Doppler Shift & Sonic Booms | Neil deGrasse Tyson Explains…
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- Опубликовано: 2 окт 2024
- What is the doppler effect? Neil deGrasse Tyson, Chuck Nice, and Gary O’Reilly discuss the origins of the doppler effect and how it impacts our daily lives.
Learn about doppler shift and the noise objects make as they come towards you and go away from you. What causes a sonic boom? We discuss different frequencies and the experiments by Cristian Doppler that gave the doppler shift its name.
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Science meets pop culture on StarTalk! Astrophysicist & Hayden Planetarium director Neil deGrasse Tyson, his comic co-hosts, guest celebrities & scientists discuss astronomy, physics, and everything else about life in the universe. Keep Looking Up!
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I wished I had Neil as my teacher in my early school days The way he makes seemingly difficult science topics simple and comprehensive
Yes, and fun.
I wish I had chuck as a teacher. xD
Yep but that’s because he doesn’t have to teach you how to calculate everything he explains 😂
@@janusatthegate6201 I was going to say that ,darn it.🤔
I remember cosmo came out, around the same time of taking high-school physics, and I was learning more once a week on Fox than that whole week in school.
I listen all day to you guys all day. Love Star Talk!
I saw that Delta plane landing in LAX! I was a Delta F/A for 20 years and landed there many times. There is a parking garage in San Diego that is right under the planes landing. The sound as you stand on the top level is incredible - totally fills you up.
Gary is always a nice addition to Neil and Chuck. StarTalk posts combine fun with knowledge. A potent and appreciated combination. Thanks, guys!
I just realized that Chuck is actually the secret sauce of Startalk. As great Neil is at communicating complex ideas, Chuck's humor adds an extra layer of translation to further help us mere mortals understand, and be open to, what is being said. 👍
So here's my question: I'm driving my rocket-powered Corvette at Bonneville, and I SMASH through the sound barrier. From my perspective, can I still hear my engines? Can I hear anything at all, be it from inside the car or from the outside?
You would only hear any sound coming from in front of you at that point, nothing from behind you, as you are outrunning any sound waves coming from behind. So if it's a rear engine, you wouldn't be able to hear your own engine once you pass the sound barrier.
@@TheRealSkeletor I had the same question, thanks. Further on that, did I understand it correctly that you'll hear a "cacophony" (similar to what you'd hear if you standing by the highway) if the car drives past you?
@@controversial1994 Yeah, that's a pretty good description for it.
@@TheRealSkeletor Thanks, much appreciated.
Most of what's said here only applies to the outside air which is flowing past the vehicle faster than sound. The body of the vehicle and the air inside, as well as air in wheel wells and other holes depending on the shape, will be moving more slowly, or not at all, relative to you, the listener. All of these things will transmit sound as expected by Doppler, and you'll definitely hear your engine, no matter what part of the vehicle it or you are inside of.
If the top's down, you probably won't hear anything but a sharp ringing, because your eardrums have burst.
Neil making these sounds have made my day!
Found it fascinating, and specially that it goes till the speed of sound.
Thanks Dr.Tyson
Amazing explanation about the Doppler Shift and I love how neil used cars and aircrafts to make examples of how sound works relative to the observer.
If you want the Doppler effect at a car race, go to a Formula 1 race, you'll be in Doppler heaven
Especially before the current hybrid era. I had goosebumps when I was about couple of kms away from the track complex.
My two favorite examples of the Doppler shift are: A train blowing it's horn as it passes by, and Indy cars as they pass as well.
Just had a thought of another great D.E. of when a vicious dog’s barkin’ hysterically as it approaches &, races PAST our foothold location, after something else entirely
A favorite of mine is high speed jet passes. (At air shows and NOT war zones.)
Y'know. Another great example of this is if a motorcycle is coming towards you playing a song on the radio. You'll notice the song, especially if you know it, sounds awful and weird, up until it gets Infront of you and then it gets worse as it goes away and the pitch drops! Wow. Neat to think about it like this now.
