Regarding Water filled Telescope : Consider a star right above head w.r.t. sun. When observed through telescope the telescope should be held at an angle in the direction of motion of earth. we can imagine telescope to have large number of horizontal sections parallel to the direction of motion. Each section of telescope enters path of vertical ray falling from star consecutively. In other words the telescope will have 'Virtual Vertical Tilt'. Therefore, the medium inside the telescope ( whether air or water or any oil or even a glass cylinder will have no bearing except delay in exit of the ray). Regarding effect of motion of solar system around the galaxy. Observation over a small number of years will not reveal any changes as its effect is already got added-up in locating the star. This explanation can be extended to aberration of stars situated at an angle also.
Sorry if this is a dumb question, but if we’re looking at the constant motion of a distant star, how can we tell that it’s position is distorted due to aberration? What reference point do we have to determine the ‘true’ position of where the star should be?
Not a dumb question. My take on this is that you take measurements of the position of a star throughout the year. The resulting change in position is twice the angle of the stellar aberration. The change of position must be due to the aberration of light because stellar paralax is about 3 orders of magnitude lower than stellar aberration - stellar paralax to the closest star is about 0.77 arcsec. Assuming circular orbit of Earth, the value for stellar aberration from Earth is same for all stars (unlike paralax), thus you can confirm your measurements (by observing other stars) even if you don't know how far a particular star is.
Great explanation overall. But it wasn't clear how a stationary ether would cause no aberration. If you illustrated that, it would have been easier to understand.
I've heard that back and forth stellar aberrations cannot be observed for binary star systems, such that the binary star system always seems to look like a single star. Is there a logical explanation for this?
Very helpful. Thanks Earth is speeding around its orbit. Is our sun and the distant object star stationary? If not, the prediction method here may be incomplete?
I`ll give you a clue ...... . “The idea that aberration . . . may be described in terms of the relative motions of the bodies concerned is immediately refuted by the existence of spectroscopic binaries with velocities comparable with that of the earth in its orbit. These exhibit aberrations no different from other stars.” . You can draw your own conclusions about relativity from that. Assuming this message is not censored by the google thought police or mr "explaining scientism" :) If only I could say what I really want to without the unpleasant consequences ... One day I might not care anymore. You hear that google ?
Thank you but if you could leave alone religion. Heliocentrism was not a religion theory but one of the highest philosopher of the Reason Aristotle and a scientific guy Ptoleme. Many scholars didn t see any inconvenience with heliocentrism, expressed it and weren t burned for it. One of the most prominent was Nicolas de Cues a clerk close to the Pope in XV century. The fact is that Galile found a much better performing system but wasn t able to prove Heliocentrism.
BTW. Gamma Draconis was selected because it was relatively bright star (in fact brightest in Draco), and was very close to Zenith in London. The most favorable conditions and biggest aberration would be measured during Equinoxes, early March, and late September. Same star was used later by Airy in his measurement of aberrations too, showing that aeather basically doesn't exist. Closeness to Zenith was important, because it lowered the atmospheric refraction effects, allowed to observe the star even after sunrise or before sunset, and allowed to align telescope more precisely, as well eliminate alignment issue by a method of telescope reversal - rotating it 180 degree around optical axis). It also was important, to have the star close to axis of ecliptic, so the parallax is not a source of big motion. For that to work the star must be sufficiently distant, but even the closest star Proxima Centauri, would only introduce about 0.8 arcsec change. The Gamma Draconis is further, and would introduce error of 0.021 arcsec. Way below the aberration displacement (few arcsec), and below capabilities of telescopes from 18th and even 19th century. In fact James Bradley initial intent was to measure the parallax of Gamma Draconis, but he couldn't do it, it was too small to be measured by his telescope and instruments, but he did discover aberration. First observation and measurement of parallax was done by Friedrich Bessel in 1838 of star 61 Cygni. The measurement of parallax was so hard that even in year 1910 we only had 100 stars measured this method.
"showing that aeather basically doesn't exist" That is incorrect and I don`t just mean the spelling. Airy would not be impressed by that blatant misrepresentation. Or perhaps you have not really thought this though ? OK ,so lets rule out. entrained aether. moving earth and a stationary frictionless aether. relativity (no aether but possessing magical properties nonetheless) “The idea that aberration . . . may be described in terms of the relative motions of the bodies concerned is immediately refuted by the existence of spectroscopic binaries with velocities comparable with that of the earth in its orbit. These exhibit aberrations no different from other stars.” Sherlock Holmes might say ....
I could have used a little more explanation around 12:00 when you dicussed Airey's failure. He expected to see a different aberration tilt assuming only that: Light travels slower in water than in the vacuum of space. This is the same assumption we make today. I don't see what disbelief/belief in ether has anything to do with his experiment.
