Richard Harris

Before we get to the fireworks on the Fourth of July, we might see some pyrotechnics from a giant physics experiment near Geneva, Switzerland.

Scientists there are planning to gather that morning to hear the latest about the decades-long search for a subatomic particle that could help explain why objects in our universe actually weigh anything.

The buzz is that they're closing in on the elusive Higgs particle. That would be a major milestone in the quest to understand the most basic nature of the universe.

The Rio+20 Conference on Sustainable Development was the biggest United Nations conference ever, but it may be one of the biggest duds. It produced no major agreements — just a vaguely worded declaration that has been widely derided.

More than 45,000 people registered for the event in Rio de Janeiro, but diplomats couldn't even agree about the meeting's objective until 2:45 a.m. on Tuesday, just before heads of state and other high-level delegates started arriving in Rio.

Diplomats and activists from around the world are meeting in Rio de Janeiro this week to talk about how the planet's growing population can live better lives without damaging the environment. The Rio+20 meeting marks the 20th anniversary of the United Nations Earth Summit in Rio, a watershed meeting to address topics as diverse as climate change and biodiversity.

At this follow-up meeting, delegates hope to highlight an issue that was almost absent from the Earth Summit: making energy available to everyone in the world.

Imagine how tough life would be if raindrops weighed 3 tons apiece as they fell out of the sky at 20 mph. That's how raindrops look to a mosquito, yet a raindrop weighing 50 times more than one can hit the insect and the mosquito will survive.

How?

Put yourself in a mosquito's shoes — or rain boots — for a moment and step outside into a downpour of seemingly gigantic raindrops.

What snarky headline writer could resist a story about "hot tuna?" Or how about "tuna meltdown?"

Really, it seems just plain daffy to ignore a new study that says some Pacific bluefin tuna picked up traces of radioactive material from the Fukushima nuclear disaster last year and brought it across the Pacific Ocean.

They're calling it a "rogue earthquake."

On April 11 of this year, one of the 10 biggest earthquakes ever recorded struck off the coast of Indonesia. It was felt from Bangladesh to Australia.

You may not have even heard of this magnitude 8.6 quake. It barely made the news in the U.S. because it did very little damage. Two people died, but there was no massive tsunami.

Energy ministers from around the world met in London this week and got a scolding. The International Energy Agency warned the ministers that they are falling way behind in their efforts to wean the world from dirty sources of energy. Nations are nowhere near being on track to avert significant climate change in the coming decades.

It turns out that right now, just about everything is conspiring to make it harder to clean up the world's energy supply.

The Himalayas are sometimes called the world's "third pole" because they are covered with thousands of glaciers. Water from those glaciers helps feed some of the world's most important rivers, including the Ganges and the Indus. And as those glaciers melt, they will contribute to rising sea levels.

So a lot is at stake in understanding these glaciers and how they will respond in a warming world. Researchers writing in the latest issue of Science magazine make it clear they are still struggling at that task.

Shell Oil plans to explore for petroleum off Alaska's north coast this summer. The native people of Alaska have a big stake in both oil revenue and environmental protection. That conflict has played out in recent trips by Inupiats to Washington, D.C., to argue their case.