Starship Asterisk*

http://apod.nasa.gov/apod/ap080718.html

Intriguing image... the setting of ancient crumbling stonework with Jupiter balanced in the background set off a series of synapse activities within my cortex. First I thought special moments like these are relatively fleeting in that Earth will eventually move away from the current mote in the “eye” of Jupiter relative to the Sun and both planets will meander within their expected movements until some other interesting alignment event occurs.

Then my second thought… what if Earth was to abruptly stop rotating dead in its tracks… According to the numbers, I would leave the ground at roughly 832 mph given my present latitude. But then I realized that I am inside a building that is much more anchored to the ground than I, so there would be a conflict in our ground departure. I expect I would be safer in some open area, perhaps even safer in my airbag equipped SUV. And then I thought a little more… what about the Earth crust floating on all that molten magma… I guess there would be differentiating anchoring in the Earth’s surface as well… And what about orbital velocity, should Earth stop dead in its orbit......

Uh oh, time to go back to work now. Maybe this requires a bit more thought. At least for now, I’m going to try and spend more time out of doors.

Jupiter and the moon were lovely last night at The Police concert in Wheatland, CA, Sleep Train Amphiteater. The full moon and Jupiter were just above and to the left of the stage the band played on, giving a wonderful sight. =)

You have an interesting thought train, emc.

I just had to say it's a stunning picture. The ancient Roman architecture is a very fitting complement to a picture featuring Jupiter.

I was looking for more pictures of the Temple of Hadrian, and I found this scrolling panorama (requires Java )

http://sailturkey.com/panoramas/ephesus/hadrian.html

emc wrote:http://apod.nasa.gov/apod/ap080718.html

(SNIP)
Then my second thought… what if Earth was to abruptly stop rotating dead in its tracks… According to the numbers, I would leave the ground at roughly 832 mph given my present latitude. But then I realized that I am inside a building that is much more anchored to the ground than I, so there would be a conflict in our ground departure. I expect I would be safer in some open area, perhaps even safer in my airbag equipped SUV. And then I thought a little more… what about the Earth crust floating on all that molten magma… I guess there would be differentiating anchoring in the Earth’s surface as well… And what about orbital velocity, should Earth stop dead in its orbit......

Uh oh, time to go back to work now. Maybe this requires a bit more thought. At least for now, I’m going to try and spend more time out of doors.

While inside your concrete structure, the oustide would become subjected to 1000+ mph winds (earth rotation + jet stream + current relative air speed) and You would be slammed against the western wall at appx mach 1.1 - 1.3. You would likely be flat.
The safest place would likely be in a jet traveling with the flow of the wind as the earth would then stop beneath you and you wouldn't be subjected to the winds. (Just massive ammounts of turbulance at the atmosphere reacted to the grounds sudden stop) You would just appear to have a dramatically increased ground speed.
Landing might prove problematic though. How long would it take the average wind speed to decrease sufficiently to allow for a safe landing???

BMAONE23 wrote:

emc wrote:http://apod.nasa.gov/apod/ap080718.html

(SNIP)
Then my second thought… what if Earth was to abruptly stop rotating dead in its tracks… According to the numbers, I would leave the ground at roughly 832 mph given my present latitude. But then I realized that I am inside a building that is much more anchored to the ground than I, so there would be a conflict in our ground departure. I expect I would be safer in some open area, perhaps even safer in my airbag equipped SUV. And then I thought a little more… what about the Earth crust floating on all that molten magma… I guess there would be differentiating anchoring in the Earth’s surface as well… And what about orbital velocity, should Earth stop dead in its orbit......

Uh oh, time to go back to work now. Maybe this requires a bit more thought. At least for now, I’m going to try and spend more time out of doors.

