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A breakdown of the data on the homeless crisis across the U.S.

A breakdown of the data on the homeless crisis across the U.S.

Nov 2021

Is the US in the midst of a homelessness crisis? Many people think so, but that’s largely based on based on anecdotes. What does the data say?

overall homelessness in the US between 2010 and 2020

At a glance, this doesn’t look very crisisy. Since 2015, things have gone up by less than three percent.

Still, I think there is a crisis, we just have to work harder to see it. We need to look at different locations, rates of change, different types of homelessness, and mental health and substance abuse issues. Let’s do that.

Homelessness in general

Homelessness is much higher in some places.

The rate of homelessness varies hugely between different states. Here’s the percentage of the population in each state that was homeless in 2020.

map of rates of homelessness rate in each US state

In Mississippi it is 1 in 2500 (0.04%), while in New York State it is 1 in 210 (0.47%). That’s a huge difference.

Now, when we talk about a crisis, there’s an implication that things are getting worse. (You don’t hear much about the everyone you love will die and be forgotten “crisis”…) We already saw that things are pretty stable at the national level. How are things changing in individual states?

Homelessness is increasing in some places and decreasing in others.

Here’s the change between 2015 and 2020, again as a percentage of each state’s population.

map of changes in homlessness in each US state between 2015 and 2020

The general pattern is increases close to California and decreases close to Florida. The exceptions are the random huge decreases in Nevada and North Dakota (maybe because of the end of the fracking boom?), and the confusing mess in the Northeast.

This is a relatively simple story so far, but I don’t think it fully captures what’s going on. We have to go deeper.

Types of homelessness

There are different types of homelessness.

Some people run out of money, get evicted, and stay at a shelter for a few weeks before moving in with family and eventually getting back on their feet. Other people have mental health issues and stay on the street for years. When we talk about a “homelessness crisis”, we should try to distinguish these different situations.

Let’s back up. Where is all this data coming from? Well, every year during the last 10 days of January, the US tries to count every homeless person. This is done by hundreds of local government organizations and nonprofits that cover almost the entire country. They must participate in the counting or they won’t get any funding from the US Department of Housing and Urban Development (HUD), which collects all the data.

We’ll look at two attributes that people get during this count. First, people are classified as sheltered or unsheltered. Someone is sheltered if they are staying in an emergency shelter, transitional housing program, or a safe haven. Someone is unsheltered if they’re staying in a vehicle, an abandoned building, or on the street. Second, people are chronically homeless if they’ve been so for at least a year, and otherwise non-chronically homeless.

Aside: Technically—because nothing can be simple—the definition of “chronically homeless” is much more complex. You also qualify if you’ve been homeless for a total of a year in the last three years, plus that happened in at least four episodes, plus those episodes were separated by at least a week. Yes, that means that someone homeless their entire life except the first week of each year is “non-chronic”, and yes that is crazy, but probably it never happens and anyway these categorizations are done by random people around the country who may not much care about the legalistic definition anyway. Oh, and also, this changed in 2016.

So, what types of homelessness does the US have?

Most homeless are non-chronic, and most non-chronic homeless are sheltered. But the chronic homeless are usually unsheltered.

Here are the fractions of people that fell into each of the four possible groups in 2020.

Non-ChronicChronic
Sheltered53.5%7.6%
Unsheltered25.8%13.2%


Here’s how I think about this:

  1. Most homeless are non-chronic (around 80%).
  2. The non-chronic homeless are mostly sheltered (around 2/3).
  3. The chronic homeless are mostly unsheltered (around 2/3).

That’s the overall mix. But we have to worry about two things. First, is the mix changing over time? And second, how does the mix vary in different places?

Unsheltered and chronic homelessness is increasing.

Unfortunately, the mix is changing, and for the worse. The “best” type of homelessness (sheltered and non-chronic) is decreasing, while the other types are increasing.

different types of homelessness in the US over time

Since it’s a bit hard to see, here’s the number of people in each group in 2020 divided by the number in 2015:

Non-ChronicChronic
Sheltered87.5%119.3%
Unsheltered131.5%128.4%


While sheltered and non-chronic homelessness remains the most common, it actually decreased by around 12.5% since 2015, whereas all the other types have increased by around 25%.

OK, but how do things look in different places?

Different types in different places

Chronic and unsheltered homelessness is much more common in some places than others.

