Martin Rees

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An artist’s impression of the James Webb Space Telescope (JWST), which was launched on board an Ariane 5 rocket on Christmas Day. Photograph: ESA/D.DUCROS HANDOUT/EPA

After years of delay, and massive cost over-runs, the James Webb space telescope (the JWST) was launched on Christmas Day. It will need to perform complex automated operations now it’s in space.

The first and most challenging is happening this week: unfurling a heat shield the size of a tennis court. After this, its 6.5-metre mirror must be assembled from 18 pieces packed within the launching rocket’s nose-cone. There’s much that can go wrong and astronomers will remain anxious for the several months that will elapse before all necessary manoevres and tests are completed.

After the Hubble Space Telescope was launched more than 30 years ago, its mirror turned out to be poorly aligned.…  Seguir leyendo »

Sled dogs wade through water on the sea ice of Greenland as the Arctic faces the consequences of global warming. DANISH METEOROLOGICAL INSTIUTUTE/STEFFEN OLSEN/GETTY IMAGES

Covid-19 should not have struck us so unawares. Why did the warnings of Bill Gates and others go unheeded? Why were even rich countries so unprepared? The answer is clear. Governments recognise a duty to prepare for floods, terrorist acts and other risks that are likely to occur in the short term and be restricted to their own countries. But they have little incentive to tackle longer-term threats that are likely to occur long after they’ve left office and which are global rather than local.

Such threats are many and varied — and looming ever larger. As we’ve discovered to our cost, pandemics can strike at any time; so can worldwide failures of infrastructure.…  Seguir leyendo »

Los avances biomédicos de las últimas décadas han sido enormemente beneficiosos, sobre todo para los pobres del mundo, cuya expectativa de vida ha aumentado de manera radical. Sin embargo, el futuro está cargado de riesgos. Si bien las constantes innovaciones seguirán mejorando las vidas de las personas, también darán paso a nuevas amenazas y agudizarán algunos dilemas éticos acerca de la vida humana misma.

Para comenzar, muchos científicos están buscando maneras cada vez más extremas de lograr prolongar la vida humana. Pero, si bien se puede decir que daríamos la bienvenida a una mayor esperanza de vida en buenas condiciones de salud, muchos no querríamos hacerlo si nuestra calidad de vida o diagnóstico cayera por debajo de un umbral determinado.…  Seguir leyendo »

Nasa's Curiosity, the rover now on Mars, may find evidence for creatures that lived early in Martian history; firm evidence for even the most primitive bugs would have huge import. There could be life in the ice-covered oceans of Jupiter's moon Europa. But what really fuels popular imagination is the prospect of advanced life – the "aliens" familiar from science fiction – and nobody expects a complex biosphere in those locations.

Suppose, however, we widen our gaze beyond our solar system. Astronomers have learnt that other stars have planets circling round them. Nasa's Kepler spacecraft monitors about 150,000 stars, measuring their brightness sensitively enough to detect the very slight dimming (about one part in 10,000) that occurs when an Earth-like planet transits a sun-like star.…  Seguir leyendo »

Dirigimos esta carta a las personalidades políticas y empresariales, así como a la opinión pública en general. Este año hemos presenciado fenómenos climáticos extremos en muchas regiones del planeta. Nadie puede asegurar con certeza que el cambio climático se encuentre en el origen de acontecimientos tales como las inundaciones de Pakistán, los episodios climáticos sin precedentes en algunas partes de Estados Unidos, la ola de calor y la sequía de Rusia o las inundaciones y los corrimientos de tierra del norte de China. Sin embargo, estos acontecimientos constituyen una severa advertencia. Los fenómenos climáticos extremos aumentarán de frecuencia e intensidad a medida que lo haga la temperatura del planeta.…  Seguir leyendo »

Einstein averred that “the most incomprehensible thing about the Universe is that it is comprehensible”. He was right to be astonished. Our minds evolved to cope with life on the African savannah, but can comprehend a great deal about the counterintuitive microworld of atoms, and about the vastness of the cosmos.

Indeed, Einstein would have been specially gratified at how our cosmic horizons have expanded. Our Sun is one of a hundred billion stars in our galaxy, which is itself one of many billion of galaxies in range of our telescopes. And there is firm evidence that these all emerged from a hot dense “beginning” nearly 14 billion years ago.…  Seguir leyendo »

Until the 1950s space travel was a futuristic concept, familiar from H. G. Wells and Jules Verne — and from comics and cornflake packets. But Sputnik, followed by Yuri Gagarin’s (and John Glenn’s) circling of the Earth made it real. The advent of the space age crystallised into reality human fantasies that dated back centuries.

The Moon landings came less than 70 years after the first powered flight — Orville Wright’s “brief hop” at Kitty Hawk — and only 12 years after the launch of Sputnik. Had the space race sustained its momentum, one might by now have expected a permanent lunar base, or an expedition to Mars.…  Seguir leyendo »

It is more than 35 years since Harrison Schmidt and Eugene Cernan, the last men on the Moon, returned to Earth. The Apollo programme now seems a remote historical episode: children all over the world learn that America landed men on the Moon, just as they learn that the Egyptians built the Pyramids; but the motivations seem almost as bizarre in the one case as in the other.

The recent film In the Shadow of the Moon depicted these historic - indeed heroic - events, but to today's young audiences the outdated gadgetry and the “right stuff” values seemed almost as antiquated as a traditional Western.…  Seguir leyendo »