Ironically Gary's bad joke created a very funny moment, therefore Gary should tell more jokes because it adds to the humor big time haha
As for the car parts that are stationary, and the train parts that are moving backwards-even though the respective vehicles are moving forward: Neil is, of course, talking about wheels. Specifically, the portion of the wheel that's momentarily in contact with the road or rail is momentarily stationary. And the portion of the train's wheels that are below the region of contact-the flanges-are momentarily moving backward. Assuming, of course, that the vehicle is not skidding! 🤣
But that got me thinking: Surely there are other parts that are moving backward as well? Depending on how they're mounted, it could be portions of: piston / crank / cam shaft, flywheel, fan blade, fan belt, and any number of valves, actuators, gears, rotors, and internal wheels. I've excluded sound waves, air, wiper fluid etc. since they are not car parts.
You are correct and it all just depends on the reference point from which the observer observes 😮
I would say the very centre of the wheel, that rotates with 0 speed.
There is also a portion of those same wheels that is travelling at twice the speed of the vehicle, relative to ground. This, of course, would be TDC (top dead center for you non-machinists) of the wheel.
@@mikeorr3333Yes, and on train wheels, the top exceeds twice the speed of the train.
@@kilroy1964 barely due to weight compression of the contact patch of the wheel, right? This is like arguing that fuel at 3.999$/ gal isn't 4$ a gallon
I want a whole compilation video of Neil doing the sound with as many ridiculous things in it as possible....so funny. Every time Neil made the sound, Chuck laughed...Gary just kinda smirked. I find it so funny.
so when you move twice the speed of sound, the sound just goes backward at a normal speed & volume?
That imagery at 11:25 of the F/A-18 fighter was of a Vapor Cone, not from breaking the sound barrier. Vapor Cones are a condition of moist air and temperature at transonic speeds.
I make this point because it’s often misconstrued that the two events are the same.
You don't get a visible vapor cone from anything traveling at subsonic speeds, so they are related phenomena.
@@TheRealSkeletor you’re wrong, I’m a photographer and every airshow I’ve been to with moisture in the air has shown this phenomenon. The fighter jets are not allowed to travel at supersonic speeds during airshows without the permission of the FAA.
You don’t have to take my word for it, Google is your friend.
@@TheRealSkeletor you get vapor cone from subsonic speeds, but still, speeds close to mach 1
@@NaughtyShepherd the speed needed for the cone is still close enough to speed on sound. And in the clip, you dont know are you cant know it its breaking the speed of sound or not, it has a vapor cone yeah, but that doesnt mean its not breaking the barrier. Just that having the cone is not necessarily a sign for it
I totally agree with your assessment.
I live right at the south end of DFW airport for a while on Valley View Lane.
Being fascinated with aircraft anyway I would sit out there and watch them as they came over and if the humidity was high and especially if it was foggy... almost spooky looking the way the fog swirled around the top and back of the plane.
I'm not a genius and I don't have much education but I think it has a lot to do with the vacuum the Lord air pressure causes the moisture to become so thick that it becomes more visible because there is just more water there.
Someone who knows correct me if I'm wrong but I believe it's totally because of a lord air pressure in certain areas more water vapor out of the air
Thanks Neil!!! I enjoy your content so so much!!❤
When cars are all electric will they stop racing, or will it still be needed to test things?
The tires go backward.
The engines are still around 40-60% powered at that In-N-Out. Airliners don't go fully idle until just 20-30 feet above the runway.
Neil, could you possibly do an explainer on "wave drag" and explain why commercial airplanes have effectively had a speed limit of just below the speed of sound implemented on them despite engines becoming more efficient and powerful?
Sorry about the run-on sentence.
Yes please
Boom boom on the no run on, great Q.
Doc, I would like to hear a discussion of John Boyd’s Energy Maneuverability Theory.
HEY NEIL! I need help with my new years resolution. I've figured out how to change the stars by stopping hurricanes. What I mean is, for stopping hurricanes, I get 7 things and one of those 7 things is to change the stars.
My idea for changing the stars includes Orion and Pleiades (Subaru). I figure it's time to put something up there that's relevant to us, don't you think? Take Orion's belt and Betelgeuse becomes the head with a baseball hat. Below the belt are two legs bending at the knee. The feet aligning perfectly under the bent knees. The 3 stars of Orion's belt align perfectly as the 3 fat belt loops on a baseball uniform. The spear pointing at "Subaru" is the bat being swung and "Pleiades" is the baseball flying away after being hit. Put it all together and you get, "THE ALL-STAR." In my case I drew a 7 on the jersey to make him, "Mickey," but you can put any number you want.