While inside your concrete structure, the oustide would become subjected to 1000+ mph winds (earth rotation + jet stream + current relative air speed) and You would be slammed against the western wall at appx mach 1.1 - 1.3. You would likely be flat.
The safest place would likely be in a jet traveling with the flow of the wind as the earth would then stop beneath you and you wouldn't be subjected to the winds. (Just massive ammounts of turbulance at the atmosphere reacted to the grounds sudden stop) You would just appear to have a dramatically increased ground speed.
Landing might prove problematic though. How long would it take the average wind speed to decrease sufficiently to allow for a safe landing???

My Bold.
That's easy. Head into the wind and you could hover in a Jumbo Jet. And do a nice soft vertical landing like a Harrier VSTOL.
Possibly.

Ahhh!!! Imagine the force it would take to stop the Earth from rotating. It would probably have to collide with something big. Going against the grain of rotation; no less.
Orin

http://en.wikipedia.org/wiki/Herostratus

<<Herostratus (Ancient Greek: ‘Ηρόστρατος) was a young man who set fire to the Temple of Artemis at Ephesus (in what is now western Turkey) in his quest for fame on July 21, 356 BC. The temple was constructed of marble and was considered the most beautiful of some thirty shrines built by the Greeks to honor their goddess of the hunt and the wild. The temple was also one of the Seven Wonders of the Ancient World.

Far from attempting to evade responsibility for his act of arson, Herostratus proudly claimed credit in order to immortalize his name in history. In order to dissuade similar-minded fame-seekers, the Ephesean authorities not only executed Herostratus, but condemned him to a legacy of obscurity by forbidding mention of his name under the penalty of death. Obviously, this harsh stipulation did not preclude Herostratus from achieving his goal, as the ancient historian Theopompus recorded the event and Herostratus in his history.

The name of Herostratus lived on in classical literature, and has been passed on into modern languages.

* In German, for example, Herostrat is an individual in constant pursuit of fame.

* The English term Herostratic fame, likewise, relates to Herostratus.

* Jean-Paul Sartre wrote a short story titled "Erostratus" as part of his 1939 Le mur (The Wall). In the story, a man plans to commit a crime of random violence as a means of achieving fame.

* The Japanese version of the Momus CD Oskar Tennis Champion contains a track titled "Erostratus" in which he gloats about his posthumous fame. It references the Sartre story in describing Erostratus's name as enduring "like a black diamond".

* Herostratus is a 1967 British film by Australian film-maker Don Levy.>>

Tunç Tezel is a skilled photographer and photo planner/processor whose apods we've discussed before. So here's my question about what he captured this time:

What is the source of the lighting on the terrestrial structures in the foreground? Did they wire the ruins for lighting? If so, where are the lights? Is is too late for rays of sunset to be peeking at the tops of the buildings? (The Milky Way is out, so I guess yes.) I'm betting the exposure time was more than a snapshot and that the actual light is quite dim, but I really can't tell.

What's your analysis, Spock?

Hello BMAONE23,

Wouldn't that be the East wall?

orin stepanek wrote:Imagine the force it would take to stop the Earth from rotating. It would probably have to collide with something big.

If the Earth collides with something big enough to stop it from rotating, it will be big enough to do a lot more than that.

Now that's the scary truth

It was the light of some sodium-vapor projectors installed to a gendarmerie station at the northern entrance to the site. The brightening of sky near Jupiter was caused by similar lights installed to the eastern entrance.

In fact, there are decorative lights in some parts of the city including the places I photographed (and I took many more) and the security asked if I wanted them switched on and I said no. I went there with a special permit obtained from Efes Müzesi to take pictures after the visiting hours.

Good day,

Tunç Tezel

[quote="apodman"]Tunç Tezel is a skilled photographer and photo planner/processor whose apods we've discussed before. So here's my question about what he captured this time:

What is the source of the lighting on the terrestrial structures in the foreground? Did they wire the ruins for lighting? If so, where are the lights? Is is too late for rays of sunset to be peeking at the tops of the buildings? (The Milky Way is out, so I guess yes.) I'm betting the exposure time was more than a snapshot and that the actual light is quite dim, but I really can't tell.

