OverlordAlex/pagetext

## pagetext
<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8" />
    <link rel="stylesheet" type="text/css" href="/css/style.css" />
    <link rel="shortcut icon" type="image/ico" href="/imgs/favicon.ico" />
    <link rel="apple-touch-icon" href="/imgs/apple-touch-icon.png" />
    <title>Relativistic Baseball</title>
    <script type="text/x-mathjax-config">
      MathJax.Hub.Config({
      extensions: ["tex2jax.js"],
      jax: ["input/TeX", "output/HTML-CSS"],
      tex2jax: {
       inlineMath: [ ['$','$'], ["\\(","\\)"] ],
       displayMath: [ ["\\[","\\]"] ],
       processEscapes: true
      },
      TeX: {
       extensions: ["AMSmath.js", "AMSsymbols.js"]
      },
      "HTML-CSS": { availableFonts: ["TeX"] }
      });
    </script>
    <script type="text/javascript" src="//cdn.mathjax.org/mathjax/latest/MathJax.js"></script>
    <link rel="alternate" type="application/atom+xml" href="/feed.atom" />
<script>
  (function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){
  (i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o),
  m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m)
  })(window,document,'script','//www.google-analytics.com/analytics.js','ga');

  ga('create', 'UA-25700708-6', 'xkcd.com');
  ga('send', 'pageview');

</script>
  </head>

  <body>
    <div id="header-wrapper">
      <header>
	<a href="/"><img class="logo" src="/imgs/whatif-logo.png" alt="logo"/></a>
	<a href="//whatif.xkcd.com/book/"><img src="//c0.xkcd.com/whatif/news" width="400" height="100"></a><br />
      </header>
    </div>

    <div id="main-wrapper">
     <div id="entry-wrapper">
   <nav class="main-nav">
 <ul class="nav-buttons">

