Arizona State University

University of Southern California

Fermilab

Author, <em>Is God a Mathematician?</em>

Space Telescope Science Institute

MIT Department of Mechanical Engineering

Science Writer

Tufts University

Princeton University

Author, <em>Our Mathematical Universe</em>

Massachusetts Institute of Technology

travel-light-years-lifetime-merl.jpg

Time Dilation and Intergalactic Travel

upload-brain-merl.jpg

Could You Upload Your Brain?

Do We Live in an Anamorphic Universe?

<p>A new model suggests that the early universe may have contracted and expanded&mdash;at the same time.</p>


A new model suggests that the early universe may have contracted and expanded—at the same time.

<p>What is The Nature of Reality? It’s a blog, and it’s pretty much the biggest question we could think of. We can’t promise that we’ll answer the question once and for all – in fact, we can pretty much guarantee that we won’t – but we promise a space that welcomes big ideas about space, time, and the universe; where we take questions as seriously as we take answers; where physics is about way more than inclined planes and levers and pulleys. Stick around; we just might expand your cosmic horizons.</p>

What is The Nature of Reality? It’s a blog, and it’s pretty much the biggest question we could think of.

The Nature of Reality

<p>What is The Nature of Reality? It’s a blog, and it’s pretty much the biggest question we could think of.</p>

Koch Foundation

Draper





  
      <div class="rich-text"><p></p><p>Time dilation is possibly the weirdest part of Einstein’s Theory of Special Relativity. According to time dilation, the faster you travel, the slower your time moves. But why does this happen? It’s actually a result of the fact that light always travels at the same speed, regardless of one’s frame of reference.</p><p>The first of these two videos describes how the constancy of the speed of light implies the existence of time dilation. The second video explains how time dilation allows for intergalactic travel, and in this case to the Andromeda Galaxy.</p><p>Time Dilation Explained:</p><p>Intergalactic Travel &amp; Time Dilation:</p></div>
  







  
      <div class="rich-text"><p></p><p>The discovery that light gets redder as its source moves away from Earth led astronomers to uncover some of the universe’s strangest truths, including dark energy, dark matter, and the expansion of the universe.</p><p>How well can you read these five clues and decode the universe’s best kept secrets?</p></div>
  



5 of the Biggest Puzzles about the Universe





  
      <div class="rich-text"><p></p><p>Just over a century ago, even the most pioneering astronomers still pictured the universe as a small, static thing that ended at the edges of the Milky Way Galaxy. But that all changed after an Indiana farm boy discovered a strange quirk of the cosmos in 1912: redshift.</p><p>Over the course of a century, redshift, the shifting of light toward the red end of the spectrum, became a tool that led astronomers to uncover some of the biggest cosmic mysteries — and to discover the incredible breadth of the universe itself.</p></div>
  



How Redshift Revealed the Universe





  
      <div class="rich-text"><p></p><p>What the Physics?!, hosted by Dr. Greg Kestin, a theoretical physicist at Harvard University, is about the physics in you, the physics of you, and the physics around you.</p><p>If you’ve been enjoying our videos, <a href="http://youtube.com/whatthephysics">find us on YouTube</a> to catch up on old episodes or subscribe to find out about new ones.</p></div>
  



What the Physics?! Trailer





  
      <div class="rich-text"><p>What would it take to make a copy of your brain?</p><p>With the days of blurry mimeographs behind us and the technology to make copies spreading into 3D- and cyberspace, the possibilities might seem almost limitless. But are they?</p><p>Physics itself—not technology, not human ingenuity—forbids perfect cloning, which might throw a kink in your plan to upload your brain.</p></div>
  







  
      <div class="rich-text"><p></p><p>Imagine the Earth gets swallowed by a black hole. Then, like all black holes, this one slowly evaporates away as particles radiate from its event horizon, until—poof—there’s nothing left.</p><p>What happens to everything that has fallen in? Has it just been deleted from the universe? Could information somehow escape from behind the event horizon? Or did it never truly fall in in the first place?</p><p>Ultimately, no one knows—and each one of these three unlikely answers breaks physics as we know it.</p></div>
  



The Black Hole Information Paradox





  
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   If you jumped into a black hole, not even the strongest rope could keep you from plunging into its depths toward singularity. Your plunge would be as unstoppable as the march of time is to you and me.
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   Even before you crossed the event horizon—the point of no return—the universe as you know it would become very strange. But at the event horizon, your fate becomes complicated and not fully understood. It depends on the perspective of who’s asking and which of the two pillars of physics—quantum mechanics or gravity—is ultimately correct.
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   Play the video below to begin your own adventure into a black hole.
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  Play the video below to take a 360-degree dive into a black hole!
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Brand: The Nature of Reality

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Time Dilation and Intergalactic Travel

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Could You Upload Your Brain?

Do We Live in an Anamorphic Universe?

Explore Topic: The Nature of Reality

Time Dilation and Intergalactic Travel

5 of the Biggest Puzzles about the Universe

How Redshift Revealed the Universe

What the Physics?! Trailer

Could You Upload Your Brain?

The Black Hole Information Paradox

Choose Your Own Adventure into a Black Hole