A Visceral Experience of our Rotational Speed
Barrett's Solar Geospeedometer Description
This educational device, comprised of off-the-shelf parts, gives young students a real-time experience, a visceral experience, of the fact that we are speeding along at a speed of several hundred miles an hour on the surface of a giant sphere. Intellectually, we gradually learn to accept this fact as we progress through our childhood, but few of us are able to witness or verify this phenomenon except for astronauts and high-altitude pilots. Here is a device that allows one to experience, and thus verify, this concept from the ground.
First, the observer is grounded by placing them in a reclining or zero-gravity chair so that they feel locked to the earth while looking at the sun through solar eclipse protective glasses. They are given some time to adjust to their new situation.
Next, a viewscreen is swung into place replacing the view of the sun. On that screen, there is another image of the sun that is coming from a telescope on the ground next to the observer. After the screen is in place, the viewer is asked to remove their sunglasses. There is now a new enlarged image of the sun is now in place of where the real sun was just minutes ago and it is 20 times larger.
The new sun is now 2.5 inches in diameter on the screen, and In addition, the sun on the viewscreen is also moving 20 times faster than it is in the sky. The 2.5 inch sun on the screen moves through its diameter in 2 minutes and 7 seconds. It is now moving a little more than an inch a minute across the screen.
This movement is barely discernable, except for the spaced reference lines that have been drawn on the surface of the screen revealing the slow but steady movement of the sun as it creeps along.
The observer is then given some time to absorb this phenomenon.
The teacher then presents the student with a 3-foot diameter beach ball and a pea, and then asks the student: "of these two object, which would be the sun and which would be the earth?" If the student gives the wrong answer, they are corrected. The diameter of the earth is one hundredth the diameter of the sun, and, at this scale, the earth would be at a distance of 300 feet from the sun. After considering this, we can agree that the sun is at the pivot point, the center, of our system - that it doesn't move (within the realm of our solar system).
Next, we also come to an agreement that the earth while travelling around the sun is also rotating every 24 hours (a globe of the earth might help here). We'll have to also agree that though the sun appears to be moving on the screen, it is not the object that is really moving, and that the viewfinder, and thus the viewer , the chair and the earth that the chair is attached to, are moving. That we are the ones who are steadily rolling under the sun.
The student is then given the chance to continue to observe and contemplate this situation until they finally grasp, to viscerally grasp, that they are the ones who are moving. That we are passengers riding the earth under the sun, just like a passenger on a train viewing a landscape that they are passing through. Once the whole concept is absorbed into the mind of the student, they will know, undisputedly, that they riding on a ball, alone in space. A ball of finite resources. This is the purpose of this device.
The Solar Geospeedometer at this point of development, is a conglomeration of several separate components consisting of a neutral density solar filter mounted on a 20X magnification spotting scope with a WiFi camera attached to the viewing end of the scope which feeds an image to a viewscreen (phone/laptop) with a grid inscribed on it. A specially designed scope could incorporate all three of the first features into one device ( that is, a solar scope wifi assembly). Following is a description of the separate components of the Solar Geospeedometer.
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Gallery of components
The astronomical solar filter looks silver because it blocks out about 95% of the light. It is placed on the scope so that the top mounting screw is accurately centered on the top of the scope barrel. This screw produces a shadow that is used later - in the spotting scope alignment process.
This is a typical adjustable spotting scope of 20 to 60 magnification. The 20 times magnification works just fine. The black knob on top is the focusing knob. In this photo, the wifi camera is attached to the scope eyepiece.
This WiFi eyepiece camera clamps around the eyepiece and is rotatable, the green dot at the bottom is used for orientation and is rotated so that the image of the sun travels in the same direction on the viewscreen as in the sky overhead.
The tripod is placed on a firm surface. We use a 10 pound weight to firmly stabilize the device. This shows a typical altazimuth mount. An equatorial mount is preferable for extended use. In order to set up the equatorial mount, the user will have to download compass and leveling apps on their phon
This is a 9.7 inch viewing pad with clear screen protector attached. The image of the sun is about 2 1/4" in diameter and the line are drawn 3/4" apart. The sun travels three lines (its diameter) in 127 seconds; in a little more than 2 minutes.
