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Velociraptor42

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  1. Velociraptor42
    Oh jeez, more fluids? Thank god this post is more about the images than the workings behind it.

    Back on point though - vortices are ubiquitous, seen wherever there are fluids. Which is everywhere in the universe. And since vortices act similarly no matter what the size, even the smallest of swirls can help us understands occurances such as cyclones and superstorms.

    From smallest to largest, here are some examples:

    In the wake of a water skeeter


    Incense smoke


    Colored smoke in the wake of a landing plane (this one's for you, Bobby)


    The aurora


    Clouds


    Phytoplankton in the ocean


    The center of the HEXAGONAL storm on the polar cap of Saturn


    Aand to top it off, Spiral Galaxy NGC 4921


    For the rest of this series including 24 more stunning photographs as well as the sources, visit here
  2. Velociraptor42
    Currently, we use a method called astronomical parallax to measure the distance from the Earth to various stars among our home galaxy and others. Well, we'll still be using it. Unfortunately, this post isn't about a literal tape measure from Earth to the stars.

    The usual way of measuring distance has to do with observing angles as the Earth goes around the sun, as is illustrated below


    But now, we have found a way to utilize the Hubble Space Telescope for yet another purpose: spacial scanning. With this new technique, we won't have to wait the half a year it takes for the Earth to move far enough around the sun to make these measurements. Instead, we can use the famous space telescope to make measurements that are correct within 5 billionths of a degree.

    The hope is that the more precise measurements will allow us to delve deeper into the mystery of dark energy.

    Read the article here
  3. Velociraptor42

    Growing Snow

    By Velociraptor42,

    I'll admit that this has more to do with chemistry than physics, but really when it boils down to it, everything is physics.

    EVERYTHING

    To celebrate that the snow is over (hopefully), let's watch how it grows in the first place

    http://vimeo.com/87342468

    Quite beautiful, isn't it? Especially with the music and all. So why do they grow that way? Well, it all has to do with the formation of hydrogen bonds. Usually, when water goes below the freezing temperature, the bonds form a nice crystal-lattice structure that leads to regular ice. However, due to the changing temperatures within clouds and the fact that hydrogen bonds form hexagonal structures, snowflakes happen. They start as hexagonal prisms that slowly form arms and branches while transitioning from temperature to temperature, resulting in the special snowflakes we all know and love - as long as they stay in the winter where they should be

    https://www.youtube.com/watch?v=VYrF3sFBY20's a video that shows it nicely
  4. Velociraptor42
    I nearly forgot the story of the month! Or, at this piont, last month. St. Patrick's day to be exact.

    Anyways, physicists have now detected direct proof of the big bang and, more specifically, inflation! I can't explain it very well, but my source is not cooperating, so I shall try. Because of the vast size of the universe, there hasn't been enough time for light and information to get from one end to the other. So how is it all the same temperature?

    That's where inflation comes into play. As the less than a trillionth of a second old universe inflated faster than the speed of light, making everything in that huge range the same temperature. Any small fluctuations in the field blew up into huge structures of the universe. Now, researchers have detected the swirly polarization that would have happened to light in one of those fluctuations.

    Meaning that we have now seen for the first time direct proof of inflation, and into the beginning of the universe itself.

    But really, if you're at all interested, check this out and scroll to where you see the pictures
  5. Velociraptor42
    Cytherean mountains (AKA mountans on planet Venus) cannot be seen directly. The surface of our sister planet is completely obscured by the thick clouds that also heat the surface to a balmy 900 or so degrees Fahrenheit. So, how do we know that the mountains are there?

    Fluids, of course! (dear god why)

    To put it simply (seeing as I can't make it more complicated if I wanted) the atmosphere of Venus is more like an ocean than a conventional Earth-like atmosphere, with a hotter under layer and cooler top layer. When the lower atmosphere passes over an obstacle such as a mountain, it causes ripples up top, much like an ocean wave after passing over an underwater mountain. Actually, studying that is what lead to the realization of yes, this indeed means Cytherean mountains

    so, have some pictures of indirect proof of mountains

  6. Velociraptor42
    First and foremost, a video! Huzzah!



    So, why do these bubbles evaporate into mist instead of freezing and shattering? Well, that is due to the properties of fluids and fluid dynamics.

    Have I mentioned before that I'm really bad at fluids? The oil of the soap, the cold air, and the surface tension of the water/soap mixture all mis together with SCIENCE and create wispy frozen bubble clouds. Technical terms of course.