Don`t think about it too much !! This line of thinking will lead you to FE !! check the "globebusters" channel if you want to begin this journey :) The guy is gaslighting you. Relativity explains nothing in relation to this. In fact this observation debunks relativity. The facts of stellar aberration, known since 1728, are not in dispute. As the Earth moves in its orbit, the position of a star varies slightly, depending on its direction relative to the Earth’s motion. Just as a man running in the rain must incline his umbrella forward if he is to stay dry, so a telescope must be angled forward if the starlight is to enter the telescope. The forward inclination is the angle of aberration. All stars have the same maximum angle of aberration-about 20 seconds of arc. In his special relativity paper, Einstein used the same method to derive the formulae for the Doppler Effect (which exists for both light and sound), and for stellar aberration. Einstein argued that the aberration of starlight is simply a function of the relative velocity of the star and the Earth. But if the stars in the sky are moving at different speeds relative to us, why do they all show the same aberration? By Einstein’s theory there should be different aberrations for different stars. But that isn’t so.
The rules for an aether theory - 1/ Photon Momentum must be conserved 2/ The speed of light relative to the aether is always c. Let us consider, according to the MM Experiment, that aether is entirely dragged. This means that as a photon approaches the earth perpendicularly that it would encounter aether moving perpendicular to it. So the assumption has always been that this would mean that a photon would be “blown” in that direction. In that case, it has a component of velocity added laterally, but to maintain c that would mean that it's velocity component toward earth would need to decrease. But how could that happen? There is no force opposing the photon! For the photon to change direction would mean we break the law of conservation of momentum. The momentum can only change if the component of velocity toward earth is decreased, and again, there is no force present to do that. Energy travelling in a medium is not a feather blowing in a breeze! Aether cross winds do not effect photons.
Page 13:00 water filled telescope can makes theta larger? Yes - if we are take the equation by the face value (ie mathematician wearing physicist hat). No - the water column in telescope acts like a flat prism producing an exit angle equals to the incidence angle. No net angle change with or without it. A dumb experiment to a dumb conclusion.
The ad hoc-derived mathematical equation for aberration was shown to be flawed with a water-filled telescope. And the raindrop explanation ignores the undefinable fact that the source of the drops is exactly where it is supposed to be and is not projected in the direction of the motion of the observer. The equation itself cannot replace a logical explanation. Bradley's explanation is nonsense. Replace the raincloud with a shower, and you can see the fallacy. And if we assume light is propagating like a wave and not a Newtonian particle, we can hear that if the wave were a sound, there's no aberration. In other words, the explanation is circularly reasoned based on observation with no Earthbound analogy we can demonstrate. A more likely explanation, assuming Bradley didn't massage his data like so many scientists do, might have to do with the fact that in order to view a star in its location over the course of a year, one has to be able to see the star during the day as well as night. And Bradley would have never thought of the interaction of Earth's magnetosphere with the Sun as having anything to do with his observed minute "aberration". Bradley had no idea that Earth had an ionosphere. Bradley knew nothing about the plasma that surrounds Earth. Nor did he understand anything about electromagnetism. And if you look into how tiny stellar aberration is, you will see that this is much ado about nothing.
One can argue that stellar aberration in 3 ways. 1) Light is photon propagates without a medium, 2) light is wave ride on a medium but non sync with earth and 3) in sync with earth. That Bradley fail to specify. 1) if light is photon use no medium our mid event translate to a leading object image. (In favor to Bradley) 2) light is wave ride on a medium non sync with earth and our movement translate to a leading object image. (In favor to Bradley) 3) light is wave ride on a medium in sync with earth and our movement translates to a lagging object image. (Against Bradley)
@@ikediamond you can compare the measurements in two different locations to take a parallax measurement. For example, if you hold your finger in front of you and close one eye you can see it move position slightly
Light is neither a particle nor a wave. A wave isn't what something is but rather how something behaves. This whole theory sounds like an excuse to explain away something that proved that the model is wrong.
Stellar aberration and parallax in no way "prove" heliocentrism. Both are explained by geocentrism as well. So saying they "prove" heliocentrism is a bit ignorant and/or dishonest.
No. The ellipses observed annually in the stars are a reflection of the elliptical path of the Earth as it moves around the Sun. On a fixed Earth with the stars rotating around it, these ellipses would NOT be observed. And the possibility of observing parallax would only be limited to the Earth's diameter, and not to the diameter of the Earth's annual trajectory.
