#Doppler Effect

[todays-xkcd]

The Doppler effect is a mysterious wavelength-shifting phenomenon which seems to primarily affect sirens, which is why the 🚨 emoji is red.

Doppler Effect [Explained]

Transcript

[Miss Lenhart is pointing with a stick to a whiteboard with various scientific drawings and words, including but not only a graph.] Miss Lenhart: The more distant a galaxy is, the redder its light. Miss Lenhart: Why? Well, that's an interesting question.

[Zoom in on Miss Lenhart.] Miss Lenhart: Ever notice how, when a siren is approaching, it sounds like Bweeeeeeeeee...

[Zoom in on Miss Lenhart with her arms raised.] Miss Lenhart: ...but then it zooms past you and goes Nyeeeeooooowww? Miss Lenhart: And sometimes they hit a button that makes it go Pyeew! Pyeew! really loud?

[Miss Lenhart with her finger raised is standing in front of the whiteboard and holding the stick down.] Miss Lenhart: And in Europe they go Ooooeeeeooooeeee... Off-panel voice: So why are galaxies red? Miss Lenhart: Oh, no idea. Miss Lenhart: Anyway, another siren I like is...

[thinkingimages]

[macmanx]

Star Trek TNG Theme, but the theme is coming from the Enterprise-D.

[schroedingerscryptid]

so like even though redshifts and blueshifts are two different things, since they operate on the same principle, can we call them Doppler-gängers

[diabloindigo]

Clip from Invincible season 2 trailer. Also, Ben Schwartz as Shapesmith.

[schibborasso]

Der Doppler-Effect #02

[victusinveritas]

[mishalogic]

Moments in Nature

A butterfly flapped its wings in Australia

Nature felt it in Canada

and the ocean it did too!

Nature knew of it and gave a tender loving sigh!

We may not understand this,

But please give it a try ... Doppler effect

[cucumberlover99]

Do coma patients still grow hair?

If I was in an extended coma the worst part for sure is that my loved ones could see me unshaved.

[magickgarlick]

I, too, have managed to crawl my way through high school just well enough to comprehend this joke. This is proof that I am Intelligent and Know Things.

(walks into door twice, has to look up "what are taxes" every year)

[notsosmartedmund]

Did you know that Black Hole would look a little bit blue to the side because of the Doppler effect? (Image is making process of Black Hole(Gargantua) in Interstellar)

What is Doppler effect?

Doppler effect is basically what makes the sound louder or more quite depending on how far it is from you. If it is closer to you it has higher pitch frequency, further from you - lower pitch frequency . The same with the light , for example we have a green light moving, if it gets closer to us , the frequency will be higher meaning the color we will see will be some kind of blue or purple. If it gets further away from us , the frequency will be lower meaning the color we will see will be red.

In case of Black Hole , some part of it will be closer to us , some further meaning some parts of it will be reddish some will be bluish

More about Doppler effect , Black Hole or Gargantua in Interstellar

[arduino-diy]

Proximity sensing is a very common application in electronics. There are several ways to accomplish this. The most common way is by using a PIR sensor. PIR Sensor senses the change in ambient infrared radiation caused by warm bodies. I have already covered this in my Tutorial No. 5: "PIR Sensor Tutorial - With or Without Arduino". However, since PIR sensors detect movement from living objects, they can generate false alarms. These sensors are also inefficient in hot environments, as they rely on heat signatures.

The other common methods of proximity sensing involve, using reflected ultrasonic or light beams. Using these sensors, the intruding object is detected by the reflected beam back to its source. The time delay between transmission and reception is measured to calculate the distance to the object. In this tutorial, we are going to look at another method of proximity sensing using "Microwaves" and "Doppler Effect".  In my hand is an inexpensive RCWL-0516 Microwave Radar Motion Sensor. The RCWL-0516 microwave sensor detects "any movement" from "any object" and does not rely on heat, making it more reliable in hot environments. I am going to use this sensor to create a Geo-fence around my house to detect motion and get notifications.

[jonathanmorse]

Fräulein Doppler

[whats-in-a-sentence]

In 1929, Edwin Hubble, using the 100-inch telescope at the Mount Wilson observatory in Pasadena, California, found that the couple of dozen galaxies he could detect were all rushing away.⁵

5. The physical phenomenon involved here, as discussed in Chapter 11, is known as redshift. Common atoms such as hydrogen and oxygen emit light at wavelengths that have been well documented through laboratory experiments. When such substances are constituents of galaxies that are rushing away, the light they emit is elongated, much as the siren of a police car that's racing away is also elongated, making the pitch drop. Because red is the longest wavelength of red light that can be seen with the unaided eye, this stretching of light is called the redshift effect. The amount of redshift grows with increasing recessional speed, and hence by measuring the received wavelengths of light and comparing with laboratory results, the speed of distant objects can be determined. (This is actually one kind of redshift, akin to the Doppler effect. Redshifting can also be caused by gravity: photons elongate as they climb out of a gravitational field.)

"The Fabric of the Cosmos" - Brian Greene

[basicallymysavedfolder]

looking for something