galactic recession

Directory

References

Discover

King Cobra snake in Malaysia. (reptile)

9 of the World’s Deadliest Snakes

July, 2006, Launch of Space Shuttle Discovery STS-121. See attached for full caption information.

Will Light-Speed Space Travel Ever Be Possible?

Illustration for Demystified "How Dangerous is Quicksand"

How Deadly Is Quicksand?

Lusitania sinking, illustration from The War of the Nations (New York), December 31, 1919. World War I, WWI. This image is one of three on the page. (See source file for the other two.)

7 of the World’s Deadliest Shipwrecks

illustration of the walking titanosaurus, Patagotitan mayorum

Titanosaurs: 8 of the World's Biggest Dinosaurs

Small, white rat (genus Rattus) on a glass table. (rodent, laboratory, experiment)

Cruel and Unusual Punishments: 15 Types of Torture

African Americans demonstrating for voting rights in front of the White House as police and others watch, March 12, 1965. One sign reads, "We demand the right to vote everywhere." Voting Rights Act, civil rights.

Timeline of the American Civil Rights Movement

galactic recession

astronomy

Learn about this topic in these articles:

cosmology

In cosmology: Finite or infinite?
His discovery of the systematic recession of the galaxies provided an escape, however. At first people thought that the redshift effect alone would suffice to explain why the sky is dark at night—namely, that the light from the stars in distant galaxies would be redshifted to long wavelengths beyond the…
Read More

determining galactic distances

In astronomy: Determining astronomical distances
…the speeds with which those galaxies are receding from Earth (as determined from the Doppler shift in the wavelengths of their emitted light). This correlation is expressed in the Hubble law: velocity = H × distance, in which H denotes Hubble’s constant, which must be determined from observations of the…
Read More