What's your analysis, Spock?[/quote]

orin stepanek wrote:Imagine the force it would take to stop the Earth from rotating. It would probably have to collide with something big. Going against the grain of rotation; no less.

Lets start with the rotational energy of the earth.

E = ½ I ω²

where E is the energy, I is the moment of inertia and ω is the circle frequency of the rotating earth.

The moment of inertia of a massive sphere with constant density (not quite the case for the earth, but a simple approximation) is given by

I = (2/5) M R²

with M the mass of the earth and R the radius of the earth. which leaves us for the rotational energy:

E = (1/5) M (ωR)²

R = 6.37E6 m. M = 6E24 kg. ω = 2 π /86160 = 7.29E-5 [1/s]. The term ωR is synonymous with the equatorial velocity of the earth, 464.5 m/s, which is mach 1.5. So the rotational energy amounts to:

E = 2.5E29 J.

For a comparison: a lightbulb of 50W uses during an hour 1.8E5J.

Now assume a body with the same mass as the earth collides with the earth and by some miraculous coincidence of all factors, it transfers its entire kinetic energy to the earth and manages to stop the earth from rotating. -Not likely-

Question: What velocity does this similar earth would need to be able to transfer all its kinetic energy to stop our earth from rotating?

E_rot = (1/5) M (ωR)²
E_kin = (1/2) M v²

Substituting E_rot = E_kin we find:

(1/5) M (ωR)² = (1/2) M v²

v = ωR √(2/5) ≈ 294 m/s

The earth itself moves around the sun with a velocity of 30 km/s. The necessary velocity to stop the earth from rotating in the collision is 1% of the earths orbital velocity.

Similarly, if the earth collides with your 'something big', orbiting in a similar orbit (and velocity) as the earth, your 'something big' must have just 10 ppm of the earth mass: 6E20 kg. Dione and Thetys, both moons of Saturn, qualify for such mass. Our own Moon is at least 100 times too heavy.

Ephesus is the location of bearing for three books of the Bible making this APOD a bit more interesting for some. My synapse regarding the Earth’s rotation was somewhat based in Scripture as there are two instances whereby time or planetary mechanics were altered such that a day was added and about 30 minutes were reversed. So my thoughts about the Earth stopping are not singularly stemmed from my twisted and unhinged thinking but stemmed from ancient Writing, therefore I cannot take full credit for postulating the physical anomaly. I do like to use this scenario every once in a while if someone asks me “How’s it going?” my response at times is, “Fine, the Earth’s still spinning!”

This APOD is most intriguing for bringing the distant past into a more present frame. The image makes me wonder about the people walking the streets when the stonework was fresh. Perhaps they witnessed such a Jupiter as is captured in this land, sky, space "scape".

Hello emc,

Yes it must have been something with there structures new or as they were being built. The photo info on the technique used to create the image was interestting. I know also that the concept of "painting with light" can be utilized. That's where one leaves the shutter open on a dark scene and uses a flashlight or other light source (strobes, etc.) to "paint" the subject. It takes some practice but the results can be intriguing.

The last time the Earth stood still
http://www.youtube.com/watch?v=OfpSXI8_UpY
Orin

astrolabe wrote:Hello BMAONE23,

Wouldn't that be the East wall?

quite right

orin stepanek wrote:Ahhh!!! Imagine the force it would take to stop the Earth from rotating. It would probably have to collide with something big. Going against the grain of rotation; no less.
Orin

Seeing as the Moon has slowed the Earth's rotation from what used to be a theorized 6 hour rotation period to its current 24 hour rotation, It could likely take something like a jupiter mass rogue planetary body (or larger like a brown dwarf star) passing us in a path directly opposite to our rotational axes. Whether it would stop us or merely slow us, and how quick the affect would be, I couldn't guess???