Let’s compare New York and California:

pie chart of types of homelessness in New York in 2020

pie chart of types of homelessness in California in 2020

Homelessness overall is similarly high in both places—0.47% in New York and 0.41% in California. But California has much more unsheltered and chronic homelessness.

Aside: Did you know that there is a constitutional right to shelter in New York? This is a result of a 1979 New York State Supreme Court decision. Two other places have a weaker version of this. Massachusetts has a mandate from a 1983 law but it only applies to families, not individuals. The District of Columbia guarantees shelter to families year-round, and to individuals when the temperature is below 32° F or above 95 °F (below 0° C or above 35 °C).

Anyway, we can picture the situation for all states by visualizing the four types of homelessness on a map. Here they all are, each as a percentage of the state’s population. (Click for a .pdf if you want to look closer.)

maps of rates of each type of homelessness in the US

For sheltered non-chronic homelessness, the West Coast isn’t exceptional. Instead, the standouts are New York at 0.42% and—press your face against the screen—the District of Columbia at 0.49%. These are followed by Massachusetts at 0.23% and Alaska at 0.20%.

But unsheltered chronic homelessness is very different. It’s almost nonexistent in some places—it’s 0.10% in California and 0.08% in Hawaii, but 0.0013% in Wisconsin. In Wisconsin, that is 80 people total. In California, that’s 42,195.

However, let me remind you—I can’t emphasize this enough—this survey is done in late January, when it’s cold in New York and stupidly cold in Wisconsin. You have to imagine that things would look different if things were done in Summer, though it’s hard to quantify. Still, the difference might be significant in that almost all homeless people in cold places have at least some occasional contact with social services.

OK. The types of homelessness are different in different places, and they are changing over time. But how are they changing in each place? We still need to go deeper.

Unsheltered and chronic homelessness is getting worse in some places, particularly the West coast.

How are the different types of homelessness changing over time in each state? Let’s again contrast New York and California:

changes in each type of homelessness in New York between 2011 and 2020

changes in each type of homelessness in California between 2011 and 2020

The situation in New York is reasonably stable since 2015, albeit at very high levels. Meanwhile, California has a small decline in sheltered non-chronic homelessness, but big increases in the other groups.

Other places are different. For example, in Florida, everything is decreasing at once.

changes in each type of homelessness in Florida between 2011 and 2020

What does the rest of the country look like? Remember, that for the country as a whole, we saw above that sheltered non-chronic homelessness is decreasing, and the other categories are increasing.

But what about individual states? Since it’s not convenient to look at 50 different charts, I made four maps to show the change in each type of homelessness between 2015 and 2020, again as a percentage of each state’s population. In each of these, grey is a decrease, white is no change, and a non-grey color is an increase. (Click for a .pdf to zoom.)

maps of changes in each type of homlessness between 2015 and 2020

How should we think about this? Here’s my best attempt at a summary:

  1. Sheltered non-chronic homelessness decreased almost everywhere.
  2. All homelessness declined in Florida and places near Florida.
  3. Chronic and unsheltered homelessness increased a lot in California and places near California.

There are some exceptions. For one thing, despite being close to California, Nevada and some of the Montana-esque states saw big decreases in certain categories. For another, the Northeast is weird and defies any attempt to summarize. Sheltered non-chronic homelessness decreased a lot in Massachusetts and Vermont but barely changed in New York or New Hampshire. Every other category is a random mishmash with no pattern. I tell you, on my worst days it’s almost like reality is just completely indifferent to our desires to understand it with tidy little narratives.

Drugs and mental health

And what about meth? Theories abound that mental health and substance abuse are a huge part of the homelessness crisis.

Well, the yearly homelessness survey collects data on if the homeless are “severely mentally ill” or suffer from “chronic substance abuse”. I can’t figure out exactly how these are defined. It’s implied that it’s done by literally asking people, but I think it varies from place to place.

Unfortunately, HUD doesn’t publish data on these numbers. However, they do publish reports, both for the entire nation, for individual states, and for each individual region.

So, I did the sensible thing. I downloaded the .pdf files for each of the 6082 different reports, wrote a script to convert each .pdf to plain text, wrote a parser for that text, compensated for 8 billion inconsistencies in how the reports were laid out, damn you HUD, damn you to hell, extracted the data for each of the above categories, and made plots.

