A top class puzzle from Goliath.
A trademark witty and fun puzzle. Many thanks to the setter.

NO BODY (a problem investigating homicide)
MA (mum) gets LADIES (women’s)
ALAS (sadly) by K[ore]A (‘s borders)
WAIN (youngster, Glaswegian) masking POUT* (*unusual)
[li]KE EM[bracing]< (some, <from the east)
From the biblical phrase ‘The meek shall inherit the earth’, which has also made its way into popular culture many times. For the curious, see the Wiki article here, under ‘Cultural uses’
MAKE (build) + TRACKS (railway)
(PEED (tinkled) + O[ver] F[lute] (intros)) in SLIGHT (minor)
C is the mathematical symbol representing the speed of light
“PENCIL” (writer, “heard”) + (A VAIN)* (*review)
(LLAMAS OPEN)* (*ground)
ROOM< (<back)
I AIL< (I don’t feel right, <backing) + SONS (boys)
Referring to the well-known novel ‘Dangerous Liaisons’, originally a French novel by de Laclos in 1782, but reinvented in many shapes and forms over the years
To invest OX (some stock) in BING (web browser)
(S[et] T[he] E[lectric] D[evice] E[xperiment] (starts to)) including AMP (current)
AB (sailor) and “SAIL” (what he does, “report”)
NEAR (by) + MISS (young woman)
BRACE (couple) + LET (permitted)
D[ispla]Y K[nowledg]E (banks)
MADE* (*to suffer) in (AC (current) + ICY (cold)) + ERA* (*perhaps)
AFTERS (desserts) + HAVE (possess)
I’M (Goliath’s) + PACT (deal)
[courte]SAN EST[ablishments] (of)
DEN< (study, <to raise) after (CHILLI FAN)* (*collapsed)
PISS< (<up) after L[ecturer’s] (first) foray into ID; EGO (elements of Freudian psyche)
(I MENTION)* (*disruption)
(A GIRL)* (*is upset) with MAD (angry)
PS (afterthought) on ALMS (charity)
Biblical book
(A PALAC[e])* (endlessly, *rebuilding)
‘Either way’ letting us know we need to find a palindrome
Loved this. A typically entertaining puzzle. He has a knack of creating anomalous contrasts between the surface reading and the answer which tickle my fancy.
Many faves but speed of light, bracelet, aftershave, and perhaps best of all (despite lost marks for potty mouthed cluing) idle gossip. Thanks both.
Hugely enjoyable, thank you Goliath, with plenty of smiles. And I learnt what a wain is, and when British academic years begin (handy if I ever decide to do a PhD at Oxford or Cambridge).
Do hope we leave something habitable for the meek (Peter’s fingers much needed for the 3ds) but meanwhile, yes, enjoyable puzzle, ta Goliath and Oriel.
I second your hope, gratinfreo. At least, they are not likely to complain.
Very satisfied to have completed this. I knew 15a was SPEED OF LIGHT but could not parse it. Now I see it, and it’s a Doh! All in all, very enjoyable, and this is evidently at my level. Time now for another coffee.
Like Eric E.@5.I should have remembered e=mc2.
Great puzzle. Thanks to both.
Worth doing for SPEED OF LIGHT’s definition alone.
Thanks both
Thanks for the blog , usual high standard of clues and typical fission for MOOR .
c was well hidden for the SPEED OF LIGHT ( actually for a vacuum but fine for a crossword ) . I have never found a convincing reason for c as the symbol , Maxwell had the first equations to predict the value of c but he used V , so did Einstein in early papers .
[ Geoff@2 it is a DPhil at Oxford , the modern universities usually offer a PhD .
Grant@3 I fear there will not be anything worthwhile for the meek to inherit . ]
Very enjoyable. Favourites IDLE GOSSIP, MEEK, PENNSYLVANIA and NO BODY which made me laugh. I’m congratulating myself on actually remembering that c is the SPEED OF LIGHT (lovely clue), but I didn’t know that spelling of the Glaswegian youngster (I know it as “wean”). Thanks Goliath and Oriel.
Thanks Goliath for almost all of the puzzle and Oriel for the whole of the blog.
12ac: I really think this needs a question mark on the end of the clue. The idea of the meek being global heirs is at best a piece of unsound political dogma, and probably better regarded as pure fiction.
22ac: I had to go to Collins online to find backroom as a noun, and, yes, it means the same as “back room”. In my view, Goliath has spoilt the surface of this clue by leaving out the space and expecting solvers to put the space back without any indication of that being necessary. Yes, I know a lot of people on this website enjoy doing that, but should the FT crossword editor regard the balance of opinion on this forum as an indication of his target audience?
Apart from that, there was much to enjoy in this puzzle.