BMAONE23 wrote:

orin stepanek wrote:... probably have to collide with something big.

... Whether it would stop us or merely slow us, and how quick the affect would be, I couldn't guess

(elsewhere) henk21cm wrote:follow my motto: "start simple, complicate later"

I picture the Earth running into an object of its own mass fast enough to produce an inelastic collision. If this object is also rotating with the same angular momentum as the Earth in the same direction (the opposite of two meshed gears that rotate in opposite directions), it will exactly stop the Earth's rotation. The effect would be immediate.

Now we can vary the speed of impact, angle of impact, and the impact's offset from center to introduce the conditions of a grazing impact. Since the gravity of the two bodies will pull them together at a speed at least equal to the escape velocity of the more massive body (I think), not all speeds and angles are permissible. Separate problems may need to be set up for inelastic and partially elastic collisions. The permissible values still have three variables to contend with (speed, angle, offset), so some 3D minimax calculus (gradient, etc.) will likely be needed to find the impact vector that requires the smallest object to stop the Earth's rotation. I'm not sufficiently curious to solve the problem myself, being more of "a solution exists" kind of guy.

I might only introduce the fourth variable (rate of the object's rotation) after solving the problem above.

In my quick reading of henk21cm's equations above (unless I missed something), the objects impacting the Earth are not rotating themselves. If the nature of the collision allows the conversion of rotational inertia into momentum, then the smaller the impacting body and the less complete the conversion, the faster it needs to be rotating to produce the same result (or a larger body with more complete conversion rotating more slowly). In other words (in theory), the Earth could run into a vast immovable object and stop with a slight grazing impact, or run into a small rock spinning very very fast and halt its rotation completely.

A non-spinning object could impact the Earth in such a manner that it is sent away spinning, thereby carrying off some of the momentum from the collision as rotational inertia and complicating our problem just a little bit more.

Note for those not familiar with "elastic" and "inelastic". If two flying gobs of peanut butter hit each other and stick together, the collision is inelastic. If two hard rubber balls (or subatomic particles) bounce off each other, together retaining a sum of 100% of their incoming kinetic energy, the collision is elastic. If you drop a billiard ball on a resilient floor, you can tell that the collision is not perfectly elastic because the ball does not bounce back to its original height, and because you can hear that some of the energy of the collision has been converted into sound. An "elastic" collision conserves kinetic energy - see http://hyperphysics.phy-astr.gsu.edu/Hbase/elacol2.html and http://hyperphysics.phy-astr.gsu.edu/Hb ... on.html#c1 . A "collision" of galaxies in not a true collision at all in this sense (and therefore the concept of elasticity doesn't apply), since their masses do not interact as two objects colliding.

apodman wrote:If this object is also rotating with the same angular momentum as the Earth in the same direction (the opposite of two meshed gears that rotate in opposite directions), it will exactly stop the Earth's rotation.

Not just the amount of energy needs to be the same, the alignment of the axes of rotation needs to be exactly parallel. Some thoughts:

• The two colliding planets need to be massive. You may remember the demonstration with a rotating (raw) egg. When you gently lay your hand on the spinning egg, the rotation is stopped instantly. When you remove your hand, rather unexpectedly the egg will start spinning again, since the liquid interior of the egg was still spinning.
• To be smooth is not a demand. Any protruding mountains will be grinded in the process of collision. The process of stopping however is no longer instantly.
• To stop both earth and the colliding spinning planet instantly, there must be good friction between the surfaces. If both surfaces slip, the proces is no longer instantly. Nevertheless slip will dissipate energy and bring both to a halt. In the process a considerable layer of both planets crusts will melt or even vapourize.
• If the collision is not perfectly (100%) inelastic, the alignment of the orbits must be perfectly parallel when the collision takes place. A grazing impact. Any elastic component might push both planets away from each other. Only gravitational force might prevent such separation.

apodman wrote:In my quick reading of henk21cm's equations above (unless I missed something), the objects impacting the Earth are not rotating themselves.