The above video shows how fast the viewer is moving under the sun. This is a morning video and the viewer is seated facing East as the sun is rising. At latitude 35N when the sun has moved through three lines, its diameter, the earth has moved 30 miles eastward. Each line in this video indicates that the viewer has moved 10 miles in each 42 second period.
The pad is viewed so that solar image travels in the same direction as the sun overhead.
DETERMINING THE SPEED OF THE VIEWER
Depending on the number of lines that the sun image traverses and the latitude of the observer, it is possible to determine the amount of distance that the observer has moved as the sun moves from one line to the next.
1) Determine the surface velocity of the observer in miles per hour which depends on the latitude of the observer, visit:
https://www.dailymail.co.uk/sciencetech/article-2546864/How-fast-YOU-spinning-Earths-axis.html . For example, in North Carolina at 35 degrees north latitude we are moving at around 840 miles per hour. The velocity diminishes as one moves further away from the equator.
2) Determine how many line spaces the sun image occupies and divide that into the surface velocity. For example, in the above video the sun image occupies 3 spaces. Dividing the velocity of 840 mph by 60 reveals that the earth moves 14 miles per minute. The sun takes 2.12 minutes to travel its diameter so when it has traveled its diameter (3 lines) it has traveled approximately 14 x 2.2 or 30 miles, thus 10 miles per line.
CONCLUSION
We are attempting to evolve an intellectual spatial concept into a visceral experience. Experience, visceral experience, is one of the most effective ways to grasp a concept. We've seen it in the eyes of people we've shown this device to.
This combination of off-the-shelf components could easily be reduced into a single device that could be mounted on a stable tripod and aimed at the sun – passed out to every school on the planet. The production cost of the final integrated viewing device could be less than $100,
TECHNICAL DETAILS: The sun occupies .53 degrees of arc in the sky and it moves through that distance, through its own diameter, in 2 minutes and 7 seconds. The movement is slow but discernable. This movement becomes more discernable with the solar geospeedometer because the sun's image and speed is highly magnified and a set behind a grid of small lines.
We've been working on this idea since June 2017. It was first concieved as an experiential environmental sculpture, an Solar Geothrone. The Geothrone creates the same experience as the solar Geoscope - at a much greater cost. This immersive environmental art piece consists of a firmly grounded reclining throne in the center of a hemispherical 40 ft diameter gridwork dome. The Geothrone will be described later on.
Assembly and Operation
Assembly
Assemble the tripod, draw the lines on the plastic screen protector so that it is ready to install on to the screen. The spacing of the lines is important for. they tell the observer how far they have traveled under the sun when it moves from line to line. We use 3/4" spacing for a 9" viewpad which rounds out to about 10 miles of travel per line at 35 degrees N Latitude. An explanation follows.
Operation
SETTING UP THE EQUTORIAL AND ALTAZIMUTH TRIPODS - PHOTOS FOLLOWING
This system requires 2 viewpads, a small one for monitoring the image, placed near the scope and a large one to be placed in the underside of the sun shade on the viewing chair.
The best tripod choice would be the equatorial mount tripod; the setup takes time to learn but, once set up, it is quite easy to track the sun. The equatorial tripod requires the use of a level and a compass. Since you will not be doing astrophotography, which requires a precise orientation, the setup is quite simple.
EQUTORIAL MOUNT TELESCOPE PROCEDURE
Warning: this type of tripod is more difficult to set up and operate.
The tripod is first leveled and then the mount axis is oriented to the north pole. Then the vertical angle (declination) is set at the latitude of the observer. In this orientation, the spot scope will rotate along the same axis as the sun, so all it will require a single adjustment knob to keep it tracking properly once the sun is located, Photos below will explain. The scope must be balanced with the adjustable weight and the proper orientation of the the components will change when going from morning observation to afternoon observation. Your tripod manual will explain this issue. Once the scope has been set up a few times it will become an easy task.
