Stephen Hawking’s Ted Talk

Stephen Hawking was invited to this Ted talk to answer some questions about the universe.  How did the universe begin? How did life begin? Are we alone? — and discusses how we might go about answering them.

On his wheelchair and his voice synthesiser patiently delivered his 10 minute speech and answered a question from the audience.

Stephen Hawking Ted Talk

Aerogel, world’s most powerful insulator

This amazing material is considered the best insulators in the world.  This super low density insulator can sustain temperatures from -78ºC to 1000ºC 39 times more insulation than the best fiber glass insulation.  Its complex porous structure makes it very difficult for heat conduction, so in the future it is expected to be used also as a home insulator.

Aerogel
Astronaut Peter Tsou with a sample of aerogel at Jet Propulsion Laboratory, California Institute of Technology. (Wikipedia)

Aerogel It is currently used in aerospace to make astronaut suits and spacecraft insulation.  Aerogel was also used in the Stardust space mission to collect space particles that impacted the aerogel at high speeds without destroying the particles.  The most amazing part of the aerogel is that it is 99% air, the remaining 1% is highly advance nanotechnology fibers of silicon dioxide.  Aerogel is so light that 1 gram of it could cover the size of a football field.  For its density it is extremely strong and it can sustain up to 4000 times its weight.

aerogel

Aerogel Explained

 

Time Travel Explained by Michio Kaku

One of the greatest enigmas of modern science is the possibility of time travel.  Einstein proved through the general theory of relativity time travel into the future.  However, time travel into the past is much more complex to understand in modern physics.

Michio Kaku explains in this video a theoritical model where the fabric of space time can be manipulated to travel into the past.  This model impossible to build today with our current technology might be a reality in the distant future, making possible time travel possible in a commercial scale.