Have a causally consistent new year

… so what? Another year, another orbit of the earth. What’s the big deal, you say?

Well! I have some New Year’s news for you. Firstly, did you know that this year we get an extra second? To deal with this I suggest counting like a computer scientist; …3, 2, 1, 0! Happy New Year!

This year will, apparently, be the International Year of Astronomy! Georgia at Earth & Sky Science has found a great way to celebrate: 365 days of Astronomy Podcasts.

If that’s not enough, why not follow your lightcone this year? I found a great site that provides an RSS feed of astronomical bodies you (yes you!) could possibly have influenced since your birth.

… what’s a lightcone, you ask?

A lightcone is the 4-D surface in space and time that a flash of light forms as it travels away from its origin. The name is actually a bit misleading. It’s less of a cone, and more of a hyper-cone; that is a cone in four dimensions. Imagine a flash of light. As it moves forward in time the light will move outwards in all directions. At any point in time the light will be confined to the area of a sphere. As time progresses, the sphere will grow in size at a constant rate. If we think of time as another dimension, and tried to draw a 4-D graph of the flash, it would be a hyper-cone.

If you are still confused, a good way to begin thinking about this is to imagine a very small circle lying flat on the ground. Now, imagine it growing and as it grows you move it upwards. Every time the circle grows one centimeter in radius, it moves one centimeter higher up. This traces out the 3-D cone you know and love. The upward direction represents time and the other directions represent a 2-D space. To generalize to a 3-D space with time, you change the idea of a growing circle to a growing sphere. Et voila: a lightcone.

… ok, so what’s so special about a lightcone, you ask?

Since a lightcone is the boundary on which a flash of light travels, and nothing can travel faster than light, the lightcone also marks the boundary of influence of a certain action. Let’s say, for example, you sneezed. Achoo. At some other time, in some other place, let’s say a book fell over. Could your sneeze have possibly caused the book to fall over? What you could do is mark two points on a graph; one representing the time and place of your sneeze and the other representing the time and place of the falling book. You could draw a lightcone originating at the sneeze point. If the other point is outside this lightcone then it is physically impossible for your sneeze to have caused the book to fall over.

You could also do the same for your birth. Draw a cone originating from earth at your birthday. Now draw points for all the stars in the sky at time: today. Any points inside your lightcone could have been influenced by your birth. The word “could” is in italics because it’s really saying: “sure, the laws of special relativity don’t disagree with you… but… there’s more to cause and effect than lightcones”. Still, it’s a fun way to learn about astronomy!

So this year be aware of your lightcone and keep track of the people and events inside it. The range of influence of your actions is probably a lot more vast than you originally thought…

Intermission

This is a rather non-serious post. You can blame Clifford at Asymptotia for it. His recent post pointed to a site called typealyzer that claims to measure your blog’s “type”. This type classification seems to be based on the Myers-Briggs type indication tests. I thought I’d play along just for fun. Here are the results:

INTP – The Thinkers
The logical and analytical type. They are especially attuned to difficult creative and intellectual challenges and always look for something more complex to dig into. They are great at finding subtle connections between things and imagine far-reaching implications.

They enjoy working with complex things using a lot of concepts and imaginative models of reality. Since they are not very good at seeing and understanding the needs of other people, they might come across as arrogant, impatient and insensitive to people that need some time to understand what they are talking about.

Well, I’m satisfied with that… except for maybe the part about me possibly coming across as arrogant, impatient and insensitive. Oh well. It also gave me a picture of my brain. Apparently there is an abundance of logic, mathematics, imagination and symbols.

