LIFE Selects Best-Ever Science Photos

The still-astonishing April 30, 1965 LIFE cover image by the pioneering Swedish photographer Lennart Nilsson features an 18-week-old fetus inside its amniotic sac. As the cover text notes, the color image of the fetus and placenta was a photographic breakthrough at the time, with LIFE proudly writing, "This is the first portrait ever made of a living embryo inside its mother's womb." You may also like: <a href="http://www.life.com/gallery/66711/the-75-best-life-covers-of-all-time#index/0">The 75 Best LIFE Covers of All Time</a> <a href="http://www.life.com/gallery/67131/the-75-best-life-photos#index/0">The 75 Best LIFE Photos</a> <a href="http://www.life.com/gallery/67341/life-photographers-look-back#index/0">LIFE Photographers Look Back</a> <a href="http://www.life.com/gallery/66721/lifes-20-worst-covers#index/0">LIFE's 20 Worst Covers</a> (Lennart Nilsson/Time & Life Pictures/LIFE.com)

LIFE's Alfred Eisenstaedt took iconic photos of some of the 20th century's most famous figures -- Marilyn Monroe, Sophie Loren, and more -- but for immediacy and intimacy, none of his portraits surpassed this picture of the single most recognizable scientist in history. You may also like: <a href="http://www.life.com/gallery/66711/the-75-best-life-covers-of-all-time#index/0">The 75 Best LIFE Covers of All Time</a> <a href="http://www.life.com/gallery/67131/the-75-best-life-photos#index/0">The 75 Best LIFE Photos</a> <a href="http://www.life.com/gallery/67341/life-photographers-look-back#index/0">LIFE Photographers Look Back</a> <a href="http://www.life.com/gallery/66721/lifes-20-worst-covers#index/0">LIFE's 20 Worst Covers</a> (Alfred Eisenstaedt/Time & Life Pictures/Getty Images/LIFE.com)

The Missouri-born Edwin Powell Hubble (1889-1953) is responsible for discoveries including what is now known as Hubble's Law, which states that the farther a galaxy is from ours, the faster it's moving away from us. His proof that the universe is expanding at an inconceivably rapid rate helped paved the way for the "Big Bang" theory. Here, in a Bourke-White image that is, arguably, the single greatest photograph ever made of a scientist at work, Hubble gazes at the heavens in 1937 through the massive 100-inch Hooker telescope at California's Mt. Wilson Observatory. You may also like: <a href="http://www.life.com/gallery/66711/the-75-best-life-covers-of-all-time#index/0">The 75 Best LIFE Covers of All Time</a> <a href="http://www.life.com/gallery/67131/the-75-best-life-photos#index/0">The 75 Best LIFE Photos</a> <a href="http://www.life.com/gallery/67341/life-photographers-look-back#index/0">LIFE Photographers Look Back</a> <a href="http://www.life.com/gallery/66721/lifes-20-worst-covers#index/0">LIFE's 20 Worst Covers</a> (MARGARET BOURKE-WHITE/TIME & LIFE Pictures/LIFE.com)

A gigantic cloud of radioactive dust rises from the desert floor in Nevada while seven miles away photographers -- including LIFE's J.R. Eyerman -- and other members of the press watch an A-bomb test in 1953. You may also like: <a href="http://www.life.com/gallery/66711/the-75-best-life-covers-of-all-time#index/0">The 75 Best LIFE Covers of All Time</a> <a href="http://www.life.com/gallery/67131/the-75-best-life-photos#index/0">The 75 Best LIFE Photos</a> <a href="http://www.life.com/gallery/67341/life-photographers-look-back#index/0">LIFE Photographers Look Back</a> <a href="http://www.life.com/gallery/66721/lifes-20-worst-covers#index/0">LIFE's 20 Worst Covers</a> (J. R. Eyerman./Time & Life Pictures/Getty Images/LIFE.com)

"Scientists have discovered a startlingly ingenious way to transmit images around corners and a whole new American industry is being born." So LIFE wrote in its October 17, 1960 issue, discussing an innovation called "fiber optics." Here, LIFE's Fritz Goro celebrates the breakthrough as Dr. Walter P. Siegmund, an optics specialist scientist, demonstrates. You may also like: <a href="http://www.life.com/gallery/66711/the-75-best-life-covers-of-all-time#index/0">The 75 Best LIFE Covers of All Time</a> <a href="http://www.life.com/gallery/67131/the-75-best-life-photos#index/0">The 75 Best LIFE Photos</a> <a href="http://www.life.com/gallery/67341/life-photographers-look-back#index/0">LIFE Photographers Look Back</a> <a href="http://www.life.com/gallery/66721/lifes-20-worst-covers#index/0">LIFE's 20 Worst Covers</a> (Fritz Goro/Time & Life Pictures/Getty Images/LIFE.com)

Photographic evidence of a medical first: Ralph Morse's picture of heart transplant patient George Debord examining his own (former) diseased heart. You may also like: <a href="http://www.life.com/gallery/66711/the-75-best-life-covers-of-all-time#index/0">The 75 Best LIFE Covers of All Time</a> <a href="http://www.life.com/gallery/67131/the-75-best-life-photos#index/0">The 75 Best LIFE Photos</a> <a href="http://www.life.com/gallery/67341/life-photographers-look-back#index/0">LIFE Photographers Look Back</a> <a href="http://www.life.com/gallery/66721/lifes-20-worst-covers#index/0">LIFE's 20 Worst Covers</a> (Ralph Morse/Time & Life Pictures/Getty Images/LIFE.com)

The industrialist, aviator, and film producer Howard Hughes sits with an engineer inside the cavernous sea plane, "the Spruce Goose," in Los Angeles on November 6, 1947. The Goose (made, in fact, primarily of birch, not spruce) was the largest flying boat ever built. J.R. Eyerman's portrait of Hughes inside his enormously ambitious invention -- the interior of which seems to recede into the distance, endlessly, behind him -- hints at not only the plane's monumental scale, but at Hughes' audacity as an engineer and a showman. You may also like: <a href="http://www.life.com/gallery/66711/the-75-best-life-covers-of-all-time#index/0">The 75 Best LIFE Covers of All Time</a> <a href="http://www.life.com/gallery/67131/the-75-best-life-photos#index/0">The 75 Best LIFE Photos</a> <a href="http://www.life.com/gallery/67341/life-photographers-look-back#index/0">LIFE Photographers Look Back</a> <a href="http://www.life.com/gallery/66721/lifes-20-worst-covers#index/0">LIFE's 20 Worst Covers</a> (J. R. Eyerman/Getty Images/LIFE.com)