@@arriamirorei1925Incorrect. You can have ellipses on a geocentric model too. Its not exclusive. Youre just affirming the consequent and reifying your model. Circular reasoning at its finest. If you disagree with this, you disagree with einstein and general relativity.
@@Awakeintheaether You don't even know what you are saying. Could you explain how it is possible for stars to trace ellipses over the course of a year due to stellar aberration if the Earth is stationary?
@@arriamirorei1925I do. YOU dont understand it. And thats ok. Theres a few ways it could work. One way is a modified tychonic model. All you do is add ellipses to tychos original model like kepler added to the copernican model. Then, you put the universe into rotation fixed on the sun as it revolves around a fixed earth at the center of mass of the whole system. Boom. Parallax, aberration, and retrograde all explained from a geocentric position. Again, if you dispute this you dispute Einstein and General Relativity.
@@Awakeintheaether You are just talking things without coherent explanation. The parallax in your model would not match the observed parallax, which would still be based on the diameter of the Earth. And the stars would also not trace the observed annual ellipses due to the aberration but more complicated orbits. If you can't come up with a reasonable explanation of how the annual ellipses observed from a stationary Earth could be explained, the best you can do is stop to write stupid comments in UA-cam.
man that rain
:-)
Thanks for simple and informative explanation!
I couldn't grasp the idea behind math without the video!
Thank you
Awesome video on such a niche topic!
Rain is too loud.
It certainly can be
This helped me a lot to understand, thanks
You're welcome!
great video just the right level of detail for me
Glad you liked it!
Thanks for the clear explanation. Really informative.
Thanks, i am planning to upload more videos over the next few months. So please keep keep coming back
Superb explanation!
I’m glad you enjoyed the video. You may want to look at some more video on
ua-cam.com/users/explainingscience
or subscribe to the channel.
thank you very much, you're helping me out with my astronomy course
Thank you you're very welcome
Regarding Water filled Telescope : Consider a star right above head w.r.t. sun. When observed through telescope the telescope should be held at an angle in the direction of motion of earth. we can imagine telescope to have large number of horizontal sections parallel to the direction of motion. Each section of telescope enters path of vertical ray falling from star consecutively. In other words the telescope will have 'Virtual Vertical Tilt'. Therefore, the medium inside the telescope ( whether air or water or any oil or even a glass cylinder will have no bearing except delay in exit of the ray). Regarding effect of motion of solar system around the galaxy. Observation over a small number of years will not reveal any changes as its effect is already got added-up in locating the star. This explanation can be extended to aberration of stars situated at an angle also.
Sorry if this is a dumb question, but if we’re looking at the constant motion of a distant star, how can we tell that it’s position is distorted due to aberration? What reference point do we have to determine the ‘true’ position of where the star should be?
For my part I have neither seen either the question or the answer
Not a dumb question. My take on this is that you take measurements of the position of a star throughout the year. The resulting change in position is twice the angle of the stellar aberration. The change of position must be due to the aberration of light because stellar paralax is about 3 orders of magnitude lower than stellar aberration - stellar paralax to the closest star is about 0.77 arcsec. Assuming circular orbit of Earth, the value for stellar aberration from Earth is same for all stars (unlike paralax), thus you can confirm your measurements (by observing other stars) even if you don't know how far a particular star is.
If stellar aberration does not vary with the distance of the star, how can it be related to light?
The scientific method requires dependant and independent variables.
Great explanation overall. But it wasn't clear how a stationary ether would cause no aberration. If you illustrated that, it would have been easier to understand.
That’s assuming a stationary ether exists to debate over
@@markcollins1497 I meant hypothetically. Of course, no ether exists; it's a long-discarded idea.
How does that much larger effect not messup the parallax measurements? Are those compensated for in parallax calculation?
There must also be some fluctuation in wavelength, yeah? That is, in the perceived wavelengths of the star's light.
Is that why sometimes we see stars through the moon?
bradley et al's "velocity of light" explanation is wrong tho
What about Airy's Failure?
How does the Earth's tilt come into this?
I've heard that back and forth stellar aberrations cannot be observed for binary star systems, such that the binary star system always seems to look like a single star. Is there a logical explanation for this?
thanks sir
Very helpful. Thanks
Earth is speeding around its orbit. Is our sun and the distant object star stationary? If not, the prediction method here may be incomplete?
I`ll give you a clue ......
.
“The idea that aberration . . . may be described
in terms of the relative motions of the bodies concerned is immediately refuted by the existence of spectroscopic binaries with velocities comparable with that of the earth in its orbit. These exhibit aberrations no different from other stars.”
.
You can draw your own conclusions about relativity from that.
Assuming this message is not censored by the google thought police or mr "explaining scientism" :)
If only I could say what I really want to without the unpleasant consequences ...
