Archiv: light (electromagnetic radiation / visible / non-visible) / Licht (elektromagnetische Strahlung / sichtbar / unsichtbar)


24.04.2023 - 13:21 [ Science.org ]

A global environmental crisis 42,000 years ago

(19 Feb 2021)

Do terrestrial geomagnetic field reversals have an effect on Earth‘s climate? Cooper et al. created a precisely dated radiocarbon record around the time of the Laschamps geomagnetic reversal about 41,000 years ago from the rings of New Zealand swamp kauri trees. This record reveals a substantial increase in the carbon-14 content of the atmosphere culminating during the period of weakening magnetic field strength preceding the polarity switch. The authors modeled the consequences of this event and concluded that the geomagnetic field minimum caused substantial changes in atmospheric ozone concentration that drove synchronous global climate and environmental shifts.

(…)

We precisely characterize the geomagnetic reversal and perform global chemistry-climate modeling and detailed radiocarbon dating of paleoenvironmental records to investigate impacts. We find that geomagnetic field minima ~42 ka, in combination with Grand Solar Minima, caused substantial changes in atmospheric ozone concentration and circulation, driving synchronous global climate shifts that caused major environmental changes, extinction events, and transformations in the archaeological record.

24.04.2023 - 13:16 [ ORF.at ]

Erdmagnetfeld: Polwanderung veränderte das Weltklima

Ungefilterte Strahlung aus dem Weltraum zerriss Luftpartikel in der Erdatmosphäre, trennte Elektronen ab und emittierte Licht. Diese ionisierte Luft brutzelte die Ozonschicht weg, heißt es in einer Presseaussendung zur Studie. In Folge dürften überall auf dem Globus Polarlichter aufgetaucht sein, nicht nur rund um den geographischen Nord- und Südpol wie heute. (…)

Das Erdmagnetfeld schwächelt bereits seit rund 2.000 Jahren wieder. Verglichen mit den ersten direkten Messungen vor 170 Jahren wurde eine Abschwächung um neun Prozent festgestellt, im Bereich des Südatlantiks sogar um dreißig Prozent.

28.10.2022 - 15:35 [ Schenectady Gazette / Google.com ]

Methane, Ammonia on Mars? Mariner 7 Sees Hint of Life

(8.August 1969)

Pimentel´s evidence was from an infrared spectrometer, designed to detect elements by measuring their radiation.

20.02.2021 - 12:20 [ Jet Propulsion Laboratory / NASA.gov ]

Using Light to Study Planets

In this activity, students will build a spectrometer using basic materials to observe the light emitted and absorbed by several sources. This will be used as a model for how NASA uses spectroscopy to determine the nature of elements found on Earth and other planets. For higher grades, this activity can also be used to discuss advanced spectroscopic topics, such as how NASA research is advancing spectroscopic techniques to teach us more about plant life on Earth.

20.02.2021 - 11:33 [ Schenectady Gazette / Google.com ]

Methane, Ammonia on Mars? Mariner 7 Sees Hint of Life

(8.August 1969)

Pimentel´s evidence was from an infrared spectrometer, designed to detect elements by measuring their radiation.

14.05.2020 - 21:31 [ Wired ]

The Science of Temperature Is Weirder Than You Think

One way to transfer energy is with electromagnetic waves. Visible light is one type of electromagnetic radiation; there’s also infrared, x-rays, gamma rays. These are all the same type of waves but with different wavelengths. And they can all transfer energy.