I really have figured out how to change the stars by stopping hurricanes. Don't worry, I've technically already done the easy part and changed the stars. My parents were teachers and for over 3 decades, they taught their students my constellation. Those kids will teach their kids. So on and so on. See, stars changed. I just need help to make it legit and with the rest. No, I'm not kidding. Yes, I'm serious. Figured Neil has taken on the IAU and won, he can help. If, rather when, my idea for stopping hurricanes works it could be converted to a larger scale and EASILY regulate temperature, end drought, stop wildfires. It'd be wrong of me to not, at least, try. This is me, trying. Will you please reach out to me and let me know that your interested in helping to stop hurricanes and change the stars? Thank you and don't worry, where I come from, crazy is a compliment. ;-P
I like how melody sheep can make Neil & all the other astronomers sing while talking. I really enjoy these videos. They are funny.
I think at the end of the video, Neil was talking about the wheels, which are simply rotating but not going forward (or backward).
The train type Is the old steam locomotive, which has a 'rod', which turns the main wheel, and it goes once forfards, faster than the train, but after that backwards, and in the next cycle forwards and backwards again.
Hovewer, you can't cheat the police with either of those because it is all relative to the moving object. The whole object as a system is still going to move towards the police radar, and it will always be able to measure the speed until you manage to disable the reflection of the radar signs, or you send stronger fake radio waves at similar frequency.
The rod does not go backwards but at one point it will be stationary wrt he ground. As is seemingly "goes backwards" it is actually approaching the point where it is stationary.
@@madman2096 Yes, my description is relative to the moving object, I mentioned that later. At the moment the wheel touches the ground the rod stops relative to the ground, to start speeding up in the next moment.
What Neil hinted at is not relative to the type of vehicle. The point of the wheels touching the ground or rail is not moving, relative to the ground or rail. (By the same principle, the top of the wheel is moving at exactly double the vehicle speed.) The rims of the train wheel (even those ones they add to service pickup trucks) are moving slightly backward below the active rail surface.
We tune 10-20 khz to receive low earth orbiting amateur radio satellites and the ISS, and tune down as it approaches and continue tuning below their transmit frequency until Loss of signal because of that earth curvature.
Thank you sir for bringing such informative videos to us through these exciting videos ✨... Neeeaaoonn!!
We always learned in high school about doppler effect with the sound of Ambulances
Which is wrong because sirens _don't_ demonstrate the Doppler effect. Siren on emergency vehicles-ambulances, police cars, fire trucks etc.-do _not_ emit sound at a constant frequency. They are specifically designed to continuously vary their pitch, tone, and overall sound pattern in order to grab everybody's attention. So, regardless of whether it's stationary or moving relative to you, you're going to hear the siren's pitch change constantly. It's _not_ due to the Doppler effect.
And yet, so many people mistakenly use ambulance sirens as an example of Doppler shift. Sad 😢.
@@nHans yes the pitch changes as well, because averything is subject to doppler effects. I live in a enormous city where one airport is far away from where most people live, and another is one where the aproach is made over sea. Couldnt use that as an example
ruclips.net/video/imoxDcn2Sgo/видео.html
@@nHans you are confused nHans and spreading misinformation. Moving sirens are affected by Doppler Shift. I understand what you mean; siren pitches vary purposely but those patterned sequences are affected as a whole as the siren approaching is higher in general pitch and lower as it leaves or moves away from the listener. Please apologize for misunderstanding and misinforming anyone else you have made this reply to.
@nHans was confused and misinformed you in his reply. You learning about Doppler Shift with an ambulance siren as an example is fine as long as you understand the shift of its pitch as it approaches then passes and goes away is the affected sound of the siren due to Doppler Shift. Good day!
@@stevemccoy6434 Nevermind that. I wish there were more kind people like you in the internet nowadays - the problem is is my city that was the only sound loud enough and common enough to be used as an example.
Apollogies very well accepted!
What would it take to break the speed of sound under water?
1500 meters/sec. Just a faster speed is all.