One day I might not care anymore.
You hear that google ?
@@decadent. If you are saying that Einstein's work is illogical nonsense, you are 100% correct.
Thank you but if you could leave alone religion. Heliocentrism was not a religion theory but one of the highest philosopher of the Reason Aristotle and a scientific guy Ptoleme. Many scholars didn t see any inconvenience with heliocentrism, expressed it and weren t burned for it. One of the most prominent was Nicolas de Cues a clerk close to the Pope in XV century.
The fact is that Galile found a much better performing system but wasn t able to prove Heliocentrism.
Music used is horrible
:-)
@@ExplainingScience You've got sound issues when you use the rain ☔ sound 🔊 effect.
BTW. Gamma Draconis was selected because it was relatively bright star (in fact brightest in Draco), and was very close to Zenith in London. The most favorable conditions and biggest aberration would be measured during Equinoxes, early March, and late September. Same star was used later by Airy in his measurement of aberrations too, showing that aeather basically doesn't exist. Closeness to Zenith was important, because it lowered the atmospheric refraction effects, allowed to observe the star even after sunrise or before sunset, and allowed to align telescope more precisely, as well eliminate alignment issue by a method of telescope reversal - rotating it 180 degree around optical axis). It also was important, to have the star close to axis of ecliptic, so the parallax is not a source of big motion. For that to work the star must be sufficiently distant, but even the closest star Proxima Centauri, would only introduce about 0.8 arcsec change. The Gamma Draconis is further, and would introduce error of 0.021 arcsec. Way below the aberration displacement (few arcsec), and below capabilities of telescopes from 18th and even 19th century. In fact James Bradley initial intent was to measure the parallax of Gamma Draconis, but he couldn't do it, it was too small to be measured by his telescope and instruments, but he did discover aberration. First observation and measurement of parallax was done by Friedrich Bessel in 1838 of star 61 Cygni. The measurement of parallax was so hard that even in year 1910 we only had 100 stars measured this method.
"showing that aeather basically doesn't exist"
That is incorrect and I don`t just mean the spelling.
Airy would not be impressed by that blatant misrepresentation. Or perhaps you have not really thought this though ?
OK ,so lets rule out.
entrained aether.
moving earth and a stationary frictionless aether.
relativity (no aether but possessing magical properties nonetheless)
“The idea that aberration . . . may be described
in terms of the relative motions of the bodies concerned is immediately refuted by the existence of spectroscopic binaries with velocities comparable with that of the earth in its orbit. These exhibit aberrations no different from other stars.”
Sherlock Holmes might say ....
I could have used a little more explanation around 12:00 when you dicussed Airey's failure. He expected to see a different aberration tilt assuming only that:
Light travels slower in water than in the vacuum of space.
This is the same assumption we make today. I don't see what disbelief/belief in ether has anything to do with his experiment.
Don`t think about it too much !!
This line of thinking will lead you to FE !! check the "globebusters" channel if you want to begin this journey :)
The guy is gaslighting you.
Relativity explains nothing in relation to this. In fact this observation debunks relativity.
The facts of stellar aberration, known since
1728, are not in dispute. As the Earth moves in its orbit, the position of a
star varies slightly, depending on its direction relative to the Earth’s
motion. Just as a man running in the rain must incline his umbrella forward
if he is to stay dry, so a telescope must be angled forward if the starlight is
to enter the telescope. The forward inclination is the angle of aberration.
All stars have the same maximum angle of aberration-about 20 seconds of
arc.
In his special relativity paper, Einstein used the same method to derive
the formulae for the Doppler Effect (which exists for both light and sound),
and for stellar aberration. Einstein argued that the aberration of starlight is
simply a function of the relative velocity of the star and the Earth. But if
the stars in the sky are moving at different speeds relative to us, why do
they all show the same aberration? By Einstein’s theory there should be
different aberrations for different stars. But that isn’t so.
@@decadent. Good point there Dec . Interesting that someone deleted your original comment :)
The rules for an aether theory -
1/ Photon Momentum must be conserved
2/ The speed of light relative to the aether is always c.
Let us consider, according to the MM Experiment, that aether is entirely dragged. This means that as a photon approaches the earth perpendicularly that it would encounter aether moving perpendicular to it. So the assumption has always been that this would mean that a photon would be “blown” in that direction. In that case, it has a component of velocity added laterally, but to maintain c that would mean that it's velocity component toward earth would need to decrease. But how could that happen? There is no force opposing the photon! For the photon to change direction would mean we break the law of conservation of momentum. The momentum can only change if the component of velocity toward earth is decreased, and again, there is no force present to do that.
