Dr Michael Denin The Real Physics Of Space Travel Special And Generalrelativity Explained

It's good to see someone up there who's based in the reality of strict science. It shows how today's UFO movement is not just about sightings and aliens but also about true science. This is the draw that makes such shows as Through the Wormhole so popular. People like to see the potential of what we can do and where we can go in the future. This guy is part of a trend of people out there who are mixing UFOlogy and Science. I'm looking forward to hearing this lecture...PresentationApparently, he was on the TV Show Ancient Aliens. What would it take for us to reach the stars and what would it take for them to reach us?-Science gives a framework of what is possible.-Critical to understand fundamental limits from technological limits. -Where are the open questions in science?Set the scale: -we're 93 million miles from the sun. That's considered as "1 AU" Astronomical Unit-Distance to nearest star is 4.3 light years. -1 light year is 186000 miles per second. -Distance to center of this galaxy: 26000 light years. -distance to Andromeda is 2.36 million light years away.No longer an issue-Exoplanets: they're there! -trying to see planets in another place in the universe is incredibly difficult. It's like trying to find a tennis ball on the moon.Technology vs Physics-Special and General Relativity - these are fundamental features of the universe-Energy Conservation-- an even more fund feature of the universe. -Technology will not allow for violation of the laws of physics no matter how cool it is!Can you make an invisibility cloak?-Fundamental issue: behavior light-Technological issue: material design for bending lightlights waves bend just like water waves bend for example, around a rock in middle of a stream. So far scientists have only been able to bend small amount of light which means for example, only the color RED goes away but the other colors in the spectrum do not. Three Issues-Standard Travel - Special Relativity-Warp Drive - General Relativity-Are there any loop holes?Special Relativity is not that difficult to understand.Basic Travel-Position = velocity times time-Velocities add: throw a ball out of a moving car. so even though you're moving forward fast... the ball is still also moving forward as well so when you throw it in a moving car, it goes up in relation to your velocity. -Strange idea: speed of light sis the same to all observers.Overcoming Intuition: How do you know if you're moving or not?Galileo had the first idea of motion is relative. We can tell when we are accelerating because of physical reaction of the object moving. However, there is no way in science to tell if an object is at rest or moving. It's a fact of nature. Physics is the same whether you are moving or not.What about light?Einstein had a thought since he couldn't measure if he's moving or not. So he realized maybe measuring LIGHT would give an indication of this. ChoiceTime is an absolute.C = distance / timec(speed)haha He said we all think of time as speed until we get into a physics lecture then it slows down. :)Time is just a "dimension" which means how many lines you can use to tell someone where they are. To tell time, you need 3 numbers, and time. three numbers for the position and time for when.Understanding Dimensions.Distance between two points is a fixed quantity.how we compute that distance depends on our frameHow showed an example of holding a pen in front of your face then rotating it slightly so, if you forget about depth perception, it looks shorter. He says this is an example of distance being relative.Time and length linked by creating a Light ClockLight travels at same speed so you can use it as a measure. Actually, it becomes increasingly even more difficult to measure because even though two objects may be traveling at speed of light, the time it takes for two objects to see each other is different. One will be more than the other because the angle that light needs to trabel on is longer than the other. So what happens is one person's time appears to be quicker (or slower) than the other. He gives an example of muons entering earth's atmosphere but I wasn't able to catch the specifics. What about space Flight?Need to consider change in change between the traveler and the people on the planet. Time will appear to speed up for the traveler.First real question is what is it going to take to travel in space? Need to consider acceleration and what it takes to get out there a, into space and traveling at an acceptable speed. you also have to go quite fast and it takes about a year just to get up to the speed of light. Can't go that fast right away for many reasons. Challenges of travelDifferent times... called Time Dilation as mentioned above.Energy Required. it gets larger and larger and actually approaches infinity. KE = 1/2 MV 2(squared) Kinetic Energy(KE)So we really need to find fuel but these challenges make it virtually impossible to be able to travel in space at or close to the speed of light.What's Next?-Acceleration and gravity can not be distinguished - think elevatorto understand general relativity, ride in an elevator.Person in elevator in a sealed room.. just standing there feels nothing if not moving How do you know you're moving / accelerating? You can't. This is GENERAL RELATIVITY. You cna't ell diff between acceleration and gravityWe know that light bends during acceleration. space-time bends...Energy/mass bends space-time.Things actually don't move in a straight line like we learned in class. They typically travel on a curve. Thusly, time travels on a curve. He showed us a piece os rubbery material with grid lines drawn on it. He then stretched this material and said that this is exactly what mass does in General Relativity. This brings us to the topic of Warp Drives. what does General Relativity (GR) allow?So How do we warp space? The challenge is getting a mass distribution to bend.Also how much mass of energy would it take to stretch that far and take our object from point A to point C.The main problem is there isn't enough energy to be able to do this. Worm holes:Do they exist already or do we make them? If I'm not mistaken this is also called an "Einstein-Rosen Bridge".a big challenge of bending space for a worm hole is how to handle the massive amount of gravity you're dealing with. Also, some of these solutions are allowed but they're not stable. In other words, worm holes are prone to collapse.Some possible loopholes are:Quantum mechanics., Dark Energy.New fundamental understandingBlack holes and quantum mechanics... in the nothingness of space, particles appear out of nowhere.If it's possible to generate enough energy and mass, he speculates warp drives won't be like tv shows or movies on a space ship but rather a Warp Highway that allows you to travel from point to point very quickly. Another cool thing to speculate would be to actually find wormholes.Finally, he speculates that it would be cool to become nomads in a ship and travel around space and explore. Closing Thoughts-energy is the ultimate issue.-Energy is part technology and part a fundamental issue. Given cost- hard to imagine secret visits. Given size - hard to imagine how to get there! In other words, how did aliens get past the limits laid out in this presentation. So he doesn't actually believe in UFOs or Aliens who visit the planet because of these things but is an optimist to us going into space.