  <li class="nav-next"><a href="/2/">Next</a></li>
 </ul>
</nav>

 <article class="entry">
  <a href="//what-if.xkcd.com/1/"><h1>Relativistic Baseball</h1></a>
  <p id="question">What would happen if you tried to hit a baseball pitched at 90% the speed of light?</p>
<p id="attribute">- Ellen McManis</p>
<p>Let’s set aside the question of how we got the baseball moving that
fast. We&#39;ll suppose it&#39;s a normal pitch, except in the instant the
pitcher releases the ball, it magically accelerates to 0.9c. From that
point onward, everything proceeds according to normal physics.:</p>
<img class="illustration" title="pitcher throwing ball" src="/imgs/a/1/01.png">
<p>The answer turns out to be “a lot of things”, and they all happen very
quickly, and it doesn’t end well for the batter (or the pitcher). I sat
down with some physics books, a Nolan Ryan action figure, and a bunch of
videotapes of nuclear tests and tried to sort it all out. What follows
is my best guess at a nanosecond-by-nanosecond portrait:</p>
<p>The ball is going so fast that everything else is practically
stationary. Even the molecules in the air are stationary. Air molecules
vibrate back and forth at a few hundred miles per hour, but the ball is
moving through them at 600 <em>million</em> miles per hour. This means that as
far as the ball is concerned, they’re just hanging there, frozen.</p>
<p>The ideas of aerodynamics don’t apply here. Normally, air would flow
around anything moving through it. But the air molecules in front of
this ball don’t have time to be jostled out of the way. The ball smacks
into them so hard that the atoms in the air molecules actually fuse with
the atoms in the ball’s surface. Each collision releases a burst of
gamma rays and scattered particles.</p>
<img class="illustration" title="fusion illustration" src="/imgs/a/1/02.png">
<img class="illustration" title="fusion zone of baseball" src="/imgs/a/1/03.png">
<p>These gamma rays and debris expand outward in a bubble centered on the
pitcher’s mound. They start to tear apart the molecules in the air,
ripping the electrons from the nuclei and turning the air in the stadium
into an expanding bubble of incandescent plasma. The wall of this bubble
approaches the batter at about the speed of light—only slightly ahead of
the ball itself.</p>
<img class="illustration" title="t=30 nanoseconds" src="/imgs/a/1/04.png">
<p>The constant fusion at the front of the ball pushes back on it, slowing
it down, as if the ball were a rocket flying tail-first while firing its
engines. Unfortunately, the ball is going so fast that even the
tremendous force from this ongoing thermonuclear explosion barely slows
it down at all. It does, however, start to eat away at the surface,
blasting tiny particulate fragments of the ball in all directions. These
fragments are going so fast that when they hit air molecules, they
trigger two or three more rounds of fusion.</p>
<p>After about 70 nanoseconds the ball arrives at home plate. The batter
hasn&#39;t even seen the pitcher let go of the ball, since the light
carrying that information arrives at about the same time the ball does.
Collisions with the air have eaten the ball away almost completely, and
it is now a bullet-shaped cloud of expanding plasma (mainly carbon,
oxygen, hydrogen, and nitrogen) ramming into the air and triggering more
fusion as it goes. The shell of x-rays hits the batter first, and a
handful of nanoseconds later the debris cloud hits.</p>
<p>When it reaches the batter, the center of the cloud is still moving at
an appreciable fraction of the speed of light. It hits the bat first,
but then the batter, plate, and catcher are all scooped up and carried
backward through the backstop as they disintegrate. The shell of x-rays
and superheated plasma expands outward and upward, swallowing the
backstop, both teams, the stands, and the surrounding neighborhood—all
in the first microsecond.</p>
<p>Suppose you’re watching from a hilltop outside the city. The first thing
you see is a blinding light, far outshining the sun. This gradually
fades over the course of a few seconds, and a growing fireball rises
into a mushroom cloud. Then, with a great roar, the blast wave arrives,
tearing up trees and shredding houses.</p>
<p>Everything within roughly a mile of the park is leveled, and a firestorm
engulfs the surrounding city. The baseball diamond is now a sizable
crater, centered a few hundred feet behind the former location of the
backstop.</p>
<img class="illustration" title="mushroom cloud" src="/imgs/a/1/05.png">
<p>A careful reading of official Major League Baseball Rule 6.08(b)
suggests that in this situation, the batter would be considered &quot;hit by
pitch&quot;, and would be eligible to advance to first base.</p>
</article>

 <nav class="main-nav">
 <ul class="nav-buttons">

  <li class="nav-next"><a href="/2/">Next</a></li>
 </ul>
</nav>


</div>

    </div>

    <div id="footer-wrapper">
      <footer>
	<!--<div id="search-box">Google search code here</div>-->

	<div id="footer-links">
	  <ul>
	    <li><a href="/archive">archive</a></li>
	    <li><a href="/feed.atom">feed</a></li>
	    <li><a href="http://xkcd.com">xkcd: comic</a></li>
	    <li><a href="http://store.xkcd.com">xkcd: store</a></li>
	  </ul>
	</div>

	<div id="submit">
	  <a href="mailto:whatif@xkcd.com">Submit a Question</a>
	</div>

	<p id="copyright">Copyright ©2012-14 <a href="http://xkcd.com/">xkcd</a>. Design by <a href="http://cgleason.org">cgleason design</a></p>
      </footer>
    </div>

    <script src="//ajax.googleapis.com/ajax/libs/jquery/1.10.1/jquery.min.js"></script>
    <script>
      jQuery.noConflict();
      jQuery(function() {
        jQuery(".refbody").hide();
        jQuery(".refnum").click(function(event) {
          jQuery(this.nextSibling).toggle();
          event.stopPropagation();
        });
        jQuery("body").click(function(event) {
          jQuery(".refbody").hide();
        });
      });
    </script>

