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Accelerator Energies

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Title text: Fans at Daytona always get extra excited when officials decide to introduce some antimatter cars circling the track in the opposite direction.

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Explanation

In this comic, the Daytona International Speedway, a track for car races, is compared with various particle accelerators, even though the two are completely different things.

"eV" stands for "electron Volt", a non-SI unit of energy. It's typically used in particle physics, where exceedingly small & light particles are accelerated to exceedingly high velocities approaching the speed of light. Trying to increase the resulting energy leads to ever larger machines, having circumferences of dozens of kilometers, necessary because of the energy losses as the particles are turned at those speeds. This also makes them far more expensive. Judging by collision energy alone, a racecar is a far cheaper way to cause a collision than a particle accelerator (and it has a shorter track).

At first glance, it may seem remarkable that a simple raceway produces collisions with energies so much higher than those of the various particle colliders, by about 24 orders of magnitude. It's important to note that the comparison needs to take into account the masses of the colliding objects. A vehicle might have a mass of 1000 kg; the Large Hadron Collider operates on particles ranging from protons (1 atomic mass unit, 1.66 x 10^-27 kg) to lead atom nuclei (204 to 208 AMUs, 3.388 x 10^-25 to 3.45 x 10^-25 kg). The particle colliders provide much higher (energy/mass) values.

In a cyclotron, introducing antimatter circling in the opposite direction would allow more energy to be put into the collision products because the original particles are destroyed (at least in theory; with baryons, it is often the case that only some of the quarks/antiquarks annihilate), so the equivalent energy of their rest mass—and, more significantly, their remaining kinetic energy after the collision—does not detract from the energy budget available to create collision products. This does not matter as much as people think it does, but it would lead to audience excitement because of pure energy, i.e. light, being emitted.

Introducing a hypothetical antimatter race car going in the wrong direction thus not only results in even more carnage but in spectacular fireworks as well. The fact that you, as the spectator in the stands, would not survive such an energy blast (the Hiroshima atomic blast released the energy equivalent to only a few grams of matter) is typical of XKCD.

Transcript

[A scatter plot graph. The Y axis is labeled "Collision Energy" and shows values from 1 eV to 10²⁷ eV, marked at every 3rd order of magnitude, using SI prefixes up to 1 PeV, then switching to scientific notation from 10¹⁸ eV. The X axis is labeled "Track Length" and shows values from 10 cm to 100 km, marked at every order of magnitude.]

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This Week's Explanation for Improvement

As part of the Explanation Improvement Project, each week the community selects one older, stagnant, or otherwise neglected explanation to expand and polish together. This week's pick is comic 186: Console Lines, you can help us by editing its explanation!

To get involved with the project, you can also nominate an explanation that you think should be improved, or vote on current nominations!

Console Lines

|< < Prev #186 (November 20, 2006) Next > >|

Title text: If I get a Wii, it will be the first game console I've owned.

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Explanation

Welcome to This Week's Explanation for Improvement! Anyone is encouraged to help explain comic 186: Console Lines; click here to get started! If you are new to wiki editing, you can read our editing FAQ for guidance. Here are some suggestions for improving this explanation:   Why are the Nintendo people more kind than the Sony/Microsoft people? Explain!   Explain what a "Nintendo Wii" is for readers who have never heard of it.   Explain the necessary historical context of when this comic was published.   Why does Randall say that a Wii will be the first game console he will ever own? Are there other comics posted after this one where he says he owns a different console?   Improve the explanation of the double meaning of "console" in the comic.

This comic relates to video game consoles. At the time this comic was published, there were three major competing products: the Playstation 3 by Sony, the Xbox 360 by Microsoft, and the Wii by Nintendo. The Wii was released on November 19, 2006, the day before this comic was published. When a game console gets released, fans are often seen queueing outside the stores or camping on the pavement in order to be among the first to get their hands on a console. The comic shows such a console camp and points out the differences between the fan communities. While the fans waiting in line for a Sony or Microsoft product are very rude, the Nintendo fans are apologetic and try to comfort (that is to say, console) those who arrived too late to obtain a package. The cliché that Nintendo fans are nicer and more polite may be attributed to the fact that the Wii is targeted at children and families, while the PS3 and the Xbox are targeted at the more "serious gamer" crowd.

The comic also pokes fun at the fact that console has two meanings. A game console, like the Wii, Xbox, and Playstation, is an object that allows you to play video games as much as you want, most of the time even multiple different video games. However, to console can also mean to make someone feel better, after a disappointment, like, well, not getting in line for a video game console.

The title text primarily expresses Randall's distance from the console wars (he has never owned a game console before), but also indicating an inclination towards the Wii, Nintendo's 5th major home console, which came out in 2006 and was known for its innovative (at the time) motion controls.

Transcript

Fans turning away latecomers to all-night game console campouts:

[Two different lines, presumably leading to video game stores, are shown.]

[In the line labeled Sony/Microsoft:]

[Cueball, Megan, and another Cueball are in line, while Cueball and Hairy are just outside of the line]

Cueball: The line is full, asshole! Fuck off!

[In the line labeled Nintendo:]

[Cueball, a chair, another Cueball, a third Cueball, and Ponytail are in line, while Cueball and Hairy are just outside of the line]

Cueball: I'm so sorry, all the consoles are spoken for.

Cueball: Do... do you want a hug?

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