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[ortwin]

Maybe the simplest rule: Tops that don't fall compete only among themselves.

I am afraid that would not really do: imagine the record in the category with the highest prestige, the falling tops, is at some point at 45 minutes. Now someone does a spin with a top, and at 47 minutes it is still spinning a bit. The person doing the and filming the spin suspects that in the end that top might not fall. So now he or she gently blows against the top to make sure it will fall but at the same time the blowing should not be heard in the video.  A new record in the falling category!
We would not want such things to happen really.

[ta0]

So now he or she gently blows against the top to make sure it will fall but at the same time the blowing should not be heard in the video.  A new record in the falling category!

He doesn't even have to blow and cheat on purpose. Just gets close to the top and the vibrations from him stepping on the floor make the top fall. He may not even realize it.
But if somebody wants to cheat on camera, it's almost imposible to stop it.

I suggest that the official records are obtained in the presence of others (like many records need to be). It could be at a festival, world contest, EDC meeting or even perhaps with just witnesses approved by ITSA.

I would suggest that just after the fall, the top is spun again but slowly enough that it falls in about 1 minute (after having slept). It would prove that the top didn't developed a flat spot. This could be done by the certifying witness/judge.

[Iacopo]

I suggest that the official records are obtained in the presence of others (like many records need to be). It could be at a festival, world contest, EDC meeting or even perhaps with just witnesses approved by ITSA.

This is probably the best solution.

[Jeremy McCreary]

I suggest that the official records are obtained in the presence of others (like many records need to be). It could be at a festival, world contest, EDC meeting or even perhaps with just witnesses approved by ITSA.

This is probably the best solution.

Would the witnesses have to be present the entire spin? Getting someone to watch an endurance top sleep with no visible action for the better part of an hour is a big ask.

[ta0]

Would the witnesses have to be present the entire spin? Getting someone to watch an endurance top sleep with no visible action for the better part of an hour is a big ask.

Yes. The record pursuer might bring pastries and coffee for the witnesses. Also, playing dominoes or Dungeons & Dragons during the spin is allowed. 

[Jeremy McCreary]

Maybe hire a professional top watcher — willing to travel and certified by the ITSA, of course.

Could be a nice side-hustle for an enterprising member.

[zaggernut]

Indeed, it is simply too easy to record an invalid run on video, whether intentional or otherwise. Video game proof standards are simply not enough for real life records of this nature. As troublesome as it is, an in-person witness is probably necessary. But if we are going to be this formal about validation, to ensure fairness we might as well additionally require a barometer and anemometer reading for the duration of the run.

Although personally, with such requirements I would more than likely settle for an unofficial youtube record, if I ever reach the point of being able to compete for the title.   

PS Perhaps a live video call with a witness could suffice, if the one attempting has a barometer/anemometer on hand.

[ortwin]

... to ensure fairness we might as well additionally require a barometer and anemometer reading for the duration of the run.
...

Why is that? Are you expecting much longer runs in Mexico city than in Florida because of reduced air resistance? And why the anemometer?

...
Although personally, with such requirements I would more than likely settle for an unofficial youtube record, if I ever reach the point of being able to compete for the title.   
...

Even for an unofficial youtube record it would be helpful if we state some rules people could refer to if they try to set some record there. That we can not make sure that they really followed the rules is a different point. It would give the in person contests and records a higher status.

[Iacopo]

PS Perhaps a live video call with a witness could suffice, if the one attempting has a barometer/anemometer on hand.

Good but not perfect yet, the top should be checked also for the presence of magnets, maybe hidden motors, or whatever other strange things not apparent in a video. 

Maybe, if the mountain will not go to Mahoma, Mahoma could go to the mountain.

Along with the method of obtaining official records suggested by Ta0, the record pursuer could have the alternative to make a video with his record, then he ships the top to someone trusted in the commitee who will check that everything in the top is within the rules. Topple dynamics, spin decay, (which must be very similar to that in the video), and so on. Then the top is shipped back to the owner.  Everything at the expenses of the record pursuer. 

[zaggernut]

Why is that? Are you expecting much longer runs in Mexico city than in Florida because of reduced air resistance? And why the anemometer?