  </body>
</html>
	<!DOCTYPE html>
	<html>
	<head>
	<meta charset="utf-8" />
	<link rel="stylesheet" type="text/css" href="/css/style.css" />
	<link rel="shortcut icon" type="image/ico" href="/imgs/favicon.ico" />
	<link rel="apple-touch-icon" href="/imgs/apple-touch-icon.png" />
	<title>Relativistic Baseball</title>
	<script type="text/x-mathjax-config">
	MathJax.Hub.Config({
	extensions: ["tex2jax.js"],
	jax: ["input/TeX", "output/HTML-CSS"],
	tex2jax: {
	inlineMath: [ ['$','$'], ["\\(","\\)"] ],
	displayMath: [ ["\\[","\\]"] ],
	processEscapes: true
	},
	TeX: {
	extensions: ["AMSmath.js", "AMSsymbols.js"]
	},
	"HTML-CSS": { availableFonts: ["TeX"] }
	});
	</script>
	<script type="text/javascript" src="//cdn.mathjax.org/mathjax/latest/MathJax.js"></script>
	<link rel="alternate" type="application/atom+xml" href="/feed.atom" />
	<script>
	(function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]\|\|function(){
	(i[r].q=i[r].q\|\|[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o),
	m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m)
	})(window,document,'script','//www.google-analytics.com/analytics.js','ga');

	ga('create', 'UA-25700708-6', 'xkcd.com');
	ga('send', 'pageview');

	</script>
	</head>

	<body>
	<div id="header-wrapper">
	<header>
	<a href="/"><img class="logo" src="/imgs/whatif-logo.png" alt="logo"/></a>
	<a href="//whatif.xkcd.com/book/"><img src="//c0.xkcd.com/whatif/news" width="400" height="100"></a><br />
	</header>
	</div>

	<div id="main-wrapper">
	<div id="entry-wrapper">
	<nav class="main-nav">
	<ul class="nav-buttons">

