Here, we thought we would explain the difference between the terms and how they interact with light (from both a wave and particle point of view): http://www.fromquarkstoquasars.com/gravitational-lensing-refraction-diffraction-three-sides-to-the-same-coin/
Original Image Credit: Unknown (But if you do, please let us know)
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Wednesday, December 18, 2013
Gravitational Lensing, Refraction & Diffraction: Three Sides to the Same Coin?
Sunday, December 1, 2013
Unifying Gravity and Quantum Mechanics:
Quantum mechanics may seem like it is beyond our realm of experience; however, it is an integral part of the physics that governs our lives. Yet, it is not without its problems. There is one very important aspect of our everyday experience that is not described in a quantum framework-- and that is gravity. Because it keeps matter together, gravity is one of the driving forces of the cosmos -- and of life itself.
For quite some time, we have struggled with the goal of uniting gravity and quantum mechanics. Nowadays, physicists have had many ideas (some great, others not so much); however, nothing experimentally verifiable (like string theory) has surfaced. That is, until now.
Some physicists are starting to think that gravity itself is the ultimate decoherence, or the weakest form of background noise. To learn about new experiments that can help us solve this problem, see:
http://www.fromquarkstoquasars.com/unifying-gravity-and-quantum-mechanics/
Image source:
NASA
The Problem with Quantum Mechanics and General Relativity:
The quantum realm is rife with enigmas -- inexplicable things that leave us puzzled. Unsurprisingly, since we have the (modest) ambition of obtaining a complete mathematical picture of the entire universe, it seems like there are many properties of particle physics that are completely removed from our existence on Earth. However, that previous sentence is a bit of a paradox, because the quantum world is utterly ingrained into our surroundings. For starters, it can be seen emanating from the sun, as photons of electromagnetism bounce off of everyday objects, before arriving near our retinas. It can also be seen in the form of waves slamming into the shorelines, with the molecules of water slowly eroding large rocks into tiny pebbles of sand. These tiny grains, in turn, accumulate by the trillions, eventually forming the beaches we all love.
In short, we know that the realm of the very small is intricately related to our everyday experiences, and that our level of existence is only a tiny piece of a much larger puzzle. To progress as a species, it is imperative that we have a comprehensive understanding of the world around us.
However, we have had a hard time uniting the physics of the very small with the physics of the very large – Quantum Mechanics and General Relativity. To learn all about this problem, see:
http://www.fromquarkstoquasars.com/the-problem-with-quantum-mechanics-and-general-relativity/
Image source:
CERN
Friday, November 29, 2013
MOND: Trying to Solve the Problem of the Missing Universe
One of the greatest mysteries of astronomy is the problem of the missing universe. Well, the universe isn’t exactly missing, but a lot of its mass is. Ultimately, all of the matter scientists can see in the universe accounts for only a small percent of the observed gravity. Everything on Earth, everything we’ve ever observed with our instruments, all normal matter—it all adds up to less than 5% of the Universe. Essentially, some unobservable something in influencing the motions of the cosmos.
Astronomers often use dark matter to explain this missing matter. However, the dark matter interactions that scientists believe they observed remain inconclusive. Thus, scientists have yet to definitively determine that dark matter exists. In fact, we may never actually be able to detect it... and it isn"t ideal at predicting all manner of situations. As you see, dark matter does have some problems.
Some researchers think that the problem is really our understanding of gravity. In order to explain why the universe seems to behave as if there"s so much more matter in it, some scientists advocate MOND (Modified Theory of Newtonian Dynamics) instead of dark matter.
Learn about this alternative at:
http://www.fromquarkstoquasars.com/mond-trying-to-solve-the-problem-of-the-missing-universe/
Image source:
http://astroweb.case.edu/ssm/mond/DMtrees.html
Wednesday, November 27, 2013
The Subjectiveness of Time:
We like stability. We like to know that each day the Sun is going to rise, the mailman will bring our paper, and time will march slowly on -- just the same as it always has. What’s more, we like to image that this experience is larger than ourselves. When the Sun rises, we know that it’s rising for everyone, not just for us. When the mailman brings the paper, he isn’t making a special trip; he’ll stop at the neighbors as well. These are the common, everyday experiences that unite is all.
However, as it turns out, we are a bit more isolated that we might initially assume.
Want to know how time isolates us? Take a look at:
http://www.fromquarkstoquasars.com/the-subjectiveness-of-time/
Image source:
http://www.fotopedia.com/items/flickr-406635986/slideshow