The part of the car/train that isn’t moving is the contact patch of the tire at any given instant
Why on earth would datona deny fans the doppler? That's half the attraction.
I'm assuming the part of the tire that's in contact with the road at any given time is not going forwards.
I used to lay on a grassy street divider that used to be where they built that In and Out… snd film jets landing directly over me. 😊
That part moving backwards is part of the wheels.
Its the lower portions of the tires that are moving "in reverse"..... though technically, i think itd be a net zero in movement as it would be the point of contact
wheels. contact point is 0, opposite side is *2 forward vehicle velocity. the tires would break sound barrier at only half the speed of sound of the rest of the vehicle.
its sad that you dont understand that the speakers are not there to reproduce the car sounds....
there are no mics from car sounds going to the on track speakers...
I can say this with confidence because I have worked for NASCAR directly, specifically doing things involving sound
the cars are so loud, that you will hear all the dopplars from all of the cars all at once.. this masks the actual dopplar sound so it will sound like one giant roar...they become indistinct
the gaint roar is even louder if you are in the infield as it gets compounded by being reflected off the walls
Hearing these people imitating the different sound effects was just hilarious!
I'm with Chuck. Don't withold information for adherence. Just say for educational purposes to dissolve personal liability, and all is good. 😂
Chuck's wit exceeds the speed of sound. That guy is right on cue every time.
Another great example of what sound a plane makes just by gliding through the air is the Space Shuttle, most landing footage from Kennedy Space Center had great audio of the Shuttle, in the past i would think where is the jet fighter flying overhead but no it was just the Shuttle sound :)
Throw a brick fast enough and you should be able to replicate that sound. ;)
In the stands at NHRA drag racing is the purest sound and you can actually feel it move left to right across your chest, or right to left
I've been to a lot of NASCAR races in my life, and I have no idea what Neil meant by not hearing the Doppler Effect. If he was in a suite, up high, far from the track, enclosed in glass, with speakers I maybe can see where he's coming from. But if you're outside/up close, the actual exhaust sounds overpower any speaker systems when the cars pass by. Typically at Daytona the cars run grouped together in a draft and if they are far away from you (the daytona backstretch is probably a mile away from the main grandstands) I imagine there shouldn't be much of a noticeable pitch change. Also, the speaker systems aren't used to (intentionally) emit engine sounds, it might just be excess noise getting into the track announcer's mic!
I think the guy who did the orchestras on the train name is pronounced Buys a Lot
Im always reminded of Sheldon Cooper in fancy dress as the Dpoler Effeect on The Big Bang Theory...Ha !!!
I was just talking to my kids about sonic booms this week and why doesn't the Flash make a sonic boom every time he runs faster than sound
There is flex in the components of most machines. Unless you invent a device that starts and stops every atom in the in the assembly within the same time reference, all of those individual atoms will be crashing into one another, and pulling apart from one another, on the scales that we design them to handle. However, I am very curious about this stuff, and happy to be wrong and learn whatever i can.
One of the eeriest experiences I had with sound was at the top of an airport garage on the final approach to San Diego airport, where are the planes or just a couple of hundred feet above you. After jets passed close by there would be this roaring noise, and I realized it was the wing tips vortexes (which in jets’ landing figuration are very strong). One of them roared very loudly, and ended with a very loud snap as it broke up that really startled me. It took me a while to figure out what had caused it.
Go to the Datona 200 mc race. No speakers an 18000 rpm screaming engine
I would love to buy a car in which I can alter the pitch on a button press to compensate the Doppler shift. I would drive by Neil all day long :)
Hello Dr. Tyson. Could space crafts be propelled by sound? Enough to where it could make an impact on space travel/maneuverability?
No. Sound only travels through matter and sound ends when molecules or atoms cannot touch each other directly. No sound is transmitted in the upper limits of the atmosphere, or in space.
Residual heat may be radiated by sound interaction, but that effect is not directional enough to propel a vehicle, nor efficient for the amount of work done to produce sound.
Gary is hilarious. Chuck is too, but he always is. Gary had his coffee this morning.
