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Warp Speed March 25, 2012

Posted by peterxu422 in astrophysics, cosmos, Science, Technology.
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Even if you are not a card-carrying sci-fi fan, you may have at some point encountered the term warp speed and perhaps even contemplated about its realities. While inter-galatctic travel and teleportation are still a far reach technologically, theoretically, that is within the known laws of physics, they are not in violation with our understanding of nature.

Warp speed, if you are not familiar, is traveling through space much faster than the speed of light. According to Einstein’s theory of Special Relativity, the fundamental speed limit in the universe is the speed of light, 300 million meters per second. Sounds fast right? But let’s put that number in perspective. If you were to travel at the speed of light from Earth to the center of the Milky Way, it would take you 25,000 years to get there. Forget about going to another galaxy within a reasonable time period. Also from relativity, due to a phenomenon known as length contraction, we know that objects get contracted as they get faster and faster. If an object travels at the speed of light, it will ultimately become contracted and squeezed into nothingness. Not very convenient for space travel either.

But if the speed of light is the ultimate speed limit, how do we get around this problem? The potential solution lies in Einstein’s theory of General Relativity, which tells us how space is curved and can be warped. The one thing that can move faster than light is how fast space itself stretches. We know this because during the Big Bang, space expanded faster than the speed of light. Thus, to travel between two distant points in space, we can manipulate space itself to get to our destination.

The way to do this would be to expand the space behind you and compress it in front of you. The expansion of the space behind you gives the appearance of a push while the compressing space in front of you is dragging you forward. But realize that this does not violate Einstein’s postulate that nothing can travel faster than the speed of light. You yourself are not moving, but space is and it can move as fast as it wants.

The best way to imagine this is by taking a balloon, where the surface of the balloon represents space. Suppose you draw two dots A and B. You are at A but B is located very far away. Now imagine taking a cut-out spaceship and taping it to a ribbon that can wrap around the balloon so that the ribbon is tied around the balloon, but not bound to it. If you squeeze the portion of the balloon in front of the spaceship, “space” is being compressed. But you’ll also notice that point A got farther away from the spaceship and point B got closer. From your perspective, the spaceship did not actually move, space did.

How then do we actually go about warping space? Well, it’s not easy, and certainly requires technology beyond anything humanity possesses currently. But in theory, a way to accomplish this is by using a HUGE amount of energy, specifically negative energy. Negative energy has an opposite effect on things. For example, if something were about to collapse in on itself, negative energy would hold it outward. If something falls down, negative energy would make it float up. A combination of negative and positive energy pushing and pulling on the space around the spacecraft would give the desired warping effect of space. So a spaceship with warp drive capabilities would have on it an engine that could create something like a bubble of this negative and positive energy enveloping the vessel.

Also, as you may have seen in sci-fi flicks that when spaceships go into warp drive, the light from point sources in space begin to stretch and get all line-y. The reason it is rendered this way is because as the spaceship moves faster, it is catching up in speed to these light beams and so the crew on-board sees how the light actually looks in its beam form. But remember, the ship itself isn’t moving faster, the space around it is.

VIDEO: World Science Festival Warp Drive, Lawrence Krauss

Star Trek 2009 Warp

The Need To Look Up March 17, 2012

Posted by peterxu422 in astronomy, astrophysics, cosmos, Science.
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Whenever I leave campus during the evening, I look up at the clear night sky. First, I look for the moon, if it is visible. I then look at stars that have not been drowned out by light pollution. Finally, I look for Jupiter and Venus, which have recently been particularly visible. There is something marvelous about being able to look at a planet with the naked eye that makes you feel a lot more connected with the cosmos, which is often perceived as distant and separate from humanity.

Questions that arise while stargazing include “Is there life out there?” and “When will humans live in space?” Scientists search for intelligent life based on a potential civilization’s energy consumption. They categorize them as Type I, Type II, and Type III civilizations.

