3975: The Cause of Much Pain by Samuel

Samuel gave us a puzzle with unusual clues, in 22 clues, one letter had somehow moved to the clue above. In clue order the letters spelled out WHAT GOES UP MUST COME DOWN.  Five thematically relevant answers had to be discovered and these were ROCKET, LIANA, LIFT, BALLOON and CO-PILOT. In the completed grid, these words moved down to reach the bottom row, with letters displaced from other answers moving to fill gaps so created and always keeping their original order. This movement revealed the word GRAVITATION. Finally, a sixth movement was required and the word APPLE also moved down but stopped at N, representing Newton, thus re-enacting a supposed historical event – the apple falling on Newton and the discovery of gravity.

Gregson enjoyed the theme but was disconcerted by the appearance of non-words and suspects that there could be some errors this week.

Letters to be omitted from clues are shown in []. Letters to be added are shown in upper-case in the explanations to clues.

1 Smitten s[w]eep travelling west carrying nurse's heart (5)
EPRIS R (centre of NURSE) in SIPE (reversed)
5 Breaking secondary picket could present red Tony with means of reducing selling (8)
ICE-PACKS (means of reducing sWelling) Compound Anagram SECONDARY PICKET less letters of RED TONY
10 Plausible lines added to copy of will, expunging the rights of Auntie Rut[h] (7)
PROBALL PROBATE less T + E right-hand letters of RUT + AUNTIE + LL (lines)
12 Equip in full all but eight (6, two words)
RIG OUT RIGHT OUT less HT (Height)
13 Tip fag end on sheet (8)
15 [A]head of noon and king's to be found in beer joint (5)
ANKLE N (head of NOON) + K (king) in ALE
17 One interrupting interminable complimentary lunch (4)
FIRE (lAunch) I in FRE(E)
19 Def[t] fish swallows a mound of debris (7)
STELLAR (DEF= EXCELLENT) TELL (mound of debris) in SAR
21 Stupidly narrow-minded and backward girl almost cut the op (6)
POLLED (cut the Top) PO + DELL(A) reversed
22 In Oz, dog bone tipped with [g]old (4)
TOTO (Dorothy’s dog in The Wizard of Oz) TOT (bone) + O (old)
23 Garter-snake upset asp after win (5)
ELAPS EL (winG) + anag. ASP
26 Abandoning new rule, Lord Lieutenants smashed up bangers (13)
ANDOUILLETTES anagram Lord Lieutenants less N (new) + R (rule)
29 M[o]an goodbye to ... (5)
32 ... huffs, only child, roughly ten, leaving infants (4)
INNS (hOuffs) INNOCENTS less (OC (only child) + anagram TEN)
34 Brick office bas[e]s (6)
BURDEN BUR (brick) + DEN
36 Go warn, perhaps, journalist about one coming with teeth (7)
IVORIED I (Ego) + VOR (warn) + ED (journalist) containing I (one)
38 Beat an unknown, one of the slowest in the RAF (4)
YERK Y (unknown) + ERK (RAF slang)
40 He created a colourful hero from orc zygotes (5)
ORCZY Hidden (She created a colourful hero; ref. Baroness Orczy, creator of the Scarlet Pimpernel)
41 French chalk's [u]sed at first on making love wearing support (8)
STEATITE S (initial of SED) + AT IT (making love!) in TEE
44 Honeydew melon, just the starter we'd sent back, having found nit left inside (6)
MILDEW M (start of MELON) + W’ED (reversed) containing I (Unit)
45 Bank's quiet without s[p]in (7)
46 Welsh girl swallowing all but the last drop of ale from close to the English border? (8)
SILURIAN LURI(D) (Pale) in SIAN (Welsh form of JANE)
47 Played out time in old squadron (5)
TIRED T + I + RED (former squadron of British fleet)

1 Measures of he[m]p, hashish (5)
EPHAS Hidden
2 Person regularly avoided trap (3)
PRO (traMp – here PRO is short for PROSTITUTE) PeRsOn less even letters
3 D[u]ress down under finally cut short Aussie oaf having trouble without money (6)
ROCKET (Dress down, scold) R (last letter of UNDER) + OCKE(R) + T (TROUBLE less ROUBLE)
4 Wood used to make sites, perhaps, in the aspect of overturned goddess (6)
SAPELE (Wood used to make sUites) AS (reversed + PELE (goddess)
5 Misfortunes? Rather not [s]ay! (4)
6 Shifting and, after sign of hesitation, beginning to go (3)
ERG (Shifting Sand) ER + G(o)
7 A number of card holders knock [t]out who's only just left? (5)
PINKO PIN (number) + KO (knock out)
8 Get one old urn for a flier (7)
CO-PILOT COP + I + LOT (Turn obs.)
9 [C]ox nearly drowns gutless Arabs, perhaps (6)
STEEDS STEE(R) (OX) + D(rown)S
11 Dane in Scotland, we note, is swell (7)
BALLOON BALL (danCe) + OO (WE in Scotland)
14 A universal g[o]od character (4)
AURA A + U + RA (god)
16 Something written in Java: try out fruit (5)
APPLE APPLET less T (trOy)
18 Hydrocarbon network turning up in compound (6)
RETENE NET reversed in REE (compound)
20 [M]utter "no" to returning string instrument (6)
TONGUE No T(o) reversed + GUE
24 For a link with missing leaders of Icelandic sledge expedition, arrest missing British climber (5)
LIANA LIA(ISE) less I S E (initial letters) + NA(B) less B(ritish)
25 Troublemaker's the first to spray strip[e] on casualty in Boston (7)
STIRRER S(pray) + TIRR + ER (emergency room)
27 Dad capturing two rooks with a bit of ease for famous naturalist (7)
DURRELL DULL (dEad) containing RR (2 rooks) + E
28 To endure mobile service, more than one gorge[d] (6)
ABYSMS ABY (endure) + SMS
30 Independent newspaper supporting a pound off? (4)
LIFT (Doff) L (£) + I (independent) + FT (Financial Times)
31 Overly artificial, a producer of food h[o]ard for koalas to chew? (6)
TOOART (strong-timbered Eucalyptus) TOO + Art.
33 Mate well with Ann, and take seed (6)
NICKAR NICK (to mate well) + A (annO) + R (take)
35 Some seized in arrest [w]ere supplying barbiturate, maybe (5)
ESTER Hidden
37 About a quarter of ales used colourings cut by France (5)
DYFED (part of Wales) F in DYED
39 Fix leak with tip of nail (4)
PEEN + PEE + N(ail)
42 Commonwealth tribe won independence after the end of Ami[n] (3)
IWI (am)I + W (won) + I (independence, again)
43 An intro to Cars by electro genius (3)
ACE A + C(ars) + E (electroN)