I have been to that In-N-Out burger next to LAX many times, enjoying the burgers and hanging out at the little park across the street enjoying the great views of the airplanes landing at LAX, it's especially awesome when you get to see a 747 or an A380👍🙂
Definitely enjoying those Doppler sounds from those big airplanes arriving and the turbulent air sounds trailing behind them✈👍🙂
Doppler shift refers to the change in frequency or wavelength of a wave as observed by someone moving relative to the wave source, commonly experienced with sound and light waves. In the context of sonic bombs, the Doppler effect can create intense and disorienting sounds by compressing or stretching sound waves, potentially amplifying their impact. This phenomenon highlights how Doppler shift can influence not just scientific measurements but also practical applications with significant effects. How might our understanding of Doppler shift and its applications in sound technology evolve with advancements in acoustic research?
Lord Nice's humor is half the reason I love these videos so much.
The next episode is going to be fire. Let's just say, it'll be where the rubber meets the road.
I enjoy the visuals you use. Also, Chuck is the master of black jokes.
0:29 I disagree, Doctor. Remember, Chuck knows the true sound of the sirens because he's always inside the vehicle...🤔👍🤣
Is there any study of Dopler effect at supersonic speeds?
Sounds nice to see what happens
So what if an object (traveling fast enough to perceive a doppler effect) were able to do a circle or loopty-loop around a fixed point? Would the wave frequency warble like a bunch of waves overlapping? Or would it sound like a normal doppler eeeeeeeeewuuuuur sound
Below the speed of sound, the Doppler effect would act normally based on the machine's speed relative to the listener, regardless of any sideways travel. Toward or away are all that counts with the Doppler effect. If you're standing in the middle of the circle, there is no distance change so (other than road noise) it's the same as if the vehicle is stationary with wind travelling over it. You would, however, get stereo bouncing as the thing went left-right and back. (Same as if you spun in place near the stationary vehicle.)
Above the speed of sound it's all a very loud mess that doesn't translate easily to any of these imaginary situations. The air itself is making noise here as a secondary effect, on top of all the vehicle's direct noise. This is basically the sound version of when fire is so hot that air around it also burns.
In either situation, it's very hard to get the object moving fast enough that if you were outside the circle, its sounds on the near side would have any interaction with the sounds from the far side. (I think that's what you meant with the overlap part.) The circle would have to be extremely small, or the vehicle speed exceeding enough _beyond_ the speed of sound to catch up to older waves. We're talking rocket cruising speeds on even a little quarter mile track. The sideways G's would be horrible for any passenger or pilot, and the decibels bad for everybody, lol.
So Russia's supersonic missiles traveling 4 to 5 times the speed of sound cannot be heard when in mid-flight to its destination ?
NEIL PLEASE ANSWER ME: JWST has detected galaxies far more developed than predicted in the begining of the universe. Can it be that TIME ITSELF has beeng stretching too and thats why we see those galaxies as so developed? Maybe time itself on that early universe run at a different speed from ours? A Time´s Dopller Effect? I CAN NOT SLEEP THINKING ON THIS
Neil does Doppler sound more effective than the original 😂
I feel like this episode was done purely for the memes 🤣
And wait I want to know how to speed and get away with it!
Gary tell your jokes my man. Not sure why that put down from Neil was necessary but we need some of that British “humour” 🙂 🇬🇧
I wish Neil deGrasse Tyson would read and study the book, The Art of Dowsing - Separating Science from Superstition ($14.95), for learning all of the physics involved in dowsing and how to build the modern light weight ball bearing dowsing rod. Also, anyone can become a professional dowser by practicing the book's dowsing lessons. Late summer of 2023 a new RUclips channel, The Art of Gold Dowsing, will begin posting videos which will teach the physics involved in dowsing with on-ground dowsing demonstrations for dowsing buried pipelines and electrical cables, tunnels or voids, precious metal placer and lode deposits, dowsing for treasure, dowsing for any element, amplified long distance dowsing from a moving vehicle, and dowsing on water from a boat. Also, demonstrations will be shown for precisely dowsing the all edges, exact center, depth buried with angle of deposition, and most important is grading of the sought element that is contained in the elemental mass that is being dowsed.