Type I is planetary. They control the energy of a planet. They have the ability to tap the energies of tornadoes, volcanoes, and earthquakes as opposed to running away from them.
Type II is stellar. They control the energy of a star, much like the Federation of Planets from Star Trek.
Type III is galactic. They control the energy of billions of stars in their galaxies, like the Empire from Star Wars.

We are a Type 0 civilization. Humans gather their energy from dead plants (oil and coal). But we are seeing the birth pangs of a Type I civilization. For example, the European Union is the beginning of a Type I economy. English is a Type I language. The Internet is the beginning of a Type I communication system. Rock and Roll, Rap music, Gucci, Prada, Hollywood celebrities are signs of a Type I culture.

While the transition from Type 0 to Type I is perhaps the most glorious of transformations, it is also the most dangerous. Type 0 civilizations are rather primitive and vulnerable. They are subjected to nuclear warfare, germ warfare, terrorism, fatal asteroid collisions, and many other dangers to which they do not have the means to stop. It is not certain whether we will make it to Type I.

I see the issues that our civilization faces and I become more convinced of the necessity of space exploration and extending our means of survival beyond the Earth. A rising world population comes with tremendous demand. As resources grow scarce, violence and aggression will spread as people fight to survive. The Earth will be unable to sustain us indefinitely, and it will simply be too much to keep asking people to compromise the comforts of their lives. Space colonization is the optimal, inevitable, and necessary solution.

But at the current rate efforts in space exploration are being promoted, it is not likely the solution will be achieved in time to meet the problems we face. NASA receives only half a penny for every tax dollar. Their entire 50 year running budget is less than the $850 billion bank bailout. That funding has paid for space rovers, spaceships, the Hubble telescope, sending a man to the moon – all monumental achievements that have pushed our understanding of the universe and our technological capabilities to horizons beyond. Imagine what our world would be like if they had the other half of the penny. But more importantly, when making efforts to pioneer space exploration, you do not make advancements in one field, but across many other disciplines like electrical engineering, mechanical, robotics, materials science, biology. The space program is the tent pole to the entire scientific enterprise that can give manifold benefits in various ways.

How then do we make this happen? I think the first step is that more people should start looking up. Appreciate the heavens, the possibilities, and the necessity of expanding our understanding of the cosmos. And hopefully, this collective desire will trickle over to those who have the capacity to take action and the vision to partake in great opportunities. Maybe then, we will have the chance to reach Type I.

VIDEO: Neil Tyson at UB: What NASA Means to America’s Future

Expansion Into Infinite Oblivion November 20, 2011

Posted by peterxu422 in astronomy, cosmos, Science.
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Can you name 5 Nobel Laureates? It turns out not many people can answer this question. The works of Nobel Laureates are quite remarkable and they make great contributions to society’s collective understanding. Therefore, I feel it is important that I remain aware about the news of the Nobel world, in particular the prize in physics. So let me share with you some fascinating information about this year’s Nobel Winners in Physics and their mind blowing work. It’s literally bigger than anything in the entire universe.

The Nobel Prize in Physics were awarded one half to Saul Perlmutter (UC Berkeley) and the second half jointly to Brian Schmidt (Australian National University) and Adam Riess (Johns Hopkins University) for the discovery of the accelerating expansion of the universe.

It is almost widely known that the universe has been expanding for the last 5 million years. Space itself has been stretching and expanding. Imagine a balloon that has been partially blown up, with the surface representing our universe. If you draw dots with a marker on various locations of the surface, and you blow the balloon again, you will find that the marks are further apart from each other than they were initially. The space between them has expanded. This is the same thing that is happening to our universe. The space between our galaxy and all other galaxies are stretching and we are getting further away from each other. You may ask why is it that we do not notice this stretching on Earth? Locally, the stretching is so small and insignificant that it cannot be noticed. But since the universe is very large, over a lot of space all these contributions add up and become noticeable (think calculus).

