JWST

• Instead, without needing to brave the hazards of the forest, Light Detection and Ranging (Lidar) has revealed networks of buried roads and earthen mounds.
• The point of exploratory science is to reveal what has so far been hidden.
• So has 300 years of research and recent technological advances left us with little left to be discovered?
• The changes in technology are wonderful tools that help me find and model history, but they do not deplete it.

Why excavation is key to understanding

• They have opened up areas of exploration that were previously too remote, too deep, or too dangerous.
• But seeing an image of something in the ground or at the bottom of the sea is only the most preliminary step in discovery.
• You cannot truly understand an image until you have seen the artefacts associated with ancient constructions and you have studied the occupational history.
• In the excavation, coins, the evidence of burning, catapult stones and ceramics were discovered.

More and more sites to study

• The challenges in the field are not that we are running out of things to study, but that we lack the resources to study and protect the abundance of poorly understood ancient sites.
• The increased capacity to find sites highlights the need to conserve these places and protect them from development and looting.
• Profound knowledge comes with the study of the culture and the vertical excavation that peels back the history of a lost civilisation.

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Jay Silverstein receives funding from the National Geographic Society and The American Research Center in Egypt.

• Early universe observations by the James Webb Space Telescope (JWST) cannot be explained by current cosmological models.
• These models estimate the universe to be 13.8 billion years in age, based on the big-bang expanding universe concept.

Frequency and distance

• The redshift of light is similar to the Doppler effect on sound: noises appear to have higher frequency (pitch) when approaching, and lower when receding.
• Redshift, a lower light frequency, indicates when an object is receding from us; the larger the galaxy distance, the higher the recessional speed and redshift.
• An alternative explanation for the redshift was due to the Doppler effect: distant galaxies are receding from us at speeds proportional to their distance, indicating that the universe is expanding.

Limitations of previous models

• Research published last year proposed to resolve the impossible early galaxy problem using the tired light model.
• However, tired light cannot satisfactorily explain other cosmological observations like supernovae redshifts and uniformity of the cosmic microwave background.
• As with any model, it will need to provide a satisfactory explanation for all those observations that are satisfied by the standard cosmological model.

Mixing models

• The approach of mixing two models to explain new observations is not new.
• Albert Einstein resurrected the particle-like nature of light to explain the photoelectric effect — that light has dual characteristics: particle-like in some observations and wave-like in others.
• Einstein believed that the universe is the same observed from any point at any time — homogeneous, isotropic and timeless.

New information

• To defend the standard big-bang model, astronomers have tried to resolve the problem by compressing the timeline for forming massive stars and primordial black holes accreting mass at unphysically high rates.
• However, a consensus is developing towards new physics to explain these JWST observations.

• The team has also identified several galaxies in the very early universe and low mass black holes in distant galaxies.
• The active black hole in CEERS 1019 existed just over 570 million years after the Big Bang and is further than any other yet identified in the early universe.
• CEERS 1019 is not only notable for how long ago it existed, but also for the surprising size of its black hole.
• "In this galaxy we see complex structure with multiple components, suggesting that this black hole may be fueled by a galaxy merger."

• It is scheduled to lift off on a Falcon 9 rocket, built by SpaceX, from Cape Canaveral in early July.
• Euclid is designed to provide us with a better understanding of the “mysterious” components of our universe, known as dark matter and dark energy.
• Euclid will map this “dark universe”, using a suite of scientific instruments to shed light on different aspects of dark energy and dark matter.

A light in the dark

• Euclid will join the James Webb Space Telescope (JWST) at this point and will be the perfect companion to that amazing space observatory.
• Both used different techniques, and therefore different instruments, to study the dark universe, and ESA was struggling to decide between them.
• But Euclid also carries some of the biggest digital cameras deployed in space with fields of view hundreds of times greater than JWST’s.

Shapes and colours

• This gravitational lensing effect is weak, only one part in a hundred thousand for most galaxies, thus requiring lots of galaxies to see the effect in high definition.
• VIS, however, can’t measure the colours of objects.
• That history is vital for testing possible models of dark energy including suggested modifications to Einstien’s Theory of General Relativity.

Treasure trove

• Like JWST, Euclid will be a treasure-trove of new discoveries in many areas of astronomy.
• This software has also been checked and verified using some of the largest simulations of the universe that have ever been constructed.
• Seeing the project come together in this way makes me proud to call myself a “Euclidian”.