The part of the tire that is inconstant contact with the ground is not moving forward
one of the obvious doppler shift effect is an ambulance. as it passes you it sounds like the siren has gone wonky off pitch
Please do a compliment episode on Acceleration Doppler Effect
nice add for mercedez
Omg I laughed too hard at Chuck‼️🤣🤣🤣
what would be funny is if someone purposely puts speakers with a sound that plays a lower tone as they approach you and then changes it higher as they pass you to totally mess with your mind.
If they perfectly matched the frequencies and played them on the speakers, it would be silent....
@@Bendigo1 that would need to be exactly 180 degrees out of phase though. it's called noise cancelling. I'm just talking about fake car sound purposely to make the sounds the same approaching and leaving, would be so weird. lol
Hi, Neil. Thanks for the meme! ^^
I really think they undertalked the part where something goes beyond the speed of sound.. I haven't done research about this, but I'm thinking, wouldn't the sound formed not only start to shift the opposite way from that point on but also sound in reverse?? (only applying to something coming towards the listener) because the sound is produced in front of the previous wave as the sound is made, so if you scream "hello" the "o" is going to be closer to the listener than the "e", therefore it will sound earlier
I just had a realization, I think Neil said the sound is just a mess "collapsing" because the waves coming in front merge with the next waves going backwards.. but what if the sound was made with a special speaker which blocks most of the sound going backwards, would the reverse sound happen?
@@JuankQuinteroMejia You get a sonic boom. All the sound waves merging and building up all together.
@@MrT------5743 that's when you go exactly Mach 1, and if you go faster, the waves keep merging together because the waves going backwards meet the previous waves going forward, but what's the result if you cancel waves going backwards (e.g a very loud speaker that concentrates it's sound only in forward direction)?
@@JuankQuinteroMejia Above Mach 1, the sounds travel in a teardrop-shaped cone behind the vehicle. They don't reverse order, they simply don't do anything in front of the vehicle's wave front. There are no waves going out of the front of a supersonic vehicle that _could_ be reversed because the vehicle is moving faster than the medium (air) can react. Everything is sideways and behind, in natural order but varying frequencies.
Normal sound acts like the waves caused by dropping a pebble in water, but in all directions around the sound's source. Supersonic sound waves look like a boat's wake, but a cone with a round base (the teardrop shape above) instead of a triangle. You can also try this out with your finger in a bathtub, plopping or dragging across the surface. If you're slow, the waves are round. If you're fast, the waves turn into a wake. If you're careful you might be able to see the water speed equivalent of Mach 1 where you're making circles but they all converge on one side of your finger.
Dr. Tyson, does the sonic boom ONLY occur at the moment the plane goes trans-sonic….or does it continue and could then be heard by spectators say, a mile down range AS the plane passes them as well??
The boom is the compressed air at the cone-shaped wave front. It travels with the vehicle as long as it's going at least Mach 1 and is in sufficiently dense air. Eventually it diffuses, but I remember being many tens of miles away and hearing the sonic booms when the Space Shuttle came in for landings in southern California.
@@VoltisArt my question is does this boom CONTINUALLY happen…..or only once when the plane goes supersonic.
Example: would an observer further away than audible distance from the original boom also hear when when the plane passes them (say 2000mi away from the first)?
As children, when USA bombed my country, we learned to distinguish sonic boom from actual bomb explosion. It was scary until we've gotten used to it...
I'm sorry to hear that is something you actually got used to. Peace to you and yours.
So that's why the warning not to go more than 5 mph over the speed limit. Well, well!
0:48 the original meme :p
Neil can you please do an episode on the missing Malaysian B777.And how Immarsat used the Doppler shift of the pings of the Engine motoring system to determine its final flight path? .Thank you.
Question if you were in water and you make a wave and then make a stronger wave behind it that is strong enough to catch it it makes the original wave stronger and faster do sound waves work the same
Yes, sound waves work the same way. Even light works the same way.
Is it me or does the dude look like John Travolta
"I think Chuck is jealous of my doppler shift"
It's so funny when Chuck laughs at Neil's sound effects 😂
9:25 Ok, Neil, Consider This!!
Two orchestras on the same train but on two separate flat open cars:
Orchestra #1 is closer to the direction of travel or 'front' and orchestra #2 is trailing.
If Orchestra #1 plays a note .. and Orchestra #2 is told to listen to Orchestra #1 and play the same note .. Orchestra #2 will end up playing a higher note, because even though they are not traveling any closer to orchestra #1, at any instant while they listen, they are traveling toward the LOCATION where the note was produced!!
