h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

I think you might solve this quicker by working backwards.

What? List all the researchers past and present and see how they fit in?

Is Gnomon at least on the right track?

There's one aspect to the theme you've missed, and this would make it a whole lot easier...

There are nine answers. If they were the names of the Nine Dwarfs from Snow White, that would be easy. But I can't think of any group of nine named things or people.

There were twelve apostles, twelve months in a year, seven dwarfs, seven days of the week, the secret seven, the magnificent seven, the nine planets... But aren't there only eight planets now?

How about the researchers who have been doing this month's puzzles?

We've also missed the fact that the puzzle is called "Regular". I see no reason for this title.

Are the solutions all things for keeping you regular?

Sennapods
All Bran
...

Since y'all are much better at this than I am (and I'm supposed to be working), I'll point out a possibility.

execrable: DAMNED: MAN?

If so, find the 'RECUMBENT' part?

Goofing off over here at lunch. Is this what we have so far?

execrable - DAMNED: AMN
trifle - BAUBLE: UBLE
solid - TRI-DIMENSIONAL: TRIDIM
guidebook - BAEDEKER: DEKE
compound
internal shell - CUTTLEBONE: TTLEBO
livery company - IRONMONGERS: ONMONG
six
mend
gum tree - CANDLE: AND
pulse
exile

1. Dmitri
2. Deke
3. DNA
4. Bluebottle
5. Gnomon
6._________man
7.
8.
9.

I didn't think of Tri-dimensional.

Execrable could be sHIte. Anybody here called Hi?

pulse could be (i)MPET(us). Have we a Temp?

I'm out of ideas and would be happy for Icy to provide the solution.

Well, I can if others agree.

Before I do, you'll find one of the solutions in a guide entry you wrote.

That only narrows it down to about 250 entries…

<BB<

I don't think you'd need to dig deep.

Ok, another guess...

I*US --> Iapetus --> Peta

Not Peta, sorry, and DNA's not correct either. As Dmitri guessed earlier, these are all regulars to these quizzes.

Compound = sulphate = S * TE + PAULH

OK. here's another summary of where we are:

Ones I'm confident of:

solid / * ENSIONAL = TRI-DIMENSIONAL = Dmitri
trifle / BA * = BAUBLE = Blue
internal shell / CU * NE = CUTTLEBONE = Bottle
livery company / IR * ERS = IRONMONGERS = Gnomon
compound / S * TE = SULPHATE = paulh

Less confident:

guidebook / BA * ER = BAEDEKER = Deke - he's not a regular, nor is he particularly historic, although he is historical

Unused clues:

execrable
six
mend
pulse
exile
gum tree

Unused Incomplete Solutions:

D * ED
E * E
I * RK
I * US
PERF *
C * LE

Some other ideas:

mend = PERFECT --> ECT - giving us TC, a regular, but an extra E
pulse = IAMBUS --> BAM ???
execrable = Damned --> MAN - could be part of Recumbentman, but I can't find "recumbent"