Energy travelling in a medium is not a feather blowing in a breeze! Aether cross winds do not effect photons.
Page 13:00 water filled telescope can makes theta larger?
Yes - if we are take the equation by the face value (ie mathematician wearing physicist hat).
No - the water column in telescope acts like a flat prism producing an exit angle equals to the incidence angle. No net angle change with or without it. A dumb experiment to a dumb conclusion.
The ad hoc-derived mathematical equation for aberration was shown to be flawed with a water-filled telescope. And the raindrop explanation ignores the undefinable fact that the source of the drops is exactly where it is supposed to be and is not projected in the direction of the motion of the observer. The equation itself cannot replace a logical explanation. Bradley's explanation is nonsense. Replace the raincloud with a shower, and you can see the fallacy. And if we assume light is propagating like a wave and not a Newtonian particle, we can hear that if the wave were a sound, there's no aberration. In other words, the explanation is circularly reasoned based on observation with no Earthbound analogy we can demonstrate.
A more likely explanation, assuming Bradley didn't massage his data like so many scientists do, might have to do with the fact that in order to view a star in its location over the course of a year, one has to be able to see the star during the day as well as night. And Bradley would have never thought of the interaction of Earth's magnetosphere with the Sun as having anything to do with his observed minute "aberration". Bradley had no idea that Earth had an ionosphere. Bradley knew nothing about the plasma that surrounds Earth. Nor did he understand anything about electromagnetism.
And if you look into how tiny stellar aberration is, you will see that this is much ado about nothing.
@@Chicken_Little_Syndrome Well said.
One can argue that stellar aberration in 3 ways. 1) Light is photon propagates without a medium, 2) light is wave ride on a medium but non sync with earth and 3) in sync with earth. That Bradley fail to specify.
1) if light is photon use no medium our mid event translate to a leading object image. (In favor to Bradley)
2) light is wave ride on a medium non sync with earth and our movement translate to a leading object image. (In favor to Bradley)
3) light is wave ride on a medium in sync with earth and our movement translates to a lagging object image. (Against Bradley)
One question begged here is how was the distance from Earth to Sun determined.
The transit of Venus across the face of the sun was observed. They used parallax observations from England and France to determine the distance.
@@Daz912 do explain how the distance between France and England has anything to do with the distance from Earth to Sun.
@@ikediamond you can compare the measurements in two different locations to take a parallax measurement. For example, if you hold your finger in front of you and close one eye you can see it move position slightly
@@Daz912 my finger to my eye is easily measured. The distance to Sun is not.
@@ikediamond not sure what your question is then
Brasil
fala doido
Light is neither a particle nor a wave. A wave isn't what something is but rather how something behaves. This whole theory sounds like an excuse to explain away something that proved that the model is wrong.
And what thing would that be?
@@Flaystray light is perturbation of the aether
@@AddisonJamesHoward Oh good. I was hoping it was something that had been disproven for a century
lol
Stellar aberration and parallax in no way "prove" heliocentrism. Both are explained by geocentrism as well. So saying they "prove" heliocentrism is a bit ignorant and/or dishonest.
No. The ellipses observed annually in the stars are a reflection of the elliptical path of the Earth as it moves around the Sun. On a fixed Earth with the stars rotating around it, these ellipses would NOT be observed. And the possibility of observing parallax would only be limited to the Earth's diameter, and not to the diameter of the Earth's annual trajectory.
@@arriamirorei1925Incorrect. You can have ellipses on a geocentric model too. Its not exclusive. Youre just affirming the consequent and reifying your model. Circular reasoning at its finest. If you disagree with this, you disagree with einstein and general relativity.
@@Awakeintheaether You don't even know what you are saying. Could you explain how it is possible for stars to trace ellipses over the course of a year due to stellar aberration if the Earth is stationary?
@@arriamirorei1925I do. YOU dont understand it. And thats ok. Theres a few ways it could work. One way is a modified tychonic model. All you do is add ellipses to tychos original model like kepler added to the copernican model. Then, you put the universe into rotation fixed on the sun as it revolves around a fixed earth at the center of mass of the whole system. Boom. Parallax, aberration, and retrograde all explained from a geocentric position. Again, if you dispute this you dispute Einstein and General Relativity.
@@Awakeintheaether You are just talking things without coherent explanation. The parallax in your model would not match the observed parallax, which would still be based on the diameter of the Earth. And the stars would also not trace the observed annual ellipses due to the aberration but more complicated orbits.
If you can't come up with a reasonable explanation of how the annual ellipses observed from a stationary Earth could be explained, the best you can do is stop to write stupid comments in UA-cam.