If Orchestra #2 plays a note, and #1 is told to listen and play the same note, #1 will end up playing a lower note, because at any instant while they listen, they are traveling farther away from the location where the note was produced.
Another amazing video!
good editing guys! we love the more expanatory and visual editing for us
Mythbusters did an episode on trying to defeat a radar gun. They didn't find any material you could coat your car with that did the job. Plus, the cops they interviewed pointed out that if they see a car covered in some kind of strange stuff or having unusual things affixed to the roof or something, that is only going to attract their attention more.
So tying the ex up there is not a good idea.
Love this trio. Hilarious.
Tisztelt Tyson! Ott volt a lehetőség igaz! Önök miért nem javasolták a Dopplert? Hisz nagy tudósok ! Mert fogalmuk sincs az egészről ! Csak bla ,bla ,bla !
5:27 Then I recommend a rally event! Those are as authentic and raw as possible! Just don't stand too close to a turn or a jump, that is not safe!
I think tyre and smoke are the things that are not going forward.
Neil and Chuck is epic.
Does sound accelerate or is it instantly “the speed of sound”?
Sound's a vibration in a medium. If you shout, your vocal chords make the air jiggle, which makes the air around it jiggle, all the way to someone's ear which has a membrane that jiggles and gets decoded by your brain as a sound. Sound isn't a thing in and of itself; there's no sound waves in space because there's nothing there to vibrate.
If you string up two cans together, the vibration gets carried through the string. People in space can talk to each other by putting their helmets together so the glass vibrates.
So the 'speed of sound' is the speed at which the vibration gets pushed along in air. The _matter_ can be moving but the _sound_ is a thing generated by motion at a certain threshold, so your question doesn't make sense. Which is fine; now you know.
14:33. I don't think the police radars are looking for microwaves. I think the radars emit radio waves that bounce back to the radar which calculates it.
The thhumbnail would suggest that car is traveling at several hundred miles per hour.
Still wondering how Doppler RADAR works to show precipitation...
🤔
The radar signals bounce off the stuff in clouds and are reflected back to the receiver. They can tell if those things are moving toward or away from the radar transmitter and its density.
8:15 it was smarter than he's used to hearing
'People sell Mangoes here (NYC), which is so weird because we're nowhere near the tropics'
'Don't worry, we will be soon'
Walking away w/o looking back, nerd drops the mic
Thank you for explaining Sheldon's Halloween costume.
What bothers me is the speed of sound and Doppler makes sense when there's a medium eg atmosphere present.
What about the Doppler of light... If the atmosphere acts as the zero speed to relate to, then what is the zero speed of space for light?
The answer must be simple but it eludes me.
The speed of light in a vacuum is constant. And there is no such thing as zero speed in space. Everything is moving relative to everything else.
@@MrT------5743 so I'm still confused, does direction have no effect? Or speed of source? I guess light moves so fast it traverses all time and is everywhere all the time? That doesn't quite add up... Or does it?
@Bear Gillium not really sure what you are asking.
I'll briefly explain how they measure the speed of distant stars. Some stars have a pretty constant spectrum they output throughout their lifespan. I think they are called type 1a main sequence stars (but I'm just going from memory). Since these stars have a reliable and predictable output spectrum (not sure how they know they are reliable) they know what frequencies the star's output is and the frequencies we measure here are slightly different. That difference is the motion of the star plus the expansion of space. So they can tell its motion.
@@MrT------5743 yup that is how I understand it as well. The issue I have is that if for example an object we're to travel at the speed of light would you not be able to see it, and from what direction could you see it from, the sides only? And then if I'm say following it at near the same speed, or at any speed other than "zero" then would I see it? Which brings the question: what speed is zero? Like where in the universe is speed of zero in all directions or it it anywhere any time? Are you confused too yet?
I like NASCAR! ^.^
13:14 Neil Missed it! Gary set him up perfectly. "Buys Ballot"!
Ahhhhhh. That would have been Perfect.
Neil. Please do an explainer on "Why it is Hard to detect earthquake". Please.❤
He’s talking bout radar jammers at the end if you’re wondering..