I'm searching interviews and/or conversations (in English) with Einstein as text. Is there something available? In particular physics (e.g. theory of relativity) would be interesting but also other (e.g. more general) interviews / conversaitons are fine.
This request for "interviews and/or conversations (in English)" (involving Einstein) suggests a search for a level of intimacy or dialogue which is not easy to reach in the available mass of published materials. But the following items do seem to provide, as part of a wider range of subjects covered, some personal insights and responses that approach the character of dialogue -- especially the extended 1949 book 'Albert Einstein, Philosopher-scientist' edited by Schilpp, with debate-like features mentioned below.
The "Notes for an Autobiography", already mentioned by nwr, are valuable: they first appeared in the "Saturday Review of Literature" (Nov.26, 1949), and are available in various formats here.
Also available are two book-form works based almost entirely on Einstein's own writing, they are perhaps as close as we can get in English to a concise form of his personal views on a great range of subjects.
The first of them stems from 1934 ("Mein Weltbild") (see background in its wikipedia entry). The most complete-appearing version of this in English (the apparent best I've found) appeared under the title 'Ideas and Opinions', edited by Carl Seelig. Several publications have used the English version of the original title ('The World as I see it') but those I've seen turn out to cover heavily abbreviated and limited extracts or selections, accordingly less useful. (For those who wish also to check the original language-version, which can often be quite important to capture nuances, the German itself has appeared in several editions, e.g. here.)
The second work is "Out of My Later Years" (1950), a further collection of articles and essays, all written after 1934: another instalment of Einstein's views on a wide range of subjects. (I haven't traced the original German from which they were translated by P A Schilpp.)
The 'notes for autobiography' mentioned first were soon afterwards (1949) extended by translator-editor P A Schilpp into a much larger book "Albert Einstein, Philosopher-scientist" (1949). This includes commentaries and criticisms by 25 of Einstein's contemporaries. The contributors of these essays include some scintillating names, such as Bohr, Born, Pauli, Lemaitre, Infeld, von Laue, Gödel, and others. There is a long essay from Einstein replying to about 18 of them, amounting to a dialogue that brings into focus among other things Einstein's differences of opinion with the quantum physicists and the attempts on both sides to sharpen, explain and resolve the points of disagreement. This is about as close as one can expect to get to a live conference and debate amongst all of those people.
Besides these items, selected for their content of at least some writing from Einstein that perhaps approaches a kind of conversational character, there are of course the academic collections of his papers. This listing does not pretend to any completeness, but it is worth mentioning the resources at
-- The 'Einstein papers project' and
-- 'The collected papers of Albert Einstein' for printed volumes of the 'Collected Papers'.
One of the Einstein-related subjects of perennial interest is in the relations between relativistic and classical physics. Einstein's own expressions of view here are naturally of more than ordinary interest. They can be found in four articles of his, in which he gives explanation of relativity and appraisals of Newton and of Kepler, designed for a general audience:
-- 'Time, Space and Gravitation' (1919) (a letter that 'The Times' newspaper invited from Einstein, in response to an article that reported results from the well-known 1919 eclipse expedition, and included the headline 'Newton Overthrown') .
-- 'Einstein on Newton', an appraisal originally published in the 'Manchester Guardian' for 1927 March 19. It appeared again in the Smithsonian Institution Annual report for 1927 (at p.201-207). (Remarkably, an offprint of the Smithsonian printing, which had been owned by Albert Einstein's son Dr Hans Albert Einstein, was sold at auction only a few years ago for GBP 13,750 !)
-- a third article on Newton, and one on Kepler, in the collection "Out of My Later Years" already mentioned above.
(Although Einstein was not a historian, these articles arguably provide a depth of perception and balance of appraisal that may not have been achieved by any commentator since, almost a must-read.)