    I really don't get fluids. They're just pretty.
  7. Velociraptor42
    The Standard Model theorizes that the Higgs Field switched on about 100 picoseconds after the big bang. Recently, though, physicists have theorized that it happened a little more gradually than "switching on" in a process more like water boiling. When these bubbles of Higgs Field met, they created massive shockwaves that would have come with sonic booms. In one of the most cool theories in the early universe, the noise would have sounded a lot like thunder.

    or this


    (let's see if this cooperates and embeds this time)
    Regardless, researchers are now trying to hear the leftovers of this sonic boom.

    SPACE THUNDER.
  8. Velociraptor42
    Though we may not think of plants as moving things, we are sorely mistaken. The force of an opening flower may be very low - in the micro if not nano newtons - but as they exist and move, they are physics. Enjoy some beauty of nature, all dictated by the ever-present laws of physics.

    photo credit to Yutaka Kitamura






    Source
  9. Velociraptor42
    Ok, so. If you were to somehow make the grave mistake of falling into a black hole, what would happen? Obviously the answer is die. That bit isn't debatable. Sorry to burst your bubble.

    However, there are three main ideas of what would happen. Either you would be spaghettified, toasted, or scrambled. Unfortunately, none of these options are as appetizing as they sound.

    For a long time, physicists believed matter would be spaghettified upon entering a black hole. That's the legitimate term for it. Spaghettification. Anyways. Because of the intense gravitational pull of the singularities postulated to be at the center of black holes, the matter at your feet would be pulled much faster than that at your head, leading to an object being stretched and sucked in to the middle.

    The problem with this theory of black holes - namely, one with a singularity at the center - is it violates the conservation of information. Ever since Hawking Radiation was introduced and it was realized that black holes will slowly leak quantum information over time until they evaporate, spaghettification has been thrown out the window. Sorry Italy.

    Idea number two is that there is nothing inside a black hole. The event horizon is in fact a ring of fire, you would be burnt upon entry and scattered back into the rest of the universe, and there is nothing inside the horizon. Nothing. Meaning that black holes would be a rip in the universe itself. This has obvious issues as it violates the Theory of General Relativity. No big deal of couse.

    Theory number three: scrambled eggs. Rather than an event horizon, this black hole would have an "apparent horizon" that would scramble any matter and information that passed it, and still no singularity. Which means that this one also violates General Relativity. Whoops.

    This
    explains it better than me, with fun animation too!
    This is making me hungry.
  10. Velociraptor42
    What? What could meteorites have to do with skydiving?



    If you watched that video, congratulations, you saw nothing! Well, unless you are extremely observant that is. Here's a slowed down gif so you can see what's going on a bit better.



    That would be a meteor during it's "dark flight" phase. This happens when the meteorite reaches terminal velocity and starts falling straight down due to drag forces and blah blah blah and we have never gotten footage of this before. Which means that the fact this skydiver caught it on his helmet cam is pretty incredible. In fact, the chances have been calculated to be that of winning the lottery....three times in a row.

    It produces a pretty awesome collage picture as well


    Source
  11. Velociraptor42
    Source

    I'm just going to leave this here without much of an explanation, other than the Hubble is incredible and... SPACE
    This is the deepest view we've gotten so far, a group of hundreds of galaxies named Abell 2744 that is 3.5 billion light years away.
  12. Velociraptor42
    Source

    For those of you not constantly checking up on astrophysics and stuff like that (not a common habit of most people), the cosmic web is a construct that binds together the majority of the universe that has been long theorized, but never imaged. Until now, that is.

    The cosmic web is made up of around 84% dark matter, which is why it is so difficult to find and photograph. As you could imagine, dark matter is invisible to us and any instruments we have except for its interactions via gravity. So the fact that this nearby quasar lights up the gas enough to show this filament is completely unheard of and incredible. The two images to the right are simulations including both gas and dark matter, and as you can see the recorded image to the left very closely matches the zoomed in image on the lower right.

    Which means that the researchers and scientists that theorized this were EXTREMELY accurate. Kudos to them.
  13. Velociraptor42
    First, as usual, watch this video:


    (easter egg: look for the Doctor Who reference at 5:30)

    Yes, that is the entire history and future of everything in seven minutes. Yes, that is kind of scary. But the inevitable heat death of the universe is, well, exactly that. Inevitable. Luckily, we will all be loooooooong dead before then, if that makes you feel any better. Actually I think I just made that worse. Oops.

    Anyways, this brings up the interesting nature of time, and our lack of ability to travel through it. Well, we can time travel, at a rate of exactly one second per second. Pretty lame, and slightly asinine of me to bring up, but it proves the point that for us, time moves only in one direction and at a set speed. I know I've talked about the nature of time multiple times (ha. haha. punny.) but it's just very intriguing. We seem to think we're so important, dividing up our time into smaller time units and carefully planning all of it out, when compared to all of time it's a speck. Yet, our measuring of time as relatively constant (not getting into special relativity of course) is what makes everything measurable in physics.

