The CNN Daily Mash-up is a roundup of some of the most interesting, surprising, curious, poignant or significant items to appear on CNN.com in the past 24 hours. We top it with a collection of the day's most striking photographs from around the world.

Here's something that works

Simon DeDeo is an Omidyar Fellow at the Santa Fe Institute, where he researches theoretical biology and physics. He tries to explain why space exploration, such as this week's landing of a rover on Mars, strikes such a chord with so many of us.

Maybe we saw something deeper in the successful landing of Curiosity. We experienced - even if vicariously - a group achieving unambiguous excellence. In a nation where a city like Detroit can nearly collapse, where consensus on important policy issues seems far off, where some of the "best and brightest" minds of finance have built fragile institutions, how is it possible that a large cast of scientists and engineers can pull off such a remarkable task?

One person's junk is a hoarder's treasure

Speaking of junk ...

Although computing power has made much of our progress in space possible, the death of the conventional personal computer may be imminent as technology marches forward. This prospect does not sit well with some of our readers, such as this one:

Dalcassian

Never, I tell you ... Never. I will chain myself to my PC. They can have it when they pry it from my cold dead hands. It's constitutional, the right to bear PCs.

Readers also turned a jaundiced eye toward the news that American judo athlete Nicholas Delpopolo had been thrown out of the Olympics after a failed drug test he blamed on inadvertently eating food that had been baked with marijuana.

pinay53

It appears the marijuana also caused him to lose any semblance of rationality.  That has to be the worst excuse I've ever heard, except for 'the dog ate my homework'.  If you want to be a pothead, live with the consequences.  "Oops, I ate a pot brownie."  This guy's credibility just went in the toilet.

Communal meal

There's a good restaurant in East Atlanta Village called Holy Taco. Maybe they could work out some kind of a deal with La Amistad Adult Daycare in Beeville, Texas, where Ernesto Garza discovered a startling image on his breakfast taco. CNN affiliate KENS has the rest of the story.

Sikhs continue on peaceful path

CNN iReporter Sonny Gill's photo shows Sikhs and supporters gathered for a candlelight vigil Monday in Palatine, Illinois. Click on the photo for more images from the event.

CNN iReporter Sonny Gill, 30, of Chicago is a member of a Sikh community in Palatine, Illinois. He took part in a vigil to honor the victims of the mass shooting at a Wisconsin Sikh temple.

"I personally went to the vigil to support our community and family of Sikhs who are going through this hard time. And to show that their strength is still here, regardless of these senseless acts," he told CNN. "The biggest thing that stuck out to me was that we received prayers and heard from various community members from different backgrounds and religions. That truly showed how united we are as Americans and that one person's act will not deter us from continuing down our path of welcoming peace."

On the horizon: Postal Service meeting, swing state poll

The U.S. Postal Service Board of Governors is expected to discuss Wednesday and Thursday the post office's failure to make its August 1 payment into a retiree health care plan, and the even bigger financial problems that default  indicates.

Peter Brown, assistant director of the Quinnipiac University Polling Institute, will hold a press conference at 10 a.m. Wednesday to discuss results of a Quinnipiac University/New York Times/CBS News poll focusing on the presidential swing states of Colorado, Virginia, and Wisconsin. Another Quinnipiac poll last week focused on Florida, Ohio and Pennsylvania.

August 8 anniversaries

Nixon resigns, 1974

1876 - Thomas Edison patents the mimeograph.

1919 - Great Britain recognizes Afghanistan's independence.

1963 - Fifteen thieves in Great Britain make off with more than $6 million in what becomes known as "The Great Train Robbery."

1974 - President Richard Nixon announces he will resign in a national television address; he leaves office the next day.

1990 - Baseball star Pete Rose begins a five-month federal prison sentence for filing false income tax returns.

2011 - Standard & Poor's downgrades U.S. sovereign debt for the first time in history.

August 8 birthdays

Dustin Hoffman

– Swimming champion/actress Esther Williams, 91

– Singer/songwriter Mel Tillis, 80

– Actor Dustin Hoffman, 75

–  Singer/actress Connie Stevens, 74

–  Actor/singer Keith Carradine, 63

– U2 guitarist The Edge (Dave Evans), 51

– Tennis star Roger Federer, 31

– Princess Beatrice of York, 24