Nationally, there is only a small uptick in mental illness and substance abuse.

national rates of homelessness with mental health and substance abuse 2007-2020

Blue is people with mental health issues, while orange is substance abuse. Some people will be in both categories, but we don’t know how many. (My guess is a lot because they’re strongly correlated.) Grey is all people, including those with no issues.

Like the other national data, this doesn’t scream crisis. If anything, it’s a bit reassuring. We already knew that unsheltered homelessness was increasing, but here we see that mental health and substance abuse aren’t increasing at the same rate.

Next, of course, we want to know how this looks in different places, and how it’s changing.

I made plots for each of the 437 regions and states (you can see them below). This data is quite noisy, which makes it a challenge to visualize. For example, here’s Los Angeles.

Los Angeles mental health substance abuse homeless

To get more reliable numbers, I combined sheltered and unsheltered homelessness, took the average of mental health and substance abuse, and then applied a smoothing function. I used the smoothed values below, which are hopefully less polluted by noise.

There are significant increases in mental illness and substance abuse in certain states.

How many homeless people are there in each state with severe mental illness of substance abuse problems? Here are the numbers in 2020.

map of mental health and substance abuse with homlessness

Again, this is high if you’re close to California and in certain parts of the Northeast. This is pretty similar to the map of homelessness overall we started with, though you’ll see a few places that stand out more here, e.g. Nevada.

OK, and how are things changing?

map of mental health and substance abuse with homelessness changes

Again, we have a crisis mostly in the West. California was already really high in 2015 and has gotten even higher. The real standout is Washington state, where things more than doubled. And sure enough, the plot for Seattle is stark.

mental illness and substance abuse homelessness in Seattle

Things just exploded between 2016 and 2017 and then went up from there. You might remember that 2016-2017 is exactly when meth metabolites in sewage in Seattle also exploded. Of course, that could just be a coincidence, or might be noise in either of these datasets. Still, I think we can see why people in Seattle might feel there’s a crisis. Maybe anecdotal knowledge ain’t so bad.


P.S. If you want to see data for your local state or city it is below.