Naturally, the second question would be to ask, “How fast is it expanding or how fast is the expansion slowing down?” which was exactly what Perlmutter, Schmidt, and Reiss sought to answer. It was believed that the expansion rate would slow down as the amount of matter accumulates in the universe and as the strength of gravity increases, the inward pull of gravity would slow down the expansion, eventually to a stop, and if powerful enough, revert the expansion and cause the universe to collapse in on itself in a Big Crunch.

The three measured this by using the brightness of Type IA supernovas (explosion of stars near the end of their lifetime) which are explosions of white dwarf stars. They also used the redshift of these stars to determine how fast they were moving away from the Earth. With these two pieces of information, they would be able to determine how fast the universe is accelerating. But their results showed that the brightness that they observed was less than what they expected, which meant that the universe’s expansion is not slowing down, but speeding up. Space itself was getting stretched faster. The laureates were actually on competing teams attempting to answer the same question, Perlmutter on one team and Schmidt and Riess on the other. Their results were so astonishing that the two teams needed to confirm each other’s results in order for it to be accepted by the scientific community.

The result of the accelerating expansion of the universe carries enormous implications. As space expands, the distance between galaxies are expanding faster and faster too. Galaxies are rushing away from us so quickly than in the distant future, their light will not even be able to reach the Earth. The universe will become a cold dark and lonely place and future astronomers will only be aware of the existence of other galaxies by the textbooks that described them in the past. The universe will not end in a Big Crunch, but a Big Rip as the expansion rate speeds out of control and rips the fabric of space time. Like a balloon being filled too quickly until the rubber membrane which holds its form tears.

Aside from this morbid interpretation, their work has also opened the doors to exciting new questions and discoveries in physics. For example, the real question was, what is driving this accelerating expansion? There must be some kind of energy in the vacuum of space that is counter-acting the inward pull of gravity, and this energy must be a lot stronger than all of the gravity in the universe. As a placeholder for this mysterious energy, physicists have dubbed it Dark Energy. Dark Energy makes up 75% of the entire universe. Another 20% is to another mysterious substance called Dark Matter, and the last 5% is to all physical matter. That means the total material composition of the stars, galaxies, planets only make up a small fraction of the composition of the entire universe. Physicists don’t know what is Dark Energy, and they cannot see it (hence ‘Dark’), but they know it’s there.

The work of Perlmutter, Schmidt, and Reiss has changed our outlook on the universe. Whether their work will have any practical applications in our life is not explicit. But the spirit of science is not to make a profit off our power to manipulate nature. It is about the quest to understanding nature through reasoning, experimentation, and asking questions. Perlmutter, Schmidt, and Reiss have certainly given us some fun questions to think about. Congratulations to the Nobel Laureates.

In my next post, I will explain in a bit more detail the actual science behind the work.
VIDEO: Dark Matter

Seeing Yourself As a Wave October 23, 2011

Posted by peterxu422 in cosmos, Science.
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If I asked you to describe what your body is made of, your response might be that it is made of particles or atoms. But did you know that it is equally accurate to describe yourself as being made of waves? A particle can be any object, big or small. In its simplest description, waves are things that vibrate periodically. It seems non-intuitive, but there is a physical relationship between the two.

Waves can be imagined as ripples in a pond. When a rock is dropped in the water, you would observe circular ripples, or waves, propagating from a source. If two rocks are dropped at the same time, you will see two waves interfere with each other.

Light can be imagined in the same way except propagating through space in all directions. Say you have a flat plate with a single slit and a detector screen behind it. If you pass light through the slit, you will see a single bright line on the screen. But if you have a plate with two slits, you will see multiple bright lines on the screen. This is called an interference pattern, and it is analogous to two waves of water interfering with each other.

A famous physics experiment called the double-slit experiment performed by Thomas Young, revealed the relationship between particles and waves. Electrons, real particles with mass, were first fired through a single slit. The screen behind the slit detected where the electrons landed. As we would intuitively expect, a single line of electrons were detected on the screen. When the electrons were fired through two slits, it was expected that two lines of electrons would be detected by the screen. But what was observed was multiple lines of electrons separated by narrow gaps, much like the interference pattern observed from the experiments with light. This led physicists to believe that matter exhibits wave-like properties as well. It changed the way they thought about matter. Now, matter cannot be thought of as solely particles, but as waves too. This is known as the wave particle duality.

