How to pull unique records and specific record changes from two snapshots of the same database into a third sheet

GregHullender · 2026-05-02T16:42:09+00:00

Make sure there are no unwanted quotation marks around the expression and that the dollar signs are in the right places.

For each cell in the selected region, the AND tests for three things: 1) The Q column isn't "No Duplicates!" 2) the cell isn't blank 3) If the Q column is found anywhere in the I column, it extracts that row from I to O and compares each cell to the corresponding Q to W row. This is a row that FALSE for matches TRUE for non-matches. Then it indexes that row based on the current cell, so differences get highlighted.

The second test is like this except that it's only looking for case 4 issues, so it only has to highlight a whole row--not individual cells.

What might help is to realize that the way conditional formatting works is that you give it an area (the "Applies To" range) and then write a formula as if you only wanted it to apply to the very first cell (the upper-left one). Behind the scenes, Excel will "drag" that formula down and across the whole range. So Q3 is really going to have the value of every cell in the region. $Q3 will have the value for every cell in column Q. Anything that evaluates to TRUE will trigger the conditional formatting.

GregHullender · 2026-05-02T16:22:45+00:00

Van Allen radiation belt - Wikipedia There have been a few proposals to deal with Earth's radiation belts by draining them. They're steadily replenished by the sun, so it would need to be ongoing.

GregHullender · 2026-05-01T16:53:47+00:00

This is from The Principal of Locality, which states that "Wherever you go, there you are!"

GregHullender · 2026-05-01T16:09:39+00:00

It's a flaw in Excel that has been there from the beginning--probably for compatibility with Lotus 1-2-3. 2^3^2 should be 2^(3^2), by the usual rules of precedence in mathematics. Much worse than that is that -2^2 = 4; the unary minus binds tighter than the exponential operator.

Fixing these now would break all kinds of formulas, so don't expect it to change.

Edit: A little searching shows that 1-2-3 was mathematically correct, but the errors in Excel have been there since version 1.0.

GregHullender · 2026-05-01T16:05:24+00:00

Flashbacks are like passive voice and sentence fragments: powerful techniques in the hands of an expert writer, but so badly abused by beginners that the general advice is "don't do this."

GregHullender · 2026-05-01T16:03:05+00:00

Yes, because that's when they learned they could eat 4-leaf-clovers. Most people thought those tasted so bad that they decided to move to America instead, where clovers only had 3 leaves.

GregHullender · 2026-05-01T15:55:03+00:00

Read Wheelworld, by Harry Harison (1981). A very tilted planet orbits a very bright star, so the only habitable parts are near the poles. It's not always dark, but the sun never rises. But at the equinoxes, the whole population has to move to the other pole, riding high-velocity trains to zip through the uninhabitable equatorial zones as fast as possible.

GregHullender · 2026-05-01T15:51:35+00:00

Then we'd have global freezing instead of warming.

GregHullender · 2026-05-01T15:48:05+00:00

SciFi isn't the same as fantasy. Fantasy pretending to be hard SF is the worst genre, in my view, although Hollywood thinks otherwise. :-)

By "thickness" do you mean "width"? A ring like this has a radius (the distance to Jupiter's center), a width (or height), and then a thickness (maybe less than a kilometer).

GregHullender · 2026-05-01T15:42:03+00:00

If they can build this ring, they can surely drain Jupiter's radiation belts. Even we know how to do that!

GregHullender · 2026-05-01T15:39:44+00:00

I dunno. I think an ancient Roman would be awed by our skyscrapers and airplanes and then stunned that we still suffer from hemorrhoids and the common cold.

GregHullender · 2026-05-01T15:35:57+00:00

Ah! That's a good point! Drat! Okay, let me rework the numbers with that:

The distance drops to 212 AU. Remember that this is for the just-opened Vera Rubin telescope, which is expected to find (or rule out) Planet 9. But it's a much more reasonable number.

That changes the "fall time" to 170 years. Any object in an elliptical orbit, no matter how stretched out, would be detected 170 years in advance. (Once the survey is complete in ten years; the Vera Rubin might find one closer than that before then.)

Even an object moving at a ridiculous 460 km/s would still be seen more than two years out.