	<li class="nav-next"><a href="/2/">Next</a></li>
	</ul>
	</nav>

	<article class="entry">
	<a href="//what-if.xkcd.com/1/"><h1>Relativistic Baseball</h1></a>
	<p id="question">What would happen if you tried to hit a baseball pitched at 90% the speed of light?</p>
	<p id="attribute">- Ellen McManis</p>
	<p>Let’s set aside the question of how we got the baseball moving that
	fast. We'll suppose it's a normal pitch, except in the instant the
	pitcher releases the ball, it magically accelerates to 0.9c. From that
	point onward, everything proceeds according to normal physics.:</p>
	<img class="illustration" title="pitcher throwing ball" src="/imgs/a/1/01.png">
	<p>The answer turns out to be “a lot of things”, and they all happen very
	quickly, and it doesn’t end well for the batter (or the pitcher). I sat
	down with some physics books, a Nolan Ryan action figure, and a bunch of
	videotapes of nuclear tests and tried to sort it all out. What follows
	is my best guess at a nanosecond-by-nanosecond portrait:</p>
	<p>The ball is going so fast that everything else is practically
	stationary. Even the molecules in the air are stationary. Air molecules
	vibrate back and forth at a few hundred miles per hour, but the ball is
	moving through them at 600 <em>million</em> miles per hour. This means that as
	far as the ball is concerned, they’re just hanging there, frozen.</p>
	<p>The ideas of aerodynamics don’t apply here. Normally, air would flow
	around anything moving through it. But the air molecules in front of
	this ball don’t have time to be jostled out of the way. The ball smacks
	into them so hard that the atoms in the air molecules actually fuse with
	the atoms in the ball’s surface. Each collision releases a burst of
	gamma rays and scattered particles.</p>
	<img class="illustration" title="fusion illustration" src="/imgs/a/1/02.png">
	<img class="illustration" title="fusion zone of baseball" src="/imgs/a/1/03.png">
	<p>These gamma rays and debris expand outward in a bubble centered on the
	pitcher’s mound. They start to tear apart the molecules in the air,
	ripping the electrons from the nuclei and turning the air in the stadium
	into an expanding bubble of incandescent plasma. The wall of this bubble
	approaches the batter at about the speed of light—only slightly ahead of
	the ball itself.</p>
	<img class="illustration" title="t=30 nanoseconds" src="/imgs/a/1/04.png">
	<p>The constant fusion at the front of the ball pushes back on it, slowing
	it down, as if the ball were a rocket flying tail-first while firing its
	engines. Unfortunately, the ball is going so fast that even the
	tremendous force from this ongoing thermonuclear explosion barely slows
	it down at all. It does, however, start to eat away at the surface,
	blasting tiny particulate fragments of the ball in all directions. These
	fragments are going so fast that when they hit air molecules, they
	trigger two or three more rounds of fusion.</p>
	<p>After about 70 nanoseconds the ball arrives at home plate. The batter
	hasn't even seen the pitcher let go of the ball, since the light
	carrying that information arrives at about the same time the ball does.
	Collisions with the air have eaten the ball away almost completely, and
	it is now a bullet-shaped cloud of expanding plasma (mainly carbon,
	oxygen, hydrogen, and nitrogen) ramming into the air and triggering more
	fusion as it goes. The shell of x-rays hits the batter first, and a
	handful of nanoseconds later the debris cloud hits.</p>
	<p>When it reaches the batter, the center of the cloud is still moving at
	an appreciable fraction of the speed of light. It hits the bat first,
	but then the batter, plate, and catcher are all scooped up and carried
	backward through the backstop as they disintegrate. The shell of x-rays
	and superheated plasma expands outward and upward, swallowing the
	backstop, both teams, the stands, and the surrounding neighborhood—all
	in the first microsecond.</p>
	<p>Suppose you’re watching from a hilltop outside the city. The first thing
	you see is a blinding light, far outshining the sun. This gradually
	fades over the course of a few seconds, and a growing fireball rises
	into a mushroom cloud. Then, with a great roar, the blast wave arrives,
	tearing up trees and shredding houses.</p>
	<p>Everything within roughly a mile of the park is leveled, and a firestorm
	engulfs the surrounding city. The baseball diamond is now a sizable
	crater, centered a few hundred feet behind the former location of the
	backstop.</p>
	<img class="illustration" title="mushroom cloud" src="/imgs/a/1/05.png">
	<p>A careful reading of official Major League Baseball Rule 6.08(b)
	suggests that in this situation, the batter would be considered "hit by
	pitch", and would be eligible to advance to first base.</p>
	</article>

	<nav class="main-nav">
	<ul class="nav-buttons">

	<li class="nav-next"><a href="/2/">Next</a></li>
	</ul>
	</nav>


	</div>

	</div>

	<div id="footer-wrapper">
	<footer>
	<!--<div id="search-box">Google search code here</div>-->

	<div id="footer-links">
	<ul>
	<li><a href="/archive">archive</a></li>
	<li><a href="/feed.atom">feed</a></li>
	<li><a href="http://xkcd.com">xkcd: comic</a></li>
	<li><a href="http://store.xkcd.com">xkcd: store</a></li>
	</ul>
	</div>

	<div id="submit">
	<a href="mailto:whatif@xkcd.com">Submit a Question</a>
	</div>

	<p id="copyright">Copyright ©2012-14 <a href="http://xkcd.com/">xkcd</a>. Design by <a href="http://cgleason.org">cgleason design</a></p>
	</footer>
	</div>

	<script src="//ajax.googleapis.com/ajax/libs/jquery/1.10.1/jquery.min.js"></script>
	<script>
	jQuery.noConflict();
	jQuery(function() {
	jQuery(".refbody").hide();
	jQuery(".refnum").click(function(event) {
	jQuery(this.nextSibling).toggle();
	event.stopPropagation();
	});
	jQuery("body").click(function(event) {
	jQuery(".refbody").hide();
	});
	});
	</script>

	</body>
	</html>