All 50 states and DC.
Alabama
Alaska
Arizona
Arkansas
California
Colorado
Connecticut
Delaware
District of Columbia
Florida
Georgia
Hawaii
Idaho
Illinois
Indiana
Iowa
Kansas
Kentucky
Louisiana
Maine
Maryland
Massachusetts
Michigan
Minnesota
Mississippi
Missouri
Montana
Nebraska
Nevada
New Hampshire
New Jersey
New Mexico
New York
North Carolina
North Dakota
Ohio
Oklahoma
Oregon
Pennsylvania
Rhode Island
South Carolina
South Dakota
Tennessee
Texas
Utah
Vermont
Virginia
Washington
West Virginia
Wisconsin
Wyoming
All 387 local cities / regions. (First choose a state, then choose a local region.)
AK
Alaska Balance of State
Anchorage
AL
Alabama Balance of State
Birmingham Jefferson, St. Clair, Shelby Counties
Florence Northwest Alabama
Gadsden Northeast Alabama
Huntsville North Alabama
Mobile City & County Baldwin County
Montgomery City & County
Tuscaloosa City & County
AR
Arkansas Balance of State
Fayetteville Northwest Arkansas
Little Rock Central Arkansas
Southeast Arkansas
AZ
Arizona Balance of State
Phoenix, Mesa Maricopa County
Tucson Pima County
CA
Alpine, Inyo, Mono Counties
Amador, Calaveras, Mariposa, Tuolumne Counties
Bakersfield Kern County
Chico, Paradise Butte County
Colusa, Glenn, Trinity Counties
Daly City San Mateo County
Davis, Woodland Yolo County
El Dorado County
Fresno City & County Madera County
Glendale
Humboldt County
Imperial County
Lake County
Long Beach
Los Angeles City & County
Marin County
Mendocino County
Merced City & County
Napa City & County
Nevada County
Oakland, Berkeley Alameda County
Oxnard, San Buenaventura Ventura County
Pasadena
Redding Shasta, Siskiyou, Lassen, Plumas, Del Norte, Modoc, Sierra Counties
Richmond Contra Costa County
Riverside City & County
Roseville, Rocklin Placer County
Sacramento City & County
Salinas Monterey, San Benito Counties
San Bernardino City & County
San Diego City and County
San Francisco
San Jose Santa Clara City & County
San Luis Obispo County
Santa Ana, Anaheim Orange County
Santa Maria Santa Barbara County
Santa Rosa, Petaluma Sonoma County
Stockton San Joaquin County
Tehama County
Turlock, Modesto Stanislaus County
Vallejo Solano County
Visalia Kings, Tulare Counties
Watsonville Santa Cruz City & County
Yuba City & County Sutter County
CO
Colorado Balance of State
Colorado Springs El Paso County
Fort Collins, Greeley, Loveland Larimer, Weld Counties
Metropolitan Denver
CT
Bridgeport, Stamford, Norwalk, Danbury Fairfield County
Connecticut Balance of State
DC
District of Columbia
DE
Delaware Statewide
FL
Charlotte County
Citrus, Hernando, Lake, Sumter Counties
Columbia, Hamilton, Lafayette, Suwannee Counties
Deltona, Daytona Beach Volusia, Flagler Counties
Fort Pierce St. Lucie, Indian River, Martin Counties
Fort Walton Beach Okaloosa, Walton Counties
Ft Lauderdale Broward County
Ft Myers, Cape Coral Lee County
Gainesville Alachua, Putnam Counties
Hendry, Hardee, Highlands Counties
Jacksonville-Duval, Clay Counties
Lakeland, Winterhaven Polk County
Miami-Dade County
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Naples Collier County
Ocala Marion County
Orlando Orange, Osceola, Seminole Counties
Palm Bay, Melbourne Brevard County
Panama City Bay, Jackson Counties
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Pensacola Escambia, Santa Rosa Counties
Sarasota, Bradenton Manatee, Sarasota Counties
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St. Petersburg, Clearwater, Largo Pinellas County
Tallahassee Leon County
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West Palm Beach Palm Beach County
GA
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Atlanta
Augusta-Richmond County
Columbus-Muscogee
DeKalb County
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Georgia Balance of State
Marietta Cobb County
Savannah Chatham County
GU
Guam
HI
Hawaii Balance of State
Honolulu City and County
IA
Des Moines Polk County
Iowa Balance of State
Sioux City Dakota, Woodbury Counties
ID
Boise Ada County
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IL
Aurora, Elgin Kane County
Bloomington Central Illinois
Champaign, Urbana, Rantoul Champaign County
Chicago
Cook County
Decatur Macon County
DuPage County
East St. Louis, Belleville St. Clair County
Joliet, Bolingbrook Will County
Madison County
McHenry County
Peoria, Pekin Fulton, Tazewell, Peoria, Woodford Counties
Rock Island, Moline Northwestern Illinois
Rockford DeKalb, Winnebago, Boone Counties
South Central Illinois
Southern Illinois
Springfield Sangamon County
Waukegan, North Chicago Lake County
West Central Illinois
IN
Indiana Balance of State
Indianapolis
KS
Kansas Balance of State
Overland Park, Shawnee Johnson County
Topeka Shawnee County
Wichita Sedgwick County
KY
Kentucky Balance of State
Lexington-Fayette County
Louisville-Jefferson County
LA
Alexandria Central Louisiana
Lafayette Acadiana Regional
Louisiana Balance of State
Monroe Northeast Louisiana
New Orleans Jefferson Parish
Shreveport, Bossier Northwest Louisiana
Slidell Southeast Louisiana
MA
Attleboro, Taunton Bristol County
Boston
Cambridge
Cape Cod Islands
Fall River
Gloucester, Haverhill, Salem Essex County
Lynn
Massachusetts Balance of State
New Bedford
Pittsfield Berkshire, Franklin, Hampshire Counties
Quincy, Brockton, Weymouth, Plymouth City and County
Springfield Hampden County
Worcester City & County
MD
Annapolis Anne Arundel County
Baltimore
Baltimore County
Carroll County
Frederick City & County
Harford County
Howard County
Mid-Shore Regional
Montgomery County
Prince George's County
Wicomico, Somerset, Worcester Counties
ME
Maine Statewide
MI
Battle Creek Calhoun County
Dearborn, Dearborn Heights, Westland Wayne County
Detroit
Eaton County
Flint Genesee County
Grand Rapids, Wyoming Kent County
Grand Traverse, Antrim, Leelanau Counties
Holland Ottawa County
Jackson City & County
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Lenawee County
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Michigan Balance of State