    Well, time for me to end this post. Cricket's begging to sit on the laptop, and I need to stop making horrific puns.
  14. Velociraptor42
    Yes, this is totally a physics post, and not just an excuse to post this gif

    This is Waffles the cat. And his job is to remind us all about winter driving. As any of us who have been behind the wheel on a snowy day know, the coefficient of friction between regular tires and the snowy road is veeeery low. Dangerously so. Just around .15, compared to around .7 on a dry road. Even with snow tires, it can still be hard to stop due to low coefficients of both rolling and sliding friction.

    Moral of the story: low coefficients of friction mean that frictional force will be lower, meaning that it will take longer to break.

    I also wanted an excuse to post a video of a cat failing in slow motion, I'll be honest.


  15. Velociraptor42

    Cyborg Bullsperm

    By Velociraptor42,

    Yup, that's a pretty terrifying title. And yes, that's exactly what this is.



    Tell me that I could name this anything different. Biomedical Engineering at it's most amusingly accessible right here!

    So, what's physics-y about this? Apart from, you know, everything in existence being physics. First of all: magnets. These things are "remote controlled" by magnets and magnetic fields. You know, those things that you can't see but you have to contort your hands to figure out which direction they go and all that. I swear if any of you ask "magnets, how do they work?" you'll be deported off my blog

    Also, since physics is all about movement, I should point out that the method of propulsion of this spermbot (yess I get to use that in real speech/typing!) is ingenious. Rather than use something that would have trouble maneuvering within the human body or which would create waste products, they used human cells that can easily propel themselves throughout viscous fluids (gross yes but needed) and that would have no trouble with the immune system.

    Altogether, another useful product of BME
  16. Velociraptor42
    Not quite a physics post, but something really cool that came out recently



    Now you know what it's like to see through the eyes of five different animals!

    I'm still waiting to see a mantis shrimp though... 8 color receptors compared to our three? How does that even work? Where do they fit in the electromagnetic spectrum? Extra colors that is. Maybe within our lifetimes we'll be able to find out.
  17. Velociraptor42

    Beauty of Orbits

    By Velociraptor42,

    I think that the way this was originally sent to me conveys the meaning better than any rewording I could do:


    Equation of orbit of a small mass around a much greater mass


    Equation of human awe of earth orbit

    So now that you've watched it, you should have a greater appreciation of gravitational forces and centripetal ones, the whole Fc=mv2/r and Fg=GM1M2/r2 and such.

    Or maybe you just affirmed that space is really freaking awesome, and a lot prettier than anyone gives it credit for. I'll take that too. Earth looks pretty cool from up there.
  18. Velociraptor42
    Hooray for a cool
    many physics applications!
    Alright, so if you can't quite tell, these crazy NASA engineers built a complex rig in order to record cool things at 7,200 FPS for the hell of it. Though we're not doing optics this year, they had to do a lot of considering with that, buying special mirrors that lose less light with each reflection than your standard hardware store mirror. Sure, warping occurred, and the lens they used made the objects look farther away, but just look at how awesome it is.

    Although you should have already done that by this point.

    Apart from the camera rig itself, the shots themselves are (like everything else in the world) filled with physics. Watch the inertia of the water as it falls straight down despite the balloon around it being dragged sideways. See the conservation of momentum in action.

    And most importantly, watch two cool guys shoot things with slingshots and have the video go in a circle. Because science is cool.

    Source
  19. Velociraptor42
    If you guys happen to look at nearly anything nerdy, you have likely seen the original video for this or a reaction to it.

    In essence, a
    came out trying to prove to the general public how 1+2+3+4+... all the way to infinity equals -1/12. You know the drill. Go on, watch it. I'll still be here when you get back. Or at least my post will
    "So what?" you're probably asking. Or maybe you do know the so what, who am I to judge? Anyway. If you don't believe the video and think it's all stupid, ponder this. Euler, great mathematician, proved it for all real numbers. Reimann did it again for complex numbers. A third mathematician did it again completely separately.

    The incredible part happens when the physics comes into play. Whether you believe it or not, this sum is essential to Quantum Electrodynamics. And when something is used in the most correct theory in history (not the best wording, but best proven, etc), you can assume that it itself is pretty damn accurate. It only seems fair that a confusing equation that makes no sense yet perfect sense is used in proving a theory that makes even less sense yet describes the world perfectly.


    Psst. If you're interested in further proof, read this blog post from physicsbuzz
  20. Velociraptor42

    SMBC Comic

    By Velociraptor42,

    Dear Mr. Fullerton: I am not crazy for laughing so hard during class about this. It's real.
    Sincerely, velociraptor

    Source: Saturday Morning Breakfast Cereal
    http://www.smbc-comics.com/index.php?id=3186#comic
  21. Velociraptor42

    Dancing Droplets

    By Velociraptor42,

    Despite my last entry clearly dictating that I have no idea what's going on when it comes to fluid dynamics, here I go again.

