It's a basic law of physics: The amount of matter and energy in the universe is fixed. No more can be created or destroyed, although - and this is key to remember as acting Gov. Jane Swift considers an anti-telemarketing bill - they can change form.

The bill sounds great, doesn't it? Simply put your name on a ``do not call'' list, and never get another dinnertime pitch for a Florida time share again.

But just as fat squeezed by a girdle doesn't disappear, only chased elsewhere, so too would the anti-telemarketing bill solve one problem and create another. Or several.

The legislation would let consumers put their phone numbers on a no-call list starting Jan. 1 by calling an 800 number or by filling in a box on an Internet site. The list would be maintained by the Office of Consumer Affairs, and telemarketers who made unauthorized calls would face fines up to $5,000.

Ha! Right? Well, maybe not.

Like a wily virus that changes its strategy in response to attacks by its host, the telemarketers will no doubt adapt to the new climate and conquer it. They didn't build a $700 billion industry by being complete idiots (all evidence to the contrary).

OK, fine, they can't call you or make unsolicited sales pitches via fax, but the bill says nothing about their showing up on your doorstep. And this time, like an animal that's been wounded but not killed by a gunshot, they're going to be mad.

Telemarketer (ringing bell repeatedly, without waiting to see if it's answered): ``Hello, is a Miss Beth Tertelli in, please?????''

Me (opening the door): ``I'm sorry, she's not available.''

Telemarketer: ``I see you standing right in front of me.''

Me: ``May I ask what you're visiting in reference to?''

Telemarketer (pushing his way in): ``I'd like to tell you about a special promotion we're running . . .''

If you feel bad hanging up on an anonymous voice on the other end of the phone line, imagine how hard it will be to wrestle an actual person out of your house.

Under the proposed law, consumers would be responsible for putting their phone numbers on a no-call list, a move that will no doubt be taken by all sane people. The only problem is that the so-called ``opt-out'' mechanism will leave the mentally feeble (for who else will remain on the please-call list?) to fend for themselves.

As a society, don't we have an obligation to our weakest members? Without protection provided by the herd, it's only going to get worse for them. With far fewer people to call, the telemarketers will harass the same 100 people day and night.

Massachusetts, of course, isn't the only state going after telemarketers. Twenty-five other states already have no-call lists, and a guy I spoke with at the Direct Marketing Association, Mike Faulkner, a senior vice president of segments and affiliates, told me he expects legislation to sweep the rest of the country within 18 months.

As he talked, I began to wonder what it would be like to be a telemarketer, to work for Big Ring. I asked him how he felt about being so, well, hated. I expected him to shrug it off in a jokey way, like the professionally cheerful PR people who work for Philip Morris.

But Faulkner instead went on the attack, accusing the public of being just as bad. We practice ``inbound telemarketing'' - to use his term.

``It's when you call up to make a reservation or call a catalog company or decide to go to a Broadway show (and buy a ticket over the phone),'' he explained.

``There is something that says it's OK for you to call somebody,'' he continued, ``but just don't call me. I believe we have a problem with people wanting seclusion. People are hibernating and they don't want to talk to anyone, and that includes their family and their friends, unless they initiate the call.''

I hate to say it, but I was starting to see his point. The next time a telemarketer reaches out to me, I'm going to take the call. ``Yes, this is Miss Tertelli, what would you like to sell me?''