On the viewing pad, the screen orientation has to be locked to horizontal so that the SME camera will present the largest image. Turn on the SME spot scope camera so that the green light comes on, then go to settings on the pad and set the wifi source to access the spot scope address, and then turn on the app. It should reveal an image of whatever the end of the camera is pointed at.
Attach the solar filter with one of the tightening knobs lined up with the focusing knob on top of the scope. Then use the shadow of the filter knob on the focus knob (pictured below) to orient to the the proper latitude and elevation, focus the image of the sun once discovered, then attach the SME wifi camera with the green light at 6 o’clock and adjust the right ascension so that the sun travels from bottom to top on the screen during sunrise and just the opposite direction in the afternoon, as the sun is setting. It may be necessary to mount the viewing pad upside down and/or rotate the the spotting scope orientation.
The viewer is placed into the zero gravity reclining chair and a shading cloth is used to cover the sun shade. in this orientation the sun on the screen moves in the same direction as the sun above, that is, with the chair facing East in the morning and facing West in the afternoon.
ALTAZIMUTH TRIPOD SETUP PROCEDURE
Prepare a firm surface to set up the tripod (this is based on the Celestron tripod).
Mount the spotting scope at the very rear of the mounting track
Attach and orient solar filter so that the top screw knob is pointing directly up in the center of the top of the objective.
Orient the tripod so that the front leg points directly towards the sun.
Be sure the shadow of the front leg aligns with the center strut of tripod accessories pan.
MORNING SETUP
The adjustments on the altazimuth tripod require adjusting both the declination (altitude) knob as well as the horizontal (azimuth) knob. In this section we are discussing the Celestron altazimuth tripod.
In the morning setup, the viewscreen is so mounted that the sun rises from the center of the bottom of the screen to the top of the center of the screen. The afternoon setup follows the setting sun, so the sun moves down the screen.
SETTING THE SCREW TRAVELERS
The sun will be moving L to R (E to W) , so move the screw traveler of the left knob all the way forward by turning the knob CCW until the traveler is just below the “L” in “Celestron”. The sun will be rising, so the declination knob, the right knob, needs to be turned CW to bring the screw traveler to near the bottom of its travel so that it has plenty of room to move up.
The scope is firmly attached to the tripod but the mounting track can be elevated manually without using the elevation knob – it is movable and can be forced up or down manually on its altitude axis . Bring the scope up or down manually until the shadow of the center sun filter knob is centered on the center of the small focusing knob on top of the scope. If you view into the scope, the sun should be visible, or can be found by keeping the shadow of the solar filter screw knob in the center of the focusing knob and moving it up and down.
Now it is time to set up the viewscreen. On your viewpad: be sure lock your viewpad into the horizontal or landscape orientation, turn on the spot scope camera so that the green light comes on, then go to settings on the pad and set the wifi source to access the spot scope address, and then turn on the app. It should reveal an image of whatever it is pointed at.
View through the scope and use the adjustment knobs to bring the sun into the center of the viewing field and then focus it properly so that it is sharp.
Now it is time to attach the wifi camera to the eyepiece by rotating the locking rings; then rotate the spot scope so that the green dot on the camera is at about 5 o’clock an image of the sun should appear on your pad.
Now it is time to get used to the adjusting knobs:
Turn the viewing pad vertical, this arrangement will show the sun moving from the center of the bottom to the center of the top, place in front of the viewing chair.
In the morning setup, the left knob of the Celestron Altazimuth tripod moves the sun up and down the screen according to the movement of the left knob tangent to the 4 o’clock position (cw:down, ccw:up)
In this setup, the right knob of the Celestron Altazimuth tripod moves the sun right and left according to the movement of the knob tangent at 7 o’clock position (cw:left, ccw:right). This will take getting used to.
Adjust the knobs so the sun image is brought to the bottom of the center of the screen and it will slowly move up the screen to the center of the top. Then, using the adjustment knobs, bring it back down to the center of the bottom.
Attach the lined protection screen so that the sun’s movement becomes more apparent.
If viewing in the afternoon, the viewing pad should be oriented in its holder, that is, reversed, so that the sun moves down from the top – just as it is moving in the sky, setting.
Be sure to practice this procedure before showing it to anyone else.