Monroe City & County
Norton Shores, Muskegon City & County
Pontiac, Royal Oak Oakland County
Portage, Kalamazoo City & County
Saginaw City & County
St. Clair Shores, Warren Macomb County
Washtenaw County
MN
Dakota, Anoka, Washington, Scott, Carver Counties
Duluth St. Louis County
Minneapolis Hennepin County
Moorhead West Central Minnesota
Northeast Minnesota
Northwest Minnesota
Rochester Southeast Minnesota
Southwest Minnesota
St. Cloud Central Minnesota
St. Paul Ramsey County
MO
Joplin Jasper, Newton Counties
Missouri Balance of State
Springfield Greene, Christian, Webster Counties
St. Charles City & County, Lincoln, Warren Counties
St. Joseph Andrew, Buchanan, DeKalb Counties
St. Louis City
St. Louis County
MP
Northern Mariana Islands
MS
Gulf Port Gulf Coast Regional
Jackson Rankin, Madison Counties
Mississippi Balance of State
MT
Montana Statewide
NC
Asheville Buncombe County
Chapel Hill Orange County
Charlotte Mecklenburg County
Durham City & County
Fayetteville Cumberland County
Gastonia Cleveland, Gaston, Lincoln Counties
Greensboro, High Point
North Carolina Balance of State
Northwest North Carolina
Raleigh Wake County
Wilmington Brunswick, New Hanover, Pender Counties
Winston-Salem Forsyth County
ND
North Dakota Statewide
NE
Lincoln
Nebraska Balance of State
Omaha, Council Bluffs
NH
Manchester
Nashua Hillsborough County
New Hampshire Balance of State
NJ
Atlantic City & County
Bergen County
Burlington County
Camden City & County Gloucester, Cape May, Cumberland Counties
Elizabeth Union County
Jersey City, Bayonne Hudson County
Lakewood Township Ocean County
Monmouth County
Morris County
New Brunswick Middlesex County
Newark Essex County
Paterson Passaic County
Salem County
Somerset County
Trenton Mercer County
Warren, Sussex, Hunterdon Counties
NM
Albuquerque
New Mexico Balance of State
NV
Las Vegas Clark County
Nevada Balance of State
Reno, Sparks Washoe County
NY
Albany City & County
Binghamton, Union Town Broome, Otsego, Chenango, Delaware, Cortland, Tioga Counties
Buffalo, Niagara Falls Erie, Niagara, Orleans, Genesee, Wyoming Counties
Columbia, Greene Counties
Elmira Steuben, Allegany, Livingston, Chemung, Schuyler Counties
Franklin, Essex Counties
Glens Falls, Saratoga Springs Saratoga, Washington, Warren, Hamilton Counties
Ithaca Tompkins County
Jamestown, Dunkirk Chautauqua County
Jefferson, Lewis, St. Lawrence Counties
Kingston Ulster County
Nassau, Suffolk Counties
New York Balance of State
New York City
Newburgh, Middletown Orange County
Poughkeepsie Dutchess County
Rochester, Irondequoit, Greece Monroe County
Rockland County
Schenectady City & County
Syracuse, Auburn Onondaga, Oswego, Cayuga Counties
Troy Rensselaer County
Utica, Rome Oneida, Madison Counties
Wayne, Ontario, Seneca, Yates Counties
Yonkers, Mount Vernon Westchester County
OH
Akron, Barberton Summit County
Canton, Massillon, Alliance Stark County
Cincinnati Hamilton County
Cleveland Cuyahoga County
Columbus Franklin County
Dayton, Kettering Montgomery County
Ohio Balance of State
Toledo Lucas County
Youngstown Mahoning County
OK
Norman Cleveland County
North Central Oklahoma
Northeast Oklahoma
Oklahoma Balance of State
Oklahoma City
Southeastern Oklahoma Regional
Southwest Oklahoma Regional
Tulsa City & County
OR
Central Oregon
Clackamas County
Eugene, Springfield Lane County
Hillsboro, Beaverton Washington County
Medford, Ashland Jackson County
Oregon Balance of State
Portland, Gresham Multnomah County
Salem Marion, Polk Counties
PA
Beaver County
Bristol, Bensalem Bucks County
Chester County
Eastern Pennsylvania
Erie City & County
Harrisburg Dauphin County
Lancaster City & County
Lower Merion, Norristown, Abington Montgomery County
Philadelphia
Pittsburgh, McKeesport, Penn Hills Allegheny County
Reading Berks County
Scranton Lackawanna County
Upper Darby, Chester, Haverford Delaware County
Western Pennsylvania
Wilkes-Barre, Hazleton Luzerne County
York City & County
PR
Puerto Rico Balance of Commonwealth
South-Southeast Puerto Rico
RI
Rhode Island Statewide
SC
Charleston Low Country
Columbia Midlands
Greenville, Anderson, Spartanburg Upstate
Sumter City & County
SD
South Dakota Statewide
TN
Appalachian Regional
Central Tennessee
Chattanooga Southeast Tennessee
Jackson West Tennessee
Knoxville Knox County
Memphis Shelby County
Morristown Blount, Sevier, Campbell, Cocke Counties
Murfreesboro Rutherford County
Nashville-Davidson County
Upper Cumberland
TX
Amarillo
Austin Travis County
Bryan, College Station Brazos Valley
Dallas City & County, Irving
El Paso City & County
Fort Worth, Arlington Tarrant County
Houston, Pasadena, Conroe Harris, Fort Bend, Montgomery Counties
San Antonio Bexar County
Texas Balance of State
Waco McLennan County
Wichita Falls Wise, Palo Pinto, Wichita, Archer Counties
UT
Provo Mountainland
Salt Lake City & County
Utah Balance of State
VA
Alexandria
Arlington County
Charlottesville
Fairfax County
Fredericksburg Spotsylvania, Stafford Counties
Harrisonburg, Winchester Western Virginia
Loudoun County
Lynchburg
Newport News, Hampton Virginia Peninsula
Norfolk, Chesapeake, Suffolk Isle of Wight, Southampton Counties
Portsmouth
Prince William County
Richmond Henrico, Chesterfield, Hanover Counties
Roanoke City & County, Salem
Virginia Balance of State
Virginia Beach
VI
Virgin Islands
VT
Burlington Chittenden County
Vermont Balance of State
WA
Everett Snohomish County
Seattle King County
Spokane City & County
Tacoma, Lakewood Pierce County
Vancouver Clark County
Washington Balance of State
WI
Madison Dane County
Milwaukee City & County
Racine City & County
Wisconsin Balance of State
WV
Charleston Kanawha, Putnam, Boone, Clay Counties
Huntington Cabell, Wayne Counties
West Virginia Balance of State
Wheeling, Weirton Area
WY
Wyoming Statewide
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The big alcohol study that didn't happen: My primal scream of rage