You did not have missed a thing, your assumption is correct. The purpose of the equations is to make a comparison between the rotational energy of the earth and some other (huge) amount of energy. The comparison with e.g. the energy release of a hydrogen bomb would have been an option. Since orin stepanek introduced the idea of an impact, i followed that lead.

IMO it is very unlikely that an object impacting on the earth could stop the rotation of the earth instantly. Nevertheless a considerable amount of rotational energy is likely to be lost in such huge collisions, making a day longer.

The Jupiter, Earth and Sun alignment reported in this APOD is expected, anticipated and will occur again and again if nothing major changes. We tend to rationalize everything (including unhinged and twisted imaginations) with what we understand of how our physical universe behaves. Your ponderings in this thread of how the Earth might “stand still” is more proof of that. Some very interesting, rational and funny thoughts and I always enjoy and learn something from my posting friends at Asterisk.

But what about the metaphysical... (for any fan of Science fiction and/or Christian Writings) According to the Bible, Jesus transcended death and was reported to “appear” in a locked door room with at least eleven witnesses. There are other instances where He is reported to have “appeared” (but it is inconclusive as to what is meant at every instance by “appeared”). If you ponder credibility for the Writings, this promotes synapse activity regarding interaction outside of the time space continuum. If such existence is possible, then it does not require a gigantic collision to stop the Earth’s movement.

What if... it is possible to live in and out of time and on top of that, transcend astronomical distances... seems irrational doesn't it?

... a chance to dream, to dream of a chance.

It is reassuring to believe we will keep spinning and Jupiter will always be there for us. Reckon it would be a good idea to keep a lookout though... never know what's around the bend...

http://en.wikipedia.org/wiki/Temple_of_ ... estruction

The Temple of Artemis at Ephesus was destroyed on July 21, 356 BC in an act of arson committed by Herostratus. According to the story, his motivation was fame at any cost, thus the term herostratic fame.
...
The Ephesians, outraged, announced that Herostratus' name never be recorded (Damnatio memoriae). Strabo later noted the name, which is how we know it today.

That very same night, Alexander the Great was born. Plutarch remarked that Artemis was too preoccupied with Alexander's delivery to save her burning temple. Alexander later offered to pay for the temple's rebuilding, but the Ephesians refused. Eventually, the temple was restored after Alexander's death, in 323 BC.

neufer wrote:<Herostratus (Ancient Greek: ‘Ηρόστρατος) was a young man who set fire to the Temple of Artemis at Ephesus [snipped]... attempting to evade responsibility for his act of arson, Herostratus proudly claimed credit in order to immortalize his name in history.

bystander wrote:The Temple of Artemis at Ephesus was destroyed on July 21, 356 BC in an act of arson committed by Herostratus. According to the story, his motivation was fame at any cost, thus the term herostratic fame.

An obvious success...

Perhaps we should keep a closer eye on henk21cm and his ability to calculate catastrophe. (scroll down to his blueprinting an Earth orbit change... and you get what I mean) You might also note how quick he was able to figure out how to stop the Earth from spinning... (as you should have noticed earlier in this thread) ... I don't know though... he seems like such a nice guy. Maybe I'm the one you need to watch out for...

Breathtakingly spectacular image like nothing I have ever seen, the increased magnification capability maximizing its breadth and scope to the utmost. Beautifully eerie, profoundly haunting in a way that makes me feel as if having traveled back in time. Spooky. Wow.

Ephesus first constructed on bay where Kucuk Menderes river reached the sea in western Anatolia. This area is almost in middle of ancient lonia, which has mild, wet climate, so that it has many natural advantages as a place for people to settle. It was not only situated at important point joining West and the East, but was also at the crossroads between Miletus & lonia. The fine arts, sciences & philosophers such as Heraclitus and Thales developed in lonia.

Ancient Ephesus