Depending on the size of the screen and the magnification of the scope, the image of the sun will only last on the screen for about 8 minutes before it exits, this will require that the screen is monitored quite often and readjusted for each viewing.
AFTERNOON SETUP
In the afternoon setup, the viewscreen is so mounted that the sun drops from the center of the top of the screen to the bottom of the center of the screen, setting.
SETTING THE SCREW TRAVELERS
The sun will be moving L to R (E to W) , so move the screw traveler of the left knob needs to be adjusted all the way forward by turning the knob CCW until the traveler is just below the “L” in “Celestron”. The sun will be setting, so the declination knob, right, needs to be turned CCW to bring the screw traveler to near the top of its travel.
The scope is firmly attached to the tripod but the mounting track can be elevated or lowered manually without using the evevation knob – it is movable and can be forced up or down manually on its altitude axis . Bring the scope up or down manually until the shadow of the center sun filter knob is centered on the center of the small focusing knob on top of the scope. If you view into the scope, the sun should be visible.
Now it is time to set up the viewscreen. On your viewpad: be sure lock your viewpad into the horizontal or landscape orientation for the best size image, turn on the spot scope camera so that the green light comes on, then go to settings on the pad and set the wifi source to access the spot scope address, and then turn on the app. It should reveal an image of whatever it is pointed at.
View through the scope and use the adjustment knobs to bring the sun into the center of the viewing field and then focus it properly so that it is sharp.
Now it is time to attach the wifi camera to the eyepiece by rotating the locking rings; then rotate the spot scope so that the green dot on the camera is at about 7 o’clock an image of the sun should appear on your pad.
Now it is time to get used to the adjusting knobs:
Turn the viewing pad vertical and upside down, this arrangement will show the sun moving from the center of the top to the center of the bottom, place it in front of the viewing chair.
In the morning setup, the left knob of the Celestron Altazimuth tripod moves the sun up and down the screen according to the movement of the left knob tangent to the 2 o’clock position (cw:down, ccw:up).
In this setup, the right knob of the Celestron Altazimuth tripod moves the sun right and left according to the movement of the knob tangent at 5 o’clock position (cw:left, ccw:right). This will take getting used to.
Adjust the knobs so the sun image is brought to the top of the center of the screen and it will slowly move down the screen to the center of the bottom. Then, using the adjustment knobs, bring it back up to the center of the top.
Attach the lined protection screen so that the sun’s movement becomes more apparent.
Mount the screen above the viewing chair, which is now facing West.
There are also many laptop and cellphone controlled automatic tripod mounts that can do all the calculations and adjustments automatically.
Be sure to practice this procedure before showing it to anyone else.
Depending on the size of the screen and the magnification of the scope, the image of the sun will only last on the screen for about 8-10 minutes before it exits, this will require that the screen is monitored quite often. Keeping track of the sun is more convenient with the equatorial mount tripod. The size of the sun at 20x magnification is 1 7/8” on the mini Ipad and 2 ¼” on a 9.7” Ipad, at 30x magnification, the mini pad image is 2 ¾” and the regular Ipad image is 3 3/8”.
Props are always helpful, such as a diagram of the solar system, a marble and a 3 foot beach ball to illustrate the comparative sizes of the earth and the sun, and a 12 inch globe to illustrate where we are on the earth and how we are turning in relation to the sun.
Tripod and Scope Setup
All the set screws on the solar filter should begin at the same depth and tightened equally so that the top screw is aligned straight up and aligned with center of the axis of the scope
When the top screw is properly aligned, the shadow of the top screw will line up with the center of the focusing knob further back. This will be used for aiming the scope later on.
When the shadow of the top screw is lined up in the center of the focus knob like this, the solar image should come in to view on the wifi camera ready for final positioning. Instructions on positioning to follow.
The balance counterweight compensates for the weight of the scope. Once the scope is properly set up the fine adjustment knobs are used to reposition the solar image for viewing.
A 3" wide plate is attached to the top of the frame of the sunshade.
This is a modified iPhone bicycle mounting rack pinion that has been attached to the underside of the recliner sunshade.