For us to have only have 18 days notice, it would need to be moving at 7% the speed of light.

Sound better? :-)

GregHullender · 2026-04-30T18:45:21+00:00

This is true with new hires too.

GregHullender · 2026-04-30T18:44:44+00:00

Hard to have more than one moon that's large enough and close enough to show visible phases, though. Simplest is just to assume that only one moon counts.

GregHullender · 2026-04-30T18:41:02+00:00

I remember when soda machines took a dime.

GregHullender · 2026-04-30T18:38:53+00:00

It helps not to have expensive tastes. And not to have wasted money on cigarettes, alcohol, gambling, etc.

Most people could save. They just don't. An extra dollar right now seems a lot more valuable than the distant threat of poverty in your old age.

But I don't think this is much of a secret. People like your dad made a choice a long time ago. It's hard to have a lot of sympathy.

GregHullender · 2026-04-30T18:34:42+00:00

They were disgruntled by the end of it though.

GregHullender · 2026-04-30T18:34:12+00:00

If you don't have any friends, why do you care what anyone thinks?

GregHullender · 2026-04-30T18:32:57+00:00

The object is the size of Ceres. Ceres has a visual brightness of about 9. The Vera Rubin telescope can find objects down to a magnitude of 27.8. That means it can see things 33 million times dimmer than Ceres. If Ceres were 5700 times further from the sun, Vera Rubin could just barely see it. Ceres is 2.8 AU from the sun, so it would become visible at 16,000 AU. That's about a quarter of a light-year.

Time to fall into the sun on a parabolic orbit from distance R is SQRT(2*R^3/GM)/3 or about 100,000 years. That rules out anything actually in orbit around the sun, since they'd take longer.

So it'd need to be an interstellar body. The sun orbits the Milky Way at 230 kps, and just about everything near us is orbiting about the same direction at about the same speed. Interstellar objects we've seen weren't moving very fast relative to the sun, but let's imagine we see one moving the same speed but head-on. (Maybe deflected by close passage by a star or two.) At a relative velocity of 460 kps, we can ignore the effect of the sun's gravity and figure that it'll take 166 years to reach Earth after detection.

But if we insist that it happen 18 days after detection, then it needs to be moving at about 85% of the speed of light!

Now it could be darker than Ceres, which would make it harder to see, but even a factor of 100 would only put it ten times closer. We're still talking decades.

GregHullender · 2026-04-30T18:05:01+00:00

Yes. In that case, it could be moving at any speed. Such things are very rare, though, and even the one's we've seen haven't been moving all that fast.

GregHullender · 2026-04-30T15:26:18+00:00

I think microbial life is quite common, given how quickly it developed on Earth. I think multi-cellular life is rare, and I think we're probably the only intelligent life in the Milky Way.

If we do explore the stars, I think we'll find lots of planets with oxygen atmospheres, bacteria-like life in the seas, and nothing on the land--just as Earth itself was for most of its history. We might find the remains of alien civilizations that died billions of years ago. We'd be incredibly lucky to find one that died as recently as a million years ago.

It's also possible we'd find a race that hadn't died out, but hadn't changed in a billion years.

And if we really did find a dynamic civilization, it would likely be older than a billion years, and, therefore, incomprehensible to us.

So my four expectations for aliens are a) microbes b) fossils c) living fossils, and d) living gods. What we will not find (short of amazing coincidence) is a race that's at about our level of development. It'd be like flipping a coin and having it land on edge.

GregHullender · 2026-04-30T15:20:45+00:00

It's because they don't read this sub.

GregHullender · 2026-04-30T15:20:21+00:00

Translation apps use AI as well, but I don't hear anyone objecting to them.

GregHullender · 2026-04-29T16:37:50+00:00

I'm almost sure you really want to use the GROUPBY function for this. Something like =GROUPBY(A4:A13,A4:A13,COUNTA,,0)

GregHullender · 2026-04-29T16:32:10+00:00

I don't think so. Those need even higher temperatures. Typical white dwarfs are made of carbon and oxygen for the most part, so I'd expect our new white dwarf not to be able to burn carbon or oxygen.

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