Theory & Modeling (*)

Expedition Blogging, Part 1: A Satellite Phone-Based System

A series of articles evaluating platforms for social media, photo blogging, and two-way email communications.

Just Say No To Wicking: Non-Traditional Base Layers Based on a Next-to-Skin Fishnet Model

A Survey of Water Hazards and Water Treatment Methods – Part 6: Ultra-Violet Light Methods

A Survey of Water Hazards and Water Treatment Methods – Part 5: Filtration Methods

A Survey of Water Hazards and Water Treatment Methods – Part 4: Chemical Methods

A look at several different chemical techniques for treating water in the backcountry.

A Survey of Water Hazards and Water Treatment Methods – Part 3

Part 3 of this series takes a critical look at several water treatment technologies available to backpackers

A Survey of Water Hazards and Water Treatment Methods – Part 2

Remove, kill, or inactivate? Part two of this series analyzes the legal and technical definitions as well as the practical significance of water purification and filtration.

A Survey of Water Hazards and Water Treatment Methods – Part 1

The first part of this series provides an overview of the threats that can exist in untreated (and in some cases treated) water sources. Squeamish and hypochondriac readers be warned.

The Myth of Pressure Regulators

Part 1 in a two part series analyzing some of the claims made by stove manufacturers about pressure regulation technologies. Marketing spin or proven performance? ***Updated with Addendum on 6/12/12***

Storm Resistance of Ultralight Shelters

Evaluating the wind and snow loading of shelters for ultralight backpacking in inclement conditions.

Apparatus for Testing Thermal Insulation Properties

When it comes to assessing things like air mats, foam mats, and other insulating things, the common measurement is called an R-value - meaning thermal resistance. We describe equipment designed and built to provide calibrated measurements of R-value for BPL articles.

The Effect of Cold on Gas Canisters

Ever tried to use your stove in the cold only to find that it just won't work, even although shaking the canister tells you there is plenty of fuel left? Then, when you check it at home to see what's the matter, it works perfectly. What is going on?

Therapeutic Ultralight: Using Lightweight Backpacking to Help Troubled Boys

Getting emotionally disturbed boys working together to take a backpacking trip is a big job... with many setbacks, limited gear, and almost no budget.

Podcast: NOLS and the 40 Pound Initiative

NOLS Rocky Mountain discusses the process and progress of the 40-Pound Initiative, a branch effort to reduce student pack weights to 40 pounds or less for all Wind River courses.

Catenary Curvature as an Element of Ultralight Tarp Design