These waves of matter represent the probability of a particle being at a particular location in space. If you calculate mathematically how large these waves are, the larger the wave is at a particular location, the greater probability the particle has of being found there. What this means is that all particles, including the ones in our body, have a probability of being anywhere in the universe. So there is a probability of you right now spontaneously appearing on Jupiter. However, the probability of this is so small and rare that it will take a take a time greater than the lifetime of the universe for it to happen.

The world of atoms and subatomic particles, the “small,” is known as the quantum world. The field of studying how things behave in the quantum world is called Quantum Mechanics. When you enter the quantum world, strange and spooky things happen. Common sense logic does not apply and what you experience is not what you would expect. The wave properties of matter are much more noticeable and apparent in small objects than large. That is why we do not notice the wave properties of everyday objects that we interact with. While Quantum Theory is indeed strange and confusing, the reason it is powerful is that it works. It makes accurate predictions of systems and behaviors in the quantum world. It is also responsible for the birth of the Informational and Technological Age.

Feeling confused? Don’t worry. It took me a while to get my head around this idea. But it is amazing to think about nonetheless. No one really knows yet why things behave this way. They just do. As the great physicist Richard Feynman once said, “If you think you understand Quantum Mechanics, you don’t understand Quantum Mechanics.”

Watch a fun explanation of the Double Slit Experiment.

Simple Ideas About The Universe Pt. 3 September 17, 2011

Posted by peterxu422 in astronomy, cosmos, Science.
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Global Warming has been the subject of much talk in the last few years. Have you ever wondered where the idea of Global Warming affecting the Earth originated? It actually came from studying the atmosphere of Venus that led to the consideration that Earth was experiencing a similar phenomenon. I myself, never learned the full explanation as to why this claim is true, but I can certainly use what I already know and surmise a possible explanation. In fact, this is actually the first time I really thought about this, so join me in trying to understand why we can believe Venus exhibits greenhouse effects.

I know there is a relationship between radiation and element types. Most radiation comes in the form of Electromagnetic Radiation. You experience this everyday from the light that enters your eyes (visible), to the inner workings of your microwave oven (microwave), to the warmth that radiates out of your body (infrared). These forms of radiation are waves and they all fall under what is called the Electromagnetic Spectrum. Electromagnetic Spectrum All Electromagnetic Radiation have the form of waves and they have a specific wavelength associated with it that distinguishes it from other types of waves.

Atoms can emit radiation when they’re “excited” or when they receive energy. The electrons jump to a higher orbital in the atom and when they fall back down, the atom emits radiation. This radiation will have a certain wavelength. What scientists discovered was that certain atoms emitted unique patterns of light when they were excited. Therefore, by observing a certain pattern of light emitted from a system, we can determine, more or less, what elements compose of that system.

Scientists are always looking at planets and using different lenses to look at the radiation emitted by them. Taking the ideas I just described, it is possible that in observing the type of electromagnetic radiation being exhibited by Venus, scientists were able to determine what its atmosphere was composed of. According to Wikipedia, Venus’s atmosphere is composed of 95% Carbon Dioxide, the main proponent for greenhouse effects.

At this point, I would like to make it clear that I do not claim this is the way it was originally done. This is merely my attempt at justifying the initial claim using what I know. Nonetheless, I hope this gives you an idea of what it is like to think scientifically. It requires being logical, analytical, and using previously known information. Very often, it also requires thinking creatively, especially when attempting to explain things that are not obvious.

Watch the video below of Astrophysicist, Dr. Neil deGrasse Tyson, answering cosmic questions. Skip to 7:49 for the discussion regarding Venus and Global Warming, but I highly recommend watching the entire clip. It’s fun!

VIDEO: Ask the Astrophysicist: Neil deGrasse Tyson (Questions & Answers)

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