10ac: I managed to find “wean² (also wain)” in the Concise Oxford 2011 p 1636, and similarly in the two volume Shorter Oxford 2007 p 3594, but I could not find wain with the required meaning in any of the three large single volume dictionaries which I cite most often.
Enjoyable puzzle, but Bing is a search engine, not a web browser; and “minor c” is a strange wording of what would be more natural as “C minor”. (I realise it’s written that way to make the clue work.)
I came to say what #13 Andrew said, Bing should be search engine which I found a bit annoying.
Salmon Leap held me up because I read it as 4,6 and I could not see it at all!
Also agree with #12 that Wain is not expected but Google suggests it as an alternative spelling or incorrect form!
Still, minor quibbles.
Loved Speed of Light.
Late to this and can only echo those who enjoyed the puzzle for its customary wit. A setter who is always light on his feet, in my view, and so entertaining. I enjoyed (ruefully) the ‘global heirs’ and those dangerous LIAISONS, one of my all-time favourite novels and, as Oriel notes, frequently interpreted. I’m eager to see what the wonderful Lesley Manville, currently on Broadway, makes of La Marquise de Merteuil in the National Theatre’s production.
Thanks Goliath and Oriel.
SPEED OF LIGHT and IDLE GOSSIP are both great clues. Roz@8 I thought it was called c because it was constant?
[GDU@2: I’m afraid that the clue for “Academic Year” won’t help you with Oxford and Cambridge who start their terms in October. What do you expect when Cambridge has “May Week” in June? Also a DPhil doesn’t really have terms, it’s a year-round thing. ]
[Roz @8: I had read that c is derived from the Latin “celeritas” meaning speed and have seen it used in intermediate physics texts for wave velocities before one learns to distinguish group and phase velocities.]
I though the use of Id and Ego in “idle gossip” was inspired but I disagree with the praise for “speed of light” because of the objections raised already, to whit “minor c” is not a phrase but “C minor” is and the capitalisation is vital here in the definition. I was also thrown by the mistake of calling “Bing” a broswer which made this clue only solvable for me with all the crossers in place. I’ve seen the “current” = “AC” trick a few times but am not a fan given that the “C” in “AC” stands for “current”.
A pity about these flaws and errors as I enjoyed everything else! Many thanks Goliath and Oriel.
[ Peter@16 and JOFT@17 , I read many 19th century papers , the first time I have seen it is Weber’s force constant , which turns out later to be root two times the speed . Maxwell was the first to get the correct wave equation and used V . Einstein used V in 1905 for special relativity but used c in 1908 for the energy mass relationship . I have seen no evidence for celeritas . ]
Very enjoyable puzzle. And thanks everybody for a variety of entertaining comments as well.
Hate to be a pedant (no I don’t) but the thing alluded to @25 is not a browser. It’s a search engine. Thanks to Goliath for a fun puzzle.
JOFT @17: in the US, it’s a month earlier: the posh universities–your Harvards and Princetons–begin in September, while most public universities start in mid to late August. I had remembered a “perhaps” in the clue to cover this sort of ambiguity, but looking back on it that’s the anagrind for ERA. So we don’t want that word doing double duty.
I assumed the clue for SPEED OF LIGHT contained a misprint until the solution was forced, as it reads like nonsense. It’s depressing that such a poorly written clue is so lauded.
I found this middling difficulty, and loved the combination of tight cluing wth humour that we see so reliably with Goliath and that others have noted.
Loved SALMON LEAP, ALSAKA, PENNSYLVANIA, PSALMS, loved PISS up in 14 and the whole clue once I worked it through and MALADIES (so elegant, and my LOI that took ages to see). My parodical-setter-led study of UK English enabled me to parse BOXING, despite the error in the clue.
I had some grumbles, but others have covered them
Thanks Goliath and Oriel
[Roz@19: A lovely article from DESY with 49 references seems to untangle the story rather well. I’ll give the full URL as well as a link you can click on: https://www.desy.de/user/projects/Physics/Relativity/SpeedOfLight/c.html]
Thanks for the info JOFT@25.
The reference to DESY takes me back to 1968 when I was an articled clerk working for a company in Surrey that was building a nuclear accelerator for DESY. I had a memorable visit to Hamburg which made a welcome break from Gutter Lane where the accountants were based .
What is DESY, please?
Thanks JOFT@25 , I never click on links but I should be able to get someone to print this .
Martyn@27 it is the centre for Particle Physics research in Germany , mainly Hamburg but other sites and quite a few accelerators .
https://en.wikipedia.org/wiki/DESY
Me neither Martyn
Sorry Martin@27 but I see others have replied – as my comment was an aside to someone who would know the acronym I decided it was not necessary to expand it but, seeing some of the other comments on here, I think it’s safer to assume that, no matter how eclectic a comment, someone else may well be interested!
Very enjoyable