Why did a huge alcohol RCT get cancelled? A strange story of science, academia, bureaucratic maneuvering, ambition, politics, capitalism, the deep state, secret emails, and slippery ethical slopes.

What does drinking do to your health? We can say two things with confidence: 1. Drinking is associated with lots of health problems. 2. Heavy drinking is bad for you. Here's a graph of some associations. Someone who averages 10...

A review of early split-brain experiments

What happens if you cut your brain in half?

What happens if you cut your cortex in half? When this was first tried on animals, the answer seemed to be not much. But starting in the late 1950s, a series of experiments found that very weird things happen under...

Alcohol, health, and the ruthless logic of the Asian flush

Why did the Asian flush evolve? What does this say about alcoholism? What does this have to do with Odysseus?

Say you’re an evil scientist. One day at work you discover a protein that crosses the blood-brain barrier and causes crippling migraine headaches if someone’s attention drifts while driving. Despite being evil, you’re a loving parent with a kid learning...

Napoleon's failure in Russia as an analogy for T-cell based viral immunity

How the immune system's memory cells are like the Russian strategy for resisting Napoleon's invasion.

In June of 1812 Napoleon assembled the largest European army in history and invaded Russia. After months of bloody fighting, the French finally arrived in Moscow in September, surprised to find the city mostly abandoned. That night, remaining Russians set...

What happens if you drink acetone?

How dangerous is it to drink acetone or nail-polish remover? Here's the key scientific facts, compared to ethanol.

Question: Should you drink acetone? Answer: No. But, out of interest, what if you did? This question is asked repeatedly on the web, with with many answers smugly stating that even tiny amounts of acetone will instantly kill you, you...