Longer enough to matter at least, of that I am certain. Location as well as weather and time of day matter. Today's station pressure in Mexico city is around 77 kPa, Miami's is 101 kPa, 30% more. Someone with the proper setup could test how much of effect this may have on spin time, but if Iacopo's vacuum tests are anything to go by, even smaller differences should be noticeable, let alone this extreme case. I do not know what amount of variation should be allowed, and I am not keen on scaling spin times based on barometric pressure as you would also need to know tip friction losses to do that scaling any justice.
The anemometer is there to pick up external air currents that might provide torque to the top. For example, some EDC top makers I have seen on facebook use asymmetric knurling for left and right handers, which turns the top into a very shoddy wind turbine. Actually, a couple blade of grass or paper might work even better than a budget anemometer, and you can place them in multiple locations.

Even for an unofficial youtube record it would be helpful if we state some rules people could refer to if they try to set some record there. That we can not make sure that they really followed the rules is a different point. It would give the in person contests and records a higher status.

Yes, by unofficial youtube record I meant doing everything required in an official record, except no live witness.

Good but not perfect yet, the top should be checked also for the presence of magnets, maybe hidden motors, or whatever other strange things not apparent in a video. 

The idea of a live video call is that the witness can ask the challenger to do certain things to rule out foul play. Such as showing a closeup of the top, showing the underside of the spinning surface, testing for magnets with a compass etc., things that an in-person witness should be doing anyway. But yes, shipping the top off for verification would be more foolproof, especially for checking things such as motors. And most certainly cheaper and less hassle for some people than a flight to the nearest spinning top meetup.

[Iacopo]

Today's station pressure in Mexico city is around 77 kPa, Miami's is 101 kPa, 30% more.

This is a very old graph I made about RPM lost per minute in a wooden top spinning at the average speed of 540 RPM at the changing of the air pressure. The RPM loss for the tip friction alone was about 38 RPM/minute, at 540 RPM.  The graph is about the total RPM loss, (tip friction + air drag).



This wooden top loses 160 RPM/minute at 1000 millibar, and 140 RPM/minute at 770 millibar.
With these proportions, a top spinning for 30 minutes in Miami, could maybe spin for approximately 34 minutes in Mexico city, but the difference should be littler in the case of metal tops, (where the ratio between tip friction and air drag is higher), maybe two or three minutes out of half an hour spins.

[zaggernut]

With these proportions, a top spinning for 30 minutes in Miami, could maybe spin for approximately 34 minutes in Mexico city, but the difference should be littler in the case of metal tops, (where the ratio between tip friction and air drag is higher), maybe two or three minutes out of half an hour spins.

Huh, that difference is noticeable yet surprisingly little, even in the worst case of wood top+mexico city. I suppose a barometer reading would not be necessary, and the location of the record would only be a problem in some edge cases. It would still be best to have more concrete data regarding this, by comparing 2 full spins on metal tops at the 2 pressure extremes (and more pressures should the need arise). 540 RPM may not be the best middle ground to extrapolate the entire spin from.

[ta0]

I think the record should be valid regardless of ambient pressure. If I recall correctly, the first sub 10 second 100 meters was at the Olympics in Mexico City. If somebody wants to go to La Paz, Bolivia, to get the world record, so be it.
I guess it's air density and not directly air pressure what affects the spin. A hot place would help . . .
I'm very doubtful that wind (ambient natural wind) would have a positive effect on the spin. And I think most people would want to attempt the record indoors.

More interesting: are tops with movable parts allowed? I'm undecided about this, but I'm inclined to accept them.
For example, the stem could collapse after the start, would would decrease the air drag.
But a much more effective idea: make the a tip with a shaft that slides with friction inside the top. You start with the tip extended out, what will give you clearance to do a strong start without hitting the base. As the top straightens up, the tip slowly slides inn, ending with a very shallow clearance and a low center of mass or low critical speed. Plus you get the ground effect that decreases the air drag.

[ortwin]

...
More interesting: are tops with movable parts allowed? I'm undecided about this, but I'm inclined to accept them.
...

Tops with movable parts I would definitely not want to see in the the main categories! There is just too much that can be done there. I am thinking of springs and balls and a pump top would also be possible. Sure it would be interesting to see what ideas people come up with, but it should all be done in some special category.


 

[Iacopo]

540 RPM may not be the best middle ground to extrapolate the entire spin from.

I add that the diameter of the tested wooden top is 125 mm, which is quite large, compared to our metal finger tops.
The air drag of a spinning thin disk is proportional to r⁴ and v^1.5, (stating to Von Karman, as explained by Jeremy).
A spinning top is not exactly a thin disk but its air drag is certainly very sensitive to the diameter and quite more to it than to the angular speed.
The test I made is approximative, but I believe that we shouldn't worry too much about the ambient air pressure, (but vacuum systems should be forbidden !)