wave physics

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A human brain has around 86 billion neurons, and the communication between these neurons are constant. The sheer scale of these interactions mean a computer (an EEG) can register this electrical activity, with different frequencies indicating different mental states.

Sources

You are made from pieces.
Every day they begin their dance through your veins, through your neurons, through the breath you take oven in over to keep you alive. For one particular reason.
If you stop - they stop. If you keep going - they go, keeping you alive for a purpose.
You are motion. Be sure to keep it flow.

The simple harmonic oscillator

Anonymous asked: Please explain the intuition of solving the SHM equation.

Okay Anon! Here you go, this is my rendition.


The problem

You have a mass suspended on a spring. We want to know where the mass will be at any instant of time.

Describe the motion of the mass


The physical solution

Now before we get on to the math, let us first visualize the motion by attaching a spray paint bottle as the mass.

Oh, wait that seems like a function that we are familiar with - The sinusoid.

Without even having to write down a single equation, we have found out the solution to our problem. The motion that is traced  by the mass is a sinusoid.


But what do I mean by a sinusoid ?

If you took the plotted paper and tried to create that function with the help of sum of polynomials i.e x, x2, x3 … Now you this what it would like :

By taking an infinite of these polynomial sums you get the function Since this series of polynomial occurs a lot, its given the name - sine.

I hope this shed some light on the intuition of the SHM equation. Have fun!

There are over 7 billion brains transmitting and receiving information on this beautiful planet, imagine if we shared the same flow state of love what a different world this would be.

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There is sound in space, thanks to gravitational waves

“These waves are maddeningly weak, and their effects on the objects in spacetime are stupendously tiny. But if you know how to listen for them — just as the components of a radio know how to listen for those long-frequency light waves — you can detect these signals and hear them just as you’d hear any other sound. With an amplitude and a frequency, they’re no different from any other wave.”

You’ve likely heard that there’s no sound in space; that sound needs a medium to travel through, and in the vacuum of space, there is none. That’s true… up to a point. If you were only a few light years away from a star, stellar remnant, black hole, or even a supernova, you’d have no way to hear, feel, or otherwise directly measure the pressure waves from those objects. But they emit another kind of wave that can be interpreted as sounds, if you listen correctly: gravitational waves. These waves are so powerful, that in the very first event we ever detected, the black hole-black hole merger we saw outshone, in terms of energy, all of the stars in the observable Universe combined. There really is sound in space, as long as you know how to listen for it properly.

Come learn about it, and catch a live event, live-blogged by me, this evening!

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Newest LIGO Signal Raises A Huge Question: Do Merging Black Holes Emit Light?

“The second merger held no such hints of electromagnetic signals, but that was less surprising: the black holes were of significantly lower mass, so any signal arising from them would be expected to be correspondingly lower in magnitude. But the third merger was large in mass again, more comparable to the first than the second. While Fermi has made no announcement, and Integral again reports a non-detection, there are two pieces of evidence that suggest there may have been an electromagnetic counterpart after all. The AGILE satellite from the Italian Space Agency detected a weak, short-lived event that occurred just half a second before the LIGO merger, while X-ray, radio and optical observations combined to identify a strange afterglow less than 24 hours after the merger.”

Whenever there’s a catastrophic, cataclysmic event in space, there’s almost always a tremendous release of energy that accompanies it. A supernova emits light; a neutron star merger emits gamma rays; a quasar emits radio waves; merging black holes emit gravitational waves. But if there’s any sort of matter present outside the event horizons of these black holes, they have the potential to emit electromagnetic radiation, or light signals, too. Our best models and simulations don’t predict much, but sometimes the Universe surprises us! With the third LIGO merger, there were two independent teams that claimed an electromagnetic counterpart within 24 hours of the gravitational wave signal. One was an afterglow in gamma rays and the optical, occurring about 19 hours after-the-fact, while the other was an X-ray burst occurring just half a second before the merger.

Could either of these be connected to these merging black holes? Or are we just grasping at straws here? We need more, better data to know for sure, but here’s what we’ve got so far!

“Imagine the earth to be a bag of rubber filled with water, a small quantity of which is periodically forced in and out of the same by means of a reciprocating pump, as illustrated. If the strokes of the latter are effected in intervals of more than one hour and forty-eight minutes, sufficient for the transmission of the impulse thru the whole mass, the entire bag will expand and contract and corresponding movements will be imparted to pressure gauges or movable pistons with the same intensity, irrespective of distance. By working the pump faster, shorter waves will be produced which, on reaching the opposite end of the bag, may be reflected and give rise to stationary nodes and loops, but in any case, the fluid being incompressible, its enclosure perfectly elastic, and the frequency of oscillations not very high, the energy will be economically transmitted and very little power consumed so long as no work is done in the receivers. This is a crude but correct representation of my wireless system in which, however, I resort to various refinements. Thus, for instance, the pump is made part of a resonant system of great inertia, enormously magnifying the force of the imprest impulses. The receiving devices are similarly conditioned and in this manner the amount of energy collected in them vastly increased.“

