracking the velocity of plasma discharging from the surface, that a wave-pattern is clearly present in the velocity of the plasma discharge. That means that plasma is streaming off the sun in alternating periods of fast-slow, fast-slow, over and over again, ad infinitum. From the footage I watched, the plasma seems to have variable velocity across different patches of the surface, but the period of each wave (the time it takes cycle from one particular velocity back to that same velocity again) seems to be fixed across the entire surface. Considering the size of the sun, this is a huge feat of synchronization.

This interesting find gives some insight into what’s going on under the frothy heat layers over there. My guess is that the sun must have some sort of rippling energetic mass near its middle that is making some waves.

This is probably obvious, but it seems to me that waves are a part of everything, and it should be acknowledged. They say that solar bursts cause ripples across the surface of the sun, like ripples on water, and that the sun rings like a bell in the process. These are surface waves. Now they are also saying that the sun has these core-to-surface velocity waves perpendicular to the surface that manifest in the solar wind. It’s obvious that waves have a fundamental coolness. Is it a coincidence that in math, one can use ‘wavelets’ to approximate any function, with any amount of variables? That means that the sum of waves can be used to represent anything you see in 2D (paper), 3D ( the world ), 4D (3d plus time), and anything in higher dimensions. The universe works in waves it seems. I find that interesting…

One last sun factoid: they say that the emitting plasma waves might give insight into why it is that the outer atmosphere of the sun, called its corona, is hotter than the sun itself. This fact is something that has perplexed scientists ever since it was discovered. Think about it. If you scaled the sun’s situation down to, say, toaster-oven size, this would be like saying that the space just in front of a toaster oven gets one-thousand times hotter than that inside the oven. If you were to throw some toast in there and crank the ‘toast’ knob up, reaching for it upon hearing the chime would cause you severe bodily harm! And you wouldn’t even be able to reach the toast!

Maybe this velocity-wave business has something to do with that. If the speed of the escaping plasma is constantly changing speed as it escapes the sun, I can see it causing a build-up of energy around the atmosphere as all that mass bursts out of the surface. The fluctuating fast-and-slow motion of the escaping plasma is probably creating a situation such that no inertia in the surrounding space can stabilize over time. Incoming plasma will always clash with the existing atmospheric plasma in a maximum of friction, and therefore, heat. Maybe it’s hotter around the sun than in it because there’s more friction out there.

So sun is great. And I don’t mean the guys that made Java! Though they aren’t so bad I guess.

That’s all I have for now. Adios!

-CJ