Right now my brain is filled with mathematics. I’m doing some of my first TA work; correcting around 300 midterms for a Special Relativity class. I’ll let you know how that goes if I survive…

In the mean time, if you need something to read, I’d recommend checking out this essay by Alfie Kohn about how current grading schemes actually inhibit learning in our education system, and what can be done about it. (Link via: think twice)

Welcome CV readers

So… I checked my blog this morning. Turns out I’ve got a CV spike;a huge spike in visitor stats thanks to a link on Cosmic Variance. This is my new record for daily visitors, and it’s only the morning…

I thought I’d just say: Welcome! This is a relatively fresh blog I’ve brewed up ( I, being relatively new to blogging ). I try to post every few days and I tend to keep the posts science related in some way. If you want to know more about this blog, as usual, check the about section for words. If you want to get a feel for this blog, I’d recommend browsing over these past posts:

• Conservation of money and the distributions of wealth
• Our elevators are more awesome…
• Measuring the speed of light with chocolate and a microwave oven
• Climate engineering as a band-aid solution
• It’s not just about access, it’s about accessibility
• Space and Time are Curved

Cheers and have fun!

-Jasper

Speaking of geckos…

… what’s that? Nobody mentioned the word geckos?

Oh.

Well anyway, I just discovered a neat article on Physicsworld describing a new wonder material made of carbon nanotubes that mimics the sticky padding on a gecko’s foot… the interesting thing is: the imitation is ten times stickier! Carbon nanotubes are exactly what they sound like; they are very thin tubes made of carbon. What you can’t tell from the name is that the walls of carbon nanotubes are just a single atom of carbon thick.

Somehow, physicists have been able to coax the nanotubes into a fiberous forest similar to that on the pads of a gecko’s fingers. Just like a gecko’s fingers, this material interacts with surfaces creating forces between the molecules of the material and the surface (aka: Van der Waals Forces) that resist motion parallel to the surface. If you pull the material away perpendicular to the surface, the nanotubes peel off fairly easily.

Apparently they are trying to (and I quote) “optimize the structure and scale it up so that they can make ’spiderman’ gloves“.

Could those physicists’ research be any cooler?

Edit: Arg. Why does boingboing always beat me to it.

Best Science Images of 2008 (via National Geographic)

Check it out. National Geographic has released their set of this year’s best science images.

The picture to the right is a real piece of string that vibrated about ten or twenty times over a two second exposure. I’m still wondering why the person was photographing a piece of string though…

To Kill Time: 15/09/08

“John McCain talks science, says he’s Wi-Fi’s main man” from Scientific American

In a page out of the Al Gore playbook, McCain boasts that “under my guiding hand, Congress developed a wireless spectrum policy that spurred the rapid rise of mobile phones and Wi-Fi technology.”

“First Picture Of Likely Planet Around Sun-like Star” from Science Daily

“This is the first time we have directly seen a planetary mass object in a likely orbit around a star like our Sun,[...] If we confirm that this object is indeed gravitationally tied to the star, it will be a major step forward.”

“Easily caught in a web of sinister untruths” from Times Online

[...]“evolution” is simply not a worldview, It is, rather, the best scientific hypothesis we have, by miles, for how species develop. By contrast both creationism and its sly relative, intelligent design, are readily falsifiable by scientific method.

“Bubble Magic!” from Asymptotia

Sterling Johnson during his marvellous presentation last night in Categorically Not!: Bubbles at the Santa Monica Art Studios.

“Reading On-Line and in College” from Uncertain Principles

In the eye-tracking test, only one in six subjects read Web pages linearly, sentence by sentence. The rest jumped around chasing keywords, bullet points, visuals, and color and typeface variations.

“Sticky Notes” from Backreaction

Dull office? Here’s a suggestion [...]

“Clear explanation of how LHC works and how the protons get their grooves” from Talk Like a Physicist

“Shoot the Moon” from Built on Facts

If you were on the moon, which is a vacuum, and tried to shoot a gun, would it fire? After all combustion needs an atmosphere with oxygen… or does the casing of the bullet create its own atmosphere? If so, the bullet would travel farther in the reduced gravity, but would it travel faster than it does on the earth?

“How supermassive black holes help galaxies evolve” from the physics arXiv blog

[...] what makes Heckman’s discussion highly provocative is the suggestions that a symbiotic relationship exists between galaxies and supermassive black holes, that they need each other to form. So supermassive black holes are as important in galactic evolution as gas, dust and gravity.