–Nikola Tesla

“Famous Scientific Illusions.” Electrical Experimenter, February, 1919.
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5 Reasons Why The 21st Century Will Be The Best One Ever For Astrophysics

“There’s always a temptation to think that our best days are behind us, and that the most important and revolutionary discoveries have already been made. But if we want to comprehend the biggest questions of all — where our Universe comes from, what it’s truly made of, how it came to be, where it’s headed in the far future, how it will all end — we still have work to do. With unprecedented telescopes in size, range, and sensitivity set to come online, we’re poised to learn more that we’ve ever known before. There’s never a guarantee of victory, but every step we take brings us one step closer to our destination. No matter where that turns out to be, the journey continues to be breathtaking.”

What does the future of astrophysics look like? Have we already made all of the fundamental discoveries we’re going to make? Is the rest just categorization of objects, identification of more examples of what’s already known, and minor refinements of the knowledge we already have? Or are there fundamental discoveries still to come, just waiting for us to reveal them? There are so many big questions still out there, and a great many of them have astrophysical consequences! In addition to new observatories, larger telescopes than ever, and problems like dark matter and the matter/antimatter asymmetry, there are five recent discoveries – within the last generation – that have significant implications for the Universe.

Come take a look at five of them: neutrino mass, the accelerating universe, exoplanets, the Higgs boson, and gravitational waves, and learn what the future holds!

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Drip food coloring into water and you can often see a torus-shaped vortex ring after the drop’s impact. That vortex rings form during droplet impact has been well known for over a century, but only recently have we begun to understand the process that leads to that vortex ring. Part of the challenge is that the vortex formation is very small and very fast, but recent work with x-ray imaging has allowed experimentalists to finally capture this event.

When a drop impacts a pool, surface tension draws some of the pool liquid up the sides of the drop. At the same time, the impact causes ripple-like capillary waves down the sides of the drop. This causes pool liquid to penetrate sharply into the drop, triggering the spirals that mark the forming vortex ring. When drops impact with even higher momentum, multiple vortex spirals can form, as seen on the lower right image. The authors observed as many as four rings during an impact. For more, check out the (open access) article.  (Image and research credit: J. Lee et al., source)

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Water stuck in a bus window

How do we know light is a wave?

Before I answer this question, I’ll need to briefly go over a wave property called superposition. Basically, superposition is the idea that two waves can be in the same position at the same time, and interfere with each other:

When the two waves add to each other and make a larger wave, we call this constructive interference. When the waves cancel each other out, we call this destructive interference. 

Now we’re going to move on to the Double Slit Experiment. Basically, you shine a beam of light at a piece of metal, cardboard, etc with two slits in it, with a surface behind it where you can see the light hit it. 

If light is a wave, what we’d expect to see would be an interference pattern created by the light from the first slit interfering with light from the second slit, which is exactly what we see. It’s a pattern of constructive interference (brighter regions) and destructive interference (darker regions), looking like this:

These images are helpful:

that is how we know light acts as a wave!!

Letters on Wave Mechanics. Schrödinger Planck • Einstein • Lorentz, Edited by K. Przibram for the Austrian Academy of Sciences, Translated and with an Introduction by Martin J. Klein, Philosophical Library, New York, 1967

On the travelling wave: An intuition

The aim of this post is to understand the traveling wave solution. It is sometimes not explained in textbook as to why the solution “travels”.

We all know about our friend – ‘The sinusoid’.

y becomes 0 whenever sin(x) = 0 i.e x = n π


Now the form of the traveling sine wave is as follows:

When does the value for y become 0 ? Well, it is when


As you can see this value of x is dependent on the value of time ‘t’, which means as time ticks, the value of x is pushed forward/backward based on the value of  ω  .

When the value of ω > 0, the wave moves forward and when ω < 0 , the wave moves backward.

Here is a slowly moving forward sine wave for reference.

Have a great day!

Despite its proximity, Venus remains largely mysterious, thanks to its cloudy atmosphere and incredible harsh conditions. A recent study using data from the Japanese satellite Akatsuki revealed an enormous bow-shaped wave in the Venusian atmosphere. The wave appeared at an altitude of about 65 km and stretched more than 10,000 km long, across both the northern and southern hemispheres. Although surface winds on Venus are believed to be small due to its incredibly slow rotation, winds higher in the atmosphere are much faster – so it was strange to observe this wave sitting essentially stationary for five days of observation. 

When the scientists mapped the location of wave relative to the surface, they found it was sitting over the Aphrodite Terra highlands, suggesting that this structure is a gravity wave generated by winds interacting with the topography. Similar, albeit smaller, gravity waves are often observed on Earth near mountains. The finding raises questions about our understanding of Venusian atmospheric dynamics and exactly how disturbances from surface winds could create enormous structures so high in the atmosphere. (Image credit: T. Fukuhara et al.; h/t to SciShow Space)