    This time, it's droplets of water and propylene glycol and how they interact when on a glass surface.

    First, watch https://www.youtube.com/watch?v=K8Wx2PHIYGI. Now. Okay, watched it? No? Then the rest of this won't make much sense and will be pretty boring. I promise it's cool, and the music's pretty sweet too.

    Now that you've all either watched it or closed out of this post due to my incessant nagging, let's try to explain what's going on.

    The different types of droplets create a film on the glass that attracts other droplets due to surface tension differences. Once they actually meet, things happen and one droplet ends up "chasing" another. Add hydrophobic markers to the mix and a few curious scientists with a cool camera and a lot of awesome effects can be achieved.

    Read a much better explanation of what's going on (not including the one in the video itself) by people who actually understand it here.
  22. Velociraptor42

    Mushroom Clouds

    By Velociraptor42,

    We all know the standard shape of a mushroom cloud
    It looks something like this:


    The question is why do they look like this?

    Well, as can be seen in this post, the less in-depth answer is a simple difference in density between the rapidly expanding gases and the rest of the air.

    However, this is a physics blog after all, and so I'm going to get into the Rayleigh-Taylor instability. In the most understandable terms (though to be quite honest after reading up on it I still don't really understand it), one fluid accelerates into another of a different density and convection magic and PHYSICS happen and things like supernovae and mushroom clouds happen.

    I don't really get fluids. Gizmodo explains it better than me. But it's pretty cool. Woo.
  23. Velociraptor42
    Optical illusions are awesome. That cannot be debated. Ever. Some of them are used to be thought provoking, street art that looks one way from one viewpoint and completely different if you move. Some are just to screw with your brain, like many of Escher's famous pieces.

    This one is used to make you want to buy Ray Bans. No, seriously. http://www.youtube.com/watch?v=dhuUhaNIWLQ.

    So why do these things look 3D to us? Courtesy of our lovely brains, which like to detect patterns where there aren't any. Some awesome drawings with shading intact, stretching the perspective so that it would match the camera angles, and boom, things look like they pop off the table. Eyes may not be that easy to trick, but the brain interpreting the images is. After all, if we're used to things sitting on tables, why wouldn't the baseball be just another object on a table?

    Advertising tells us sunglasses are the only thing that is real. Get ready for the paper apocalypse, everyone.
  24. Velociraptor42
    Recently I've come across a physics paper describing a certain way of time travel using the awesome theme of Doctor Who (as well as a Portal reference) to explain things. Explaining the name is something I'd rather leave to the creators of this theory though, so here's that:

    The name refers to a bubble (a Domain) which moves through the spacetime at speeds greater than the speed of light (it is Achronal); it moves backwards in time (Retrograde to the arrow of time outside the bubble); and finally, it can transport massive objects (it is Traversable)

    So, what exactly is this TARDIS? Glad you asked. And if you didn't, well, too bad. You're going to hear about it anyway. Or just leave this post. Either way. TARDIS. So. Basically. A light cone is a boundary that shows you what and where can be traveled. If a point source of light were turned on and you watched its 2D passage through time, it would create a cone.
    this probably explains it a bit better than I can
    Anything outside of the light cone would therefore have to move faster than light. Past the event horizon of a black hold, light cones all point inward and so no matter can escape without going faster than light and therefore backwards in time. Well, what if you could bend the direction these cones, and time itself? By creating a circular path (which would require faster than light particles - whoops), you could go back in time, then accelerate forward, even going sideways in time, as long as you ended in the same place you started. Kind of like a loop. However, the fun parts happen when you splice these achronal loops. You could end up in a point in time just prior to when you first started traveling, or if you cut a "donut" (that's what they seem like to me) in half, you could stay moving backwards in time, essentially becoming antimatter (note: look up single electron universe theory if this seems interesting)

    As always, the source explains it much better than I, along with diagrams and other cool stuff and even fandoms.
  25. Velociraptor42
    "Mathematics, rightly viewed, possesses not only truth, but supreme beauty — a beauty cold and austere, without the gorgeous trappings of painting or music." —Betrand Russell

    Physics is, in essence, applied mathematics. It's how math applies to life, and the results thereof. And math is... beauty? That's not how one would usually think. However, there is a certain beauty to math and how everything resolves itself when it is applied. The way tree growth and snowflakes resemble fractals, light waves follow the simplicity of a sine curve, a top wobbles back and forth, light bends around a magnifying glass - heck, we learned some of these last year in physics B. But while analyzing the theory behind it, how many of us stepped back to think of the beauty?

    However I explain it, watching it makes it better.

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